add imgui + glfw

.gitignore

@@ -1,4 +1,6 @@
+build/
 *~
 *.swo
 *.swp
 rntviewer
+*.gdbhist

Makefile

@@ -1,7 +1,15 @@
 CXX = clang++
+CFLAGS = -Wall -Wextra -pedantic
+INC = -Ithird_party -Ithird_party/imgui
+LIBS = -lglfw -lROOTNTuple
 
+all: build/imgui.o d
+
+build/imgui.o: src/imgui_inc.cpp
+	$(CXX) -O3 -fPIC -c -Ithird_party/imgui $< -o $@
+	
 d:
-	$(CXX) -DDEBUG -g -O0 -o rntviewer rntviewer.cpp $(shell root-config --cflags --libs) -lROOTNTuple -lasan
+	$(CXX) -DDEBUG -g -O0 $(CFLAGS) -fsanitize=undefined $(INC) $(shell root-config --cflags) -o rntviewer src/rntviewer.cpp build/imgui.o -lasan $(shell root-config --libs) $(LIBS)
 
 r:
-	$(CXX) -O2 -o rntviewer rntviewer.cpp $(shell root-config --cflags --libs) -lROOTNTuple
+	$(CXX) -O2 $(CFLAGS) $(INC) -o rntviewer src/rntviewer.cpp $(shell root-config --cflags --libs) $(LIBS)

imgui.ini

@@ -0,0 +1,10 @@
+[Window][Debug##Default]
+Pos=60,60
+Size=400,400
+Collapsed=0
+
+[Window][test]
+Pos=0,0
+Size=1152,1414
+Collapsed=0
+

rntviewer.cpp

@@ -1,79 +0,0 @@
-#include <ROOT/RNTupleReader.hxx>
-#include <ROOT/RNTuple.hxx>
-#include <TFile.h>
-
-#include <cstdio>
-#include <cstdint>
-
-#include <sys/mman.h>
-#include <unistd.h>
-
-#ifdef DEBUG
-#include <sanitizer/asan_interface.h>
-#endif
-
-#include "types.h"
-#include "defer.hpp"
-#include "mem.h"
-
-#include "mem.cpp"
-
-using namespace ROOT::Experimental;
-
-static size_t file_size(FILE *f)
-{
-  fseek(f, 0, SEEK_END);
-  size_t res = ftell(f);
-  fseek(f, 0, SEEK_SET);
-  return res;  
-}
-
-int main(int argc, char **argv)
-{
-  if (argc < 3) {
-    fprintf(stderr, "Usage: %s <ntuple_name> <ntuple_file.root>\n", argv[0]);
-    return 1;
-  }
-
-  // Collect arguments
-  const char *ntpl_name = argv[1];
-  const char *fname = argv[2];
-
-  // Allocate memory
-  Arena *arena = arena_alloc();
-  if (!arena) {
-    fprintf(stderr, "Failed to allocate memory\n");
-    return 1;
-  }
-  defer { arena_release(arena); };
-
-  // Open and map the file
-  FILE *file = fopen(fname, "rb");
-  defer { fclose(file); };
-
-  const int fd = fileno(file);
-  const size_t fsize = file_size(file);
-  void *fmem = mmap(0, fsize, PROT_READ, MAP_SHARED_VALIDATE, fd, 0);
-  if (!fmem) {
-    fprintf(stderr, "Failed to open file %s\n", fname);
-    return 1;
-  }
-  defer { munmap(fmem, fsize); };
-
-  // Open the TFile
-  TFile *tfile = TFile::Open(fname, "READ");
-  if (!tfile) {
-    fprintf(stderr, "Failed to open TFile.\n");
-    return 1;
-  }
-  defer { delete tfile; };
-
-  // Get the RNTuple information
-  const RNTuple *anchor = tfile->Get<RNTuple>(ntpl_name);
-  if (!anchor) {
-    fprintf(stderr, "RNTuple '%s' not found in %s.\n", ntpl_name, fname);
-    return 1;
-  }
-
-  return 0;
-}

src/imgui_inc.cpp

@@ -0,0 +1,8 @@
+#include <../glad/glad.h>
+
+#include <imgui.cpp>
+#include <imgui_widgets.cpp>
+#include <imgui_draw.cpp>
+#include <imgui_tables.cpp>
+#include <backends/imgui_impl_glfw.cpp>
+#include <backends/imgui_impl_opengl3.cpp>

src/input.h

@@ -0,0 +1,38 @@
+enum Input_Key {
+	KEY_UP,
+	KEY_DOWN,
+	KEY_LEFT,
+	KEY_RIGHT,
+	KEY_Q,
+	KEY_ALT,
+	KEY_TAB,
+
+	KEY_COUNT
+};
+
+enum Mouse_Button {
+	MOUSE_BTN_LEFT,
+	MOUSE_BTN_RIGHT,
+
+	MOUSE_BTN_COUNT
+};
+
+enum Mouse_Button_State : u16 {
+	MOUSE_BTN_STATE_IS_DOWN = 0x1,
+	MOUSE_BTN_STATE_JUST_PRESSED = 0x2,
+	MOUSE_BTN_STATE_JUST_RELEASED = 0x4,
+};
+
+enum Key_State : u16 {
+	KEY_STATE_IS_DOWN = 0x1,
+	KEY_STATE_JUST_PRESSED = 0x2,
+	KEY_STATE_JUST_RELEASED = 0x4,
+};
+
+struct User_Input {
+	u16 key_state[KEY_COUNT];
+
+	u16 mouse_btn_state[MOUSE_BTN_COUNT];
+	struct { i32 x; i32 y; } mouse_pos;
+};
+

src/mainloop.cpp

@@ -0,0 +1,94 @@
+internal inline void monitor_key(GLFWwindow *window, u16 *key_state, i32 glfw_key, Input_Key haru_key) {
+	u16& state = key_state[haru_key];
+	if (glfwGetKey(window, glfw_key) == GLFW_PRESS) {
+		if (!(state & KEY_STATE_IS_DOWN)) state |= KEY_STATE_JUST_PRESSED;
+		state |= KEY_STATE_IS_DOWN;
+	} else if (glfwGetKey(window, glfw_key) == GLFW_RELEASE) {
+		if (state & KEY_STATE_IS_DOWN) state |= KEY_STATE_JUST_RELEASED;
+		state &= ~KEY_STATE_IS_DOWN;
+	}
+}
+
+internal inline void monitor_mouse_btn(GLFWwindow *window, u16 *mouse_btn_state, i32 glfw_btn, Mouse_Button haru_btn) {
+	u16& state = mouse_btn_state[haru_btn];
+	if (glfwGetMouseButton(window, glfw_btn) == GLFW_PRESS) {
+		if (!(state & MOUSE_BTN_STATE_IS_DOWN)) state |= MOUSE_BTN_STATE_JUST_PRESSED;
+		state |= MOUSE_BTN_STATE_IS_DOWN;
+	} else if (glfwGetMouseButton(window, glfw_btn) == GLFW_RELEASE) {
+		if (state & MOUSE_BTN_STATE_IS_DOWN) state |= MOUSE_BTN_STATE_JUST_RELEASED;
+		state &= ~MOUSE_BTN_STATE_IS_DOWN;
+	}
+}
+
+internal void run_main_loop(GLFWwindow *window, Arena *arena)
+{
+  App_State app {};
+
+  f32 delta_time;
+  chr::time_point last_saved_time = chr::high_resolution_clock::now();
+  
+  b8 running = true;
+  while (running) {
+		chr::time_point frame_start = chr::high_resolution_clock::now();
+		u64 time_since_prev_frame_us = chr::duration_cast<chr::microseconds>(frame_start - last_saved_time).count();
+		delta_time = time_since_prev_frame_us * 0.000'001f;
+		last_saved_time = frame_start;
+
+		glfwPollEvents();
+
+		// Update window size
+		{
+			Window_Data &wdata = app.win_data;
+
+			i32 prev_width = wdata.width;
+			i32 prev_height = wdata.height;
+
+			glfwGetWindowSize(window, &wdata.width, &wdata.height);
+
+			wdata.size_just_changed = prev_width != wdata.width || prev_height != wdata.height;
+		}
+
+		ImGui_ImplOpenGL3_NewFrame();
+		ImGui_ImplGlfw_NewFrame();
+		ImGui::NewFrame();
+
+		if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS ||
+				glfwWindowShouldClose(window))
+		{
+			running = false;
+			break;
+		}
+
+		b32 focused = glfwGetWindowAttrib(window, GLFW_FOCUSED);
+		if (focused) {
+			// TODO Update keyboard / mouse
+			// Update keyboard
+			u16 *key_state = app.user_input.key_state;
+			monitor_key(window, key_state, GLFW_KEY_Q, KEY_Q);
+			monitor_key(window, key_state, GLFW_KEY_UP, KEY_UP);
+			monitor_key(window, key_state, GLFW_KEY_DOWN, KEY_DOWN);
+			monitor_key(window, key_state, GLFW_KEY_LEFT, KEY_LEFT);
+			monitor_key(window, key_state, GLFW_KEY_RIGHT, KEY_RIGHT);
+			monitor_key(window, key_state, GLFW_KEY_LEFT_ALT, KEY_ALT);
+			monitor_key(window, key_state, GLFW_KEY_TAB, KEY_TAB);
+
+			// Update mouse
+			f64 mposx, mposy;
+			glfwGetCursorPos(window, &mposx, &mposy);
+
+			app.user_input.mouse_pos.x = (i32)mposx;
+			app.user_input.mouse_pos.y = (i32)mposy;
+
+			u16 *mouse_btn_state = app.user_input.mouse_btn_state;
+			monitor_mouse_btn(window, mouse_btn_state, GLFW_MOUSE_BUTTON_LEFT, MOUSE_BTN_LEFT);
+			monitor_mouse_btn(window, mouse_btn_state, GLFW_MOUSE_BUTTON_RIGHT, MOUSE_BTN_RIGHT);
+		}
+
+		update_and_render(arena, app, delta_time);
+
+		ImGui::Render();
+		ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+		glfwSwapBuffers(window);
+  }  
+}

src/render.cpp

@@ -0,0 +1,22 @@
+struct Window_Data {
+	// Real width and height of the window
+	i32 width;
+	i32 height;
+	bool size_just_changed;
+
+	f32 desired_aspect_ratio;
+};
+
+struct App_State {
+  Window_Data win_data;
+  User_Input user_input;
+};
+
+internal void update_and_render(Arena *arena, App_State &app, f32 delta_time)
+{
+  ImGui::SetNextWindowPos({ 0, 0 });
+  ImGui::SetNextWindowSize({ (f32)app.win_data.width, (f32)app.win_data.height });
+  if (ImGui::Begin("test")) {
+    ImGui::End();
+  }
+}

src/rntviewer.cpp

@@ -0,0 +1,154 @@
+#include <ROOT/RNTupleReader.hxx>
+#include <ROOT/RNTuple.hxx>
+#include <TFile.h>
+
+#include <cstdio>
+#include <cstdint>
+#include <chrono>
+
+#include <sys/mman.h>
+#include <unistd.h>
+
+#ifdef DEBUG
+#include <sanitizer/asan_interface.h>
+#endif
+
+#include <imgui/imgui.h>
+#include <imgui/backends/imgui_impl_glfw.h>
+#include <imgui/backends/imgui_impl_opengl3.h>
+
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+
+#include "types.h"
+#include "defer.hpp"
+#include "mem.h"
+#include "input.h"
+
+namespace chr = std::chrono;
+
+#include "mem.cpp"
+#include "render.cpp"
+#include "mainloop.cpp"
+
+using namespace ROOT::Experimental;
+
+internal size_t file_size(FILE *f)
+{
+  fseek(f, 0, SEEK_END);
+  size_t res = ftell(f);
+  fseek(f, 0, SEEK_SET);
+  return res;  
+}
+
+internal b8 init_imgui(GLFWwindow* window) {
+	IMGUI_CHECKVERSION();
+	ImGui::CreateContext();
+	ImGuiIO& io = ImGui::GetIO(); (void) io;
+	io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+
+	ImGui::StyleColorsDark();
+
+	ImGui_ImplGlfw_InitForOpenGL(window, true);
+	ImGui_ImplOpenGL3_Init("#version 460");
+
+	return true;
+}
+
+internal void glfw_error_callback(i32 error, const char *description) {
+	fprintf(stderr, "GLFW error %d: %s\n", error, description);
+}
+
+internal GLFWwindow* init_glfw(i32 desired_win_width, i32 desired_win_height)
+{
+	glfwSetErrorCallback(glfw_error_callback);
+	glfwInit();
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	glfwWindowHint(GLFW_DOUBLEBUFFER, GLFW_TRUE);
+	glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
+	glfwWindowHint(GLFW_DECORATED, GLFW_TRUE);
+	glfwWindowHint(GLFW_DEPTH_BITS, 32);
+#if defined(HARU_SLOW)
+	glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, true);
+#endif
+
+	GLFWwindow *window = glfwCreateWindow(
+			desired_win_width, desired_win_height,
+			"RNTuple Viewer",
+			nullptr,
+			nullptr
+			);
+
+	glfwMakeContextCurrent(window);
+	//glfwSetFramebufferSizeCallback(window, resize_keep_ratio);
+
+	return window;
+}
+
+int main(int argc, char **argv)
+{
+  if (argc < 3) {
+    fprintf(stderr, "Usage: %s <ntuple_name> <ntuple_file.root>\n", argv[0]);
+    return 1;
+  }
+
+  // Collect arguments
+  const char *ntpl_name = argv[1];
+  const char *fname = argv[2];
+
+  // Allocate program memory
+  Arena *arena = arena_alloc();
+  if (!arena) {
+    fprintf(stderr, "Failed to allocate memory\n");
+    return 1;
+  }
+  defer { arena_release(arena); };
+
+  // Init imgui and GLFW
+  GLFWwindow *window = init_glfw(800, 600);
+  if (!window) {
+    fprintf(stderr, "Failed to init GLFW\n");
+    return 1;
+  }
+  defer { glfwTerminate(); };
+  
+  if (!init_imgui(window)) {
+    fprintf(stderr, "Failed to init Imgui\n");
+    return 1;
+  }
+
+  // Open and map the file
+  FILE *file = fopen(fname, "rb");
+  defer { fclose(file); };
+
+  const int fd = fileno(file);
+  const size_t fsize = file_size(file);
+  void *fmem = mmap(0, fsize, PROT_READ, MAP_SHARED_VALIDATE, fd, 0);
+  if (!fmem) {
+    fprintf(stderr, "Failed to open file %s\n", fname);
+    return 1;
+  }
+  defer { munmap(fmem, fsize); };
+
+  // Open the TFile
+  TFile *tfile = TFile::Open(fname, "READ");
+  if (!tfile) {
+    fprintf(stderr, "Failed to open TFile.\n");
+    return 1;
+  }
+  defer { delete tfile; };
+
+  // Get the RNTuple information
+  const RNTuple *anchor = tfile->Get<RNTuple>(ntpl_name);
+  if (!anchor) {
+    fprintf(stderr, "RNTuple '%s' not found in %s.\n", ntpl_name, fname);
+    return 1;
+  }
+
+  // Start main loop
+  run_main_loop(window, arena);
+
+  return 0;
+}

src/types.h

@@ -7,7 +7,10 @@ using f32 = float;
 using f64 = double;
 
 using b8 = bool;
+using b32 = int32_t;
 using b32x = int;
 
 using i32 = int32_t;
 using i64 = int64_t;
+
+#define internal static

third_party/GLFW/glfw3native.h

@@ -0,0 +1,628 @@
+/*************************************************************************
+ * GLFW 3.3 - www.glfw.org
+ * A library for OpenGL, window and input
+ *------------------------------------------------------------------------
+ * Copyright (c) 2002-2006 Marcus Geelnard
+ * Copyright (c) 2006-2018 Camilla Löwy <elmindreda@glfw.org>
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would
+ *    be appreciated but is not required.
+ *
+ * 2. Altered source versions must be plainly marked as such, and must not
+ *    be misrepresented as being the original software.
+ *
+ * 3. This notice may not be removed or altered from any source
+ *    distribution.
+ *
+ *************************************************************************/
+
+#ifndef _glfw3_native_h_
+#define _glfw3_native_h_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/*************************************************************************
+ * Doxygen documentation
+ *************************************************************************/
+
+/*! @file glfw3native.h
+ *  @brief The header of the native access functions.
+ *
+ *  This is the header file of the native access functions.  See @ref native for
+ *  more information.
+ */
+/*! @defgroup native Native access
+ *  @brief Functions related to accessing native handles.
+ *
+ *  **By using the native access functions you assert that you know what you're
+ *  doing and how to fix problems caused by using them.  If you don't, you
+ *  shouldn't be using them.**
+ *
+ *  Before the inclusion of @ref glfw3native.h, you may define zero or more
+ *  window system API macro and zero or more context creation API macros.
+ *
+ *  The chosen backends must match those the library was compiled for.  Failure
+ *  to do this will cause a link-time error.
+ *
+ *  The available window API macros are:
+ *  * `GLFW_EXPOSE_NATIVE_WIN32`
+ *  * `GLFW_EXPOSE_NATIVE_COCOA`
+ *  * `GLFW_EXPOSE_NATIVE_X11`
+ *  * `GLFW_EXPOSE_NATIVE_WAYLAND`
+ *
+ *  The available context API macros are:
+ *  * `GLFW_EXPOSE_NATIVE_WGL`
+ *  * `GLFW_EXPOSE_NATIVE_NSGL`
+ *  * `GLFW_EXPOSE_NATIVE_GLX`
+ *  * `GLFW_EXPOSE_NATIVE_EGL`
+ *  * `GLFW_EXPOSE_NATIVE_OSMESA`
+ *
+ *  These macros select which of the native access functions that are declared
+ *  and which platform-specific headers to include.  It is then up your (by
+ *  definition platform-specific) code to handle which of these should be
+ *  defined.
+ *
+ *  If you do not want the platform-specific headers to be included, define
+ *  `GLFW_NATIVE_INCLUDE_NONE` before including the @ref glfw3native.h header.
+ *
+ *  @code
+ *  #define GLFW_EXPOSE_NATIVE_WIN32
+ *  #define GLFW_EXPOSE_NATIVE_WGL
+ *  #define GLFW_NATIVE_INCLUDE_NONE
+ *  #include <GLFW/glfw3native.h>
+ *  @endcode
+ */
+
+
+/*************************************************************************
+ * System headers and types
+ *************************************************************************/
+
+#if !defined(GLFW_NATIVE_INCLUDE_NONE)
+
+ #if defined(GLFW_EXPOSE_NATIVE_WIN32) || defined(GLFW_EXPOSE_NATIVE_WGL)
+  /* This is a workaround for the fact that glfw3.h needs to export APIENTRY (for
+   * example to allow applications to correctly declare a GL_KHR_debug callback)
+   * but windows.h assumes no one will define APIENTRY before it does
+   */
+  #if defined(GLFW_APIENTRY_DEFINED)
+   #undef APIENTRY
+   #undef GLFW_APIENTRY_DEFINED
+  #endif
+  #include <windows.h>
+ #elif defined(GLFW_EXPOSE_NATIVE_COCOA) || defined(GLFW_EXPOSE_NATIVE_NSGL)
+  #if defined(__OBJC__)
+   #import <Cocoa/Cocoa.h>
+  #else
+   #include <ApplicationServices/ApplicationServices.h>
+   #include <objc/objc.h>
+  #endif
+ #elif defined(GLFW_EXPOSE_NATIVE_X11) || defined(GLFW_EXPOSE_NATIVE_GLX)
+  #include <X11/Xlib.h>
+  #include <X11/extensions/Xrandr.h>
+ #elif defined(GLFW_EXPOSE_NATIVE_WAYLAND)
+  #include <wayland-client.h>
+ #endif
+
+ #if defined(GLFW_EXPOSE_NATIVE_WGL)
+  /* WGL is declared by windows.h */
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_NSGL)
+  /* NSGL is declared by Cocoa.h */
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_GLX)
+  /* This is a workaround for the fact that glfw3.h defines GLAPIENTRY because by
+   * default it also acts as an OpenGL header
+   * However, glx.h will include gl.h, which will define it unconditionally
+   */
+  #if defined(GLFW_GLAPIENTRY_DEFINED)
+   #undef GLAPIENTRY
+   #undef GLFW_GLAPIENTRY_DEFINED
+  #endif
+  #include <GL/glx.h>
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_EGL)
+  #include <EGL/egl.h>
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_OSMESA)
+  /* This is a workaround for the fact that glfw3.h defines GLAPIENTRY because by
+   * default it also acts as an OpenGL header
+   * However, osmesa.h will include gl.h, which will define it unconditionally
+   */
+  #if defined(GLFW_GLAPIENTRY_DEFINED)
+   #undef GLAPIENTRY
+   #undef GLFW_GLAPIENTRY_DEFINED
+  #endif
+  #include <GL/osmesa.h>
+ #endif
+
+#endif /*GLFW_NATIVE_INCLUDE_NONE*/
+
+
+/*************************************************************************
+ * Functions
+ *************************************************************************/
+
+#if defined(GLFW_EXPOSE_NATIVE_WIN32)
+/*! @brief Returns the adapter device name of the specified monitor.
+ *
+ *  @return The UTF-8 encoded adapter device name (for example `\\.\DISPLAY1`)
+ *  of the specified monitor, or `NULL` if an [error](@ref error_handling)
+ *  occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetWin32Adapter(GLFWmonitor* monitor);
+
+/*! @brief Returns the display device name of the specified monitor.
+ *
+ *  @return The UTF-8 encoded display device name (for example
+ *  `\\.\DISPLAY1\Monitor0`) of the specified monitor, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetWin32Monitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `HWND` of the specified window.
+ *
+ *  @return The `HWND` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @remark The `HDC` associated with the window can be queried with the
+ *  [GetDC](https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdc)
+ *  function.
+ *  @code
+ *  HDC dc = GetDC(glfwGetWin32Window(window));
+ *  @endcode
+ *  This DC is private and does not need to be released.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI HWND glfwGetWin32Window(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_WGL)
+/*! @brief Returns the `HGLRC` of the specified window.
+ *
+ *  @return The `HGLRC` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @remark The `HDC` associated with the window can be queried with the
+ *  [GetDC](https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdc)
+ *  function.
+ *  @code
+ *  HDC dc = GetDC(glfwGetWin32Window(window));
+ *  @endcode
+ *  This DC is private and does not need to be released.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI HGLRC glfwGetWGLContext(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_COCOA)
+/*! @brief Returns the `CGDirectDisplayID` of the specified monitor.
+ *
+ *  @return The `CGDirectDisplayID` of the specified monitor, or
+ *  `kCGNullDirectDisplay` if an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI CGDirectDisplayID glfwGetCocoaMonitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `NSWindow` of the specified window.
+ *
+ *  @return The `NSWindow` of the specified window, or `nil` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI id glfwGetCocoaWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_NSGL)
+/*! @brief Returns the `NSOpenGLContext` of the specified window.
+ *
+ *  @return The `NSOpenGLContext` of the specified window, or `nil` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI id glfwGetNSGLContext(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_X11)
+/*! @brief Returns the `Display` used by GLFW.
+ *
+ *  @return The `Display` used by GLFW, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI Display* glfwGetX11Display(void);
+
+/*! @brief Returns the `RRCrtc` of the specified monitor.
+ *
+ *  @return The `RRCrtc` of the specified monitor, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI RRCrtc glfwGetX11Adapter(GLFWmonitor* monitor);
+
+/*! @brief Returns the `RROutput` of the specified monitor.
+ *
+ *  @return The `RROutput` of the specified monitor, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI RROutput glfwGetX11Monitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `Window` of the specified window.
+ *
+ *  @return The `Window` of the specified window, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI Window glfwGetX11Window(GLFWwindow* window);
+
+/*! @brief Sets the current primary selection to the specified string.
+ *
+ *  @param[in] string A UTF-8 encoded string.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The specified string is copied before this function
+ *  returns.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwGetX11SelectionString
+ *  @sa glfwSetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI void glfwSetX11SelectionString(const char* string);
+
+/*! @brief Returns the contents of the current primary selection as a string.
+ *
+ *  If the selection is empty or if its contents cannot be converted, `NULL`
+ *  is returned and a @ref GLFW_FORMAT_UNAVAILABLE error is generated.
+ *
+ *  @return The contents of the selection as a UTF-8 encoded string, or `NULL`
+ *  if an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The returned string is allocated and freed by GLFW. You
+ *  should not free it yourself. It is valid until the next call to @ref
+ *  glfwGetX11SelectionString or @ref glfwSetX11SelectionString, or until the
+ *  library is terminated.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwSetX11SelectionString
+ *  @sa glfwGetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetX11SelectionString(void);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_GLX)
+/*! @brief Returns the `GLXContext` of the specified window.
+ *
+ *  @return The `GLXContext` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI GLXContext glfwGetGLXContext(GLFWwindow* window);
+
+/*! @brief Returns the `GLXWindow` of the specified window.
+ *
+ *  @return The `GLXWindow` of the specified window, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI GLXWindow glfwGetGLXWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_WAYLAND)
+/*! @brief Returns the `struct wl_display*` used by GLFW.
+ *
+ *  @return The `struct wl_display*` used by GLFW, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_display* glfwGetWaylandDisplay(void);
+
+/*! @brief Returns the `struct wl_output*` of the specified monitor.
+ *
+ *  @return The `struct wl_output*` of the specified monitor, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_output* glfwGetWaylandMonitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the main `struct wl_surface*` of the specified window.
+ *
+ *  @return The main `struct wl_surface*` of the specified window, or `NULL` if
+ *  an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_surface* glfwGetWaylandWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_EGL)
+/*! @brief Returns the `EGLDisplay` used by GLFW.
+ *
+ *  @return The `EGLDisplay` used by GLFW, or `EGL_NO_DISPLAY` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @remark Because EGL is initialized on demand, this function will return
+ *  `EGL_NO_DISPLAY` until the first context has been created via EGL.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLDisplay glfwGetEGLDisplay(void);
+
+/*! @brief Returns the `EGLContext` of the specified window.
+ *
+ *  @return The `EGLContext` of the specified window, or `EGL_NO_CONTEXT` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLContext glfwGetEGLContext(GLFWwindow* window);
+
+/*! @brief Returns the `EGLSurface` of the specified window.
+ *
+ *  @return The `EGLSurface` of the specified window, or `EGL_NO_SURFACE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLSurface glfwGetEGLSurface(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_OSMESA)
+/*! @brief Retrieves the color buffer associated with the specified window.
+ *
+ *  @param[in] window The window whose color buffer to retrieve.
+ *  @param[out] width Where to store the width of the color buffer, or `NULL`.
+ *  @param[out] height Where to store the height of the color buffer, or `NULL`.
+ *  @param[out] format Where to store the OSMesa pixel format of the color
+ *  buffer, or `NULL`.
+ *  @param[out] buffer Where to store the address of the color buffer, or
+ *  `NULL`.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetOSMesaColorBuffer(GLFWwindow* window, int* width, int* height, int* format, void** buffer);
+
+/*! @brief Retrieves the depth buffer associated with the specified window.
+ *
+ *  @param[in] window The window whose depth buffer to retrieve.
+ *  @param[out] width Where to store the width of the depth buffer, or `NULL`.
+ *  @param[out] height Where to store the height of the depth buffer, or `NULL`.
+ *  @param[out] bytesPerValue Where to store the number of bytes per depth
+ *  buffer element, or `NULL`.
+ *  @param[out] buffer Where to store the address of the depth buffer, or
+ *  `NULL`.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetOSMesaDepthBuffer(GLFWwindow* window, int* width, int* height, int* bytesPerValue, void** buffer);
+
+/*! @brief Returns the `OSMesaContext` of the specified window.
+ *
+ *  @return The `OSMesaContext` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI OSMesaContext glfwGetOSMesaContext(GLFWwindow* window);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _glfw3_native_h_ */
+

third_party/imgui/.editorconfig

@@ -0,0 +1,28 @@
+# See http://editorconfig.org to read about the EditorConfig format.
+# - In theory automatically supported by VS2017+ and most common IDE or text editors.
+# - In practice VS2019-VS2022 stills don't trim trailing whitespaces correctly :(
+#   - Suggest installing this to trim whitespaces:
+#      GitHub https://github.com/madskristensen/TrailingWhitespace
+#      VS2019 https://marketplace.visualstudio.com/items?itemName=MadsKristensen.TrailingWhitespaceVisualizer
+#      VS2022 https://marketplace.visualstudio.com/items?itemName=MadsKristensen.TrailingWhitespace64
+#     (in spite of its name doesn't only visualize but also trims)
+#   - Alternative for older VS2010 to VS2015: https://marketplace.visualstudio.com/items?itemName=EditorConfigTeam.EditorConfig
+
+# top-most EditorConfig file
+root = true
+
+# Default settings:
+# Use 4 spaces as indentation
+[*]
+indent_style = space
+indent_size = 4
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[imstb_*]
+indent_size = 3
+trim_trailing_whitespace = false
+
+[Makefile]
+indent_style = tab
+indent_size = 4

third_party/imgui/LICENSE.txt

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014-2023 Omar Cornut
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

third_party/imgui/backends/imgui_impl_glfw.cpp

@@ -0,0 +1,796 @@
+// dear imgui: Platform Backend for GLFW
+// This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
+// (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ or GLFW 3.4+ for full feature support.)
+
+// Implemented features:
+//  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen on Windows ONLY, using a custom WndProc hook. (#2702)
+//  2023-03-16: Inputs: Fixed key modifiers handling on secondary viewports (docking branch). Broken on 2023/01/04. (#6248, #6034)
+//  2023-03-14: Emscripten: Avoid using glfwGetError() and glfwGetGamepadState() which are not correctly implemented in Emscripten emulation. (#6240)
+//  2023-02-03: Emscripten: Registering custom low-level mouse wheel handler to get more accurate scrolling impulses on Emscripten. (#4019, #6096)
+//  2023-01-04: Inputs: Fixed mods state on Linux when using Alt-GR text input (e.g. German keyboard layout), could lead to broken text input. Revert a 2022/01/17 change were we resumed using mods provided by GLFW, turns out they were faulty.
+//  2022-11-22: Perform a dummy glfwGetError() read to cancel missing names with glfwGetKeyName(). (#5908)
+//  2022-10-18: Perform a dummy glfwGetError() read to cancel missing mouse cursors errors. Using GLFW_VERSION_COMBINED directly. (#5785)
+//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
+//  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
+//  2022-09-01: Inputs: Honor GLFW_CURSOR_DISABLED by not setting mouse position.
+//  2022-04-30: Inputs: Fixed ImGui_ImplGlfw_TranslateUntranslatedKey() for lower case letters on OSX.
+//  2022-03-23: Inputs: Fixed a regression in 1.87 which resulted in keyboard modifiers events being reported incorrectly on Linux/X11.
+//  2022-02-07: Added ImGui_ImplGlfw_InstallCallbacks()/ImGui_ImplGlfw_RestoreCallbacks() helpers to facilitate user installing callbacks after initializing backend.
+//  2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
+//  2021-01-20: Inputs: calling new io.AddKeyAnalogEvent() for gamepad support, instead of writing directly to io.NavInputs[].
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
+//  2022-01-17: Inputs: always update key mods next and before key event (not in NewFrame) to fix input queue with very low framerates.
+//  2022-01-12: *BREAKING CHANGE*: Now using glfwSetCursorPosCallback(). If you called ImGui_ImplGlfw_InitXXX() with install_callbacks = false, you MUST install glfwSetCursorPosCallback() and forward it to the backend via ImGui_ImplGlfw_CursorPosCallback().
+//  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
+//  2022-01-05: Inputs: Converting GLFW untranslated keycodes back to translated keycodes (in the ImGui_ImplGlfw_KeyCallback() function) in order to match the behavior of every other backend, and facilitate the use of GLFW with lettered-shortcuts API.
+//  2021-08-17: *BREAKING CHANGE*: Now using glfwSetWindowFocusCallback() to calling io.AddFocusEvent(). If you called ImGui_ImplGlfw_InitXXX() with install_callbacks = false, you MUST install glfwSetWindowFocusCallback() and forward it to the backend via ImGui_ImplGlfw_WindowFocusCallback().
+//  2021-07-29: *BREAKING CHANGE*: Now using glfwSetCursorEnterCallback(). MousePos is correctly reported when the host platform window is hovered but not focused. If you called ImGui_ImplGlfw_InitXXX() with install_callbacks = false, you MUST install glfwSetWindowFocusCallback() callback and forward it to the backend via ImGui_ImplGlfw_CursorEnterCallback().
+//  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
+//  2020-01-17: Inputs: Disable error callback while assigning mouse cursors because some X11 setup don't have them and it generates errors.
+//  2019-12-05: Inputs: Added support for new mouse cursors added in GLFW 3.4+ (resizing cursors, not allowed cursor).
+//  2019-10-18: Misc: Previously installed user callbacks are now restored on shutdown.
+//  2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter.
+//  2019-05-11: Inputs: Don't filter value from character callback before calling AddInputCharacter().
+//  2019-03-12: Misc: Preserve DisplayFramebufferScale when main window is minimized.
+//  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
+//  2018-11-07: Inputs: When installing our GLFW callbacks, we save user's previously installed ones - if any - and chain call them.
+//  2018-08-01: Inputs: Workaround for Emscripten which doesn't seem to handle focus related calls.
+//  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
+//  2018-06-08: Misc: Extracted imgui_impl_glfw.cpp/.h away from the old combined GLFW+OpenGL/Vulkan examples.
+//  2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors flag + honor ImGuiConfigFlags_NoMouseCursorChange flag.
+//  2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value, passed to glfwSetCursor()).
+//  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
+//  2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
+//  2018-01-25: Inputs: Added gamepad support if ImGuiConfigFlags_NavEnableGamepad is set.
+//  2018-01-25: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
+//  2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
+//  2018-01-18: Inputs: Added mapping for ImGuiKey_Insert.
+//  2017-08-25: Inputs: MousePos set to -FLT_MAX,-FLT_MAX when mouse is unavailable/missing (instead of -1,-1).
+//  2016-10-15: Misc: Added a void* user_data parameter to Clipboard function handlers.
+
+#include "imgui.h"
+#include "imgui_impl_glfw.h"
+
+// Clang warnings with -Weverything
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wold-style-cast"     // warning: use of old-style cast
+#pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#endif
+
+// GLFW
+#include <GLFW/glfw3.h>
+
+#ifdef _WIN32
+#undef APIENTRY
+#define GLFW_EXPOSE_NATIVE_WIN32
+#include <GLFW/glfw3native.h>   // for glfwGetWin32Window()
+#endif
+#ifdef __APPLE__
+#define GLFW_EXPOSE_NATIVE_COCOA
+#include <GLFW/glfw3native.h>   // for glfwGetCocoaWindow()
+#endif
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#include <emscripten/html5.h>
+#endif
+
+// We gather version tests as define in order to easily see which features are version-dependent.
+#define GLFW_VERSION_COMBINED           (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 + GLFW_VERSION_REVISION)
+#ifdef GLFW_RESIZE_NESW_CURSOR          // Let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2019-11-29 (cursors defines) // FIXME: Remove when GLFW 3.4 is released?
+#define GLFW_HAS_NEW_CURSORS            (GLFW_VERSION_COMBINED >= 3400) // 3.4+ GLFW_RESIZE_ALL_CURSOR, GLFW_RESIZE_NESW_CURSOR, GLFW_RESIZE_NWSE_CURSOR, GLFW_NOT_ALLOWED_CURSOR
+#else
+#define GLFW_HAS_NEW_CURSORS            (0)
+#endif
+#define GLFW_HAS_GAMEPAD_API            (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetGamepadState() new api
+#define GLFW_HAS_GETKEYNAME             (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwGetKeyName()
+#define GLFW_HAS_GETERROR               (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetError()
+
+// GLFW data
+enum GlfwClientApi
+{
+    GlfwClientApi_Unknown,
+    GlfwClientApi_OpenGL,
+    GlfwClientApi_Vulkan
+};
+
+struct ImGui_ImplGlfw_Data
+{
+    GLFWwindow*             Window;
+    GlfwClientApi           ClientApi;
+    double                  Time;
+    GLFWwindow*             MouseWindow;
+    GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
+    ImVec2                  LastValidMousePos;
+    bool                    InstalledCallbacks;
+    bool                    CallbacksChainForAllWindows;
+
+    // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
+    GLFWwindowfocusfun      PrevUserCallbackWindowFocus;
+    GLFWcursorposfun        PrevUserCallbackCursorPos;
+    GLFWcursorenterfun      PrevUserCallbackCursorEnter;
+    GLFWmousebuttonfun      PrevUserCallbackMousebutton;
+    GLFWscrollfun           PrevUserCallbackScroll;
+    GLFWkeyfun              PrevUserCallbackKey;
+    GLFWcharfun             PrevUserCallbackChar;
+    GLFWmonitorfun          PrevUserCallbackMonitor;
+#ifdef _WIN32
+    WNDPROC                 GlfwWndProc;
+#endif
+
+    ImGui_ImplGlfw_Data()   { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendPlatformUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+// FIXME: multi-context support is not well tested and probably dysfunctional in this backend.
+// - Because glfwPollEvents() process all windows and some events may be called outside of it, you will need to register your own callbacks
+//   (passing install_callbacks=false in ImGui_ImplGlfw_InitXXX functions), set the current dear imgui context and then call our callbacks.
+// - Otherwise we may need to store a GLFWWindow* -> ImGuiContext* map and handle this in the backend, adding a little bit of extra complexity to it.
+// FIXME: some shared resources (mouse cursor shape, gamepad) are mishandled when using multi-context.
+static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplGlfw_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
+}
+
+// Functions
+static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
+{
+    return glfwGetClipboardString((GLFWwindow*)user_data);
+}
+
+static void ImGui_ImplGlfw_SetClipboardText(void* user_data, const char* text)
+{
+    glfwSetClipboardString((GLFWwindow*)user_data, text);
+}
+
+static ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int key)
+{
+    switch (key)
+    {
+        case GLFW_KEY_TAB: return ImGuiKey_Tab;
+        case GLFW_KEY_LEFT: return ImGuiKey_LeftArrow;
+        case GLFW_KEY_RIGHT: return ImGuiKey_RightArrow;
+        case GLFW_KEY_UP: return ImGuiKey_UpArrow;
+        case GLFW_KEY_DOWN: return ImGuiKey_DownArrow;
+        case GLFW_KEY_PAGE_UP: return ImGuiKey_PageUp;
+        case GLFW_KEY_PAGE_DOWN: return ImGuiKey_PageDown;
+        case GLFW_KEY_HOME: return ImGuiKey_Home;
+        case GLFW_KEY_END: return ImGuiKey_End;
+        case GLFW_KEY_INSERT: return ImGuiKey_Insert;
+        case GLFW_KEY_DELETE: return ImGuiKey_Delete;
+        case GLFW_KEY_BACKSPACE: return ImGuiKey_Backspace;
+        case GLFW_KEY_SPACE: return ImGuiKey_Space;
+        case GLFW_KEY_ENTER: return ImGuiKey_Enter;
+        case GLFW_KEY_ESCAPE: return ImGuiKey_Escape;
+        case GLFW_KEY_APOSTROPHE: return ImGuiKey_Apostrophe;
+        case GLFW_KEY_COMMA: return ImGuiKey_Comma;
+        case GLFW_KEY_MINUS: return ImGuiKey_Minus;
+        case GLFW_KEY_PERIOD: return ImGuiKey_Period;
+        case GLFW_KEY_SLASH: return ImGuiKey_Slash;
+        case GLFW_KEY_SEMICOLON: return ImGuiKey_Semicolon;
+        case GLFW_KEY_EQUAL: return ImGuiKey_Equal;
+        case GLFW_KEY_LEFT_BRACKET: return ImGuiKey_LeftBracket;
+        case GLFW_KEY_BACKSLASH: return ImGuiKey_Backslash;
+        case GLFW_KEY_RIGHT_BRACKET: return ImGuiKey_RightBracket;
+        case GLFW_KEY_GRAVE_ACCENT: return ImGuiKey_GraveAccent;
+        case GLFW_KEY_CAPS_LOCK: return ImGuiKey_CapsLock;
+        case GLFW_KEY_SCROLL_LOCK: return ImGuiKey_ScrollLock;
+        case GLFW_KEY_NUM_LOCK: return ImGuiKey_NumLock;
+        case GLFW_KEY_PRINT_SCREEN: return ImGuiKey_PrintScreen;
+        case GLFW_KEY_PAUSE: return ImGuiKey_Pause;
+        case GLFW_KEY_KP_0: return ImGuiKey_Keypad0;
+        case GLFW_KEY_KP_1: return ImGuiKey_Keypad1;
+        case GLFW_KEY_KP_2: return ImGuiKey_Keypad2;
+        case GLFW_KEY_KP_3: return ImGuiKey_Keypad3;
+        case GLFW_KEY_KP_4: return ImGuiKey_Keypad4;
+        case GLFW_KEY_KP_5: return ImGuiKey_Keypad5;
+        case GLFW_KEY_KP_6: return ImGuiKey_Keypad6;
+        case GLFW_KEY_KP_7: return ImGuiKey_Keypad7;
+        case GLFW_KEY_KP_8: return ImGuiKey_Keypad8;
+        case GLFW_KEY_KP_9: return ImGuiKey_Keypad9;
+        case GLFW_KEY_KP_DECIMAL: return ImGuiKey_KeypadDecimal;
+        case GLFW_KEY_KP_DIVIDE: return ImGuiKey_KeypadDivide;
+        case GLFW_KEY_KP_MULTIPLY: return ImGuiKey_KeypadMultiply;
+        case GLFW_KEY_KP_SUBTRACT: return ImGuiKey_KeypadSubtract;
+        case GLFW_KEY_KP_ADD: return ImGuiKey_KeypadAdd;
+        case GLFW_KEY_KP_ENTER: return ImGuiKey_KeypadEnter;
+        case GLFW_KEY_KP_EQUAL: return ImGuiKey_KeypadEqual;
+        case GLFW_KEY_LEFT_SHIFT: return ImGuiKey_LeftShift;
+        case GLFW_KEY_LEFT_CONTROL: return ImGuiKey_LeftCtrl;
+        case GLFW_KEY_LEFT_ALT: return ImGuiKey_LeftAlt;
+        case GLFW_KEY_LEFT_SUPER: return ImGuiKey_LeftSuper;
+        case GLFW_KEY_RIGHT_SHIFT: return ImGuiKey_RightShift;
+        case GLFW_KEY_RIGHT_CONTROL: return ImGuiKey_RightCtrl;
+        case GLFW_KEY_RIGHT_ALT: return ImGuiKey_RightAlt;
+        case GLFW_KEY_RIGHT_SUPER: return ImGuiKey_RightSuper;
+        case GLFW_KEY_MENU: return ImGuiKey_Menu;
+        case GLFW_KEY_0: return ImGuiKey_0;
+        case GLFW_KEY_1: return ImGuiKey_1;
+        case GLFW_KEY_2: return ImGuiKey_2;
+        case GLFW_KEY_3: return ImGuiKey_3;
+        case GLFW_KEY_4: return ImGuiKey_4;
+        case GLFW_KEY_5: return ImGuiKey_5;
+        case GLFW_KEY_6: return ImGuiKey_6;
+        case GLFW_KEY_7: return ImGuiKey_7;
+        case GLFW_KEY_8: return ImGuiKey_8;
+        case GLFW_KEY_9: return ImGuiKey_9;
+        case GLFW_KEY_A: return ImGuiKey_A;
+        case GLFW_KEY_B: return ImGuiKey_B;
+        case GLFW_KEY_C: return ImGuiKey_C;
+        case GLFW_KEY_D: return ImGuiKey_D;
+        case GLFW_KEY_E: return ImGuiKey_E;
+        case GLFW_KEY_F: return ImGuiKey_F;
+        case GLFW_KEY_G: return ImGuiKey_G;
+        case GLFW_KEY_H: return ImGuiKey_H;
+        case GLFW_KEY_I: return ImGuiKey_I;
+        case GLFW_KEY_J: return ImGuiKey_J;
+        case GLFW_KEY_K: return ImGuiKey_K;
+        case GLFW_KEY_L: return ImGuiKey_L;
+        case GLFW_KEY_M: return ImGuiKey_M;
+        case GLFW_KEY_N: return ImGuiKey_N;
+        case GLFW_KEY_O: return ImGuiKey_O;
+        case GLFW_KEY_P: return ImGuiKey_P;
+        case GLFW_KEY_Q: return ImGuiKey_Q;
+        case GLFW_KEY_R: return ImGuiKey_R;
+        case GLFW_KEY_S: return ImGuiKey_S;
+        case GLFW_KEY_T: return ImGuiKey_T;
+        case GLFW_KEY_U: return ImGuiKey_U;
+        case GLFW_KEY_V: return ImGuiKey_V;
+        case GLFW_KEY_W: return ImGuiKey_W;
+        case GLFW_KEY_X: return ImGuiKey_X;
+        case GLFW_KEY_Y: return ImGuiKey_Y;
+        case GLFW_KEY_Z: return ImGuiKey_Z;
+        case GLFW_KEY_F1: return ImGuiKey_F1;
+        case GLFW_KEY_F2: return ImGuiKey_F2;
+        case GLFW_KEY_F3: return ImGuiKey_F3;
+        case GLFW_KEY_F4: return ImGuiKey_F4;
+        case GLFW_KEY_F5: return ImGuiKey_F5;
+        case GLFW_KEY_F6: return ImGuiKey_F6;
+        case GLFW_KEY_F7: return ImGuiKey_F7;
+        case GLFW_KEY_F8: return ImGuiKey_F8;
+        case GLFW_KEY_F9: return ImGuiKey_F9;
+        case GLFW_KEY_F10: return ImGuiKey_F10;
+        case GLFW_KEY_F11: return ImGuiKey_F11;
+        case GLFW_KEY_F12: return ImGuiKey_F12;
+        default: return ImGuiKey_None;
+    }
+}
+
+// X11 does not include current pressed/released modifier key in 'mods' flags submitted by GLFW
+// See https://github.com/ocornut/imgui/issues/6034 and https://github.com/glfw/glfw/issues/1630
+static void ImGui_ImplGlfw_UpdateKeyModifiers(GLFWwindow* window)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddKeyEvent(ImGuiMod_Ctrl,  (glfwGetKey(window, GLFW_KEY_LEFT_CONTROL) == GLFW_PRESS) || (glfwGetKey(window, GLFW_KEY_RIGHT_CONTROL) == GLFW_PRESS));
+    io.AddKeyEvent(ImGuiMod_Shift, (glfwGetKey(window, GLFW_KEY_LEFT_SHIFT)   == GLFW_PRESS) || (glfwGetKey(window, GLFW_KEY_RIGHT_SHIFT)   == GLFW_PRESS));
+    io.AddKeyEvent(ImGuiMod_Alt,   (glfwGetKey(window, GLFW_KEY_LEFT_ALT)     == GLFW_PRESS) || (glfwGetKey(window, GLFW_KEY_RIGHT_ALT)     == GLFW_PRESS));
+    io.AddKeyEvent(ImGuiMod_Super, (glfwGetKey(window, GLFW_KEY_LEFT_SUPER)   == GLFW_PRESS) || (glfwGetKey(window, GLFW_KEY_RIGHT_SUPER)   == GLFW_PRESS));
+}
+
+static bool ImGui_ImplGlfw_ShouldChainCallback(GLFWwindow* window)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    return bd->CallbacksChainForAllWindows ? true : (window == bd->Window);
+}
+
+void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackMousebutton != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackMousebutton(window, button, action, mods);
+
+    ImGui_ImplGlfw_UpdateKeyModifiers(window);
+
+    ImGuiIO& io = ImGui::GetIO();
+    if (button >= 0 && button < ImGuiMouseButton_COUNT)
+        io.AddMouseButtonEvent(button, action == GLFW_PRESS);
+}
+
+void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackScroll != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackScroll(window, xoffset, yoffset);
+
+#ifdef __EMSCRIPTEN__
+    // Ignore GLFW events: will be processed in ImGui_ImplEmscripten_WheelCallback().
+    return;
+#endif
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddMouseWheelEvent((float)xoffset, (float)yoffset);
+}
+
+static int ImGui_ImplGlfw_TranslateUntranslatedKey(int key, int scancode)
+{
+#if GLFW_HAS_GETKEYNAME && !defined(__EMSCRIPTEN__)
+    // GLFW 3.1+ attempts to "untranslate" keys, which goes the opposite of what every other framework does, making using lettered shortcuts difficult.
+    // (It had reasons to do so: namely GLFW is/was more likely to be used for WASD-type game controls rather than lettered shortcuts, but IHMO the 3.1 change could have been done differently)
+    // See https://github.com/glfw/glfw/issues/1502 for details.
+    // Adding a workaround to undo this (so our keys are translated->untranslated->translated, likely a lossy process).
+    // This won't cover edge cases but this is at least going to cover common cases.
+    if (key >= GLFW_KEY_KP_0 && key <= GLFW_KEY_KP_EQUAL)
+        return key;
+    GLFWerrorfun prev_error_callback = glfwSetErrorCallback(nullptr);
+    const char* key_name = glfwGetKeyName(key, scancode);
+    glfwSetErrorCallback(prev_error_callback);
+#if GLFW_HAS_GETERROR && !defined(__EMSCRIPTEN__) // Eat errors (see #5908)
+    (void)glfwGetError(nullptr);
+#endif
+    if (key_name && key_name[0] != 0 && key_name[1] == 0)
+    {
+        const char char_names[] = "`-=[]\\,;\'./";
+        const int char_keys[] = { GLFW_KEY_GRAVE_ACCENT, GLFW_KEY_MINUS, GLFW_KEY_EQUAL, GLFW_KEY_LEFT_BRACKET, GLFW_KEY_RIGHT_BRACKET, GLFW_KEY_BACKSLASH, GLFW_KEY_COMMA, GLFW_KEY_SEMICOLON, GLFW_KEY_APOSTROPHE, GLFW_KEY_PERIOD, GLFW_KEY_SLASH, 0 };
+        IM_ASSERT(IM_ARRAYSIZE(char_names) == IM_ARRAYSIZE(char_keys));
+        if (key_name[0] >= '0' && key_name[0] <= '9')               { key = GLFW_KEY_0 + (key_name[0] - '0'); }
+        else if (key_name[0] >= 'A' && key_name[0] <= 'Z')          { key = GLFW_KEY_A + (key_name[0] - 'A'); }
+        else if (key_name[0] >= 'a' && key_name[0] <= 'z')          { key = GLFW_KEY_A + (key_name[0] - 'a'); }
+        else if (const char* p = strchr(char_names, key_name[0]))   { key = char_keys[p - char_names]; }
+    }
+    // if (action == GLFW_PRESS) printf("key %d scancode %d name '%s'\n", key, scancode, key_name);
+#else
+    IM_UNUSED(scancode);
+#endif
+    return key;
+}
+
+void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int keycode, int scancode, int action, int mods)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackKey != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackKey(window, keycode, scancode, action, mods);
+
+    if (action != GLFW_PRESS && action != GLFW_RELEASE)
+        return;
+
+    ImGui_ImplGlfw_UpdateKeyModifiers(window);
+
+    keycode = ImGui_ImplGlfw_TranslateUntranslatedKey(keycode, scancode);
+
+    ImGuiIO& io = ImGui::GetIO();
+    ImGuiKey imgui_key = ImGui_ImplGlfw_KeyToImGuiKey(keycode);
+    io.AddKeyEvent(imgui_key, (action == GLFW_PRESS));
+    io.SetKeyEventNativeData(imgui_key, keycode, scancode); // To support legacy indexing (<1.87 user code)
+}
+
+void ImGui_ImplGlfw_WindowFocusCallback(GLFWwindow* window, int focused)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackWindowFocus != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackWindowFocus(window, focused);
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddFocusEvent(focused != 0);
+}
+
+void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackCursorPos != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackCursorPos(window, x, y);
+    if (glfwGetInputMode(window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
+        return;
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddMousePosEvent((float)x, (float)y);
+    bd->LastValidMousePos = ImVec2((float)x, (float)y);
+}
+
+// Workaround: X11 seems to send spurious Leave/Enter events which would make us lose our position,
+// so we back it up and restore on Leave/Enter (see https://github.com/ocornut/imgui/issues/4984)
+void ImGui_ImplGlfw_CursorEnterCallback(GLFWwindow* window, int entered)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackCursorEnter != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackCursorEnter(window, entered);
+    if (glfwGetInputMode(window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
+        return;
+
+    ImGuiIO& io = ImGui::GetIO();
+    if (entered)
+    {
+        bd->MouseWindow = window;
+        io.AddMousePosEvent(bd->LastValidMousePos.x, bd->LastValidMousePos.y);
+    }
+    else if (!entered && bd->MouseWindow == window)
+    {
+        bd->LastValidMousePos = io.MousePos;
+        bd->MouseWindow = nullptr;
+        io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
+    }
+}
+
+void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (bd->PrevUserCallbackChar != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
+        bd->PrevUserCallbackChar(window, c);
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddInputCharacter(c);
+}
+
+void ImGui_ImplGlfw_MonitorCallback(GLFWmonitor*, int)
+{
+	// Unused in 'master' branch but 'docking' branch will use this, so we declare it ahead of it so if you have to install callbacks you can install this one too.
+}
+
+#ifdef __EMSCRIPTEN__
+static EM_BOOL ImGui_ImplEmscripten_WheelCallback(int, const EmscriptenWheelEvent* ev, void*)
+{
+    // Mimic Emscripten_HandleWheel() in SDL.
+    // Corresponding equivalent in GLFW JS emulation layer has incorrect quantizing preventing small values. See #6096
+    float multiplier = 0.0f;
+    if (ev->deltaMode == DOM_DELTA_PIXEL)       { multiplier = 1.0f / 100.0f; } // 100 pixels make up a step.
+    else if (ev->deltaMode == DOM_DELTA_LINE)   { multiplier = 1.0f / 3.0f; }   // 3 lines make up a step.
+    else if (ev->deltaMode == DOM_DELTA_PAGE)   { multiplier = 80.0f; }         // A page makes up 80 steps.
+    float wheel_x = ev->deltaX * -multiplier;
+    float wheel_y = ev->deltaY * -multiplier;
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddMouseWheelEvent(wheel_x, wheel_y);
+    //IMGUI_DEBUG_LOG("[Emsc] mode %d dx: %.2f, dy: %.2f, dz: %.2f --> feed %.2f %.2f\n", (int)ev->deltaMode, ev->deltaX, ev->deltaY, ev->deltaZ, wheel_x, wheel_y);
+    return EM_TRUE;
+}
+#endif
+
+#ifdef _WIN32
+// GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
+// Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
+static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
+{
+    LPARAM extra_info = ::GetMessageExtraInfo();
+    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
+        return ImGuiMouseSource_Pen;
+    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
+        return ImGuiMouseSource_TouchScreen;
+    return ImGuiMouseSource_Mouse;
+}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    switch (msg)
+    {
+    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
+    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
+    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
+    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
+    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
+        ImGui::GetIO().AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
+        break;
+    }
+    return ::CallWindowProc(bd->GlfwWndProc, hWnd, msg, wParam, lParam);
+}
+#endif
+
+void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    IM_ASSERT(bd->InstalledCallbacks == false && "Callbacks already installed!");
+    IM_ASSERT(bd->Window == window);
+
+    bd->PrevUserCallbackWindowFocus = glfwSetWindowFocusCallback(window, ImGui_ImplGlfw_WindowFocusCallback);
+    bd->PrevUserCallbackCursorEnter = glfwSetCursorEnterCallback(window, ImGui_ImplGlfw_CursorEnterCallback);
+    bd->PrevUserCallbackCursorPos = glfwSetCursorPosCallback(window, ImGui_ImplGlfw_CursorPosCallback);
+    bd->PrevUserCallbackMousebutton = glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
+    bd->PrevUserCallbackScroll = glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
+    bd->PrevUserCallbackKey = glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
+    bd->PrevUserCallbackChar = glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
+    bd->PrevUserCallbackMonitor = glfwSetMonitorCallback(ImGui_ImplGlfw_MonitorCallback);
+    bd->InstalledCallbacks = true;
+}
+
+void ImGui_ImplGlfw_RestoreCallbacks(GLFWwindow* window)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    IM_ASSERT(bd->InstalledCallbacks == true && "Callbacks not installed!");
+    IM_ASSERT(bd->Window == window);
+
+    glfwSetWindowFocusCallback(window, bd->PrevUserCallbackWindowFocus);
+    glfwSetCursorEnterCallback(window, bd->PrevUserCallbackCursorEnter);
+    glfwSetCursorPosCallback(window, bd->PrevUserCallbackCursorPos);
+    glfwSetMouseButtonCallback(window, bd->PrevUserCallbackMousebutton);
+    glfwSetScrollCallback(window, bd->PrevUserCallbackScroll);
+    glfwSetKeyCallback(window, bd->PrevUserCallbackKey);
+    glfwSetCharCallback(window, bd->PrevUserCallbackChar);
+    glfwSetMonitorCallback(bd->PrevUserCallbackMonitor);
+    bd->InstalledCallbacks = false;
+    bd->PrevUserCallbackWindowFocus = nullptr;
+    bd->PrevUserCallbackCursorEnter = nullptr;
+    bd->PrevUserCallbackCursorPos = nullptr;
+    bd->PrevUserCallbackMousebutton = nullptr;
+    bd->PrevUserCallbackScroll = nullptr;
+    bd->PrevUserCallbackKey = nullptr;
+    bd->PrevUserCallbackChar = nullptr;
+    bd->PrevUserCallbackMonitor = nullptr;
+}
+
+// Set to 'true' to enable chaining installed callbacks for all windows (including secondary viewports created by backends or by user.
+// This is 'false' by default meaning we only chain callbacks for the main viewport.
+// We cannot set this to 'true' by default because user callbacks code may be not testing the 'window' parameter of their callback.
+// If you set this to 'true' your user callback code will need to make sure you are testing the 'window' parameter.
+void ImGui_ImplGlfw_SetCallbacksChainForAllWindows(bool chain_for_all_windows)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    bd->CallbacksChainForAllWindows = chain_for_all_windows;
+}
+
+static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, GlfwClientApi client_api)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
+    //printf("GLFW_VERSION: %d.%d.%d (%d)", GLFW_VERSION_MAJOR, GLFW_VERSION_MINOR, GLFW_VERSION_REVISION, GLFW_VERSION_COMBINED);
+
+    // Setup backend capabilities flags
+    ImGui_ImplGlfw_Data* bd = IM_NEW(ImGui_ImplGlfw_Data)();
+    io.BackendPlatformUserData = (void*)bd;
+    io.BackendPlatformName = "imgui_impl_glfw";
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+
+    bd->Window = window;
+    bd->Time = 0.0;
+
+    io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
+    io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
+    io.ClipboardUserData = bd->Window;
+
+    // Create mouse cursors
+    // (By design, on X11 cursors are user configurable and some cursors may be missing. When a cursor doesn't exist,
+    // GLFW will emit an error which will often be printed by the app, so we temporarily disable error reporting.
+    // Missing cursors will return nullptr and our _UpdateMouseCursor() function will use the Arrow cursor instead.)
+    GLFWerrorfun prev_error_callback = glfwSetErrorCallback(nullptr);
+    bd->MouseCursors[ImGuiMouseCursor_Arrow] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_TextInput] = glfwCreateStandardCursor(GLFW_IBEAM_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNS] = glfwCreateStandardCursor(GLFW_VRESIZE_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeEW] = glfwCreateStandardCursor(GLFW_HRESIZE_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
+#if GLFW_HAS_NEW_CURSORS
+    bd->MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_RESIZE_ALL_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_RESIZE_NESW_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_RESIZE_NWSE_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_NOT_ALLOWED_CURSOR);
+#else
+    bd->MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
+    bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
+#endif
+    glfwSetErrorCallback(prev_error_callback);
+#if GLFW_HAS_GETERROR && !defined(__EMSCRIPTEN__) // Eat errors (see #5908)
+    (void)glfwGetError(nullptr);
+#endif
+
+    // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
+    if (install_callbacks)
+        ImGui_ImplGlfw_InstallCallbacks(window);
+    // Register Emscripten Wheel callback to workaround issue in Emscripten GLFW Emulation (#6096)
+    // We intentionally do not check 'if (install_callbacks)' here, as some users may set it to false and call GLFW callback themselves.
+    // FIXME: May break chaining in case user registered their own Emscripten callback?
+#ifdef __EMSCRIPTEN__
+    emscripten_set_wheel_callback(EMSCRIPTEN_EVENT_TARGET_DOCUMENT, nullptr, false, ImGui_ImplEmscripten_WheelCallback);
+#endif
+
+    // Set platform dependent data in viewport
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+#ifdef _WIN32
+    main_viewport->PlatformHandleRaw = glfwGetWin32Window(bd->Window);
+#elif defined(__APPLE__)
+    main_viewport->PlatformHandleRaw = (void*)glfwGetCocoaWindow(bd->Window);
+#else
+    IM_UNUSED(main_viewport);
+#endif
+
+    // Windows: register a WndProc hook so we can intercept some messages.
+#ifdef _WIN32
+    bd->GlfwWndProc = (WNDPROC)::GetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC);
+    IM_ASSERT(bd->GlfwWndProc != nullptr);
+    ::SetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
+#endif
+
+    bd->ClientApi = client_api;
+    return true;
+}
+
+bool ImGui_ImplGlfw_InitForOpenGL(GLFWwindow* window, bool install_callbacks)
+{
+    return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_OpenGL);
+}
+
+bool ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool install_callbacks)
+{
+    return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_Vulkan);
+}
+
+bool ImGui_ImplGlfw_InitForOther(GLFWwindow* window, bool install_callbacks)
+{
+    return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_Unknown);
+}
+
+void ImGui_ImplGlfw_Shutdown()
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    if (bd->InstalledCallbacks)
+        ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
+
+    for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
+        glfwDestroyCursor(bd->MouseCursors[cursor_n]);
+
+    // Windows: register a WndProc hook so we can intercept some messages.
+#ifdef _WIN32
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ::SetWindowLongPtr((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC, (LONG_PTR)bd->GlfwWndProc);
+    bd->GlfwWndProc = nullptr;
+#endif
+
+    io.BackendPlatformName = nullptr;
+    io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    IM_DELETE(bd);
+}
+
+static void ImGui_ImplGlfw_UpdateMouseData()
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+
+    if (glfwGetInputMode(bd->Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
+    {
+        io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
+        return;
+    }
+
+    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    {
+        GLFWwindow* window = bd->Window;
+
+#ifdef __EMSCRIPTEN__
+        const bool is_window_focused = true;
+#else
+        const bool is_window_focused = glfwGetWindowAttrib(window, GLFW_FOCUSED) != 0;
+#endif
+        if (is_window_focused)
+        {
+            // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+            if (io.WantSetMousePos)
+                glfwSetCursorPos(window, (double)io.MousePos.x, (double)io.MousePos.y);
+
+            // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
+            if (bd->MouseWindow == nullptr)
+            {
+                double mouse_x, mouse_y;
+                glfwGetCursorPos(window, &mouse_x, &mouse_y);
+                bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
+                io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
+            }
+        }
+    }
+}
+
+static void ImGui_ImplGlfw_UpdateMouseCursor()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if ((io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange) || glfwGetInputMode(bd->Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
+        return;
+
+    ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
+    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    {
+        GLFWwindow* window = bd->Window;
+        if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
+        {
+            // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
+            glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
+        }
+        else
+        {
+            // Show OS mouse cursor
+            // FIXME-PLATFORM: Unfocused windows seems to fail changing the mouse cursor with GLFW 3.2, but 3.3 works here.
+            glfwSetCursor(window, bd->MouseCursors[imgui_cursor] ? bd->MouseCursors[imgui_cursor] : bd->MouseCursors[ImGuiMouseCursor_Arrow]);
+            glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
+        }
+    }
+}
+
+// Update gamepad inputs
+static inline float Saturate(float v) { return v < 0.0f ? 0.0f : v  > 1.0f ? 1.0f : v; }
+static void ImGui_ImplGlfw_UpdateGamepads()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0) // FIXME: Technically feeding gamepad shouldn't depend on this now that they are regular inputs.
+        return;
+
+    io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+#if GLFW_HAS_GAMEPAD_API && !defined(__EMSCRIPTEN__)
+    GLFWgamepadstate gamepad;
+    if (!glfwGetGamepadState(GLFW_JOYSTICK_1, &gamepad))
+        return;
+    #define MAP_BUTTON(KEY_NO, BUTTON_NO, _UNUSED)          do { io.AddKeyEvent(KEY_NO, gamepad.buttons[BUTTON_NO] != 0); } while (0)
+    #define MAP_ANALOG(KEY_NO, AXIS_NO, _UNUSED, V0, V1)    do { float v = gamepad.axes[AXIS_NO]; v = (v - V0) / (V1 - V0); io.AddKeyAnalogEvent(KEY_NO, v > 0.10f, Saturate(v)); } while (0)
+#else
+    int axes_count = 0, buttons_count = 0;
+    const float* axes = glfwGetJoystickAxes(GLFW_JOYSTICK_1, &axes_count);
+    const unsigned char* buttons = glfwGetJoystickButtons(GLFW_JOYSTICK_1, &buttons_count);
+    if (axes_count == 0 || buttons_count == 0)
+        return;
+    #define MAP_BUTTON(KEY_NO, _UNUSED, BUTTON_NO)          do { io.AddKeyEvent(KEY_NO, (buttons_count > BUTTON_NO && buttons[BUTTON_NO] == GLFW_PRESS)); } while (0)
+    #define MAP_ANALOG(KEY_NO, _UNUSED, AXIS_NO, V0, V1)    do { float v = (axes_count > AXIS_NO) ? axes[AXIS_NO] : V0; v = (v - V0) / (V1 - V0); io.AddKeyAnalogEvent(KEY_NO, v > 0.10f, Saturate(v)); } while (0)
+#endif
+    io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+    MAP_BUTTON(ImGuiKey_GamepadStart,       GLFW_GAMEPAD_BUTTON_START,          7);
+    MAP_BUTTON(ImGuiKey_GamepadBack,        GLFW_GAMEPAD_BUTTON_BACK,           6);
+    MAP_BUTTON(ImGuiKey_GamepadFaceLeft,    GLFW_GAMEPAD_BUTTON_X,              2);     // Xbox X, PS Square
+    MAP_BUTTON(ImGuiKey_GamepadFaceRight,   GLFW_GAMEPAD_BUTTON_B,              1);     // Xbox B, PS Circle
+    MAP_BUTTON(ImGuiKey_GamepadFaceUp,      GLFW_GAMEPAD_BUTTON_Y,              3);     // Xbox Y, PS Triangle
+    MAP_BUTTON(ImGuiKey_GamepadFaceDown,    GLFW_GAMEPAD_BUTTON_A,              0);     // Xbox A, PS Cross
+    MAP_BUTTON(ImGuiKey_GamepadDpadLeft,    GLFW_GAMEPAD_BUTTON_DPAD_LEFT,      13);
+    MAP_BUTTON(ImGuiKey_GamepadDpadRight,   GLFW_GAMEPAD_BUTTON_DPAD_RIGHT,     11);
+    MAP_BUTTON(ImGuiKey_GamepadDpadUp,      GLFW_GAMEPAD_BUTTON_DPAD_UP,        10);
+    MAP_BUTTON(ImGuiKey_GamepadDpadDown,    GLFW_GAMEPAD_BUTTON_DPAD_DOWN,      12);
+    MAP_BUTTON(ImGuiKey_GamepadL1,          GLFW_GAMEPAD_BUTTON_LEFT_BUMPER,    4);
+    MAP_BUTTON(ImGuiKey_GamepadR1,          GLFW_GAMEPAD_BUTTON_RIGHT_BUMPER,   5);
+    MAP_ANALOG(ImGuiKey_GamepadL2,          GLFW_GAMEPAD_AXIS_LEFT_TRIGGER,     4,      -0.75f,  +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadR2,          GLFW_GAMEPAD_AXIS_RIGHT_TRIGGER,    5,      -0.75f,  +1.0f);
+    MAP_BUTTON(ImGuiKey_GamepadL3,          GLFW_GAMEPAD_BUTTON_LEFT_THUMB,     8);
+    MAP_BUTTON(ImGuiKey_GamepadR3,          GLFW_GAMEPAD_BUTTON_RIGHT_THUMB,    9);
+    MAP_ANALOG(ImGuiKey_GamepadLStickLeft,  GLFW_GAMEPAD_AXIS_LEFT_X,           0,      -0.25f,  -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickRight, GLFW_GAMEPAD_AXIS_LEFT_X,           0,      +0.25f,  +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickUp,    GLFW_GAMEPAD_AXIS_LEFT_Y,           1,      -0.25f,  -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickDown,  GLFW_GAMEPAD_AXIS_LEFT_Y,           1,      +0.25f,  +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickLeft,  GLFW_GAMEPAD_AXIS_RIGHT_X,          2,      -0.25f,  -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickRight, GLFW_GAMEPAD_AXIS_RIGHT_X,          2,      +0.25f,  +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickUp,    GLFW_GAMEPAD_AXIS_RIGHT_Y,          3,      -0.25f,  -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickDown,  GLFW_GAMEPAD_AXIS_RIGHT_Y,          3,      +0.25f,  +1.0f);
+    #undef MAP_BUTTON
+    #undef MAP_ANALOG
+}
+
+void ImGui_ImplGlfw_NewFrame()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplGlfw_InitForXXX()?");
+
+    // Setup display size (every frame to accommodate for window resizing)
+    int w, h;
+    int display_w, display_h;
+    glfwGetWindowSize(bd->Window, &w, &h);
+    glfwGetFramebufferSize(bd->Window, &display_w, &display_h);
+    io.DisplaySize = ImVec2((float)w, (float)h);
+    if (w > 0 && h > 0)
+        io.DisplayFramebufferScale = ImVec2((float)display_w / (float)w, (float)display_h / (float)h);
+
+    // Setup time step
+    double current_time = glfwGetTime();
+    io.DeltaTime = bd->Time > 0.0 ? (float)(current_time - bd->Time) : (float)(1.0f / 60.0f);
+    bd->Time = current_time;
+
+    ImGui_ImplGlfw_UpdateMouseData();
+    ImGui_ImplGlfw_UpdateMouseCursor();
+
+    // Update game controllers (if enabled and available)
+    ImGui_ImplGlfw_UpdateGamepads();
+}
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif

third_party/imgui/backends/imgui_impl_glfw.h

@@ -0,0 +1,47 @@
+// dear imgui: Platform Backend for GLFW
+// This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
+// (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+
+// Implemented features:
+//  [X] Platform: Clipboard support.
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+struct GLFWwindow;
+struct GLFWmonitor;
+
+IMGUI_IMPL_API bool     ImGui_ImplGlfw_InitForOpenGL(GLFWwindow* window, bool install_callbacks);
+IMGUI_IMPL_API bool     ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool install_callbacks);
+IMGUI_IMPL_API bool     ImGui_ImplGlfw_InitForOther(GLFWwindow* window, bool install_callbacks);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplGlfw_NewFrame();
+
+// GLFW callbacks install
+// - When calling Init with 'install_callbacks=true': ImGui_ImplGlfw_InstallCallbacks() is called. GLFW callbacks will be installed for you. They will chain-call user's previously installed callbacks, if any.
+// - When calling Init with 'install_callbacks=false': GLFW callbacks won't be installed. You will need to call individual function yourself from your own GLFW callbacks.
+IMGUI_IMPL_API void     ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_RestoreCallbacks(GLFWwindow* window);
+
+// GFLW callbacks options:
+// - Set 'chain_for_all_windows=true' to enable chaining callbacks for all windows (including secondary viewports created by backends or by user)
+IMGUI_IMPL_API void     ImGui_ImplGlfw_SetCallbacksChainForAllWindows(bool chain_for_all_windows);
+
+// GLFW callbacks (individual callbacks to call yourself if you didn't install callbacks)
+IMGUI_IMPL_API void     ImGui_ImplGlfw_WindowFocusCallback(GLFWwindow* window, int focused);        // Since 1.84
+IMGUI_IMPL_API void     ImGui_ImplGlfw_CursorEnterCallback(GLFWwindow* window, int entered);        // Since 1.84
+IMGUI_IMPL_API void     ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y);   // Since 1.87
+IMGUI_IMPL_API void     ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c);
+IMGUI_IMPL_API void     ImGui_ImplGlfw_MonitorCallback(GLFWmonitor* monitor, int event);

third_party/imgui/backends/imgui_impl_opengl3.cpp

@@ -0,0 +1,924 @@
+// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
+// - Desktop GL: 2.x 3.x 4.x
+// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
+// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2023-04-18: OpenGL: Restore front and back polygon mode separately when supported by context. (#6333)
+//  2023-03-23: OpenGL: Properly restoring "no shader program bound" if it was the case prior to running the rendering function. (#6267, #6220, #6224)
+//  2023-03-15: OpenGL: Fixed GL loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530)
+//  2023-03-06: OpenGL: Fixed restoration of a potentially deleted OpenGL program, by calling glIsProgram(). (#6220, #6224)
+//  2022-11-09: OpenGL: Reverted use of glBufferSubData(), too many corruptions issues + old issues seemingly can't be reproed with Intel drivers nowadays (revert 2021-12-15 and 2022-05-23 changes).
+//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
+//  2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
+//  2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
+//  2022-05-13: OpenGL: Fixed state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states.
+//  2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
+//  2021-08-23: OpenGL: Fixed ES 3.0 shader ("#version 300 es") use normal precision floats to avoid wobbly rendering at HD resolutions.
+//  2021-08-19: OpenGL: Embed and use our own minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and support for third-party loader.
+//  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
+//  2021-06-25: OpenGL: Use OES_vertex_array extension on Emscripten + backup/restore current state.
+//  2021-06-21: OpenGL: Destroy individual vertex/fragment shader objects right after they are linked into the main shader.
+//  2021-05-24: OpenGL: Access GL_CLIP_ORIGIN when "GL_ARB_clip_control" extension is detected, inside of just OpenGL 4.5 version.
+//  2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
+//  2021-04-06: OpenGL: Don't try to read GL_CLIP_ORIGIN unless we're OpenGL 4.5 or greater.
+//  2021-02-18: OpenGL: Change blending equation to preserve alpha in output buffer.
+//  2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
+//  2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
+//  2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
+//  2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
+//  2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
+//  2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
+//  2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
+//  2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
+//  2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
+//  2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
+//  2019-10-25: OpenGL: Using a combination of GL define and runtime GL version to decide whether to use glDrawElementsBaseVertex(). Fix building with pre-3.2 GL loaders.
+//  2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
+//  2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
+//  2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
+//  2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
+//  2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
+//  2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
+//  2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
+//  2019-02-20: OpenGL: Fix for OSX not supporting OpenGL 4.5, we don't try to read GL_CLIP_ORIGIN even if defined by the headers/loader.
+//  2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
+//  2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
+//  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
+//  2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
+//  2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
+//  2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
+//  2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
+//  2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
+//  2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
+//  2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
+//  2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
+//  2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a nullptr pointer.
+//  2018-03-06: OpenGL: Added const char* glsl_version parameter to ImGui_ImplOpenGL3_Init() so user can override the GLSL version e.g. "#version 150".
+//  2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
+//  2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
+//  2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
+//  2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
+//  2017-05-01: OpenGL: Fixed save and restore of current blend func state.
+//  2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
+//  2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
+//  2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
+
+//----------------------------------------
+// OpenGL    GLSL      GLSL
+// version   version   string
+//----------------------------------------
+//  2.0       110       "#version 110"
+//  2.1       120       "#version 120"
+//  3.0       130       "#version 130"
+//  3.1       140       "#version 140"
+//  3.2       150       "#version 150"
+//  3.3       330       "#version 330 core"
+//  4.0       400       "#version 400 core"
+//  4.1       410       "#version 410 core"
+//  4.2       420       "#version 410 core"
+//  4.3       430       "#version 430 core"
+//  ES 2.0    100       "#version 100"      = WebGL 1.0
+//  ES 3.0    300       "#version 300 es"   = WebGL 2.0
+//----------------------------------------
+
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include "imgui.h"
+#include "imgui_impl_opengl3.h"
+#include <stdio.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
+#include <stddef.h>     // intptr_t
+#else
+#include <stdint.h>     // intptr_t
+#endif
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+
+// Clang/GCC warnings with -Weverything
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wold-style-cast"         // warning: use of old-style cast
+#pragma clang diagnostic ignored "-Wsign-conversion"        // warning: implicit conversion changes signedness
+#pragma clang diagnostic ignored "-Wunused-macros"          // warning: macro is not used
+#pragma clang diagnostic ignored "-Wnonportable-system-include-path"
+#pragma clang diagnostic ignored "-Wcast-function-type"     // warning: cast between incompatible function types (for loader)
+#endif
+#if defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpragmas"                  // warning: unknown option after '#pragma GCC diagnostic' kind
+#pragma GCC diagnostic ignored "-Wunknown-warning-option"   // warning: unknown warning group 'xxx'
+#pragma GCC diagnostic ignored "-Wcast-function-type"       // warning: cast between incompatible function types (for loader)
+#endif
+
+// GL includes
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
+#include <OpenGLES/ES2/gl.h>    // Use GL ES 2
+#else
+#include <GLES2/gl2.h>          // Use GL ES 2
+#endif
+#if defined(__EMSCRIPTEN__)
+#ifndef GL_GLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+#endif
+#include <GLES2/gl2ext.h>
+#endif
+#elif defined(IMGUI_IMPL_OPENGL_ES3)
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
+#include <OpenGLES/ES3/gl.h>    // Use GL ES 3
+#else
+#include <GLES3/gl3.h>          // Use GL ES 3
+#endif
+#elif !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
+// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
+// Helper libraries are often used for this purpose! Here we are using our own minimal custom loader based on gl3w.
+// In the rest of your app/engine, you can use another loader of your choice (gl3w, glew, glad, glbinding, glext, glLoadGen, etc.).
+// If you happen to be developing a new feature for this backend (imgui_impl_opengl3.cpp):
+// - You may need to regenerate imgui_impl_opengl3_loader.h to add new symbols. See https://github.com/dearimgui/gl3w_stripped
+// - You can temporarily use an unstripped version. See https://github.com/dearimgui/gl3w_stripped/releases
+// Changes to this backend using new APIs should be accompanied by a regenerated stripped loader version.
+#define IMGL3W_IMPL
+#include "imgui_impl_opengl3_loader.h"
+#endif
+
+// Vertex arrays are not supported on ES2/WebGL1 unless Emscripten which uses an extension
+#ifndef IMGUI_IMPL_OPENGL_ES2
+#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+#elif defined(__EMSCRIPTEN__)
+#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+#define glBindVertexArray       glBindVertexArrayOES
+#define glGenVertexArrays       glGenVertexArraysOES
+#define glDeleteVertexArrays    glDeleteVertexArraysOES
+#define GL_VERTEX_ARRAY_BINDING GL_VERTEX_ARRAY_BINDING_OES
+#endif
+
+// Desktop GL 2.0+ has glPolygonMode() which GL ES and WebGL don't have.
+#ifdef GL_POLYGON_MODE
+#define IMGUI_IMPL_HAS_POLYGON_MODE
+#endif
+
+// Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+#endif
+
+// Desktop GL 3.3+ has glBindSampler()
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_3)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+#endif
+
+// Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_1)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+#endif
+
+// Desktop GL use extension detection
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
+#endif
+
+// [Debugging]
+//#define IMGUI_IMPL_OPENGL_DEBUG
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+#include <stdio.h>
+#define GL_CALL(_CALL)      do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0)  // Call with error check
+#else
+#define GL_CALL(_CALL)      _CALL   // Call without error check
+#endif
+
+// OpenGL Data
+struct ImGui_ImplOpenGL3_Data
+{
+    GLuint          GlVersion;               // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
+    char            GlslVersionString[32];   // Specified by user or detected based on compile time GL settings.
+    bool            GlProfileIsCompat;
+    GLint           GlProfileMask;
+    GLuint          FontTexture;
+    GLuint          ShaderHandle;
+    GLint           AttribLocationTex;       // Uniforms location
+    GLint           AttribLocationProjMtx;
+    GLuint          AttribLocationVtxPos;    // Vertex attributes location
+    GLuint          AttribLocationVtxUV;
+    GLuint          AttribLocationVtxColor;
+    unsigned int    VboHandle, ElementsHandle;
+    GLsizeiptr      VertexBufferSize;
+    GLsizeiptr      IndexBufferSize;
+    bool            HasClipOrigin;
+    bool            UseBufferSubData;
+
+    ImGui_ImplOpenGL3_Data() { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
+}
+
+// OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+struct ImGui_ImplOpenGL3_VtxAttribState
+{
+    GLint   Enabled, Size, Type, Normalized, Stride;
+    GLvoid* Ptr;
+
+    void GetState(GLint index)
+    {
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_ENABLED, &Enabled);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_SIZE, &Size);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_TYPE, &Type);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, &Normalized);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_STRIDE, &Stride);
+        glGetVertexAttribPointerv(index, GL_VERTEX_ATTRIB_ARRAY_POINTER, &Ptr);
+    }
+    void SetState(GLint index)
+    {
+        glVertexAttribPointer(index, Size, Type, (GLboolean)Normalized, Stride, Ptr);
+        if (Enabled) glEnableVertexAttribArray(index); else glDisableVertexAttribArray(index);
+    }
+};
+#endif
+
+// Functions
+bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
+
+    // Initialize our loader
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
+    if (imgl3wInit() != 0)
+    {
+        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
+        return false;
+    }
+#endif
+
+    // Setup backend capabilities flags
+    ImGui_ImplOpenGL3_Data* bd = IM_NEW(ImGui_ImplOpenGL3_Data)();
+    io.BackendRendererUserData = (void*)bd;
+    io.BackendRendererName = "imgui_impl_opengl3";
+
+    // Query for GL version (e.g. 320 for GL 3.2)
+#if !defined(IMGUI_IMPL_OPENGL_ES2)
+    GLint major = 0;
+    GLint minor = 0;
+    glGetIntegerv(GL_MAJOR_VERSION, &major);
+    glGetIntegerv(GL_MINOR_VERSION, &minor);
+    if (major == 0 && minor == 0)
+    {
+        // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
+        const char* gl_version = (const char*)glGetString(GL_VERSION);
+        sscanf(gl_version, "%d.%d", &major, &minor);
+    }
+    bd->GlVersion = (GLuint)(major * 100 + minor * 10);
+#if defined(GL_CONTEXT_PROFILE_MASK)
+    glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &bd->GlProfileMask);
+    bd->GlProfileIsCompat = (bd->GlProfileMask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT) != 0;
+#endif
+
+    bd->UseBufferSubData = false;
+    /*
+    // Query vendor to enable glBufferSubData kludge
+#ifdef _WIN32
+    if (const char* vendor = (const char*)glGetString(GL_VENDOR))
+        if (strncmp(vendor, "Intel", 5) == 0)
+            bd->UseBufferSubData = true;
+#endif
+    */
+#else
+    bd->GlVersion = 200; // GLES 2
+#endif
+
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+    printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
+#endif
+
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+    if (bd->GlVersion >= 320)
+        io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+#endif
+
+    // Store GLSL version string so we can refer to it later in case we recreate shaders.
+    // Note: GLSL version is NOT the same as GL version. Leave this to nullptr if unsure.
+    if (glsl_version == nullptr)
+    {
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+        glsl_version = "#version 100";
+#elif defined(IMGUI_IMPL_OPENGL_ES3)
+        glsl_version = "#version 300 es";
+#elif defined(__APPLE__)
+        glsl_version = "#version 150";
+#else
+        glsl_version = "#version 130";
+#endif
+    }
+    IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(bd->GlslVersionString));
+    strcpy(bd->GlslVersionString, glsl_version);
+    strcat(bd->GlslVersionString, "\n");
+
+    // Make an arbitrary GL call (we don't actually need the result)
+    // IF YOU GET A CRASH HERE: it probably means the OpenGL function loader didn't do its job. Let us know!
+    GLint current_texture;
+    glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
+
+    // Detect extensions we support
+    bd->HasClipOrigin = (bd->GlVersion >= 450);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
+    GLint num_extensions = 0;
+    glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
+    for (GLint i = 0; i < num_extensions; i++)
+    {
+        const char* extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
+        if (extension != nullptr && strcmp(extension, "GL_ARB_clip_control") == 0)
+            bd->HasClipOrigin = true;
+    }
+#endif
+
+    return true;
+}
+
+void    ImGui_ImplOpenGL3_Shutdown()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    ImGui_ImplOpenGL3_DestroyDeviceObjects();
+    io.BackendRendererName = nullptr;
+    io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    IM_DELETE(bd);
+}
+
+void    ImGui_ImplOpenGL3_NewFrame()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplOpenGL3_Init()?");
+
+    if (!bd->ShaderHandle)
+        ImGui_ImplOpenGL3_CreateDeviceObjects();
+}
+
+static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
+    glEnable(GL_BLEND);
+    glBlendEquation(GL_FUNC_ADD);
+    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+    glDisable(GL_CULL_FACE);
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_STENCIL_TEST);
+    glEnable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    if (bd->GlVersion >= 310)
+        glDisable(GL_PRIMITIVE_RESTART);
+#endif
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
+
+    // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
+#if defined(GL_CLIP_ORIGIN)
+    bool clip_origin_lower_left = true;
+    if (bd->HasClipOrigin)
+    {
+        GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
+        if (current_clip_origin == GL_UPPER_LEFT)
+            clip_origin_lower_left = false;
+    }
+#endif
+
+    // Setup viewport, orthographic projection matrix
+    // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
+    GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
+    float L = draw_data->DisplayPos.x;
+    float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
+    float T = draw_data->DisplayPos.y;
+    float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
+#if defined(GL_CLIP_ORIGIN)
+    if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
+#endif
+    const float ortho_projection[4][4] =
+    {
+        { 2.0f/(R-L),   0.0f,         0.0f,   0.0f },
+        { 0.0f,         2.0f/(T-B),   0.0f,   0.0f },
+        { 0.0f,         0.0f,        -1.0f,   0.0f },
+        { (R+L)/(L-R),  (T+B)/(B-T),  0.0f,   1.0f },
+    };
+    glUseProgram(bd->ShaderHandle);
+    glUniform1i(bd->AttribLocationTex, 0);
+    glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
+
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    if (bd->GlVersion >= 330)
+        glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
+#endif
+
+    (void)vertex_array_object;
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(vertex_array_object);
+#endif
+
+    // Bind vertex/index buffers and setup attributes for ImDrawVert
+    GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
+    GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
+}
+
+// OpenGL3 Render function.
+// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
+// This is in order to be able to run within an OpenGL engine that doesn't do so.
+void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
+{
+    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
+    if (fb_width <= 0 || fb_height <= 0)
+        return;
+
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Backup GL state
+    GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
+    glActiveTexture(GL_TEXTURE0);
+    GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
+    GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    GLuint last_sampler; if (bd->GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
+#endif
+    GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    // This is part of VAO on OpenGL 3.0+ and OpenGL ES 3.0+.
+    GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_pos; last_vtx_attrib_state_pos.GetState(bd->AttribLocationVtxPos);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_uv; last_vtx_attrib_state_uv.GetState(bd->AttribLocationVtxUV);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_color; last_vtx_attrib_state_color.GetState(bd->AttribLocationVtxColor);
+#endif
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
+#endif
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
+#endif
+    GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
+    GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
+    GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
+    GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
+    GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
+    GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
+    GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
+    GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
+    GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
+    GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
+    GLboolean last_enable_stencil_test = glIsEnabled(GL_STENCIL_TEST);
+    GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    GLboolean last_enable_primitive_restart = (bd->GlVersion >= 310) ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
+#endif
+
+    // Setup desired GL state
+    // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
+    // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
+    GLuint vertex_array_object = 0;
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GL_CALL(glGenVertexArrays(1, &vertex_array_object));
+#endif
+    ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
+
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
+    // Render command lists
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
+        const ImDrawList* cmd_list = draw_data->CmdLists[n];
+
+        // Upload vertex/index buffers
+        // - OpenGL drivers are in a very sorry state nowadays....
+        //   During 2021 we attempted to switch from glBufferData() to orphaning+glBufferSubData() following reports
+        //   of leaks on Intel GPU when using multi-viewports on Windows.
+        // - After this we kept hearing of various display corruptions issues. We started disabling on non-Intel GPU, but issues still got reported on Intel.
+        // - We are now back to using exclusively glBufferData(). So bd->UseBufferSubData IS ALWAYS FALSE in this code.
+        //   We are keeping the old code path for a while in case people finding new issues may want to test the bd->UseBufferSubData path.
+        // - See https://github.com/ocornut/imgui/issues/4468 and please report any corruption issues.
+        const GLsizeiptr vtx_buffer_size = (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
+        const GLsizeiptr idx_buffer_size = (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
+        if (bd->UseBufferSubData)
+        {
+            if (bd->VertexBufferSize < vtx_buffer_size)
+            {
+                bd->VertexBufferSize = vtx_buffer_size;
+                GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, nullptr, GL_STREAM_DRAW));
+            }
+            if (bd->IndexBufferSize < idx_buffer_size)
+            {
+                bd->IndexBufferSize = idx_buffer_size;
+                GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, nullptr, GL_STREAM_DRAW));
+            }
+            GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data));
+            GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data));
+        }
+        else
+        {
+            GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW));
+            GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW));
+        }
+
+        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+        {
+            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+            if (pcmd->UserCallback != nullptr)
+            {
+                // User callback, registered via ImDrawList::AddCallback()
+                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
+                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
+                    ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
+                else
+                    pcmd->UserCallback(cmd_list, pcmd);
+            }
+            else
+            {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+                    continue;
+
+                // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
+                GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y)));
+
+                // Bind texture, Draw
+                GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+                if (bd->GlVersion >= 320)
+                    GL_CALL(glDrawElementsBaseVertex(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)), (GLint)pcmd->VtxOffset));
+                else
+#endif
+                GL_CALL(glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
+            }
+        }
+    }
+
+    // Destroy the temporary VAO
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
+#endif
+
+    // Restore modified GL state
+    // This "glIsProgram()" check is required because if the program is "pending deletion" at the time of binding backup, it will have been deleted by now and will cause an OpenGL error. See #6220.
+    if (last_program == 0 || glIsProgram(last_program)) glUseProgram(last_program);
+    glBindTexture(GL_TEXTURE_2D, last_texture);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    if (bd->GlVersion >= 330)
+        glBindSampler(0, last_sampler);
+#endif
+    glActiveTexture(last_active_texture);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(last_vertex_array_object);
+#endif
+    glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer);
+    last_vtx_attrib_state_pos.SetState(bd->AttribLocationVtxPos);
+    last_vtx_attrib_state_uv.SetState(bd->AttribLocationVtxUV);
+    last_vtx_attrib_state_color.SetState(bd->AttribLocationVtxColor);
+#endif
+    glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
+    glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
+    if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
+    if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
+    if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
+    if (last_enable_stencil_test) glEnable(GL_STENCIL_TEST); else glDisable(GL_STENCIL_TEST);
+    if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    if (bd->GlVersion >= 310) { if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART); }
+#endif
+
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    // Desktop OpenGL 3.0 and OpenGL 3.1 had separate polygon draw modes for front-facing and back-facing faces of polygons
+    if (bd->GlVersion <= 310 || bd->GlProfileIsCompat)
+    {
+        glPolygonMode(GL_FRONT, (GLenum)last_polygon_mode[0]);
+        glPolygonMode(GL_BACK, (GLenum)last_polygon_mode[1]);
+    }
+    else
+    {
+        glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
+    }
+#endif // IMGUI_IMPL_HAS_POLYGON_MODE
+
+    glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
+    (void)bd; // Not all compilation paths use this
+}
+
+bool ImGui_ImplOpenGL3_CreateFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Build texture atlas
+    unsigned char* pixels;
+    int width, height;
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+    // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
+    GLint last_texture;
+    GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
+    GL_CALL(glGenTextures(1, &bd->FontTexture));
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
+#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
+    GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
+#endif
+    GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
+
+    // Store our identifier
+    io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
+
+    // Restore state
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
+
+    return true;
+}
+
+void ImGui_ImplOpenGL3_DestroyFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    if (bd->FontTexture)
+    {
+        glDeleteTextures(1, &bd->FontTexture);
+        io.Fonts->SetTexID(0);
+        bd->FontTexture = 0;
+    }
+}
+
+// If you get an error please report on github. You may try different GL context version or GLSL version. See GL<>GLSL version table at the top of this file.
+static bool CheckShader(GLuint handle, const char* desc)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    GLint status = 0, log_length = 0;
+    glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
+    glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
+    if ((GLboolean)status == GL_FALSE)
+        fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s! With GLSL: %s\n", desc, bd->GlslVersionString);
+    if (log_length > 1)
+    {
+        ImVector<char> buf;
+        buf.resize((int)(log_length + 1));
+        glGetShaderInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
+        fprintf(stderr, "%s\n", buf.begin());
+    }
+    return (GLboolean)status == GL_TRUE;
+}
+
+// If you get an error please report on GitHub. You may try different GL context version or GLSL version.
+static bool CheckProgram(GLuint handle, const char* desc)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    GLint status = 0, log_length = 0;
+    glGetProgramiv(handle, GL_LINK_STATUS, &status);
+    glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
+    if ((GLboolean)status == GL_FALSE)
+        fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! With GLSL %s\n", desc, bd->GlslVersionString);
+    if (log_length > 1)
+    {
+        ImVector<char> buf;
+        buf.resize((int)(log_length + 1));
+        glGetProgramInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
+        fprintf(stderr, "%s\n", buf.begin());
+    }
+    return (GLboolean)status == GL_TRUE;
+}
+
+bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Backup GL state
+    GLint last_texture, last_array_buffer;
+    glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+    glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GLint last_vertex_array;
+    glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
+#endif
+
+    // Parse GLSL version string
+    int glsl_version = 130;
+    sscanf(bd->GlslVersionString, "#version %d", &glsl_version);
+
+    const GLchar* vertex_shader_glsl_120 =
+        "uniform mat4 ProjMtx;\n"
+        "attribute vec2 Position;\n"
+        "attribute vec2 UV;\n"
+        "attribute vec4 Color;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_130 =
+        "uniform mat4 ProjMtx;\n"
+        "in vec2 Position;\n"
+        "in vec2 UV;\n"
+        "in vec4 Color;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_300_es =
+        "precision highp float;\n"
+        "layout (location = 0) in vec2 Position;\n"
+        "layout (location = 1) in vec2 UV;\n"
+        "layout (location = 2) in vec4 Color;\n"
+        "uniform mat4 ProjMtx;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_410_core =
+        "layout (location = 0) in vec2 Position;\n"
+        "layout (location = 1) in vec2 UV;\n"
+        "layout (location = 2) in vec4 Color;\n"
+        "uniform mat4 ProjMtx;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_120 =
+        "#ifdef GL_ES\n"
+        "    precision mediump float;\n"
+        "#endif\n"
+        "uniform sampler2D Texture;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_130 =
+        "uniform sampler2D Texture;\n"
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_300_es =
+        "precision mediump float;\n"
+        "uniform sampler2D Texture;\n"
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "layout (location = 0) out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_410_core =
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "uniform sampler2D Texture;\n"
+        "layout (location = 0) out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    // Select shaders matching our GLSL versions
+    const GLchar* vertex_shader = nullptr;
+    const GLchar* fragment_shader = nullptr;
+    if (glsl_version < 130)
+    {
+        vertex_shader = vertex_shader_glsl_120;
+        fragment_shader = fragment_shader_glsl_120;
+    }
+    else if (glsl_version >= 410)
+    {
+        vertex_shader = vertex_shader_glsl_410_core;
+        fragment_shader = fragment_shader_glsl_410_core;
+    }
+    else if (glsl_version == 300)
+    {
+        vertex_shader = vertex_shader_glsl_300_es;
+        fragment_shader = fragment_shader_glsl_300_es;
+    }
+    else
+    {
+        vertex_shader = vertex_shader_glsl_130;
+        fragment_shader = fragment_shader_glsl_130;
+    }
+
+    // Create shaders
+    const GLchar* vertex_shader_with_version[2] = { bd->GlslVersionString, vertex_shader };
+    GLuint vert_handle = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vert_handle, 2, vertex_shader_with_version, nullptr);
+    glCompileShader(vert_handle);
+    CheckShader(vert_handle, "vertex shader");
+
+    const GLchar* fragment_shader_with_version[2] = { bd->GlslVersionString, fragment_shader };
+    GLuint frag_handle = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(frag_handle, 2, fragment_shader_with_version, nullptr);
+    glCompileShader(frag_handle);
+    CheckShader(frag_handle, "fragment shader");
+
+    // Link
+    bd->ShaderHandle = glCreateProgram();
+    glAttachShader(bd->ShaderHandle, vert_handle);
+    glAttachShader(bd->ShaderHandle, frag_handle);
+    glLinkProgram(bd->ShaderHandle);
+    CheckProgram(bd->ShaderHandle, "shader program");
+
+    glDetachShader(bd->ShaderHandle, vert_handle);
+    glDetachShader(bd->ShaderHandle, frag_handle);
+    glDeleteShader(vert_handle);
+    glDeleteShader(frag_handle);
+
+    bd->AttribLocationTex = glGetUniformLocation(bd->ShaderHandle, "Texture");
+    bd->AttribLocationProjMtx = glGetUniformLocation(bd->ShaderHandle, "ProjMtx");
+    bd->AttribLocationVtxPos = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Position");
+    bd->AttribLocationVtxUV = (GLuint)glGetAttribLocation(bd->ShaderHandle, "UV");
+    bd->AttribLocationVtxColor = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Color");
+
+    // Create buffers
+    glGenBuffers(1, &bd->VboHandle);
+    glGenBuffers(1, &bd->ElementsHandle);
+
+    ImGui_ImplOpenGL3_CreateFontsTexture();
+
+    // Restore modified GL state
+    glBindTexture(GL_TEXTURE_2D, last_texture);
+    glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(last_vertex_array);
+#endif
+
+    return true;
+}
+
+void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    if (bd->VboHandle)      { glDeleteBuffers(1, &bd->VboHandle); bd->VboHandle = 0; }
+    if (bd->ElementsHandle) { glDeleteBuffers(1, &bd->ElementsHandle); bd->ElementsHandle = 0; }
+    if (bd->ShaderHandle)   { glDeleteProgram(bd->ShaderHandle); bd->ShaderHandle = 0; }
+    ImGui_ImplOpenGL3_DestroyFontsTexture();
+}
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif

third_party/imgui/backends/imgui_impl_opengl3.h

@@ -0,0 +1,55 @@
+// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
+// - Desktop GL: 2.x 3.x 4.x
+// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
+// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// About GLSL version:
+//  The 'glsl_version' initialization parameter should be nullptr (default) or a "#version XXX" string.
+//  On computer platform the GLSL version default to "#version 130". On OpenGL ES 3 platform it defaults to "#version 300 es"
+//  Only override if your GL version doesn't handle this GLSL version. See GLSL version table at the top of imgui_impl_opengl3.cpp.
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+// Backend API
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_Init(const char* glsl_version = nullptr);
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_NewFrame();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
+
+// (Optional) Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_CreateFontsTexture();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_DestroyFontsTexture();
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_CreateDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_DestroyDeviceObjects();
+
+// Specific OpenGL ES versions
+//#define IMGUI_IMPL_OPENGL_ES2     // Auto-detected on Emscripten
+//#define IMGUI_IMPL_OPENGL_ES3     // Auto-detected on iOS/Android
+
+// You can explicitly select GLES2 or GLES3 API by using one of the '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
+#if !defined(IMGUI_IMPL_OPENGL_ES2) \
+ && !defined(IMGUI_IMPL_OPENGL_ES3)
+
+// Try to detect GLES on matching platforms
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) || (defined(__ANDROID__))
+#define IMGUI_IMPL_OPENGL_ES3               // iOS, Android  -> GL ES 3, "#version 300 es"
+#elif defined(__EMSCRIPTEN__) || defined(__amigaos4__)
+#define IMGUI_IMPL_OPENGL_ES2               // Emscripten    -> GL ES 2, "#version 100"
+#else
+// Otherwise imgui_impl_opengl3_loader.h will be used.
+#endif
+
+#endif

third_party/imgui/backends/imgui_impl_opengl3_loader.h

@@ -0,0 +1,809 @@
+//-----------------------------------------------------------------------------
+// About imgui_impl_opengl3_loader.h:
+//
+// We embed our own OpenGL loader to not require user to provide their own or to have to use ours,
+// which proved to be endless problems for users.
+// Our loader is custom-generated, based on gl3w but automatically filtered to only include
+// enums/functions that we use in our imgui_impl_opengl3.cpp source file in order to be small.
+//
+// YOU SHOULD NOT NEED TO INCLUDE/USE THIS DIRECTLY. THIS IS USED BY imgui_impl_opengl3.cpp ONLY.
+// THE REST OF YOUR APP SHOULD USE A DIFFERENT GL LOADER: ANY GL LOADER OF YOUR CHOICE.
+//
+// IF YOU GET BUILD ERRORS IN THIS FILE (commonly macro redefinitions or function redefinitions):
+// IT LIKELY MEANS THAT YOU ARE BUILDING 'imgui_impl_opengl3.cpp' OR INCUDING 'imgui_impl_opengl3_loader.h'
+// IN THE SAME COMPILATION UNIT AS ONE OF YOUR FILE WHICH IS USING A THIRD-PARTY OPENGL LOADER.
+// (e.g. COULD HAPPEN IF YOU ARE DOING A UNITY/JUMBO BUILD, OR INCLUDING .CPP FILES FROM OTHERS)
+// YOU SHOULD NOT BUILD BOTH IN THE SAME COMPILATION UNIT.
+// BUT IF YOU REALLY WANT TO, you can '#define IMGUI_IMPL_OPENGL_LOADER_CUSTOM' and imgui_impl_opengl3.cpp
+// WILL NOT BE USING OUR LOADER, AND INSTEAD EXPECT ANOTHER/YOUR LOADER TO BE AVAILABLE IN THE COMPILATION UNIT.
+//
+// Regenerate with:
+//   python gl3w_gen.py --output ../imgui/backends/imgui_impl_opengl3_loader.h --ref ../imgui/backends/imgui_impl_opengl3.cpp ./extra_symbols.txt
+//
+// More info:
+//   https://github.com/dearimgui/gl3w_stripped
+//   https://github.com/ocornut/imgui/issues/4445
+//-----------------------------------------------------------------------------
+
+/*
+ * This file was generated with gl3w_gen.py, part of imgl3w
+ * (hosted at https://github.com/dearimgui/gl3w_stripped)
+ *
+ * This is free and unencumbered software released into the public domain.
+ *
+ * Anyone is free to copy, modify, publish, use, compile, sell, or
+ * distribute this software, either in source code form or as a compiled
+ * binary, for any purpose, commercial or non-commercial, and by any
+ * means.
+ *
+ * In jurisdictions that recognize copyright laws, the author or authors
+ * of this software dedicate any and all copyright interest in the
+ * software to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and
+ * successors. We intend this dedication to be an overt act of
+ * relinquishment in perpetuity of all present and future rights to this
+ * software under copyright law.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __gl3w_h_
+#define __gl3w_h_
+
+// Adapted from KHR/khrplatform.h to avoid including entire file.
+#ifndef __khrplatform_h_
+typedef          float         khronos_float_t;
+typedef signed   char          khronos_int8_t;
+typedef unsigned char          khronos_uint8_t;
+typedef signed   short int     khronos_int16_t;
+typedef unsigned short int     khronos_uint16_t;
+#ifdef _WIN64
+typedef signed   long long int khronos_intptr_t;
+typedef signed   long long int khronos_ssize_t;
+#else
+typedef signed   long  int     khronos_intptr_t;
+typedef signed   long  int     khronos_ssize_t;
+#endif
+
+#if defined(_MSC_VER) && !defined(__clang__)
+typedef signed   __int64       khronos_int64_t;
+typedef unsigned __int64       khronos_uint64_t;
+#elif (defined(__clang__) || defined(__GNUC__)) && (__cplusplus < 201100)
+#include <stdint.h>
+typedef          int64_t       khronos_int64_t;
+typedef          uint64_t      khronos_uint64_t;
+#else
+typedef signed   long long     khronos_int64_t;
+typedef unsigned long long     khronos_uint64_t;
+#endif
+#endif  // __khrplatform_h_
+
+#ifndef __gl_glcorearb_h_
+#define __gl_glcorearb_h_ 1
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*
+** Copyright 2013-2020 The Khronos Group Inc.
+** SPDX-License-Identifier: MIT
+**
+** This header is generated from the Khronos OpenGL / OpenGL ES XML
+** API Registry. The current version of the Registry, generator scripts
+** used to make the header, and the header can be found at
+**   https://github.com/KhronosGroup/OpenGL-Registry
+*/
+#if defined(_WIN32) && !defined(APIENTRY) && !defined(__CYGWIN__) && !defined(__SCITECH_SNAP__)
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+#include <windows.h>
+#endif
+#ifndef APIENTRY
+#define APIENTRY
+#endif
+#ifndef APIENTRYP
+#define APIENTRYP APIENTRY *
+#endif
+#ifndef GLAPI
+#define GLAPI extern
+#endif
+/* glcorearb.h is for use with OpenGL core profile implementations.
+** It should should be placed in the same directory as gl.h and
+** included as <GL/glcorearb.h>.
+**
+** glcorearb.h includes only APIs in the latest OpenGL core profile
+** implementation together with APIs in newer ARB extensions which 
+** can be supported by the core profile. It does not, and never will
+** include functionality removed from the core profile, such as
+** fixed-function vertex and fragment processing.
+**
+** Do not #include both <GL/glcorearb.h> and either of <GL/gl.h> or
+** <GL/glext.h> in the same source file.
+*/
+/* Generated C header for:
+ * API: gl
+ * Profile: core
+ * Versions considered: .*
+ * Versions emitted: .*
+ * Default extensions included: glcore
+ * Additional extensions included: _nomatch_^
+ * Extensions removed: _nomatch_^
+ */
+#ifndef GL_VERSION_1_0
+typedef void GLvoid;
+typedef unsigned int GLenum;
+
+typedef khronos_float_t GLfloat;
+typedef int GLint;
+typedef int GLsizei;
+typedef unsigned int GLbitfield;
+typedef double GLdouble;
+typedef unsigned int GLuint;
+typedef unsigned char GLboolean;
+typedef khronos_uint8_t GLubyte;
+#define GL_COLOR_BUFFER_BIT               0x00004000
+#define GL_FALSE                          0
+#define GL_TRUE                           1
+#define GL_TRIANGLES                      0x0004
+#define GL_ONE                            1
+#define GL_SRC_ALPHA                      0x0302
+#define GL_ONE_MINUS_SRC_ALPHA            0x0303
+#define GL_FRONT                          0x0404
+#define GL_BACK                           0x0405
+#define GL_FRONT_AND_BACK                 0x0408
+#define GL_POLYGON_MODE                   0x0B40
+#define GL_CULL_FACE                      0x0B44
+#define GL_DEPTH_TEST                     0x0B71
+#define GL_STENCIL_TEST                   0x0B90
+#define GL_VIEWPORT                       0x0BA2
+#define GL_BLEND                          0x0BE2
+#define GL_SCISSOR_BOX                    0x0C10
+#define GL_SCISSOR_TEST                   0x0C11
+#define GL_UNPACK_ROW_LENGTH              0x0CF2
+#define GL_PACK_ALIGNMENT                 0x0D05
+#define GL_TEXTURE_2D                     0x0DE1
+#define GL_UNSIGNED_BYTE                  0x1401
+#define GL_UNSIGNED_SHORT                 0x1403
+#define GL_UNSIGNED_INT                   0x1405
+#define GL_FLOAT                          0x1406
+#define GL_RGBA                           0x1908
+#define GL_FILL                           0x1B02
+#define GL_VENDOR                         0x1F00
+#define GL_RENDERER                       0x1F01
+#define GL_VERSION                        0x1F02
+#define GL_EXTENSIONS                     0x1F03
+#define GL_LINEAR                         0x2601
+#define GL_TEXTURE_MAG_FILTER             0x2800
+#define GL_TEXTURE_MIN_FILTER             0x2801
+typedef void (APIENTRYP PFNGLPOLYGONMODEPROC) (GLenum face, GLenum mode);
+typedef void (APIENTRYP PFNGLSCISSORPROC) (GLint x, GLint y, GLsizei width, GLsizei height);
+typedef void (APIENTRYP PFNGLTEXPARAMETERIPROC) (GLenum target, GLenum pname, GLint param);
+typedef void (APIENTRYP PFNGLTEXIMAGE2DPROC) (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void *pixels);
+typedef void (APIENTRYP PFNGLCLEARPROC) (GLbitfield mask);
+typedef void (APIENTRYP PFNGLCLEARCOLORPROC) (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
+typedef void (APIENTRYP PFNGLDISABLEPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLENABLEPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLFLUSHPROC) (void);
+typedef void (APIENTRYP PFNGLPIXELSTOREIPROC) (GLenum pname, GLint param);
+typedef void (APIENTRYP PFNGLREADPIXELSPROC) (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void *pixels);
+typedef GLenum (APIENTRYP PFNGLGETERRORPROC) (void);
+typedef void (APIENTRYP PFNGLGETINTEGERVPROC) (GLenum pname, GLint *data);
+typedef const GLubyte *(APIENTRYP PFNGLGETSTRINGPROC) (GLenum name);
+typedef GLboolean (APIENTRYP PFNGLISENABLEDPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLVIEWPORTPROC) (GLint x, GLint y, GLsizei width, GLsizei height);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glPolygonMode (GLenum face, GLenum mode);
+GLAPI void APIENTRY glScissor (GLint x, GLint y, GLsizei width, GLsizei height);
+GLAPI void APIENTRY glTexParameteri (GLenum target, GLenum pname, GLint param);
+GLAPI void APIENTRY glTexImage2D (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void *pixels);
+GLAPI void APIENTRY glClear (GLbitfield mask);
+GLAPI void APIENTRY glClearColor (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
+GLAPI void APIENTRY glDisable (GLenum cap);
+GLAPI void APIENTRY glEnable (GLenum cap);
+GLAPI void APIENTRY glFlush (void);
+GLAPI void APIENTRY glPixelStorei (GLenum pname, GLint param);
+GLAPI void APIENTRY glReadPixels (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void *pixels);
+GLAPI GLenum APIENTRY glGetError (void);
+GLAPI void APIENTRY glGetIntegerv (GLenum pname, GLint *data);
+GLAPI const GLubyte *APIENTRY glGetString (GLenum name);
+GLAPI GLboolean APIENTRY glIsEnabled (GLenum cap);
+GLAPI void APIENTRY glViewport (GLint x, GLint y, GLsizei width, GLsizei height);
+#endif
+#endif /* GL_VERSION_1_0 */
+#ifndef GL_VERSION_1_1
+typedef khronos_float_t GLclampf;
+typedef double GLclampd;
+#define GL_TEXTURE_BINDING_2D             0x8069
+typedef void (APIENTRYP PFNGLDRAWELEMENTSPROC) (GLenum mode, GLsizei count, GLenum type, const void *indices);
+typedef void (APIENTRYP PFNGLBINDTEXTUREPROC) (GLenum target, GLuint texture);
+typedef void (APIENTRYP PFNGLDELETETEXTURESPROC) (GLsizei n, const GLuint *textures);
+typedef void (APIENTRYP PFNGLGENTEXTURESPROC) (GLsizei n, GLuint *textures);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glDrawElements (GLenum mode, GLsizei count, GLenum type, const void *indices);
+GLAPI void APIENTRY glBindTexture (GLenum target, GLuint texture);
+GLAPI void APIENTRY glDeleteTextures (GLsizei n, const GLuint *textures);
+GLAPI void APIENTRY glGenTextures (GLsizei n, GLuint *textures);
+#endif
+#endif /* GL_VERSION_1_1 */
+#ifndef GL_VERSION_1_3
+#define GL_TEXTURE0                       0x84C0
+#define GL_ACTIVE_TEXTURE                 0x84E0
+typedef void (APIENTRYP PFNGLACTIVETEXTUREPROC) (GLenum texture);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glActiveTexture (GLenum texture);
+#endif
+#endif /* GL_VERSION_1_3 */
+#ifndef GL_VERSION_1_4
+#define GL_BLEND_DST_RGB                  0x80C8
+#define GL_BLEND_SRC_RGB                  0x80C9
+#define GL_BLEND_DST_ALPHA                0x80CA
+#define GL_BLEND_SRC_ALPHA                0x80CB
+#define GL_FUNC_ADD                       0x8006
+typedef void (APIENTRYP PFNGLBLENDFUNCSEPARATEPROC) (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha);
+typedef void (APIENTRYP PFNGLBLENDEQUATIONPROC) (GLenum mode);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBlendFuncSeparate (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha);
+GLAPI void APIENTRY glBlendEquation (GLenum mode);
+#endif
+#endif /* GL_VERSION_1_4 */
+#ifndef GL_VERSION_1_5
+typedef khronos_ssize_t GLsizeiptr;
+typedef khronos_intptr_t GLintptr;
+#define GL_ARRAY_BUFFER                   0x8892
+#define GL_ELEMENT_ARRAY_BUFFER           0x8893
+#define GL_ARRAY_BUFFER_BINDING           0x8894
+#define GL_ELEMENT_ARRAY_BUFFER_BINDING   0x8895
+#define GL_STREAM_DRAW                    0x88E0
+typedef void (APIENTRYP PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
+typedef void (APIENTRYP PFNGLDELETEBUFFERSPROC) (GLsizei n, const GLuint *buffers);
+typedef void (APIENTRYP PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
+typedef void (APIENTRYP PFNGLBUFFERDATAPROC) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
+typedef void (APIENTRYP PFNGLBUFFERSUBDATAPROC) (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBindBuffer (GLenum target, GLuint buffer);
+GLAPI void APIENTRY glDeleteBuffers (GLsizei n, const GLuint *buffers);
+GLAPI void APIENTRY glGenBuffers (GLsizei n, GLuint *buffers);
+GLAPI void APIENTRY glBufferData (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
+GLAPI void APIENTRY glBufferSubData (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
+#endif
+#endif /* GL_VERSION_1_5 */
+#ifndef GL_VERSION_2_0
+typedef char GLchar;
+typedef khronos_int16_t GLshort;
+typedef khronos_int8_t GLbyte;
+typedef khronos_uint16_t GLushort;
+#define GL_BLEND_EQUATION_RGB             0x8009
+#define GL_VERTEX_ATTRIB_ARRAY_ENABLED    0x8622
+#define GL_VERTEX_ATTRIB_ARRAY_SIZE       0x8623
+#define GL_VERTEX_ATTRIB_ARRAY_STRIDE     0x8624
+#define GL_VERTEX_ATTRIB_ARRAY_TYPE       0x8625
+#define GL_VERTEX_ATTRIB_ARRAY_POINTER    0x8645
+#define GL_BLEND_EQUATION_ALPHA           0x883D
+#define GL_VERTEX_ATTRIB_ARRAY_NORMALIZED 0x886A
+#define GL_FRAGMENT_SHADER                0x8B30
+#define GL_VERTEX_SHADER                  0x8B31
+#define GL_COMPILE_STATUS                 0x8B81
+#define GL_LINK_STATUS                    0x8B82
+#define GL_INFO_LOG_LENGTH                0x8B84
+#define GL_CURRENT_PROGRAM                0x8B8D
+#define GL_UPPER_LEFT                     0x8CA2
+typedef void (APIENTRYP PFNGLBLENDEQUATIONSEPARATEPROC) (GLenum modeRGB, GLenum modeAlpha);
+typedef void (APIENTRYP PFNGLATTACHSHADERPROC) (GLuint program, GLuint shader);
+typedef void (APIENTRYP PFNGLCOMPILESHADERPROC) (GLuint shader);
+typedef GLuint (APIENTRYP PFNGLCREATEPROGRAMPROC) (void);
+typedef GLuint (APIENTRYP PFNGLCREATESHADERPROC) (GLenum type);
+typedef void (APIENTRYP PFNGLDELETEPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLDELETESHADERPROC) (GLuint shader);
+typedef void (APIENTRYP PFNGLDETACHSHADERPROC) (GLuint program, GLuint shader);
+typedef void (APIENTRYP PFNGLDISABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+typedef void (APIENTRYP PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+typedef GLint (APIENTRYP PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const GLchar *name);
+typedef void (APIENTRYP PFNGLGETPROGRAMIVPROC) (GLuint program, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETPROGRAMINFOLOGPROC) (GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+typedef void (APIENTRYP PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETSHADERINFOLOGPROC) (GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+typedef GLint (APIENTRYP PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const GLchar *name);
+typedef void (APIENTRYP PFNGLGETVERTEXATTRIBIVPROC) (GLuint index, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETVERTEXATTRIBPOINTERVPROC) (GLuint index, GLenum pname, void **pointer);
+typedef GLboolean (APIENTRYP PFNGLISPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLLINKPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
+typedef void (APIENTRYP PFNGLUSEPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLUNIFORM1IPROC) (GLint location, GLint v0);
+typedef void (APIENTRYP PFNGLUNIFORMMATRIX4FVPROC) (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+typedef void (APIENTRYP PFNGLVERTEXATTRIBPOINTERPROC) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBlendEquationSeparate (GLenum modeRGB, GLenum modeAlpha);
+GLAPI void APIENTRY glAttachShader (GLuint program, GLuint shader);
+GLAPI void APIENTRY glCompileShader (GLuint shader);
+GLAPI GLuint APIENTRY glCreateProgram (void);
+GLAPI GLuint APIENTRY glCreateShader (GLenum type);
+GLAPI void APIENTRY glDeleteProgram (GLuint program);
+GLAPI void APIENTRY glDeleteShader (GLuint shader);
+GLAPI void APIENTRY glDetachShader (GLuint program, GLuint shader);
+GLAPI void APIENTRY glDisableVertexAttribArray (GLuint index);
+GLAPI void APIENTRY glEnableVertexAttribArray (GLuint index);
+GLAPI GLint APIENTRY glGetAttribLocation (GLuint program, const GLchar *name);
+GLAPI void APIENTRY glGetProgramiv (GLuint program, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetProgramInfoLog (GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+GLAPI void APIENTRY glGetShaderiv (GLuint shader, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetShaderInfoLog (GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+GLAPI GLint APIENTRY glGetUniformLocation (GLuint program, const GLchar *name);
+GLAPI void APIENTRY glGetVertexAttribiv (GLuint index, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetVertexAttribPointerv (GLuint index, GLenum pname, void **pointer);
+GLAPI GLboolean APIENTRY glIsProgram (GLuint program);
+GLAPI void APIENTRY glLinkProgram (GLuint program);
+GLAPI void APIENTRY glShaderSource (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
+GLAPI void APIENTRY glUseProgram (GLuint program);
+GLAPI void APIENTRY glUniform1i (GLint location, GLint v0);
+GLAPI void APIENTRY glUniformMatrix4fv (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+GLAPI void APIENTRY glVertexAttribPointer (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
+#endif
+#endif /* GL_VERSION_2_0 */
+#ifndef GL_VERSION_3_0
+typedef khronos_uint16_t GLhalf;
+#define GL_MAJOR_VERSION                  0x821B
+#define GL_MINOR_VERSION                  0x821C
+#define GL_NUM_EXTENSIONS                 0x821D
+#define GL_FRAMEBUFFER_SRGB               0x8DB9
+#define GL_VERTEX_ARRAY_BINDING           0x85B5
+typedef void (APIENTRYP PFNGLGETBOOLEANI_VPROC) (GLenum target, GLuint index, GLboolean *data);
+typedef void (APIENTRYP PFNGLGETINTEGERI_VPROC) (GLenum target, GLuint index, GLint *data);
+typedef const GLubyte *(APIENTRYP PFNGLGETSTRINGIPROC) (GLenum name, GLuint index);
+typedef void (APIENTRYP PFNGLBINDVERTEXARRAYPROC) (GLuint array);
+typedef void (APIENTRYP PFNGLDELETEVERTEXARRAYSPROC) (GLsizei n, const GLuint *arrays);
+typedef void (APIENTRYP PFNGLGENVERTEXARRAYSPROC) (GLsizei n, GLuint *arrays);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI const GLubyte *APIENTRY glGetStringi (GLenum name, GLuint index);
+GLAPI void APIENTRY glBindVertexArray (GLuint array);
+GLAPI void APIENTRY glDeleteVertexArrays (GLsizei n, const GLuint *arrays);
+GLAPI void APIENTRY glGenVertexArrays (GLsizei n, GLuint *arrays);
+#endif
+#endif /* GL_VERSION_3_0 */
+#ifndef GL_VERSION_3_1
+#define GL_VERSION_3_1 1
+#define GL_PRIMITIVE_RESTART              0x8F9D
+#endif /* GL_VERSION_3_1 */
+#ifndef GL_VERSION_3_2
+#define GL_VERSION_3_2 1
+typedef struct __GLsync *GLsync;
+typedef khronos_uint64_t GLuint64;
+typedef khronos_int64_t GLint64;
+#define GL_CONTEXT_COMPATIBILITY_PROFILE_BIT 0x00000002
+#define GL_CONTEXT_PROFILE_MASK           0x9126
+typedef void (APIENTRYP PFNGLDRAWELEMENTSBASEVERTEXPROC) (GLenum mode, GLsizei count, GLenum type, const void *indices, GLint basevertex);
+typedef void (APIENTRYP PFNGLGETINTEGER64I_VPROC) (GLenum target, GLuint index, GLint64 *data);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glDrawElementsBaseVertex (GLenum mode, GLsizei count, GLenum type, const void *indices, GLint basevertex);
+#endif
+#endif /* GL_VERSION_3_2 */
+#ifndef GL_VERSION_3_3
+#define GL_VERSION_3_3 1
+#define GL_SAMPLER_BINDING                0x8919
+typedef void (APIENTRYP PFNGLBINDSAMPLERPROC) (GLuint unit, GLuint sampler);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBindSampler (GLuint unit, GLuint sampler);
+#endif
+#endif /* GL_VERSION_3_3 */
+#ifndef GL_VERSION_4_1
+typedef void (APIENTRYP PFNGLGETFLOATI_VPROC) (GLenum target, GLuint index, GLfloat *data);
+typedef void (APIENTRYP PFNGLGETDOUBLEI_VPROC) (GLenum target, GLuint index, GLdouble *data);
+#endif /* GL_VERSION_4_1 */
+#ifndef GL_VERSION_4_3
+typedef void (APIENTRY  *GLDEBUGPROC)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,const void *userParam);
+#endif /* GL_VERSION_4_3 */
+#ifndef GL_VERSION_4_5
+#define GL_CLIP_ORIGIN                    0x935C
+typedef void (APIENTRYP PFNGLGETTRANSFORMFEEDBACKI_VPROC) (GLuint xfb, GLenum pname, GLuint index, GLint *param);
+typedef void (APIENTRYP PFNGLGETTRANSFORMFEEDBACKI64_VPROC) (GLuint xfb, GLenum pname, GLuint index, GLint64 *param);
+#endif /* GL_VERSION_4_5 */
+#ifndef GL_ARB_bindless_texture
+typedef khronos_uint64_t GLuint64EXT;
+#endif /* GL_ARB_bindless_texture */
+#ifndef GL_ARB_cl_event
+struct _cl_context;
+struct _cl_event;
+#endif /* GL_ARB_cl_event */
+#ifndef GL_ARB_clip_control
+#define GL_ARB_clip_control 1
+#endif /* GL_ARB_clip_control */
+#ifndef GL_ARB_debug_output
+typedef void (APIENTRY  *GLDEBUGPROCARB)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,const void *userParam);
+#endif /* GL_ARB_debug_output */
+#ifndef GL_EXT_EGL_image_storage
+typedef void *GLeglImageOES;
+#endif /* GL_EXT_EGL_image_storage */
+#ifndef GL_EXT_direct_state_access
+typedef void (APIENTRYP PFNGLGETFLOATI_VEXTPROC) (GLenum pname, GLuint index, GLfloat *params);
+typedef void (APIENTRYP PFNGLGETDOUBLEI_VEXTPROC) (GLenum pname, GLuint index, GLdouble *params);
+typedef void (APIENTRYP PFNGLGETPOINTERI_VEXTPROC) (GLenum pname, GLuint index, void **params);
+typedef void (APIENTRYP PFNGLGETVERTEXARRAYINTEGERI_VEXTPROC) (GLuint vaobj, GLuint index, GLenum pname, GLint *param);
+typedef void (APIENTRYP PFNGLGETVERTEXARRAYPOINTERI_VEXTPROC) (GLuint vaobj, GLuint index, GLenum pname, void **param);
+#endif /* GL_EXT_direct_state_access */
+#ifndef GL_NV_draw_vulkan_image
+typedef void (APIENTRY  *GLVULKANPROCNV)(void);
+#endif /* GL_NV_draw_vulkan_image */
+#ifndef GL_NV_gpu_shader5
+typedef khronos_int64_t GLint64EXT;
+#endif /* GL_NV_gpu_shader5 */
+#ifndef GL_NV_vertex_buffer_unified_memory
+typedef void (APIENTRYP PFNGLGETINTEGERUI64I_VNVPROC) (GLenum value, GLuint index, GLuint64EXT *result);
+#endif /* GL_NV_vertex_buffer_unified_memory */
+#ifdef __cplusplus
+}
+#endif
+#endif
+
+#ifndef GL3W_API
+#define GL3W_API
+#endif
+
+#ifndef __gl_h_
+#define __gl_h_
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GL3W_OK 0
+#define GL3W_ERROR_INIT -1
+#define GL3W_ERROR_LIBRARY_OPEN -2
+#define GL3W_ERROR_OPENGL_VERSION -3
+
+typedef void (*GL3WglProc)(void);
+typedef GL3WglProc (*GL3WGetProcAddressProc)(const char *proc);
+
+/* gl3w api */
+GL3W_API int imgl3wInit(void);
+GL3W_API int imgl3wInit2(GL3WGetProcAddressProc proc);
+GL3W_API int imgl3wIsSupported(int major, int minor);
+GL3W_API GL3WglProc imgl3wGetProcAddress(const char *proc);
+
+/* gl3w internal state */
+union GL3WProcs {
+    GL3WglProc ptr[59];
+    struct {
+        PFNGLACTIVETEXTUREPROC            ActiveTexture;
+        PFNGLATTACHSHADERPROC             AttachShader;
+        PFNGLBINDBUFFERPROC               BindBuffer;
+        PFNGLBINDSAMPLERPROC              BindSampler;
+        PFNGLBINDTEXTUREPROC              BindTexture;
+        PFNGLBINDVERTEXARRAYPROC          BindVertexArray;
+        PFNGLBLENDEQUATIONPROC            BlendEquation;
+        PFNGLBLENDEQUATIONSEPARATEPROC    BlendEquationSeparate;
+        PFNGLBLENDFUNCSEPARATEPROC        BlendFuncSeparate;
+        PFNGLBUFFERDATAPROC               BufferData;
+        PFNGLBUFFERSUBDATAPROC            BufferSubData;
+        PFNGLCLEARPROC                    Clear;
+        PFNGLCLEARCOLORPROC               ClearColor;
+        PFNGLCOMPILESHADERPROC            CompileShader;
+        PFNGLCREATEPROGRAMPROC            CreateProgram;
+        PFNGLCREATESHADERPROC             CreateShader;
+        PFNGLDELETEBUFFERSPROC            DeleteBuffers;
+        PFNGLDELETEPROGRAMPROC            DeleteProgram;
+        PFNGLDELETESHADERPROC             DeleteShader;
+        PFNGLDELETETEXTURESPROC           DeleteTextures;
+        PFNGLDELETEVERTEXARRAYSPROC       DeleteVertexArrays;
+        PFNGLDETACHSHADERPROC             DetachShader;
+        PFNGLDISABLEPROC                  Disable;
+        PFNGLDISABLEVERTEXATTRIBARRAYPROC DisableVertexAttribArray;
+        PFNGLDRAWELEMENTSPROC             DrawElements;
+        PFNGLDRAWELEMENTSBASEVERTEXPROC   DrawElementsBaseVertex;
+        PFNGLENABLEPROC                   Enable;
+        PFNGLENABLEVERTEXATTRIBARRAYPROC  EnableVertexAttribArray;
+        PFNGLFLUSHPROC                    Flush;
+        PFNGLGENBUFFERSPROC               GenBuffers;
+        PFNGLGENTEXTURESPROC              GenTextures;
+        PFNGLGENVERTEXARRAYSPROC          GenVertexArrays;
+        PFNGLGETATTRIBLOCATIONPROC        GetAttribLocation;
+        PFNGLGETERRORPROC                 GetError;
+        PFNGLGETINTEGERVPROC              GetIntegerv;
+        PFNGLGETPROGRAMINFOLOGPROC        GetProgramInfoLog;
+        PFNGLGETPROGRAMIVPROC             GetProgramiv;
+        PFNGLGETSHADERINFOLOGPROC         GetShaderInfoLog;
+        PFNGLGETSHADERIVPROC              GetShaderiv;
+        PFNGLGETSTRINGPROC                GetString;
+        PFNGLGETSTRINGIPROC               GetStringi;
+        PFNGLGETUNIFORMLOCATIONPROC       GetUniformLocation;
+        PFNGLGETVERTEXATTRIBPOINTERVPROC  GetVertexAttribPointerv;
+        PFNGLGETVERTEXATTRIBIVPROC        GetVertexAttribiv;
+        PFNGLISENABLEDPROC                IsEnabled;
+        PFNGLISPROGRAMPROC                IsProgram;
+        PFNGLLINKPROGRAMPROC              LinkProgram;
+        PFNGLPIXELSTOREIPROC              PixelStorei;
+        PFNGLPOLYGONMODEPROC              PolygonMode;
+        PFNGLREADPIXELSPROC               ReadPixels;
+        PFNGLSCISSORPROC                  Scissor;
+        PFNGLSHADERSOURCEPROC             ShaderSource;
+        PFNGLTEXIMAGE2DPROC               TexImage2D;
+        PFNGLTEXPARAMETERIPROC            TexParameteri;
+        PFNGLUNIFORM1IPROC                Uniform1i;
+        PFNGLUNIFORMMATRIX4FVPROC         UniformMatrix4fv;
+        PFNGLUSEPROGRAMPROC               UseProgram;
+        PFNGLVERTEXATTRIBPOINTERPROC      VertexAttribPointer;
+        PFNGLVIEWPORTPROC                 Viewport;
+    } gl;
+};
+
+GL3W_API extern union GL3WProcs imgl3wProcs;
+
+/* OpenGL functions */
+#define glActiveTexture                   imgl3wProcs.gl.ActiveTexture
+#define glAttachShader                    imgl3wProcs.gl.AttachShader
+#define glBindBuffer                      imgl3wProcs.gl.BindBuffer
+#define glBindSampler                     imgl3wProcs.gl.BindSampler
+#define glBindTexture                     imgl3wProcs.gl.BindTexture
+#define glBindVertexArray                 imgl3wProcs.gl.BindVertexArray
+#define glBlendEquation                   imgl3wProcs.gl.BlendEquation
+#define glBlendEquationSeparate           imgl3wProcs.gl.BlendEquationSeparate
+#define glBlendFuncSeparate               imgl3wProcs.gl.BlendFuncSeparate
+#define glBufferData                      imgl3wProcs.gl.BufferData
+#define glBufferSubData                   imgl3wProcs.gl.BufferSubData
+#define glClear                           imgl3wProcs.gl.Clear
+#define glClearColor                      imgl3wProcs.gl.ClearColor
+#define glCompileShader                   imgl3wProcs.gl.CompileShader
+#define glCreateProgram                   imgl3wProcs.gl.CreateProgram
+#define glCreateShader                    imgl3wProcs.gl.CreateShader
+#define glDeleteBuffers                   imgl3wProcs.gl.DeleteBuffers
+#define glDeleteProgram                   imgl3wProcs.gl.DeleteProgram
+#define glDeleteShader                    imgl3wProcs.gl.DeleteShader
+#define glDeleteTextures                  imgl3wProcs.gl.DeleteTextures
+#define glDeleteVertexArrays              imgl3wProcs.gl.DeleteVertexArrays
+#define glDetachShader                    imgl3wProcs.gl.DetachShader
+#define glDisable                         imgl3wProcs.gl.Disable
+#define glDisableVertexAttribArray        imgl3wProcs.gl.DisableVertexAttribArray
+#define glDrawElements                    imgl3wProcs.gl.DrawElements
+#define glDrawElementsBaseVertex          imgl3wProcs.gl.DrawElementsBaseVertex
+#define glEnable                          imgl3wProcs.gl.Enable
+#define glEnableVertexAttribArray         imgl3wProcs.gl.EnableVertexAttribArray
+#define glFlush                           imgl3wProcs.gl.Flush
+#define glGenBuffers                      imgl3wProcs.gl.GenBuffers
+#define glGenTextures                     imgl3wProcs.gl.GenTextures
+#define glGenVertexArrays                 imgl3wProcs.gl.GenVertexArrays
+#define glGetAttribLocation               imgl3wProcs.gl.GetAttribLocation
+#define glGetError                        imgl3wProcs.gl.GetError
+#define glGetIntegerv                     imgl3wProcs.gl.GetIntegerv
+#define glGetProgramInfoLog               imgl3wProcs.gl.GetProgramInfoLog
+#define glGetProgramiv                    imgl3wProcs.gl.GetProgramiv
+#define glGetShaderInfoLog                imgl3wProcs.gl.GetShaderInfoLog
+#define glGetShaderiv                     imgl3wProcs.gl.GetShaderiv
+#define glGetString                       imgl3wProcs.gl.GetString
+#define glGetStringi                      imgl3wProcs.gl.GetStringi
+#define glGetUniformLocation              imgl3wProcs.gl.GetUniformLocation
+#define glGetVertexAttribPointerv         imgl3wProcs.gl.GetVertexAttribPointerv
+#define glGetVertexAttribiv               imgl3wProcs.gl.GetVertexAttribiv
+#define glIsEnabled                       imgl3wProcs.gl.IsEnabled
+#define glIsProgram                       imgl3wProcs.gl.IsProgram
+#define glLinkProgram                     imgl3wProcs.gl.LinkProgram
+#define glPixelStorei                     imgl3wProcs.gl.PixelStorei
+#define glPolygonMode                     imgl3wProcs.gl.PolygonMode
+#define glReadPixels                      imgl3wProcs.gl.ReadPixels
+#define glScissor                         imgl3wProcs.gl.Scissor
+#define glShaderSource                    imgl3wProcs.gl.ShaderSource
+#define glTexImage2D                      imgl3wProcs.gl.TexImage2D
+#define glTexParameteri                   imgl3wProcs.gl.TexParameteri
+#define glUniform1i                       imgl3wProcs.gl.Uniform1i
+#define glUniformMatrix4fv                imgl3wProcs.gl.UniformMatrix4fv
+#define glUseProgram                      imgl3wProcs.gl.UseProgram
+#define glVertexAttribPointer             imgl3wProcs.gl.VertexAttribPointer
+#define glViewport                        imgl3wProcs.gl.Viewport
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+#ifdef IMGL3W_IMPL
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdlib.h>
+
+#define ARRAY_SIZE(x)  (sizeof(x) / sizeof((x)[0]))
+
+#if defined(_WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+#include <windows.h>
+
+static HMODULE libgl;
+typedef PROC(__stdcall* GL3WglGetProcAddr)(LPCSTR);
+static GL3WglGetProcAddr wgl_get_proc_address;
+
+static int open_libgl(void)
+{
+    libgl = LoadLibraryA("opengl32.dll");
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    wgl_get_proc_address = (GL3WglGetProcAddr)GetProcAddress(libgl, "wglGetProcAddress");
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { FreeLibrary(libgl); }
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    res = (GL3WglProc)wgl_get_proc_address(proc);
+    if (!res)
+        res = (GL3WglProc)GetProcAddress(libgl, proc);
+    return res;
+}
+#elif defined(__APPLE__)
+#include <dlfcn.h>
+
+static void *libgl;
+static int open_libgl(void)
+{
+    libgl = dlopen("/System/Library/Frameworks/OpenGL.framework/OpenGL", RTLD_LAZY | RTLD_LOCAL);
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { dlclose(libgl); }
+
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    *(void **)(&res) = dlsym(libgl, proc);
+    return res;
+}
+#else
+#include <dlfcn.h>
+
+static void *libgl;
+static GL3WglProc (*glx_get_proc_address)(const GLubyte *);
+
+static int open_libgl(void)
+{
+    libgl = dlopen("libGL.so.1", RTLD_LAZY | RTLD_LOCAL);
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    *(void **)(&glx_get_proc_address) = dlsym(libgl, "glXGetProcAddressARB");
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { dlclose(libgl); }
+
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    res = glx_get_proc_address((const GLubyte *)proc);
+    if (!res)
+        *(void **)(&res) = dlsym(libgl, proc);
+    return res;
+}
+#endif
+
+static struct { int major, minor; } version;
+
+static int parse_version(void)
+{
+    if (!glGetIntegerv)
+        return GL3W_ERROR_INIT;
+    glGetIntegerv(GL_MAJOR_VERSION, &version.major);
+    glGetIntegerv(GL_MINOR_VERSION, &version.minor);
+    if (version.major == 0 && version.minor == 0)
+    {
+        // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
+        if (const char* gl_version = (const char*)glGetString(GL_VERSION))
+            sscanf(gl_version, "%d.%d", &version.major, &version.minor);
+    }
+    if (version.major < 2)
+        return GL3W_ERROR_OPENGL_VERSION;
+    return GL3W_OK;
+}
+
+static void load_procs(GL3WGetProcAddressProc proc);
+
+int imgl3wInit(void)
+{
+    int res = open_libgl();
+    if (res)
+        return res;
+    atexit(close_libgl);
+    return imgl3wInit2(get_proc);
+}
+
+int imgl3wInit2(GL3WGetProcAddressProc proc)
+{
+    load_procs(proc);
+    return parse_version();
+}
+
+int imgl3wIsSupported(int major, int minor)
+{
+    if (major < 2)
+        return 0;
+    if (version.major == major)
+        return version.minor >= minor;
+    return version.major >= major;
+}
+
+GL3WglProc imgl3wGetProcAddress(const char *proc) { return get_proc(proc); }
+
+static const char *proc_names[] = {
+    "glActiveTexture",
+    "glAttachShader",
+    "glBindBuffer",
+    "glBindSampler",
+    "glBindTexture",
+    "glBindVertexArray",
+    "glBlendEquation",
+    "glBlendEquationSeparate",
+    "glBlendFuncSeparate",
+    "glBufferData",
+    "glBufferSubData",
+    "glClear",
+    "glClearColor",
+    "glCompileShader",
+    "glCreateProgram",
+    "glCreateShader",
+    "glDeleteBuffers",
+    "glDeleteProgram",
+    "glDeleteShader",
+    "glDeleteTextures",
+    "glDeleteVertexArrays",
+    "glDetachShader",
+    "glDisable",
+    "glDisableVertexAttribArray",
+    "glDrawElements",
+    "glDrawElementsBaseVertex",
+    "glEnable",
+    "glEnableVertexAttribArray",
+    "glFlush",
+    "glGenBuffers",
+    "glGenTextures",
+    "glGenVertexArrays",
+    "glGetAttribLocation",
+    "glGetError",
+    "glGetIntegerv",
+    "glGetProgramInfoLog",
+    "glGetProgramiv",
+    "glGetShaderInfoLog",
+    "glGetShaderiv",
+    "glGetString",
+    "glGetStringi",
+    "glGetUniformLocation",
+    "glGetVertexAttribPointerv",
+    "glGetVertexAttribiv",
+    "glIsEnabled",
+    "glIsProgram",
+    "glLinkProgram",
+    "glPixelStorei",
+    "glPolygonMode",
+    "glReadPixels",
+    "glScissor",
+    "glShaderSource",
+    "glTexImage2D",
+    "glTexParameteri",
+    "glUniform1i",
+    "glUniformMatrix4fv",
+    "glUseProgram",
+    "glVertexAttribPointer",
+    "glViewport",
+};
+
+GL3W_API union GL3WProcs imgl3wProcs;
+
+static void load_procs(GL3WGetProcAddressProc proc)
+{
+    size_t i;
+    for (i = 0; i < ARRAY_SIZE(proc_names); i++)
+        imgl3wProcs.ptr[i] = proc(proc_names[i]);
+}
+
+#ifdef __cplusplus
+}
+#endif
+#endif

third_party/imgui/backends/imgui_impl_osx.h

@@ -0,0 +1,45 @@
+// dear imgui: Platform Backend for OSX / Cocoa
+// This needs to be used along with a Renderer (e.g. OpenGL2, OpenGL3, Vulkan, Metal..)
+// - Not well tested. If you want a portable application, prefer using the GLFW or SDL platform Backends on Mac.
+// - Requires linking with the GameController framework ("-framework GameController").
+
+// Implemented features:
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Mouse support. Can discriminate Mouse/Pen.
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy kVK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: IME support.
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+#include "imgui.h"      // IMGUI_IMPL_API
+
+#ifdef __OBJC__
+
+@class NSEvent;
+@class NSView;
+
+IMGUI_IMPL_API bool     ImGui_ImplOSX_Init(NSView* _Nonnull view);
+IMGUI_IMPL_API void     ImGui_ImplOSX_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplOSX_NewFrame(NSView* _Nullable view);
+
+#endif
+
+//-----------------------------------------------------------------------------
+// C++ API
+//-----------------------------------------------------------------------------
+
+#ifdef IMGUI_IMPL_METAL_CPP_EXTENSIONS
+// #include <AppKit/AppKit.hpp>
+#ifndef __OBJC__
+
+IMGUI_IMPL_API bool     ImGui_ImplOSX_Init(void* _Nonnull view);
+IMGUI_IMPL_API void     ImGui_ImplOSX_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplOSX_NewFrame(void* _Nullable view);
+
+#endif
+#endif

third_party/imgui/backends/imgui_impl_osx.mm

@@ -0,0 +1,803 @@
+// dear imgui: Platform Backend for OSX / Cocoa
+// This needs to be used along with a Renderer (e.g. OpenGL2, OpenGL3, Vulkan, Metal..)
+// - Not well tested. If you want a portable application, prefer using the GLFW or SDL platform Backends on Mac.
+// - Requires linking with the GameController framework ("-framework GameController").
+
+// Implemented features:
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Mouse support. Can discriminate Mouse/Pen.
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy kVK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: IME support.
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+#import "imgui.h"
+#import "imgui_impl_osx.h"
+#import <Cocoa/Cocoa.h>
+#import <Carbon/Carbon.h>
+#import <GameController/GameController.h>
+#import <time.h>
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2023-04-09: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_Pen.
+//  2023-02-01: Fixed scroll wheel scaling for devices emitting events with hasPreciseScrollingDeltas==false (e.g. non-Apple mices).
+//  2022-11-02: Fixed mouse coordinates before clicking the host window.
+//  2022-10-06: Fixed mouse inputs on flipped views.
+//  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
+//  2022-05-03: Inputs: Removed ImGui_ImplOSX_HandleEvent() from backend API in favor of backend automatically handling event capture.
+//  2022-04-27: Misc: Store backend data in a per-context struct, allowing to use this backend with multiple contexts.
+//  2022-03-22: Inputs: Monitor NSKeyUp events to catch missing keyUp for key when user press Cmd + key
+//  2022-02-07: Inputs: Forward keyDown/keyUp events to OS when unused by dear imgui.
+//  2022-01-31: Fixed building with old Xcode versions that are missing gamepad features.
+//  2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
+//  2021-01-20: Inputs: calling new io.AddKeyAnalogEvent() for gamepad support, instead of writing directly to io.NavInputs[].
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
+//  2022-01-12: Inputs: Added basic Platform IME support, hooking the io.SetPlatformImeDataFn() function.
+//  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
+//  2021-12-13: *BREAKING CHANGE* Add NSView parameter to ImGui_ImplOSX_Init(). Generally fix keyboard support. Using kVK_* codes for keyboard keys.
+//  2021-12-13: Add game controller support.
+//  2021-09-21: Use mach_absolute_time as CFAbsoluteTimeGetCurrent can jump backwards.
+//  2021-08-17: Calling io.AddFocusEvent() on NSApplicationDidBecomeActiveNotification/NSApplicationDidResignActiveNotification events.
+//  2021-06-23: Inputs: Added a fix for shortcuts using CTRL key instead of CMD key.
+//  2021-04-19: Inputs: Added a fix for keys remaining stuck in pressed state when CMD-tabbing into different application.
+//  2021-01-27: Inputs: Added a fix for mouse position not being reported when mouse buttons other than left one are down.
+//  2020-10-28: Inputs: Added a fix for handling keypad-enter key.
+//  2020-05-25: Inputs: Added a fix for missing trackpad clicks when done with "soft tap".
+//  2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
+//  2019-10-11: Inputs:  Fix using Backspace key.
+//  2019-07-21: Re-added clipboard handlers as they are not enabled by default in core imgui.cpp (reverted 2019-05-18 change).
+//  2019-05-28: Inputs: Added mouse cursor shape and visibility support.
+//  2019-05-18: Misc: Removed clipboard handlers as they are now supported by core imgui.cpp.
+//  2019-05-11: Inputs: Don't filter character values before calling AddInputCharacter() apart from 0xF700..0xFFFF range.
+//  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
+//  2018-07-07: Initial version.
+
+#define APPLE_HAS_BUTTON_OPTIONS (__IPHONE_OS_VERSION_MIN_REQUIRED >= 130000 || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500 || __TV_OS_VERSION_MIN_REQUIRED >= 130000)
+#define APPLE_HAS_CONTROLLER     (__IPHONE_OS_VERSION_MIN_REQUIRED >= 140000 || __MAC_OS_X_VERSION_MIN_REQUIRED >= 110000 || __TV_OS_VERSION_MIN_REQUIRED >= 140000)
+#define APPLE_HAS_THUMBSTICKS    (__IPHONE_OS_VERSION_MIN_REQUIRED >= 120100 || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101401 || __TV_OS_VERSION_MIN_REQUIRED >= 120100)
+
+@class ImGuiObserver;
+@class KeyEventResponder;
+
+// Data
+struct ImGui_ImplOSX_Data
+{
+    CFTimeInterval              Time;
+    NSCursor*                   MouseCursors[ImGuiMouseCursor_COUNT];
+    bool                        MouseCursorHidden;
+    ImGuiObserver*              Observer;
+    KeyEventResponder*          KeyEventResponder;
+    NSTextInputContext*         InputContext;
+    id                          Monitor;
+
+    ImGui_ImplOSX_Data()        { memset(this, 0, sizeof(*this)); }
+};
+
+static ImGui_ImplOSX_Data*      ImGui_ImplOSX_CreateBackendData()   { return IM_NEW(ImGui_ImplOSX_Data)(); }
+static ImGui_ImplOSX_Data*      ImGui_ImplOSX_GetBackendData()      { return (ImGui_ImplOSX_Data*)ImGui::GetIO().BackendPlatformUserData; }
+static void                     ImGui_ImplOSX_DestroyBackendData()  { IM_DELETE(ImGui_ImplOSX_GetBackendData()); }
+
+static inline CFTimeInterval    GetMachAbsoluteTimeInSeconds()      { return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9); }
+
+// Forward Declarations
+static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view);
+static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
+
+// Undocumented methods for creating cursors.
+@interface NSCursor()
++ (id)_windowResizeNorthWestSouthEastCursor;
++ (id)_windowResizeNorthEastSouthWestCursor;
++ (id)_windowResizeNorthSouthCursor;
++ (id)_windowResizeEastWestCursor;
+@end
+
+/**
+ KeyEventResponder implements the NSTextInputClient protocol as is required by the macOS text input manager.
+
+ The macOS text input manager is invoked by calling the interpretKeyEvents method from the keyDown method.
+ Keyboard events are then evaluated by the macOS input manager and valid text input is passed back via the
+ insertText:replacementRange method.
+
+ This is the same approach employed by other cross-platform libraries such as SDL2:
+  https://github.com/spurious/SDL-mirror/blob/e17aacbd09e65a4fd1e166621e011e581fb017a8/src/video/cocoa/SDL_cocoakeyboard.m#L53
+ and GLFW:
+  https://github.com/glfw/glfw/blob/b55a517ae0c7b5127dffa79a64f5406021bf9076/src/cocoa_window.m#L722-L723
+ */
+@interface KeyEventResponder: NSView<NSTextInputClient>
+@end
+
+@implementation KeyEventResponder
+{
+    float _posX;
+    float _posY;
+    NSRect _imeRect;
+}
+
+#pragma mark - Public
+
+- (void)setImePosX:(float)posX imePosY:(float)posY
+{
+    _posX = posX;
+    _posY = posY;
+}
+
+- (void)updateImePosWithView:(NSView *)view
+{
+    NSWindow *window = view.window;
+    if (!window)
+        return;
+    NSRect contentRect = [window contentRectForFrameRect:window.frame];
+    NSRect rect = NSMakeRect(_posX, contentRect.size.height - _posY, 0, 0);
+    _imeRect = [window convertRectToScreen:rect];
+}
+
+- (void)viewDidMoveToWindow
+{
+    // Ensure self is a first responder to receive the input events.
+    [self.window makeFirstResponder:self];
+}
+
+- (void)keyDown:(NSEvent*)event
+{
+    if (!ImGui_ImplOSX_HandleEvent(event, self))
+        [super keyDown:event];
+
+    // Call to the macOS input manager system.
+    [self interpretKeyEvents:@[event]];
+}
+
+- (void)keyUp:(NSEvent*)event
+{
+    if (!ImGui_ImplOSX_HandleEvent(event, self))
+        [super keyUp:event];
+}
+
+- (void)insertText:(id)aString replacementRange:(NSRange)replacementRange
+{
+    ImGuiIO& io = ImGui::GetIO();
+
+    NSString* characters;
+    if ([aString isKindOfClass:[NSAttributedString class]])
+        characters = [aString string];
+    else
+        characters = (NSString*)aString;
+
+    io.AddInputCharactersUTF8(characters.UTF8String);
+}
+
+- (BOOL)acceptsFirstResponder
+{
+    return YES;
+}
+
+- (void)doCommandBySelector:(SEL)myselector
+{
+}
+
+- (nullable NSAttributedString*)attributedSubstringForProposedRange:(NSRange)range actualRange:(nullable NSRangePointer)actualRange
+{
+    return nil;
+}
+
+- (NSUInteger)characterIndexForPoint:(NSPoint)point
+{
+    return 0;
+}
+
+- (NSRect)firstRectForCharacterRange:(NSRange)range actualRange:(nullable NSRangePointer)actualRange
+{
+    return _imeRect;
+}
+
+- (BOOL)hasMarkedText
+{
+    return NO;
+}
+
+- (NSRange)markedRange
+{
+    return NSMakeRange(NSNotFound, 0);
+}
+
+- (NSRange)selectedRange
+{
+    return NSMakeRange(NSNotFound, 0);
+}
+
+- (void)setMarkedText:(nonnull id)string selectedRange:(NSRange)selectedRange replacementRange:(NSRange)replacementRange
+{
+}
+
+- (void)unmarkText
+{
+}
+
+- (nonnull NSArray<NSAttributedStringKey>*)validAttributesForMarkedText
+{
+    return @[];
+}
+
+@end
+
+@interface ImGuiObserver : NSObject
+
+- (void)onApplicationBecomeActive:(NSNotification*)aNotification;
+- (void)onApplicationBecomeInactive:(NSNotification*)aNotification;
+
+@end
+
+@implementation ImGuiObserver
+
+- (void)onApplicationBecomeActive:(NSNotification*)aNotification
+{
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddFocusEvent(true);
+}
+
+- (void)onApplicationBecomeInactive:(NSNotification*)aNotification
+{
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddFocusEvent(false);
+}
+
+@end
+
+// Functions
+static ImGuiKey ImGui_ImplOSX_KeyCodeToImGuiKey(int key_code)
+{
+    switch (key_code)
+    {
+        case kVK_ANSI_A: return ImGuiKey_A;
+        case kVK_ANSI_S: return ImGuiKey_S;
+        case kVK_ANSI_D: return ImGuiKey_D;
+        case kVK_ANSI_F: return ImGuiKey_F;
+        case kVK_ANSI_H: return ImGuiKey_H;
+        case kVK_ANSI_G: return ImGuiKey_G;
+        case kVK_ANSI_Z: return ImGuiKey_Z;
+        case kVK_ANSI_X: return ImGuiKey_X;
+        case kVK_ANSI_C: return ImGuiKey_C;
+        case kVK_ANSI_V: return ImGuiKey_V;
+        case kVK_ANSI_B: return ImGuiKey_B;
+        case kVK_ANSI_Q: return ImGuiKey_Q;
+        case kVK_ANSI_W: return ImGuiKey_W;
+        case kVK_ANSI_E: return ImGuiKey_E;
+        case kVK_ANSI_R: return ImGuiKey_R;
+        case kVK_ANSI_Y: return ImGuiKey_Y;
+        case kVK_ANSI_T: return ImGuiKey_T;
+        case kVK_ANSI_1: return ImGuiKey_1;
+        case kVK_ANSI_2: return ImGuiKey_2;
+        case kVK_ANSI_3: return ImGuiKey_3;
+        case kVK_ANSI_4: return ImGuiKey_4;
+        case kVK_ANSI_6: return ImGuiKey_6;
+        case kVK_ANSI_5: return ImGuiKey_5;
+        case kVK_ANSI_Equal: return ImGuiKey_Equal;
+        case kVK_ANSI_9: return ImGuiKey_9;
+        case kVK_ANSI_7: return ImGuiKey_7;
+        case kVK_ANSI_Minus: return ImGuiKey_Minus;
+        case kVK_ANSI_8: return ImGuiKey_8;
+        case kVK_ANSI_0: return ImGuiKey_0;
+        case kVK_ANSI_RightBracket: return ImGuiKey_RightBracket;
+        case kVK_ANSI_O: return ImGuiKey_O;
+        case kVK_ANSI_U: return ImGuiKey_U;
+        case kVK_ANSI_LeftBracket: return ImGuiKey_LeftBracket;
+        case kVK_ANSI_I: return ImGuiKey_I;
+        case kVK_ANSI_P: return ImGuiKey_P;
+        case kVK_ANSI_L: return ImGuiKey_L;
+        case kVK_ANSI_J: return ImGuiKey_J;
+        case kVK_ANSI_Quote: return ImGuiKey_Apostrophe;
+        case kVK_ANSI_K: return ImGuiKey_K;
+        case kVK_ANSI_Semicolon: return ImGuiKey_Semicolon;
+        case kVK_ANSI_Backslash: return ImGuiKey_Backslash;
+        case kVK_ANSI_Comma: return ImGuiKey_Comma;
+        case kVK_ANSI_Slash: return ImGuiKey_Slash;
+        case kVK_ANSI_N: return ImGuiKey_N;
+        case kVK_ANSI_M: return ImGuiKey_M;
+        case kVK_ANSI_Period: return ImGuiKey_Period;
+        case kVK_ANSI_Grave: return ImGuiKey_GraveAccent;
+        case kVK_ANSI_KeypadDecimal: return ImGuiKey_KeypadDecimal;
+        case kVK_ANSI_KeypadMultiply: return ImGuiKey_KeypadMultiply;
+        case kVK_ANSI_KeypadPlus: return ImGuiKey_KeypadAdd;
+        case kVK_ANSI_KeypadClear: return ImGuiKey_NumLock;
+        case kVK_ANSI_KeypadDivide: return ImGuiKey_KeypadDivide;
+        case kVK_ANSI_KeypadEnter: return ImGuiKey_KeypadEnter;
+        case kVK_ANSI_KeypadMinus: return ImGuiKey_KeypadSubtract;
+        case kVK_ANSI_KeypadEquals: return ImGuiKey_KeypadEqual;
+        case kVK_ANSI_Keypad0: return ImGuiKey_Keypad0;
+        case kVK_ANSI_Keypad1: return ImGuiKey_Keypad1;
+        case kVK_ANSI_Keypad2: return ImGuiKey_Keypad2;
+        case kVK_ANSI_Keypad3: return ImGuiKey_Keypad3;
+        case kVK_ANSI_Keypad4: return ImGuiKey_Keypad4;
+        case kVK_ANSI_Keypad5: return ImGuiKey_Keypad5;
+        case kVK_ANSI_Keypad6: return ImGuiKey_Keypad6;
+        case kVK_ANSI_Keypad7: return ImGuiKey_Keypad7;
+        case kVK_ANSI_Keypad8: return ImGuiKey_Keypad8;
+        case kVK_ANSI_Keypad9: return ImGuiKey_Keypad9;
+        case kVK_Return: return ImGuiKey_Enter;
+        case kVK_Tab: return ImGuiKey_Tab;
+        case kVK_Space: return ImGuiKey_Space;
+        case kVK_Delete: return ImGuiKey_Backspace;
+        case kVK_Escape: return ImGuiKey_Escape;
+        case kVK_CapsLock: return ImGuiKey_CapsLock;
+        case kVK_Control: return ImGuiKey_LeftCtrl;
+        case kVK_Shift: return ImGuiKey_LeftShift;
+        case kVK_Option: return ImGuiKey_LeftAlt;
+        case kVK_Command: return ImGuiKey_LeftSuper;
+        case kVK_RightControl: return ImGuiKey_RightCtrl;
+        case kVK_RightShift: return ImGuiKey_RightShift;
+        case kVK_RightOption: return ImGuiKey_RightAlt;
+        case kVK_RightCommand: return ImGuiKey_RightSuper;
+//      case kVK_Function: return ImGuiKey_;
+//      case kVK_F17: return ImGuiKey_;
+//      case kVK_VolumeUp: return ImGuiKey_;
+//      case kVK_VolumeDown: return ImGuiKey_;
+//      case kVK_Mute: return ImGuiKey_;
+//      case kVK_F18: return ImGuiKey_;
+//      case kVK_F19: return ImGuiKey_;
+//      case kVK_F20: return ImGuiKey_;
+        case kVK_F5: return ImGuiKey_F5;
+        case kVK_F6: return ImGuiKey_F6;
+        case kVK_F7: return ImGuiKey_F7;
+        case kVK_F3: return ImGuiKey_F3;
+        case kVK_F8: return ImGuiKey_F8;
+        case kVK_F9: return ImGuiKey_F9;
+        case kVK_F11: return ImGuiKey_F11;
+        case kVK_F13: return ImGuiKey_PrintScreen;
+//      case kVK_F16: return ImGuiKey_;
+//      case kVK_F14: return ImGuiKey_;
+        case kVK_F10: return ImGuiKey_F10;
+        case 0x6E: return ImGuiKey_Menu;
+        case kVK_F12: return ImGuiKey_F12;
+//      case kVK_F15: return ImGuiKey_;
+        case kVK_Help: return ImGuiKey_Insert;
+        case kVK_Home: return ImGuiKey_Home;
+        case kVK_PageUp: return ImGuiKey_PageUp;
+        case kVK_ForwardDelete: return ImGuiKey_Delete;
+        case kVK_F4: return ImGuiKey_F4;
+        case kVK_End: return ImGuiKey_End;
+        case kVK_F2: return ImGuiKey_F2;
+        case kVK_PageDown: return ImGuiKey_PageDown;
+        case kVK_F1: return ImGuiKey_F1;
+        case kVK_LeftArrow: return ImGuiKey_LeftArrow;
+        case kVK_RightArrow: return ImGuiKey_RightArrow;
+        case kVK_DownArrow: return ImGuiKey_DownArrow;
+        case kVK_UpArrow: return ImGuiKey_UpArrow;
+        default: return ImGuiKey_None;
+    }
+}
+
+#ifdef IMGUI_IMPL_METAL_CPP_EXTENSIONS
+
+IMGUI_IMPL_API bool ImGui_ImplOSX_Init(void* _Nonnull view) {
+    return ImGui_ImplOSX_Init((__bridge NSView*)(view));
+}
+
+IMGUI_IMPL_API void ImGui_ImplOSX_NewFrame(void* _Nullable view) {
+    return ImGui_ImplOSX_NewFrame((__bridge NSView*)(view));
+}
+
+#endif
+
+
+bool ImGui_ImplOSX_Init(NSView* view)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_CreateBackendData();
+    io.BackendPlatformUserData = (void*)bd;
+
+    // Setup backend capabilities flags
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
+    //io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendPlatformName = "imgui_impl_osx";
+
+    bd->Observer = [ImGuiObserver new];
+
+    // Load cursors. Some of them are undocumented.
+    bd->MouseCursorHidden = false;
+    bd->MouseCursors[ImGuiMouseCursor_Arrow] = [NSCursor arrowCursor];
+    bd->MouseCursors[ImGuiMouseCursor_TextInput] = [NSCursor IBeamCursor];
+    bd->MouseCursors[ImGuiMouseCursor_ResizeAll] = [NSCursor closedHandCursor];
+    bd->MouseCursors[ImGuiMouseCursor_Hand] = [NSCursor pointingHandCursor];
+    bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = [NSCursor operationNotAllowedCursor];
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNS] = [NSCursor respondsToSelector:@selector(_windowResizeNorthSouthCursor)] ? [NSCursor _windowResizeNorthSouthCursor] : [NSCursor resizeUpDownCursor];
+    bd->MouseCursors[ImGuiMouseCursor_ResizeEW] = [NSCursor respondsToSelector:@selector(_windowResizeEastWestCursor)] ? [NSCursor _windowResizeEastWestCursor] : [NSCursor resizeLeftRightCursor];
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = [NSCursor respondsToSelector:@selector(_windowResizeNorthEastSouthWestCursor)] ? [NSCursor _windowResizeNorthEastSouthWestCursor] : [NSCursor closedHandCursor];
+    bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = [NSCursor respondsToSelector:@selector(_windowResizeNorthWestSouthEastCursor)] ? [NSCursor _windowResizeNorthWestSouthEastCursor] : [NSCursor closedHandCursor];
+
+    // Note that imgui.cpp also include default OSX clipboard handlers which can be enabled
+    // by adding '#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS' in imconfig.h and adding '-framework ApplicationServices' to your linker command-line.
+    // Since we are already in ObjC land here, it is easy for us to add a clipboard handler using the NSPasteboard api.
+    io.SetClipboardTextFn = [](void*, const char* str) -> void
+    {
+        NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+        [pasteboard declareTypes:[NSArray arrayWithObject:NSPasteboardTypeString] owner:nil];
+        [pasteboard setString:[NSString stringWithUTF8String:str] forType:NSPasteboardTypeString];
+    };
+
+    io.GetClipboardTextFn = [](void*) -> const char*
+    {
+        NSPasteboard* pasteboard = [NSPasteboard generalPasteboard];
+        NSString* available = [pasteboard availableTypeFromArray: [NSArray arrayWithObject:NSPasteboardTypeString]];
+        if (![available isEqualToString:NSPasteboardTypeString])
+            return nullptr;
+
+        NSString* string = [pasteboard stringForType:NSPasteboardTypeString];
+        if (string == nil)
+            return nullptr;
+
+        const char* string_c = (const char*)[string UTF8String];
+        size_t string_len = strlen(string_c);
+        static ImVector<char> s_clipboard;
+        s_clipboard.resize((int)string_len + 1);
+        strcpy(s_clipboard.Data, string_c);
+        return s_clipboard.Data;
+    };
+
+    [[NSNotificationCenter defaultCenter] addObserver:bd->Observer
+                                             selector:@selector(onApplicationBecomeActive:)
+                                                 name:NSApplicationDidBecomeActiveNotification
+                                               object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:bd->Observer
+                                             selector:@selector(onApplicationBecomeInactive:)
+                                                 name:NSApplicationDidResignActiveNotification
+                                               object:nil];
+
+    // Add the NSTextInputClient to the view hierarchy,
+    // to receive keyboard events and translate them to input text.
+    bd->KeyEventResponder = [[KeyEventResponder alloc] initWithFrame:NSZeroRect];
+    bd->InputContext = [[NSTextInputContext alloc] initWithClient:bd->KeyEventResponder];
+    [view addSubview:bd->KeyEventResponder];
+    ImGui_ImplOSX_AddTrackingArea(view);
+
+    io.SetPlatformImeDataFn = [](ImGuiViewport* viewport, ImGuiPlatformImeData* data) -> void
+    {
+        ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+        if (data->WantVisible)
+        {
+            [bd->InputContext activate];
+        }
+        else
+        {
+            [bd->InputContext discardMarkedText];
+            [bd->InputContext invalidateCharacterCoordinates];
+            [bd->InputContext deactivate];
+        }
+        [bd->KeyEventResponder setImePosX:data->InputPos.x imePosY:data->InputPos.y + data->InputLineHeight];
+    };
+
+    return true;
+}
+
+void ImGui_ImplOSX_Shutdown()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
+
+    bd->Observer = nullptr;
+    if (bd->Monitor != nullptr)
+    {
+        [NSEvent removeMonitor:bd->Monitor];
+        bd->Monitor = nullptr;
+    }
+
+    ImGui_ImplOSX_DestroyBackendData();
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.BackendPlatformName = nullptr;
+    io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad);
+}
+
+static void ImGui_ImplOSX_UpdateMouseCursor()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
+        return;
+
+    ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
+    if (io.MouseDrawCursor || imgui_cursor == ImGuiMouseCursor_None)
+    {
+        // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
+        if (!bd->MouseCursorHidden)
+        {
+            bd->MouseCursorHidden = true;
+            [NSCursor hide];
+        }
+    }
+    else
+    {
+        NSCursor* desired = bd->MouseCursors[imgui_cursor] ?: bd->MouseCursors[ImGuiMouseCursor_Arrow];
+        // -[NSCursor set] generates measureable overhead if called unconditionally.
+        if (desired != NSCursor.currentCursor)
+        {
+            [desired set];
+        }
+        if (bd->MouseCursorHidden)
+        {
+            bd->MouseCursorHidden = false;
+            [NSCursor unhide];
+        }
+    }
+}
+
+static void ImGui_ImplOSX_UpdateGamepads()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    memset(io.NavInputs, 0, sizeof(io.NavInputs));
+    if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0) // FIXME: Technically feeding gamepad shouldn't depend on this now that they are regular inputs.
+        return;
+
+#if APPLE_HAS_CONTROLLER
+    GCController* controller = GCController.current;
+#else
+    GCController* controller = GCController.controllers.firstObject;
+#endif
+    if (controller == nil || controller.extendedGamepad == nil)
+    {
+        io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+        return;
+    }
+
+    GCExtendedGamepad* gp = controller.extendedGamepad;
+
+    // Update gamepad inputs
+    #define IM_SATURATE(V)                        (V < 0.0f ? 0.0f : V > 1.0f ? 1.0f : V)
+    #define MAP_BUTTON(KEY_NO, BUTTON_NAME)       { io.AddKeyEvent(KEY_NO, gp.BUTTON_NAME.isPressed); }
+    #define MAP_ANALOG(KEY_NO, AXIS_NAME, V0, V1) { float vn = (float)(gp.AXIS_NAME.value - V0) / (float)(V1 - V0); vn = IM_SATURATE(vn); io.AddKeyAnalogEvent(KEY_NO, vn > 0.1f, vn); }
+    const float thumb_dead_zone = 0.0f;
+
+#if APPLE_HAS_BUTTON_OPTIONS
+    MAP_BUTTON(ImGuiKey_GamepadBack,            buttonOptions);
+#endif
+    MAP_BUTTON(ImGuiKey_GamepadFaceLeft,        buttonX);              // Xbox X, PS Square
+    MAP_BUTTON(ImGuiKey_GamepadFaceRight,       buttonB);              // Xbox B, PS Circle
+    MAP_BUTTON(ImGuiKey_GamepadFaceUp,          buttonY);              // Xbox Y, PS Triangle
+    MAP_BUTTON(ImGuiKey_GamepadFaceDown,        buttonA);              // Xbox A, PS Cross
+    MAP_BUTTON(ImGuiKey_GamepadDpadLeft,        dpad.left);
+    MAP_BUTTON(ImGuiKey_GamepadDpadRight,       dpad.right);
+    MAP_BUTTON(ImGuiKey_GamepadDpadUp,          dpad.up);
+    MAP_BUTTON(ImGuiKey_GamepadDpadDown,        dpad.down);
+    MAP_ANALOG(ImGuiKey_GamepadL1,              leftShoulder, 0.0f, 1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadR1,              rightShoulder, 0.0f, 1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadL2,              leftTrigger,  0.0f, 1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadR2,              rightTrigger, 0.0f, 1.0f);
+#if APPLE_HAS_THUMBSTICKS
+    MAP_BUTTON(ImGuiKey_GamepadL3,              leftThumbstickButton);
+    MAP_BUTTON(ImGuiKey_GamepadR3,              rightThumbstickButton);
+#endif
+    MAP_ANALOG(ImGuiKey_GamepadLStickLeft,      leftThumbstick.xAxis,  -thumb_dead_zone, -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickRight,     leftThumbstick.xAxis,  +thumb_dead_zone, +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickUp,        leftThumbstick.yAxis,  +thumb_dead_zone, +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadLStickDown,      leftThumbstick.yAxis,  -thumb_dead_zone, -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickLeft,      rightThumbstick.xAxis, -thumb_dead_zone, -1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickRight,     rightThumbstick.xAxis, +thumb_dead_zone, +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickUp,        rightThumbstick.yAxis, +thumb_dead_zone, +1.0f);
+    MAP_ANALOG(ImGuiKey_GamepadRStickDown,      rightThumbstick.yAxis, -thumb_dead_zone, -1.0f);
+    #undef MAP_BUTTON
+    #undef MAP_ANALOG
+
+    io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+}
+
+static void ImGui_ImplOSX_UpdateImePosWithView(NSView* view)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.WantTextInput)
+        [bd->KeyEventResponder updateImePosWithView:view];
+}
+
+void ImGui_ImplOSX_NewFrame(NSView* view)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+
+    // Setup display size
+    if (view)
+    {
+        const float dpi = (float)[view.window backingScaleFactor];
+        io.DisplaySize = ImVec2((float)view.bounds.size.width, (float)view.bounds.size.height);
+        io.DisplayFramebufferScale = ImVec2(dpi, dpi);
+    }
+
+    // Setup time step
+    if (bd->Time == 0.0)
+        bd->Time = GetMachAbsoluteTimeInSeconds();
+
+    double current_time = GetMachAbsoluteTimeInSeconds();
+    io.DeltaTime = (float)(current_time - bd->Time);
+    bd->Time = current_time;
+
+    ImGui_ImplOSX_UpdateMouseCursor();
+    ImGui_ImplOSX_UpdateGamepads();
+    ImGui_ImplOSX_UpdateImePosWithView(view);
+}
+
+// Must only be called for a mouse event, otherwise an exception occurs
+// (Note that NSEventTypeScrollWheel is considered "other input". Oddly enough an exception does not occur with it, but the value will sometimes be wrong!)
+static ImGuiMouseSource GetMouseSource(NSEvent* event)
+{
+    switch (event.subtype)
+    {
+        case NSEventSubtypeTabletPoint:
+            return ImGuiMouseSource_Pen;
+        // macOS considers input from relative touch devices (like the trackpad or Apple Magic Mouse) to be touch input.
+        // This doesn't really make sense for Dear ImGui, which expects absolute touch devices only.
+        // There does not seem to be a simple way to disambiguate things here so we consider NSEventSubtypeTouch events to always come from mice.
+        // See https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/EventOverview/HandlingTouchEvents/HandlingTouchEvents.html#//apple_ref/doc/uid/10000060i-CH13-SW24
+        //case NSEventSubtypeTouch:
+        //    return ImGuiMouseSource_TouchScreen;
+        case NSEventSubtypeMouseEvent:
+        default:
+            return ImGuiMouseSource_Mouse;
+    }
+}
+
+static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
+{
+    ImGuiIO& io = ImGui::GetIO();
+
+    if (event.type == NSEventTypeLeftMouseDown || event.type == NSEventTypeRightMouseDown || event.type == NSEventTypeOtherMouseDown)
+    {
+        int button = (int)[event buttonNumber];
+        if (button >= 0 && button < ImGuiMouseButton_COUNT)
+        {
+            io.AddMouseSourceEvent(GetMouseSource(event));
+            io.AddMouseButtonEvent(button, true);
+        }
+        return io.WantCaptureMouse;
+    }
+
+    if (event.type == NSEventTypeLeftMouseUp || event.type == NSEventTypeRightMouseUp || event.type == NSEventTypeOtherMouseUp)
+    {
+        int button = (int)[event buttonNumber];
+        if (button >= 0 && button < ImGuiMouseButton_COUNT)
+        {
+            io.AddMouseSourceEvent(GetMouseSource(event));
+            io.AddMouseButtonEvent(button, false);
+        }
+        return io.WantCaptureMouse;
+    }
+
+    if (event.type == NSEventTypeMouseMoved || event.type == NSEventTypeLeftMouseDragged || event.type == NSEventTypeRightMouseDragged || event.type == NSEventTypeOtherMouseDragged)
+    {
+        NSPoint mousePoint = event.locationInWindow;
+        if (event.window == nil)
+            mousePoint = [[view window] convertPointFromScreen:mousePoint];
+        mousePoint = [view convertPoint:mousePoint fromView:nil];
+        if ([view isFlipped])
+            mousePoint = NSMakePoint(mousePoint.x, mousePoint.y);
+        else
+            mousePoint = NSMakePoint(mousePoint.x, view.bounds.size.height - mousePoint.y);
+        io.AddMouseSourceEvent(GetMouseSource(event));
+        io.AddMousePosEvent((float)mousePoint.x, (float)mousePoint.y);
+        return io.WantCaptureMouse;
+    }
+
+    if (event.type == NSEventTypeScrollWheel)
+    {
+        // Ignore canceled events.
+        //
+        // From macOS 12.1, scrolling with two fingers and then decelerating
+        // by tapping two fingers results in two events appearing:
+        //
+        // 1. A scroll wheel NSEvent, with a phase == NSEventPhaseMayBegin, when the user taps
+        // two fingers to decelerate or stop the scroll events.
+        //
+        // 2. A scroll wheel NSEvent, with a phase == NSEventPhaseCancelled, when the user releases the
+        // two-finger tap. It is this event that sometimes contains large values for scrollingDeltaX and
+        // scrollingDeltaY. When these are added to the current x and y positions of the scrolling view,
+        // it appears to jump up or down. It can be observed in Preview, various JetBrains IDEs and here.
+        if (event.phase == NSEventPhaseCancelled)
+            return false;
+
+        double wheel_dx = 0.0;
+        double wheel_dy = 0.0;
+
+        #if MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
+        if (floor(NSAppKitVersionNumber) > NSAppKitVersionNumber10_6)
+        {
+            wheel_dx = [event scrollingDeltaX];
+            wheel_dy = [event scrollingDeltaY];
+            if ([event hasPreciseScrollingDeltas])
+            {
+                wheel_dx *= 0.01;
+                wheel_dy *= 0.01;
+            }
+        }
+        else
+        #endif // MAC_OS_X_VERSION_MAX_ALLOWED
+        {
+            wheel_dx = [event deltaX] * 0.1;
+            wheel_dy = [event deltaY] * 0.1;
+        }
+        if (wheel_dx != 0.0 || wheel_dy != 0.0)
+            io.AddMouseWheelEvent((float)wheel_dx, (float)wheel_dy);
+
+        return io.WantCaptureMouse;
+    }
+
+    if (event.type == NSEventTypeKeyDown || event.type == NSEventTypeKeyUp)
+    {
+        if ([event isARepeat])
+            return io.WantCaptureKeyboard;
+
+        int key_code = (int)[event keyCode];
+        ImGuiKey key = ImGui_ImplOSX_KeyCodeToImGuiKey(key_code);
+        io.AddKeyEvent(key, event.type == NSEventTypeKeyDown);
+        io.SetKeyEventNativeData(key, key_code, -1); // To support legacy indexing (<1.87 user code)
+
+        return io.WantCaptureKeyboard;
+    }
+
+    if (event.type == NSEventTypeFlagsChanged)
+    {
+        unsigned short key_code = [event keyCode];
+        NSEventModifierFlags modifier_flags = [event modifierFlags];
+
+        io.AddKeyEvent(ImGuiMod_Shift, (modifier_flags & NSEventModifierFlagShift)   != 0);
+        io.AddKeyEvent(ImGuiMod_Ctrl,  (modifier_flags & NSEventModifierFlagControl) != 0);
+        io.AddKeyEvent(ImGuiMod_Alt,   (modifier_flags & NSEventModifierFlagOption)  != 0);
+        io.AddKeyEvent(ImGuiMod_Super, (modifier_flags & NSEventModifierFlagCommand) != 0);
+
+        ImGuiKey key = ImGui_ImplOSX_KeyCodeToImGuiKey(key_code);
+        if (key != ImGuiKey_None)
+        {
+            // macOS does not generate down/up event for modifiers. We're trying
+            // to use hardware dependent masks to extract that information.
+            // 'imgui_mask' is left as a fallback.
+            NSEventModifierFlags mask = 0;
+            switch (key)
+            {
+                case ImGuiKey_LeftCtrl:   mask = 0x0001; break;
+                case ImGuiKey_RightCtrl:  mask = 0x2000; break;
+                case ImGuiKey_LeftShift:  mask = 0x0002; break;
+                case ImGuiKey_RightShift: mask = 0x0004; break;
+                case ImGuiKey_LeftSuper:  mask = 0x0008; break;
+                case ImGuiKey_RightSuper: mask = 0x0010; break;
+                case ImGuiKey_LeftAlt:    mask = 0x0020; break;
+                case ImGuiKey_RightAlt:   mask = 0x0040; break;
+                default:
+                    return io.WantCaptureKeyboard;
+            }
+
+            NSEventModifierFlags modifier_flags = [event modifierFlags];
+            io.AddKeyEvent(key, (modifier_flags & mask) != 0);
+            io.SetKeyEventNativeData(key, key_code, -1); // To support legacy indexing (<1.87 user code)
+        }
+
+        return io.WantCaptureKeyboard;
+    }
+
+    return false;
+}
+
+static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view)
+{
+    // If we want to receive key events, we either need to be in the responder chain of the key view,
+    // or else we can install a local monitor. The consequence of this heavy-handed approach is that
+    // we receive events for all controls, not just Dear ImGui widgets. If we had native controls in our
+    // window, we'd want to be much more careful than just ingesting the complete event stream.
+    // To match the behavior of other backends, we pass every event down to the OS.
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    if (bd->Monitor)
+        return;
+    NSEventMask eventMask = 0;
+    eventMask |= NSEventMaskMouseMoved | NSEventMaskScrollWheel;
+    eventMask |= NSEventMaskLeftMouseDown | NSEventMaskLeftMouseUp | NSEventMaskLeftMouseDragged;
+    eventMask |= NSEventMaskRightMouseDown | NSEventMaskRightMouseUp | NSEventMaskRightMouseDragged;
+    eventMask |= NSEventMaskOtherMouseDown | NSEventMaskOtherMouseUp | NSEventMaskOtherMouseDragged;
+    eventMask |= NSEventMaskKeyDown | NSEventMaskKeyUp | NSEventMaskFlagsChanged;
+    bd->Monitor = [NSEvent addLocalMonitorForEventsMatchingMask:eventMask
+                                                        handler:^NSEvent* _Nullable(NSEvent* event)
+    {
+        ImGui_ImplOSX_HandleEvent(event, view);
+        return event;
+    }];
+}

third_party/imgui/backends/imgui_impl_sdlrenderer.cpp

@@ -0,0 +1,261 @@
+// dear imgui: Renderer Backend for SDL_Renderer
+// (Requires: SDL 2.0.17+)
+
+// Important to understand: SDL_Renderer is an _optional_ component of SDL.
+// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
+// If your application will want to render any non trivial amount of graphics other than UI,
+// please be aware that SDL_Renderer offers a limited graphic API to the end-user and it might
+// be difficult to step out of those boundaries.
+// However, we understand it is a convenient choice to get an app started easily.
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+
+// You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// CHANGELOG
+//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
+//  2021-12-21: Update SDL_RenderGeometryRaw() format to work with SDL 2.0.19.
+//  2021-12-03: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
+//  2021-10-06: Backup and restore modified ClipRect/Viewport.
+//  2021-09-21: Initial version.
+
+#include "imgui.h"
+#include "imgui_impl_sdlrenderer.h"
+#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
+#include <stddef.h>     // intptr_t
+#else
+#include <stdint.h>     // intptr_t
+#endif
+
+// Clang warnings with -Weverything
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#endif
+
+// SDL
+#include <SDL.h>
+#if !SDL_VERSION_ATLEAST(2,0,17)
+#error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
+#endif
+
+// SDL_Renderer data
+struct ImGui_ImplSDLRenderer_Data
+{
+    SDL_Renderer*   SDLRenderer;
+    SDL_Texture*    FontTexture;
+    ImGui_ImplSDLRenderer_Data() { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+static ImGui_ImplSDLRenderer_Data* ImGui_ImplSDLRenderer_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplSDLRenderer_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
+}
+
+// Functions
+bool ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
+    IM_ASSERT(renderer != nullptr && "SDL_Renderer not initialized!");
+
+    // Setup backend capabilities flags
+    ImGui_ImplSDLRenderer_Data* bd = IM_NEW(ImGui_ImplSDLRenderer_Data)();
+    io.BackendRendererUserData = (void*)bd;
+    io.BackendRendererName = "imgui_impl_sdlrenderer";
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+
+    bd->SDLRenderer = renderer;
+
+    return true;
+}
+
+void ImGui_ImplSDLRenderer_Shutdown()
+{
+    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    ImGui_ImplSDLRenderer_DestroyDeviceObjects();
+
+    io.BackendRendererName = nullptr;
+    io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    IM_DELETE(bd);
+}
+
+static void ImGui_ImplSDLRenderer_SetupRenderState()
+{
+	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+
+	// Clear out any viewports and cliprect set by the user
+    // FIXME: Technically speaking there are lots of other things we could backup/setup/restore during our render process.
+	SDL_RenderSetViewport(bd->SDLRenderer, nullptr);
+	SDL_RenderSetClipRect(bd->SDLRenderer, nullptr);
+}
+
+void ImGui_ImplSDLRenderer_NewFrame()
+{
+    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplSDLRenderer_Init()?");
+
+    if (!bd->FontTexture)
+        ImGui_ImplSDLRenderer_CreateDeviceObjects();
+}
+
+void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
+{
+	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+
+	// If there's a scale factor set by the user, use that instead
+    // If the user has specified a scale factor to SDL_Renderer already via SDL_RenderSetScale(), SDL will scale whatever we pass
+    // to SDL_RenderGeometryRaw() by that scale factor. In that case we don't want to be also scaling it ourselves here.
+    float rsx = 1.0f;
+	float rsy = 1.0f;
+	SDL_RenderGetScale(bd->SDLRenderer, &rsx, &rsy);
+    ImVec2 render_scale;
+	render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
+	render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
+
+	// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+	int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
+	int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
+	if (fb_width == 0 || fb_height == 0)
+		return;
+
+    // Backup SDL_Renderer state that will be modified to restore it afterwards
+    struct BackupSDLRendererState
+    {
+        SDL_Rect    Viewport;
+        bool        ClipEnabled;
+        SDL_Rect    ClipRect;
+    };
+    BackupSDLRendererState old = {};
+    old.ClipEnabled = SDL_RenderIsClipEnabled(bd->SDLRenderer) == SDL_TRUE;
+    SDL_RenderGetViewport(bd->SDLRenderer, &old.Viewport);
+    SDL_RenderGetClipRect(bd->SDLRenderer, &old.ClipRect);
+
+	// Will project scissor/clipping rectangles into framebuffer space
+	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+	ImVec2 clip_scale = render_scale;
+
+    // Render command lists
+    ImGui_ImplSDLRenderer_SetupRenderState();
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
+        const ImDrawList* cmd_list = draw_data->CmdLists[n];
+        const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
+        const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
+
+        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+        {
+            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+            if (pcmd->UserCallback)
+            {
+                // User callback, registered via ImDrawList::AddCallback()
+                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
+                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
+                    ImGui_ImplSDLRenderer_SetupRenderState();
+                else
+                    pcmd->UserCallback(cmd_list, pcmd);
+            }
+            else
+            {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
+                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
+                if (clip_max.x > (float)fb_width) { clip_max.x = (float)fb_width; }
+                if (clip_max.y > (float)fb_height) { clip_max.y = (float)fb_height; }
+                if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+                    continue;
+
+                SDL_Rect r = { (int)(clip_min.x), (int)(clip_min.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y) };
+                SDL_RenderSetClipRect(bd->SDLRenderer, &r);
+
+                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, pos));
+                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, uv));
+#if SDL_VERSION_ATLEAST(2,0,19)
+                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.19+
+#else
+                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
+#endif
+
+                // Bind texture, Draw
+				SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
+                SDL_RenderGeometryRaw(bd->SDLRenderer, tex,
+                    xy, (int)sizeof(ImDrawVert),
+                    color, (int)sizeof(ImDrawVert),
+                    uv, (int)sizeof(ImDrawVert),
+                    cmd_list->VtxBuffer.Size - pcmd->VtxOffset,
+                    idx_buffer + pcmd->IdxOffset, pcmd->ElemCount, sizeof(ImDrawIdx));
+            }
+        }
+    }
+
+    // Restore modified SDL_Renderer state
+    SDL_RenderSetViewport(bd->SDLRenderer, &old.Viewport);
+    SDL_RenderSetClipRect(bd->SDLRenderer, old.ClipEnabled ? &old.ClipRect : nullptr);
+}
+
+// Called by Init/NewFrame/Shutdown
+bool ImGui_ImplSDLRenderer_CreateFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+
+    // Build texture atlas
+    unsigned char* pixels;
+    int width, height;
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+    // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
+    bd->FontTexture = SDL_CreateTexture(bd->SDLRenderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    if (bd->FontTexture == nullptr)
+    {
+        SDL_Log("error creating texture");
+        return false;
+    }
+    SDL_UpdateTexture(bd->FontTexture, nullptr, pixels, 4 * width);
+    SDL_SetTextureBlendMode(bd->FontTexture, SDL_BLENDMODE_BLEND);
+    SDL_SetTextureScaleMode(bd->FontTexture, SDL_ScaleModeLinear);
+
+    // Store our identifier
+    io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
+
+    return true;
+}
+
+void ImGui_ImplSDLRenderer_DestroyFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    if (bd->FontTexture)
+    {
+        io.Fonts->SetTexID(0);
+        SDL_DestroyTexture(bd->FontTexture);
+        bd->FontTexture = nullptr;
+    }
+}
+
+bool ImGui_ImplSDLRenderer_CreateDeviceObjects()
+{
+    return ImGui_ImplSDLRenderer_CreateFontsTexture();
+}
+
+void ImGui_ImplSDLRenderer_DestroyDeviceObjects()
+{
+    ImGui_ImplSDLRenderer_DestroyFontsTexture();
+}
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif

third_party/imgui/backends/imgui_impl_win32.cpp

@@ -0,0 +1,861 @@
+// dear imgui: Platform Backend for Windows (standard windows API for 32-bits AND 64-bits applications)
+// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
+
+// Implemented features:
+//  [X] Platform: Clipboard support (for Win32 this is actually part of core dear imgui)
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen.
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+#include "imgui.h"
+#include "imgui_impl_win32.h"
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
+#include <windowsx.h> // GET_X_LPARAM(), GET_Y_LPARAM()
+#include <tchar.h>
+#include <dwmapi.h>
+
+// Configuration flags to add in your imconfig.h file:
+//#define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD              // Disable gamepad support. This was meaningful before <1.81 but we now load XInput dynamically so the option is now less relevant.
+
+// Using XInput for gamepad (will load DLL dynamically)
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+#include <xinput.h>
+typedef DWORD (WINAPI *PFN_XInputGetCapabilities)(DWORD, DWORD, XINPUT_CAPABILITIES*);
+typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
+#endif
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2023-04-19: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw Win32/Winapi with OpenGL. (#3218)
+//  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen. (#2702)
+//  2023-02-15: Inputs: Use WM_NCMOUSEMOVE / WM_NCMOUSELEAVE to track mouse position over non-client area (e.g. OS decorations) when app is not focused. (#6045, #6162)
+//  2023-02-02: Inputs: Flipping WM_MOUSEHWHEEL (horizontal mouse-wheel) value to match other backends and offer consistent horizontal scrolling direction. (#4019, #6096, #1463)
+//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
+//  2022-09-28: Inputs: Convert WM_CHAR values with MultiByteToWideChar() when window class was registered as MBCS (not Unicode).
+//  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
+//  2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
+//  2021-01-20: Inputs: calling new io.AddKeyAnalogEvent() for gamepad support, instead of writing directly to io.NavInputs[].
+//  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
+//  2022-01-17: Inputs: always update key mods next and before a key event (not in NewFrame) to fix input queue with very low framerates.
+//  2022-01-12: Inputs: Update mouse inputs using WM_MOUSEMOVE/WM_MOUSELEAVE + fallback to provide it when focused but not hovered/captured. More standard and will allow us to pass it to future input queue API.
+//  2022-01-12: Inputs: Maintain our own copy of MouseButtonsDown mask instead of using ImGui::IsAnyMouseDown() which will be obsoleted.
+//  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
+//  2021-12-16: Inputs: Fill VK_LCONTROL/VK_RCONTROL/VK_LSHIFT/VK_RSHIFT/VK_LMENU/VK_RMENU for completeness.
+//  2021-08-17: Calling io.AddFocusEvent() on WM_SETFOCUS/WM_KILLFOCUS messages.
+//  2021-08-02: Inputs: Fixed keyboard modifiers being reported when host window doesn't have focus.
+//  2021-07-29: Inputs: MousePos is correctly reported when the host platform window is hovered but not focused (using TrackMouseEvent() to receive WM_MOUSELEAVE events).
+//  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
+//  2021-06-08: Fixed ImGui_ImplWin32_EnableDpiAwareness() and ImGui_ImplWin32_GetDpiScaleForMonitor() to handle Windows 8.1/10 features without a manifest (per-monitor DPI, and properly calls SetProcessDpiAwareness() on 8.1).
+//  2021-03-23: Inputs: Clearing keyboard down array when losing focus (WM_KILLFOCUS).
+//  2021-02-18: Added ImGui_ImplWin32_EnableAlphaCompositing(). Non Visual Studio users will need to link with dwmapi.lib (MinGW/gcc: use -ldwmapi).
+//  2021-02-17: Fixed ImGui_ImplWin32_EnableDpiAwareness() attempting to get SetProcessDpiAwareness from shcore.dll on Windows 8 whereas it is only supported on Windows 8.1.
+//  2021-01-25: Inputs: Dynamically loading XInput DLL.
+//  2020-12-04: Misc: Fixed setting of io.DisplaySize to invalid/uninitialized data when after hwnd has been closed.
+//  2020-03-03: Inputs: Calling AddInputCharacterUTF16() to support surrogate pairs leading to codepoint >= 0x10000 (for more complete CJK inputs)
+//  2020-02-17: Added ImGui_ImplWin32_EnableDpiAwareness(), ImGui_ImplWin32_GetDpiScaleForHwnd(), ImGui_ImplWin32_GetDpiScaleForMonitor() helper functions.
+//  2020-01-14: Inputs: Added support for #define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD/IMGUI_IMPL_WIN32_DISABLE_LINKING_XINPUT.
+//  2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
+//  2019-05-11: Inputs: Don't filter value from WM_CHAR before calling AddInputCharacter().
+//  2019-01-17: Misc: Using GetForegroundWindow()+IsChild() instead of GetActiveWindow() to be compatible with windows created in a different thread or parent.
+//  2019-01-17: Inputs: Added support for mouse buttons 4 and 5 via WM_XBUTTON* messages.
+//  2019-01-15: Inputs: Added support for XInput gamepads (if ImGuiConfigFlags_NavEnableGamepad is set by user application).
+//  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
+//  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
+//  2018-06-10: Inputs: Fixed handling of mouse wheel messages to support fine position messages (typically sent by track-pads).
+//  2018-06-08: Misc: Extracted imgui_impl_win32.cpp/.h away from the old combined DX9/DX10/DX11/DX12 examples.
+//  2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
+//  2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
+//  2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
+//  2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
+//  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
+//  2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
+//  2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
+//  2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
+//  2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
+//  2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
+//  2016-11-12: Inputs: Only call Win32 ::SetCursor(nullptr) when io.MouseDrawCursor is set.
+
+struct ImGui_ImplWin32_Data
+{
+    HWND                        hWnd;
+    HWND                        MouseHwnd;
+    int                         MouseTrackedArea;   // 0: not tracked, 1: client are, 2: non-client area
+    int                         MouseButtonsDown;
+    INT64                       Time;
+    INT64                       TicksPerSecond;
+    ImGuiMouseCursor            LastMouseCursor;
+
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    bool                        HasGamepad;
+    bool                        WantUpdateHasGamepad;
+    HMODULE                     XInputDLL;
+    PFN_XInputGetCapabilities   XInputGetCapabilities;
+    PFN_XInputGetState          XInputGetState;
+#endif
+
+    ImGui_ImplWin32_Data()      { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendPlatformUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+// FIXME: multi-context support is not well tested and probably dysfunctional in this backend.
+// FIXME: some shared resources (mouse cursor shape, gamepad) are mishandled when using multi-context.
+static ImGui_ImplWin32_Data* ImGui_ImplWin32_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplWin32_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
+}
+
+// Functions
+static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
+
+    INT64 perf_frequency, perf_counter;
+    if (!::QueryPerformanceFrequency((LARGE_INTEGER*)&perf_frequency))
+        return false;
+    if (!::QueryPerformanceCounter((LARGE_INTEGER*)&perf_counter))
+        return false;
+
+    // Setup backend capabilities flags
+    ImGui_ImplWin32_Data* bd = IM_NEW(ImGui_ImplWin32_Data)();
+    io.BackendPlatformUserData = (void*)bd;
+    io.BackendPlatformName = "imgui_impl_win32";
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+
+    bd->hWnd = (HWND)hwnd;
+    bd->TicksPerSecond = perf_frequency;
+    bd->Time = perf_counter;
+    bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
+
+    // Set platform dependent data in viewport
+    ImGui::GetMainViewport()->PlatformHandleRaw = (void*)hwnd;
+    IM_UNUSED(platform_has_own_dc); // Used in 'docking' branch
+
+    // Dynamically load XInput library
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    bd->WantUpdateHasGamepad = true;
+    const char* xinput_dll_names[] =
+    {
+        "xinput1_4.dll",   // Windows 8+
+        "xinput1_3.dll",   // DirectX SDK
+        "xinput9_1_0.dll", // Windows Vista, Windows 7
+        "xinput1_2.dll",   // DirectX SDK
+        "xinput1_1.dll"    // DirectX SDK
+    };
+    for (int n = 0; n < IM_ARRAYSIZE(xinput_dll_names); n++)
+        if (HMODULE dll = ::LoadLibraryA(xinput_dll_names[n]))
+        {
+            bd->XInputDLL = dll;
+            bd->XInputGetCapabilities = (PFN_XInputGetCapabilities)::GetProcAddress(dll, "XInputGetCapabilities");
+            bd->XInputGetState = (PFN_XInputGetState)::GetProcAddress(dll, "XInputGetState");
+            break;
+        }
+#endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+
+    return true;
+}
+
+IMGUI_IMPL_API bool     ImGui_ImplWin32_Init(void* hwnd)
+{
+    return ImGui_ImplWin32_InitEx(hwnd, false);
+}
+
+IMGUI_IMPL_API bool     ImGui_ImplWin32_InitForOpenGL(void* hwnd)
+{
+    // OpenGL needs CS_OWNDC
+    return ImGui_ImplWin32_InitEx(hwnd, true);
+}
+
+void    ImGui_ImplWin32_Shutdown()
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    // Unload XInput library
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    if (bd->XInputDLL)
+        ::FreeLibrary(bd->XInputDLL);
+#endif // IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+
+    io.BackendPlatformName = nullptr;
+    io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    IM_DELETE(bd);
+}
+
+static bool ImGui_ImplWin32_UpdateMouseCursor()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
+        return false;
+
+    ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
+    if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
+    {
+        // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
+        ::SetCursor(nullptr);
+    }
+    else
+    {
+        // Show OS mouse cursor
+        LPTSTR win32_cursor = IDC_ARROW;
+        switch (imgui_cursor)
+        {
+        case ImGuiMouseCursor_Arrow:        win32_cursor = IDC_ARROW; break;
+        case ImGuiMouseCursor_TextInput:    win32_cursor = IDC_IBEAM; break;
+        case ImGuiMouseCursor_ResizeAll:    win32_cursor = IDC_SIZEALL; break;
+        case ImGuiMouseCursor_ResizeEW:     win32_cursor = IDC_SIZEWE; break;
+        case ImGuiMouseCursor_ResizeNS:     win32_cursor = IDC_SIZENS; break;
+        case ImGuiMouseCursor_ResizeNESW:   win32_cursor = IDC_SIZENESW; break;
+        case ImGuiMouseCursor_ResizeNWSE:   win32_cursor = IDC_SIZENWSE; break;
+        case ImGuiMouseCursor_Hand:         win32_cursor = IDC_HAND; break;
+        case ImGuiMouseCursor_NotAllowed:   win32_cursor = IDC_NO; break;
+        }
+        ::SetCursor(::LoadCursor(nullptr, win32_cursor));
+    }
+    return true;
+}
+
+static bool IsVkDown(int vk)
+{
+    return (::GetKeyState(vk) & 0x8000) != 0;
+}
+
+static void ImGui_ImplWin32_AddKeyEvent(ImGuiKey key, bool down, int native_keycode, int native_scancode = -1)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddKeyEvent(key, down);
+    io.SetKeyEventNativeData(key, native_keycode, native_scancode); // To support legacy indexing (<1.87 user code)
+    IM_UNUSED(native_scancode);
+}
+
+static void ImGui_ImplWin32_ProcessKeyEventsWorkarounds()
+{
+    // Left & right Shift keys: when both are pressed together, Windows tend to not generate the WM_KEYUP event for the first released one.
+    if (ImGui::IsKeyDown(ImGuiKey_LeftShift) && !IsVkDown(VK_LSHIFT))
+        ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftShift, false, VK_LSHIFT);
+    if (ImGui::IsKeyDown(ImGuiKey_RightShift) && !IsVkDown(VK_RSHIFT))
+        ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightShift, false, VK_RSHIFT);
+
+    // Sometimes WM_KEYUP for Win key is not passed down to the app (e.g. for Win+V on some setups, according to GLFW).
+    if (ImGui::IsKeyDown(ImGuiKey_LeftSuper) && !IsVkDown(VK_LWIN))
+        ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftSuper, false, VK_LWIN);
+    if (ImGui::IsKeyDown(ImGuiKey_RightSuper) && !IsVkDown(VK_RWIN))
+        ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightSuper, false, VK_RWIN);
+}
+
+static void ImGui_ImplWin32_UpdateKeyModifiers()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddKeyEvent(ImGuiMod_Ctrl, IsVkDown(VK_CONTROL));
+    io.AddKeyEvent(ImGuiMod_Shift, IsVkDown(VK_SHIFT));
+    io.AddKeyEvent(ImGuiMod_Alt, IsVkDown(VK_MENU));
+    io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_APPS));
+}
+
+static void ImGui_ImplWin32_UpdateMouseData()
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(bd->hWnd != 0);
+
+    HWND focused_window = ::GetForegroundWindow();
+    const bool is_app_focused = (focused_window == bd->hWnd);
+    if (is_app_focused)
+    {
+        // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+        if (io.WantSetMousePos)
+        {
+            POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
+            if (::ClientToScreen(bd->hWnd, &pos))
+                ::SetCursorPos(pos.x, pos.y);
+        }
+
+        // (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
+        // This also fills a short gap when clicking non-client area: WM_NCMOUSELEAVE -> modal OS move -> gap -> WM_NCMOUSEMOVE
+        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0)
+        {
+            POINT pos;
+            if (::GetCursorPos(&pos) && ::ScreenToClient(bd->hWnd, &pos))
+                io.AddMousePosEvent((float)pos.x, (float)pos.y);
+        }
+    }
+}
+
+// Gamepad navigation mapping
+static void ImGui_ImplWin32_UpdateGamepads()
+{
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    //if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0) // FIXME: Technically feeding gamepad shouldn't depend on this now that they are regular inputs.
+    //    return;
+
+    // Calling XInputGetState() every frame on disconnected gamepads is unfortunately too slow.
+    // Instead we refresh gamepad availability by calling XInputGetCapabilities() _only_ after receiving WM_DEVICECHANGE.
+    if (bd->WantUpdateHasGamepad)
+    {
+        XINPUT_CAPABILITIES caps = {};
+        bd->HasGamepad = bd->XInputGetCapabilities ? (bd->XInputGetCapabilities(0, XINPUT_FLAG_GAMEPAD, &caps) == ERROR_SUCCESS) : false;
+        bd->WantUpdateHasGamepad = false;
+    }
+
+    io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
+    XINPUT_STATE xinput_state;
+    XINPUT_GAMEPAD& gamepad = xinput_state.Gamepad;
+    if (!bd->HasGamepad || bd->XInputGetState == nullptr || bd->XInputGetState(0, &xinput_state) != ERROR_SUCCESS)
+        return;
+    io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+
+    #define IM_SATURATE(V)                      (V < 0.0f ? 0.0f : V > 1.0f ? 1.0f : V)
+    #define MAP_BUTTON(KEY_NO, BUTTON_ENUM)     { io.AddKeyEvent(KEY_NO, (gamepad.wButtons & BUTTON_ENUM) != 0); }
+    #define MAP_ANALOG(KEY_NO, VALUE, V0, V1)   { float vn = (float)(VALUE - V0) / (float)(V1 - V0); io.AddKeyAnalogEvent(KEY_NO, vn > 0.10f, IM_SATURATE(vn)); }
+    MAP_BUTTON(ImGuiKey_GamepadStart,           XINPUT_GAMEPAD_START);
+    MAP_BUTTON(ImGuiKey_GamepadBack,            XINPUT_GAMEPAD_BACK);
+    MAP_BUTTON(ImGuiKey_GamepadFaceLeft,        XINPUT_GAMEPAD_X);
+    MAP_BUTTON(ImGuiKey_GamepadFaceRight,       XINPUT_GAMEPAD_B);
+    MAP_BUTTON(ImGuiKey_GamepadFaceUp,          XINPUT_GAMEPAD_Y);
+    MAP_BUTTON(ImGuiKey_GamepadFaceDown,        XINPUT_GAMEPAD_A);
+    MAP_BUTTON(ImGuiKey_GamepadDpadLeft,        XINPUT_GAMEPAD_DPAD_LEFT);
+    MAP_BUTTON(ImGuiKey_GamepadDpadRight,       XINPUT_GAMEPAD_DPAD_RIGHT);
+    MAP_BUTTON(ImGuiKey_GamepadDpadUp,          XINPUT_GAMEPAD_DPAD_UP);
+    MAP_BUTTON(ImGuiKey_GamepadDpadDown,        XINPUT_GAMEPAD_DPAD_DOWN);
+    MAP_BUTTON(ImGuiKey_GamepadL1,              XINPUT_GAMEPAD_LEFT_SHOULDER);
+    MAP_BUTTON(ImGuiKey_GamepadR1,              XINPUT_GAMEPAD_RIGHT_SHOULDER);
+    MAP_ANALOG(ImGuiKey_GamepadL2,              gamepad.bLeftTrigger, XINPUT_GAMEPAD_TRIGGER_THRESHOLD, 255);
+    MAP_ANALOG(ImGuiKey_GamepadR2,              gamepad.bRightTrigger, XINPUT_GAMEPAD_TRIGGER_THRESHOLD, 255);
+    MAP_BUTTON(ImGuiKey_GamepadL3,              XINPUT_GAMEPAD_LEFT_THUMB);
+    MAP_BUTTON(ImGuiKey_GamepadR3,              XINPUT_GAMEPAD_RIGHT_THUMB);
+    MAP_ANALOG(ImGuiKey_GamepadLStickLeft,      gamepad.sThumbLX, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
+    MAP_ANALOG(ImGuiKey_GamepadLStickRight,     gamepad.sThumbLX, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+    MAP_ANALOG(ImGuiKey_GamepadLStickUp,        gamepad.sThumbLY, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+    MAP_ANALOG(ImGuiKey_GamepadLStickDown,      gamepad.sThumbLY, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
+    MAP_ANALOG(ImGuiKey_GamepadRStickLeft,      gamepad.sThumbRX, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
+    MAP_ANALOG(ImGuiKey_GamepadRStickRight,     gamepad.sThumbRX, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+    MAP_ANALOG(ImGuiKey_GamepadRStickUp,        gamepad.sThumbRY, +XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, +32767);
+    MAP_ANALOG(ImGuiKey_GamepadRStickDown,      gamepad.sThumbRY, -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE, -32768);
+    #undef MAP_BUTTON
+    #undef MAP_ANALOG
+#endif // #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+}
+
+void    ImGui_ImplWin32_NewFrame()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplWin32_Init()?");
+
+    // Setup display size (every frame to accommodate for window resizing)
+    RECT rect = { 0, 0, 0, 0 };
+    ::GetClientRect(bd->hWnd, &rect);
+    io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
+
+    // Setup time step
+    INT64 current_time = 0;
+    ::QueryPerformanceCounter((LARGE_INTEGER*)&current_time);
+    io.DeltaTime = (float)(current_time - bd->Time) / bd->TicksPerSecond;
+    bd->Time = current_time;
+
+    // Update OS mouse position
+    ImGui_ImplWin32_UpdateMouseData();
+
+    // Process workarounds for known Windows key handling issues
+    ImGui_ImplWin32_ProcessKeyEventsWorkarounds();
+
+    // Update OS mouse cursor with the cursor requested by imgui
+    ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
+    if (bd->LastMouseCursor != mouse_cursor)
+    {
+        bd->LastMouseCursor = mouse_cursor;
+        ImGui_ImplWin32_UpdateMouseCursor();
+    }
+
+    // Update game controllers (if enabled and available)
+    ImGui_ImplWin32_UpdateGamepads();
+}
+
+// There is no distinct VK_xxx for keypad enter, instead it is VK_RETURN + KF_EXTENDED, we assign it an arbitrary value to make code more readable (VK_ codes go up to 255)
+#define IM_VK_KEYPAD_ENTER      (VK_RETURN + 256)
+
+// Map VK_xxx to ImGuiKey_xxx.
+static ImGuiKey ImGui_ImplWin32_VirtualKeyToImGuiKey(WPARAM wParam)
+{
+    switch (wParam)
+    {
+        case VK_TAB: return ImGuiKey_Tab;
+        case VK_LEFT: return ImGuiKey_LeftArrow;
+        case VK_RIGHT: return ImGuiKey_RightArrow;
+        case VK_UP: return ImGuiKey_UpArrow;
+        case VK_DOWN: return ImGuiKey_DownArrow;
+        case VK_PRIOR: return ImGuiKey_PageUp;
+        case VK_NEXT: return ImGuiKey_PageDown;
+        case VK_HOME: return ImGuiKey_Home;
+        case VK_END: return ImGuiKey_End;
+        case VK_INSERT: return ImGuiKey_Insert;
+        case VK_DELETE: return ImGuiKey_Delete;
+        case VK_BACK: return ImGuiKey_Backspace;
+        case VK_SPACE: return ImGuiKey_Space;
+        case VK_RETURN: return ImGuiKey_Enter;
+        case VK_ESCAPE: return ImGuiKey_Escape;
+        case VK_OEM_7: return ImGuiKey_Apostrophe;
+        case VK_OEM_COMMA: return ImGuiKey_Comma;
+        case VK_OEM_MINUS: return ImGuiKey_Minus;
+        case VK_OEM_PERIOD: return ImGuiKey_Period;
+        case VK_OEM_2: return ImGuiKey_Slash;
+        case VK_OEM_1: return ImGuiKey_Semicolon;
+        case VK_OEM_PLUS: return ImGuiKey_Equal;
+        case VK_OEM_4: return ImGuiKey_LeftBracket;
+        case VK_OEM_5: return ImGuiKey_Backslash;
+        case VK_OEM_6: return ImGuiKey_RightBracket;
+        case VK_OEM_3: return ImGuiKey_GraveAccent;
+        case VK_CAPITAL: return ImGuiKey_CapsLock;
+        case VK_SCROLL: return ImGuiKey_ScrollLock;
+        case VK_NUMLOCK: return ImGuiKey_NumLock;
+        case VK_SNAPSHOT: return ImGuiKey_PrintScreen;
+        case VK_PAUSE: return ImGuiKey_Pause;
+        case VK_NUMPAD0: return ImGuiKey_Keypad0;
+        case VK_NUMPAD1: return ImGuiKey_Keypad1;
+        case VK_NUMPAD2: return ImGuiKey_Keypad2;
+        case VK_NUMPAD3: return ImGuiKey_Keypad3;
+        case VK_NUMPAD4: return ImGuiKey_Keypad4;
+        case VK_NUMPAD5: return ImGuiKey_Keypad5;
+        case VK_NUMPAD6: return ImGuiKey_Keypad6;
+        case VK_NUMPAD7: return ImGuiKey_Keypad7;
+        case VK_NUMPAD8: return ImGuiKey_Keypad8;
+        case VK_NUMPAD9: return ImGuiKey_Keypad9;
+        case VK_DECIMAL: return ImGuiKey_KeypadDecimal;
+        case VK_DIVIDE: return ImGuiKey_KeypadDivide;
+        case VK_MULTIPLY: return ImGuiKey_KeypadMultiply;
+        case VK_SUBTRACT: return ImGuiKey_KeypadSubtract;
+        case VK_ADD: return ImGuiKey_KeypadAdd;
+        case IM_VK_KEYPAD_ENTER: return ImGuiKey_KeypadEnter;
+        case VK_LSHIFT: return ImGuiKey_LeftShift;
+        case VK_LCONTROL: return ImGuiKey_LeftCtrl;
+        case VK_LMENU: return ImGuiKey_LeftAlt;
+        case VK_LWIN: return ImGuiKey_LeftSuper;
+        case VK_RSHIFT: return ImGuiKey_RightShift;
+        case VK_RCONTROL: return ImGuiKey_RightCtrl;
+        case VK_RMENU: return ImGuiKey_RightAlt;
+        case VK_RWIN: return ImGuiKey_RightSuper;
+        case VK_APPS: return ImGuiKey_Menu;
+        case '0': return ImGuiKey_0;
+        case '1': return ImGuiKey_1;
+        case '2': return ImGuiKey_2;
+        case '3': return ImGuiKey_3;
+        case '4': return ImGuiKey_4;
+        case '5': return ImGuiKey_5;
+        case '6': return ImGuiKey_6;
+        case '7': return ImGuiKey_7;
+        case '8': return ImGuiKey_8;
+        case '9': return ImGuiKey_9;
+        case 'A': return ImGuiKey_A;
+        case 'B': return ImGuiKey_B;
+        case 'C': return ImGuiKey_C;
+        case 'D': return ImGuiKey_D;
+        case 'E': return ImGuiKey_E;
+        case 'F': return ImGuiKey_F;
+        case 'G': return ImGuiKey_G;
+        case 'H': return ImGuiKey_H;
+        case 'I': return ImGuiKey_I;
+        case 'J': return ImGuiKey_J;
+        case 'K': return ImGuiKey_K;
+        case 'L': return ImGuiKey_L;
+        case 'M': return ImGuiKey_M;
+        case 'N': return ImGuiKey_N;
+        case 'O': return ImGuiKey_O;
+        case 'P': return ImGuiKey_P;
+        case 'Q': return ImGuiKey_Q;
+        case 'R': return ImGuiKey_R;
+        case 'S': return ImGuiKey_S;
+        case 'T': return ImGuiKey_T;
+        case 'U': return ImGuiKey_U;
+        case 'V': return ImGuiKey_V;
+        case 'W': return ImGuiKey_W;
+        case 'X': return ImGuiKey_X;
+        case 'Y': return ImGuiKey_Y;
+        case 'Z': return ImGuiKey_Z;
+        case VK_F1: return ImGuiKey_F1;
+        case VK_F2: return ImGuiKey_F2;
+        case VK_F3: return ImGuiKey_F3;
+        case VK_F4: return ImGuiKey_F4;
+        case VK_F5: return ImGuiKey_F5;
+        case VK_F6: return ImGuiKey_F6;
+        case VK_F7: return ImGuiKey_F7;
+        case VK_F8: return ImGuiKey_F8;
+        case VK_F9: return ImGuiKey_F9;
+        case VK_F10: return ImGuiKey_F10;
+        case VK_F11: return ImGuiKey_F11;
+        case VK_F12: return ImGuiKey_F12;
+        default: return ImGuiKey_None;
+    }
+}
+
+// Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
+#ifndef WM_MOUSEHWHEEL
+#define WM_MOUSEHWHEEL 0x020E
+#endif
+#ifndef DBT_DEVNODES_CHANGED
+#define DBT_DEVNODES_CHANGED 0x0007
+#endif
+
+// Win32 message handler (process Win32 mouse/keyboard inputs, etc.)
+// Call from your application's message handler. Keep calling your message handler unless this function returns TRUE.
+// When implementing your own backend, you can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if Dear ImGui wants to use your inputs.
+// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+// Generally you may always pass all inputs to Dear ImGui, and hide them from your application based on those two flags.
+// PS: In this Win32 handler, we use the capture API (GetCapture/SetCapture/ReleaseCapture) to be able to read mouse coordinates when dragging mouse outside of our window bounds.
+// PS: We treat DBLCLK messages as regular mouse down messages, so this code will work on windows classes that have the CS_DBLCLKS flag set. Our own example app code doesn't set this flag.
+#if 0
+// Copy this line into your .cpp file to forward declare the function.
+extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
+#endif
+
+// See https://learn.microsoft.com/en-us/windows/win32/tablet/system-events-and-mouse-messages
+// Prefer to call this at the top of the message handler to avoid the possibility of other Win32 calls interfering with this.
+static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
+{
+    LPARAM extra_info = ::GetMessageExtraInfo();
+    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
+        return ImGuiMouseSource_Pen;
+    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
+        return ImGuiMouseSource_TouchScreen;
+    return ImGuiMouseSource_Mouse;
+}
+
+IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    if (ImGui::GetCurrentContext() == nullptr)
+        return 0;
+
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+
+    switch (msg)
+    {
+    case WM_MOUSEMOVE:
+    case WM_NCMOUSEMOVE:
+    {
+        // We need to call TrackMouseEvent in order to receive WM_MOUSELEAVE events
+        ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
+        const int area = (msg == WM_MOUSEMOVE) ? 1 : 2;
+        bd->MouseHwnd = hwnd;
+        if (bd->MouseTrackedArea != area)
+        {
+            TRACKMOUSEEVENT tme_cancel = { sizeof(tme_cancel), TME_CANCEL, hwnd, 0 };
+            TRACKMOUSEEVENT tme_track = { sizeof(tme_track), (DWORD)((area == 2) ? (TME_LEAVE | TME_NONCLIENT) : TME_LEAVE), hwnd, 0 };
+            if (bd->MouseTrackedArea != 0)
+                ::TrackMouseEvent(&tme_cancel);
+            ::TrackMouseEvent(&tme_track);
+            bd->MouseTrackedArea = area;
+        }
+        POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
+        if (msg == WM_NCMOUSEMOVE && ::ScreenToClient(hwnd, &mouse_pos) == FALSE) // WM_NCMOUSEMOVE are provided in absolute coordinates.
+            break;
+        io.AddMouseSourceEvent(mouse_source);
+        io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
+        break;
+    }
+    case WM_MOUSELEAVE:
+    case WM_NCMOUSELEAVE:
+    {
+        const int area = (msg == WM_MOUSELEAVE) ? 1 : 2;
+        if (bd->MouseTrackedArea == area)
+        {
+            if (bd->MouseHwnd == hwnd)
+                bd->MouseHwnd = nullptr;
+            bd->MouseTrackedArea = 0;
+            io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
+        }
+        break;
+    }
+    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
+    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
+    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
+    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK:
+    {
+        ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
+        int button = 0;
+        if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) { button = 0; }
+        if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) { button = 1; }
+        if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) { button = 2; }
+        if (msg == WM_XBUTTONDOWN || msg == WM_XBUTTONDBLCLK) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
+        if (bd->MouseButtonsDown == 0 && ::GetCapture() == nullptr)
+            ::SetCapture(hwnd);
+        bd->MouseButtonsDown |= 1 << button;
+        io.AddMouseSourceEvent(mouse_source);
+        io.AddMouseButtonEvent(button, true);
+        return 0;
+    }
+    case WM_LBUTTONUP:
+    case WM_RBUTTONUP:
+    case WM_MBUTTONUP:
+    case WM_XBUTTONUP:
+    {
+        ImGuiMouseSource mouse_source = GetMouseSourceFromMessageExtraInfo();
+        int button = 0;
+        if (msg == WM_LBUTTONUP) { button = 0; }
+        if (msg == WM_RBUTTONUP) { button = 1; }
+        if (msg == WM_MBUTTONUP) { button = 2; }
+        if (msg == WM_XBUTTONUP) { button = (GET_XBUTTON_WPARAM(wParam) == XBUTTON1) ? 3 : 4; }
+        bd->MouseButtonsDown &= ~(1 << button);
+        if (bd->MouseButtonsDown == 0 && ::GetCapture() == hwnd)
+            ::ReleaseCapture();
+        io.AddMouseSourceEvent(mouse_source);
+        io.AddMouseButtonEvent(button, false);
+        return 0;
+    }
+    case WM_MOUSEWHEEL:
+        io.AddMouseWheelEvent(0.0f, (float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA);
+        return 0;
+    case WM_MOUSEHWHEEL:
+        io.AddMouseWheelEvent(-(float)GET_WHEEL_DELTA_WPARAM(wParam) / (float)WHEEL_DELTA, 0.0f);
+        return 0;
+    case WM_KEYDOWN:
+    case WM_KEYUP:
+    case WM_SYSKEYDOWN:
+    case WM_SYSKEYUP:
+    {
+        const bool is_key_down = (msg == WM_KEYDOWN || msg == WM_SYSKEYDOWN);
+        if (wParam < 256)
+        {
+            // Submit modifiers
+            ImGui_ImplWin32_UpdateKeyModifiers();
+
+            // Obtain virtual key code
+            // (keypad enter doesn't have its own... VK_RETURN with KF_EXTENDED flag means keypad enter, see IM_VK_KEYPAD_ENTER definition for details, it is mapped to ImGuiKey_KeyPadEnter.)
+            int vk = (int)wParam;
+            if ((wParam == VK_RETURN) && (HIWORD(lParam) & KF_EXTENDED))
+                vk = IM_VK_KEYPAD_ENTER;
+
+            // Submit key event
+            const ImGuiKey key = ImGui_ImplWin32_VirtualKeyToImGuiKey(vk);
+            const int scancode = (int)LOBYTE(HIWORD(lParam));
+            if (key != ImGuiKey_None)
+                ImGui_ImplWin32_AddKeyEvent(key, is_key_down, vk, scancode);
+
+            // Submit individual left/right modifier events
+            if (vk == VK_SHIFT)
+            {
+                // Important: Shift keys tend to get stuck when pressed together, missing key-up events are corrected in ImGui_ImplWin32_ProcessKeyEventsWorkarounds()
+                if (IsVkDown(VK_LSHIFT) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftShift, is_key_down, VK_LSHIFT, scancode); }
+                if (IsVkDown(VK_RSHIFT) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightShift, is_key_down, VK_RSHIFT, scancode); }
+            }
+            else if (vk == VK_CONTROL)
+            {
+                if (IsVkDown(VK_LCONTROL) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftCtrl, is_key_down, VK_LCONTROL, scancode); }
+                if (IsVkDown(VK_RCONTROL) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightCtrl, is_key_down, VK_RCONTROL, scancode); }
+            }
+            else if (vk == VK_MENU)
+            {
+                if (IsVkDown(VK_LMENU) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_LeftAlt, is_key_down, VK_LMENU, scancode); }
+                if (IsVkDown(VK_RMENU) == is_key_down) { ImGui_ImplWin32_AddKeyEvent(ImGuiKey_RightAlt, is_key_down, VK_RMENU, scancode); }
+            }
+        }
+        return 0;
+    }
+    case WM_SETFOCUS:
+    case WM_KILLFOCUS:
+        io.AddFocusEvent(msg == WM_SETFOCUS);
+        return 0;
+    case WM_CHAR:
+        if (::IsWindowUnicode(hwnd))
+        {
+            // You can also use ToAscii()+GetKeyboardState() to retrieve characters.
+            if (wParam > 0 && wParam < 0x10000)
+                io.AddInputCharacterUTF16((unsigned short)wParam);
+        }
+        else
+        {
+            wchar_t wch = 0;
+            ::MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, (char*)&wParam, 1, &wch, 1);
+            io.AddInputCharacter(wch);
+        }
+        return 0;
+    case WM_SETCURSOR:
+        // This is required to restore cursor when transitioning from e.g resize borders to client area.
+        if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
+            return 1;
+        return 0;
+    case WM_DEVICECHANGE:
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+        if ((UINT)wParam == DBT_DEVNODES_CHANGED)
+            bd->WantUpdateHasGamepad = true;
+#endif
+        return 0;
+    }
+    return 0;
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+// DPI-related helpers (optional)
+//--------------------------------------------------------------------------------------------------------
+// - Use to enable DPI awareness without having to create an application manifest.
+// - Your own app may already do this via a manifest or explicit calls. This is mostly useful for our examples/ apps.
+// - In theory we could call simple functions from Windows SDK such as SetProcessDPIAware(), SetProcessDpiAwareness(), etc.
+//   but most of the functions provided by Microsoft require Windows 8.1/10+ SDK at compile time and Windows 8/10+ at runtime,
+//   neither we want to require the user to have. So we dynamically select and load those functions to avoid dependencies.
+//---------------------------------------------------------------------------------------------------------
+// This is the scheme successfully used by GLFW (from which we borrowed some of the code) and other apps aiming to be highly portable.
+// ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it automatically.
+// If you are trying to implement your own backend for your own engine, you may ignore that noise.
+//---------------------------------------------------------------------------------------------------------
+
+// Perform our own check with RtlVerifyVersionInfo() instead of using functions from <VersionHelpers.h> as they
+// require a manifest to be functional for checks above 8.1. See https://github.com/ocornut/imgui/issues/4200
+static BOOL _IsWindowsVersionOrGreater(WORD major, WORD minor, WORD)
+{
+    typedef LONG(WINAPI* PFN_RtlVerifyVersionInfo)(OSVERSIONINFOEXW*, ULONG, ULONGLONG);
+    static PFN_RtlVerifyVersionInfo RtlVerifyVersionInfoFn = nullptr;
+	if (RtlVerifyVersionInfoFn == nullptr)
+		if (HMODULE ntdllModule = ::GetModuleHandleA("ntdll.dll"))
+			RtlVerifyVersionInfoFn = (PFN_RtlVerifyVersionInfo)GetProcAddress(ntdllModule, "RtlVerifyVersionInfo");
+    if (RtlVerifyVersionInfoFn == nullptr)
+        return FALSE;
+
+    RTL_OSVERSIONINFOEXW versionInfo = { };
+    ULONGLONG conditionMask = 0;
+    versionInfo.dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
+    versionInfo.dwMajorVersion = major;
+	versionInfo.dwMinorVersion = minor;
+	VER_SET_CONDITION(conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
+	VER_SET_CONDITION(conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
+	return (RtlVerifyVersionInfoFn(&versionInfo, VER_MAJORVERSION | VER_MINORVERSION, conditionMask) == 0) ? TRUE : FALSE;
+}
+
+#define _IsWindowsVistaOrGreater()   _IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
+#define _IsWindows8OrGreater()       _IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WIN8
+#define _IsWindows8Point1OrGreater() _IsWindowsVersionOrGreater(HIBYTE(0x0603), LOBYTE(0x0603), 0) // _WIN32_WINNT_WINBLUE
+#define _IsWindows10OrGreater()      _IsWindowsVersionOrGreater(HIBYTE(0x0A00), LOBYTE(0x0A00), 0) // _WIN32_WINNT_WINTHRESHOLD / _WIN32_WINNT_WIN10
+
+#ifndef DPI_ENUMS_DECLARED
+typedef enum { PROCESS_DPI_UNAWARE = 0, PROCESS_SYSTEM_DPI_AWARE = 1, PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS;
+typedef enum { MDT_EFFECTIVE_DPI = 0, MDT_ANGULAR_DPI = 1, MDT_RAW_DPI = 2, MDT_DEFAULT = MDT_EFFECTIVE_DPI } MONITOR_DPI_TYPE;
+#endif
+#ifndef _DPI_AWARENESS_CONTEXTS_
+DECLARE_HANDLE(DPI_AWARENESS_CONTEXT);
+#define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE    (DPI_AWARENESS_CONTEXT)-3
+#endif
+#ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
+#define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 (DPI_AWARENESS_CONTEXT)-4
+#endif
+typedef HRESULT(WINAPI* PFN_SetProcessDpiAwareness)(PROCESS_DPI_AWARENESS);                     // Shcore.lib + dll, Windows 8.1+
+typedef HRESULT(WINAPI* PFN_GetDpiForMonitor)(HMONITOR, MONITOR_DPI_TYPE, UINT*, UINT*);        // Shcore.lib + dll, Windows 8.1+
+typedef DPI_AWARENESS_CONTEXT(WINAPI* PFN_SetThreadDpiAwarenessContext)(DPI_AWARENESS_CONTEXT); // User32.lib + dll, Windows 10 v1607+ (Creators Update)
+
+// Helper function to enable DPI awareness without setting up a manifest
+void ImGui_ImplWin32_EnableDpiAwareness()
+{
+    if (_IsWindows10OrGreater())
+    {
+        static HINSTANCE user32_dll = ::LoadLibraryA("user32.dll"); // Reference counted per-process
+        if (PFN_SetThreadDpiAwarenessContext SetThreadDpiAwarenessContextFn = (PFN_SetThreadDpiAwarenessContext)::GetProcAddress(user32_dll, "SetThreadDpiAwarenessContext"))
+        {
+            SetThreadDpiAwarenessContextFn(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+            return;
+        }
+    }
+    if (_IsWindows8Point1OrGreater())
+    {
+        static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
+        if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness"))
+        {
+            SetProcessDpiAwarenessFn(PROCESS_PER_MONITOR_DPI_AWARE);
+            return;
+        }
+    }
+#if _WIN32_WINNT >= 0x0600
+    ::SetProcessDPIAware();
+#endif
+}
+
+#if defined(_MSC_VER) && !defined(NOGDI)
+#pragma comment(lib, "gdi32")   // Link with gdi32.lib for GetDeviceCaps(). MinGW will require linking with '-lgdi32'
+#endif
+
+float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
+{
+    UINT xdpi = 96, ydpi = 96;
+    if (_IsWindows8Point1OrGreater())
+    {
+		static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
+		static PFN_GetDpiForMonitor GetDpiForMonitorFn = nullptr;
+		if (GetDpiForMonitorFn == nullptr && shcore_dll != nullptr)
+            GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor");
+		if (GetDpiForMonitorFn != nullptr)
+		{
+			GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
+            IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
+			return xdpi / 96.0f;
+		}
+    }
+#ifndef NOGDI
+    const HDC dc = ::GetDC(nullptr);
+    xdpi = ::GetDeviceCaps(dc, LOGPIXELSX);
+    ydpi = ::GetDeviceCaps(dc, LOGPIXELSY);
+    IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
+    ::ReleaseDC(nullptr, dc);
+#endif
+    return xdpi / 96.0f;
+}
+
+float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
+{
+    HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST);
+    return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
+}
+
+//---------------------------------------------------------------------------------------------------------
+// Transparency related helpers (optional)
+//--------------------------------------------------------------------------------------------------------
+
+#if defined(_MSC_VER)
+#pragma comment(lib, "dwmapi")  // Link with dwmapi.lib. MinGW will require linking with '-ldwmapi'
+#endif
+
+// [experimental]
+// Borrowed from GLFW's function updateFramebufferTransparency() in src/win32_window.c
+// (the Dwm* functions are Vista era functions but we are borrowing logic from GLFW)
+void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
+{
+    if (!_IsWindowsVistaOrGreater())
+        return;
+
+    BOOL composition;
+    if (FAILED(::DwmIsCompositionEnabled(&composition)) || !composition)
+        return;
+
+    BOOL opaque;
+    DWORD color;
+    if (_IsWindows8OrGreater() || (SUCCEEDED(::DwmGetColorizationColor(&color, &opaque)) && !opaque))
+    {
+        HRGN region = ::CreateRectRgn(0, 0, -1, -1);
+        DWM_BLURBEHIND bb = {};
+        bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION;
+        bb.hRgnBlur = region;
+        bb.fEnable = TRUE;
+        ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
+        ::DeleteObject(region);
+    }
+    else
+    {
+        DWM_BLURBEHIND bb = {};
+        bb.dwFlags = DWM_BB_ENABLE;
+        ::DwmEnableBlurBehindWindow((HWND)hwnd, &bb);
+    }
+}
+
+//---------------------------------------------------------------------------------------------------------

third_party/imgui/backends/imgui_impl_win32.h

@@ -0,0 +1,46 @@
+// dear imgui: Platform Backend for Windows (standard windows API for 32-bits AND 64-bits applications)
+// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
+
+// Implemented features:
+//  [X] Platform: Clipboard support (for Win32 this is actually part of core dear imgui)
+//  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen.
+//  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
+//  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
+//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+IMGUI_IMPL_API bool     ImGui_ImplWin32_Init(void* hwnd);
+IMGUI_IMPL_API bool     ImGui_ImplWin32_InitForOpenGL(void* hwnd);
+IMGUI_IMPL_API void     ImGui_ImplWin32_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplWin32_NewFrame();
+
+// Win32 message handler your application need to call.
+// - Intentionally commented out in a '#if 0' block to avoid dragging dependencies on <windows.h> from this helper.
+// - You should COPY the line below into your .cpp code to forward declare the function and then you can call it.
+// - Call from your application's message handler. Keep calling your message handler unless this function returns TRUE.
+
+#if 0
+extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
+#endif
+
+// DPI-related helpers (optional)
+// - Use to enable DPI awareness without having to create an application manifest.
+// - Your own app may already do this via a manifest or explicit calls. This is mostly useful for our examples/ apps.
+// - In theory we could call simple functions from Windows SDK such as SetProcessDPIAware(), SetProcessDpiAwareness(), etc.
+//   but most of the functions provided by Microsoft require Windows 8.1/10+ SDK at compile time and Windows 8/10+ at runtime,
+//   neither we want to require the user to have. So we dynamically select and load those functions to avoid dependencies.
+IMGUI_IMPL_API void     ImGui_ImplWin32_EnableDpiAwareness();
+IMGUI_IMPL_API float    ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd);       // HWND hwnd
+IMGUI_IMPL_API float    ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor); // HMONITOR monitor
+
+// Transparency related helpers (optional) [experimental]
+// - Use to enable alpha compositing transparency with the desktop.
+// - Use together with e.g. clearing your framebuffer with zero-alpha.
+IMGUI_IMPL_API void     ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd);   // HWND hwnd

third_party/imgui/docs/BACKENDS.md

@@ -0,0 +1,145 @@
+_(You may browse this at https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md or view this file with any Markdown viewer)_
+
+## Dear ImGui: Backends
+
+**The backends/ folder contains backends for popular platforms/graphics API, which you can use in
+your application or engine to easily integrate Dear ImGui.** Each backend is typically self-contained in a pair of files: imgui_impl_XXXX.cpp + imgui_impl_XXXX.h.
+
+- The 'Platform' backends are in charge of: mouse/keyboard/gamepad inputs, cursor shape, timing, and windowing.<BR>
+  e.g. Windows ([imgui_impl_win32.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_win32.cpp)), GLFW ([imgui_impl_glfw.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_glfw.cpp)), SDL2 ([imgui_impl_sdl2.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_sdl2.cpp)), etc.
+
+- The 'Renderer' backends are in charge of: creating atlas texture, and rendering imgui draw data.<BR>
+  e.g. DirectX11 ([imgui_impl_dx11.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp)), OpenGL/WebGL ([imgui_impl_opengl3.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_opengl3.cpp)), Vulkan ([imgui_impl_vulkan.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_vulkan.cpp)), etc.
+
+- For some high-level frameworks, a single backend usually handles both 'Platform' and 'Renderer' parts.<BR>
+  e.g. Allegro 5 ([imgui_impl_allegro5.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_allegro5.cpp)). If you end up creating a custom backend for your engine, you may want to do the same.
+
+An application usually combines one Platform backend + one Renderer backend + main Dear ImGui sources.
+For example, the [example_win32_directx11](https://github.com/ocornut/imgui/tree/master/examples/example_win32_directx11) application combines imgui_impl_win32.cpp + imgui_impl_dx11.cpp. There are 20+ examples in the [examples/](https://github.com/ocornut/imgui/blob/master/examples/) folder. See [EXAMPLES.MD](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md) for details.
+
+**Once Dear ImGui is setup and running, run and refer to `ImGui::ShowDemoWindow()` in imgui_demo.cpp for usage of the end-user API.**
+
+
+### What are backends?
+
+Dear ImGui is highly portable and only requires a few things to run and render, typically:
+
+ - Required: providing mouse/keyboard inputs (fed into the `ImGuiIO` structure).
+ - Required: uploading the font atlas texture into graphics memory.
+ - Required: rendering indexed textured triangles with a clipping rectangle.
+
+ Extra features are opt-in, our backends try to support as many as possible:
+
+ - Optional: custom texture binding support.
+ - Optional: clipboard support.
+ - Optional: gamepad support.
+ - Optional: mouse cursor shape support.
+ - Optional: IME support.
+ - Optional: multi-viewports support.
+ etc.
+
+This is essentially what each backend is doing + obligatory portability cruft. Using default backends ensure you can get all those features including the ones that would be harder to implement on your side (e.g. multi-viewports support).
+
+It is important to understand the difference between the core Dear ImGui library (files in the root folder)
+and the backends which we are describing here (backends/ folder).
+
+- Some issues may only be backend or platform specific.
+- You should be able to write backends for pretty much any platform and any 3D graphics API.
+  e.g. you can get creative and use software rendering or render remotely on a different machine.
+
+
+### Integrating a backend
+
+See "Getting Started" section of [EXAMPLES.MD](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md) for more details.
+
+
+### List of backends
+
+In the [backends/](https://github.com/ocornut/imgui/blob/master/backends) folder:
+
+List of Platforms Backends:
+
+    imgui_impl_android.cpp    ; Android native app API
+    imgui_impl_glfw.cpp       ; GLFW (Windows, macOS, Linux, etc.) http://www.glfw.org/
+    imgui_impl_osx.mm         ; macOS native API (not as feature complete as glfw/sdl backends)
+    imgui_impl_sdl2.cpp       ; SDL2 (Windows, macOS, Linux, iOS, Android) https://www.libsdl.org
+    imgui_impl_sdl3.cpp       ; SDL2 (Windows, macOS, Linux, iOS, Android) https://www.libsdl.org (*EXPERIMENTAL*)
+    imgui_impl_win32.cpp      ; Win32 native API (Windows)
+    imgui_impl_glut.cpp       ; GLUT/FreeGLUT (this is prehistoric software and absolutely not recommended today!)
+
+List of Renderer Backends:
+
+    imgui_impl_dx9.cpp        ; DirectX9
+    imgui_impl_dx10.cpp       ; DirectX10
+    imgui_impl_dx11.cpp       ; DirectX11
+    imgui_impl_dx12.cpp       ; DirectX12
+    imgui_impl_metal.mm       ; Metal (with ObjC)
+    imgui_impl_opengl2.cpp    ; OpenGL 2 (legacy, fixed pipeline <- don't use with modern OpenGL context)
+    imgui_impl_opengl3.cpp    ; OpenGL 3/4, OpenGL ES 2, OpenGL ES 3 (modern programmable pipeline)
+    imgui_impl_sdlrenderer.cpp; SDL_Renderer (optional component of SDL2 available from SDL 2.0.18+)
+    imgui_impl_vulkan.cpp     ; Vulkan
+    imgui_impl_wgpu.cpp       ; WebGPU
+
+List of high-level Frameworks Backends (combining Platform + Renderer):
+
+    imgui_impl_allegro5.cpp
+
+Emscripten is also supported!
+The SDL+GL, GLFW+GL and SDL+WebGPU examples are all ready to build and run with Emscripten.
+
+### Backends for third-party frameworks, graphics API or other languages
+
+See https://github.com/ocornut/imgui/wiki/Bindings for the full list (e.g. Adventure Game Studio, Cinder, Cocos2d-x, Game Maker Studio2, Godot, LÖVE+LUA, Magnum, Monogame, Ogre, openFrameworks, OpenSceneGraph, SFML, Sokol, Unity, Unreal Engine and many others).
+
+### Recommended Backends
+
+If you are not sure which backend to use, the recommended platform/frameworks for portable applications:
+
+|Library |Website |Backend |Note |
+|--------|--------|--------|-----|
+| GLFW | https://github.com/glfw/glfw | imgui_impl_glfw.cpp | |
+| SDL2 | https://www.libsdl.org | imgui_impl_sdl2.cpp | |
+| Sokol | https://github.com/floooh/sokol | [util/sokol_imgui.h](https://github.com/floooh/sokol/blob/master/util/sokol_imgui.h) | Lower-level than GLFW/SDL |
+
+
+### Using a custom engine?
+
+You will likely be tempted to start by rewrite your own backend using your own custom/high-level facilities...<BR>
+Think twice!
+
+If you are new to Dear ImGui, first try using the existing backends as-is.
+You will save lots of time integrating the library.
+You can LATER decide to rewrite yourself a custom backend if you really need to.
+In most situations, custom backends have fewer features and more bugs than the standard backends we provide.
+If you want portability, you can use multiple backends and choose between them either at compile time
+or at runtime.
+
+**Example A**: your engine is built over Windows + DirectX11 but you have your own high-level rendering
+system layered over DirectX11.<BR>
+Suggestion: try using imgui_impl_win32.cpp + imgui_impl_dx11.cpp first.
+Once it works, if you really need it, you can replace the imgui_impl_dx11.cpp code with a
+custom renderer using your own rendering functions, and keep using the standard Win32 code etc.
+
+**Example B**: your engine runs on Windows, Mac, Linux and uses DirectX11, Metal, and Vulkan respectively.<BR>
+Suggestion: use multiple generic backends!
+Once it works, if you really need it, you can replace parts of backends with your own abstractions.
+
+**Example C**: your engine runs on platforms we can't provide public backends for (e.g. PS4/PS5, Switch),
+and you have high-level systems everywhere.<BR>
+Suggestion: try using a non-portable backend first (e.g. win32 + underlying graphics API) to get
+your desktop builds working first. This will get you running faster and get your acquainted with
+how Dear ImGui works and is setup. You can then rewrite a custom backend using your own engine API...
+
+Generally:
+It is unlikely you will add value to your project by creating your own backend.
+
+Also:
+The [multi-viewports feature](https://github.com/ocornut/imgui/issues/1542) of the 'docking' branch allows
+Dear ImGui windows to be seamlessly detached from the main application window. This is achieved using an
+extra layer to the Platform and Renderer backends, which allows Dear ImGui to communicate platform-specific
+requests such as: "create an additional OS window", "create a render context", "get the OS position of this
+window" etc. See 'ImGuiPlatformIO' for details.
+Supporting the multi-viewports feature correctly using 100% of your own abstractions is more difficult
+than supporting single-viewport.
+If you decide to use unmodified imgui_impl_XXXX.cpp files, you can automatically benefit from
+improvements and fixes related to viewports and platform windows without extra work on your side.

third_party/imgui/docs/CONTRIBUTING.md

@@ -0,0 +1,80 @@
+# Contributing Guidelines
+
+## Index
+
+- [Getting Started & General Advice](#getting-started--general-advice)
+- [Issues vs Discussions](#issues-vs-discussions)
+- [How to open an Issue](#how-to-open-an-issue)
+- [How to open a Pull Request](#how-to-open-a-pull-request)
+- [Copyright / Contributor License Agreement](#copyright--contributor-license-agreement)
+
+## Getting Started & General Advice
+
+- Article: [How To Ask Good Questions](https://bit.ly/3nwRnx1).
+- Please browse the [Wiki](https://github.com/ocornut/imgui/wiki) to find code snippets, links and other resources (e.g. [Useful extensions](https://github.com/ocornut/imgui/wiki/Useful-Extensions)).
+- Please read [docs/FAQ.md](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md).
+- Please read [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) if your question relates to fonts or text.
+- Please read one of the [examples/](https://github.com/ocornut/imgui/tree/master/examples) application if your question relates to setting up Dear ImGui.
+- Please run `ImGui::ShowDemoWindow()` to explore the demo and its sources.
+- Please use the search function of your IDE to search in for comments related to your situation.
+- Please use the search function of GitHub to look for similar issues. You may [browse issues by Labels](https://github.com/ocornut/imgui/labels).
+- Please use a web search engine to look for similar issues.
+- If you get a crash or assert, use a debugger to locate the line triggering it and read the comments around.
+- Please don't be a [Help Vampire](https://slash7.com/2006/12/22/vampires/).
+
+## Issues vs Discussions
+
+If you:
+- Cannot BUILD or LINK examples.
+- Cannot BUILD, or LINK, or RUN Dear ImGui in your application or custom engine.
+- Cannot LOAD a font.
+
+Then please [use the Discussions forums](https://github.com/ocornut/imgui/discussions) instead of opening an issue.
+
+If Dear ImGui is successfully showing in your app and you have used Dear ImGui before, you can open an issue. Any form of discussions is welcome as a new issue.
+
+## How to open an issue
+
+You may use the Issue Tracker to submit bug reports, feature requests or suggestions. You may ask for help or advice as well. But **PLEASE CAREFULLY READ THIS WALL OF TEXT. ISSUES IGNORING THOSE GUIDELINES MAY BE CLOSED. USERS IGNORING THOSE GUIDELINES MIGHT BE BLOCKED.**
+
+Please do your best to clarify your request. The amount of incomplete or ambiguous requests due to people not following those guidelines is often overwhelming. Issues created without the requested information may be closed prematurely. Exceptionally entitled, impolite, or lazy requests may lead to bans.
+
+**PLEASE UNDERSTAND THAT OPEN-SOURCE SOFTWARE LIVES OR DIES BY THE AMOUNT OF ENERGY MAINTAINERS CAN SPARE. WE HAVE LOTS OF STUFF TO DO. THIS IS AN ATTENTION ECONOMY AND MANY LAZY OR MINOR ISSUES ARE HOGGING OUR ATTENTION AND DRAINING ENERGY, TAKING US AWAY FROM MORE IMPORTANT WORK.**
+
+Steps:
+
+- Article: [How To Ask Good Questions](https://bit.ly/3nwRnx1).
+- **PLEASE DO FILL THE REQUESTED NEW ISSUE TEMPLATE.** Including Dear ImGui version number, branch name, platform/renderer back-ends (imgui_impl_XXX files), operating system.
+- **Try to be explicit with your GOALS, your EXPECTATIONS and what you have tried**.  Be mindful of [The XY Problem](http://xyproblem.info/). What you have in mind or in your code is not obvious to other people. People frequently discuss problems and suggest incorrect solutions without first clarifying their goals. When requesting a new feature, please describe the usage context (how you intend to use it, why you need it, etc.). If you tried something and it failed, show us what you tried.
+- **Attach screenshots (or GIF/video) to clarify the context**. They often convey useful information that is omitted by the description. You can drag pictures/files in the message edit box. Avoid using 3rd party image hosting services, prefer the long-term longevity of GitHub attachments (you can drag pictures into your post). On Windows, you can use [ScreenToGif](https://www.screentogif.com/) to easily capture .gif files.
+- **If you are discussing an assert or a crash, please provide a debugger callstack**. Never state "it crashes" without additional information. If you don't know how to use a debugger and retrieve a callstack, learning about it will be useful.
+- **Please make sure that your project has asserts enabled.** Calls to IM_ASSERT() are scattered in the code to help catch common issues. When an assert is triggered read the comments around it. By default IM_ASSERT() calls the standard assert() function. To verify that your asserts are enabled, add the line `IM_ASSERT(false);` in your main() function. Your application should display an error message and abort. If your application doesn't report an error, your asserts are disabled. 
+- **Please provide a Minimal, Complete, and Verifiable Example ([MCVE](https://stackoverflow.com/help/mcve)) to demonstrate your problem**. An ideal submission includes a small piece of code that anyone can paste into one of the examples applications (examples/../main.cpp) or demo (imgui_demo.cpp) to understand and reproduce it. Narrowing your problem to its shortest and purest form is the easiest way to understand it. Please test your shortened code to ensure it exhibits the problem. **Often while creating the MCVE you will end up solving the problem!** Many questions that are missing a standalone verifiable example are missing the actual cause of their issue in the description, which ends up wasting everyone's time.
+- Please state if you have made substantial modifications to your copy of Dear ImGui or the back-end.
+- If you are not calling Dear ImGui directly from C++, please provide information about your Language and the wrapper/binding you are using.
+- Be mindful that messages are being sent to the mailbox of "Watching" users. Try to proofread your messages before sending them. Edits are not seen by those users unless they browse the site.
+
+**Some unfortunate words of warning**
+- If you are involved in cheating schemes (e.g. DLL injection) for competitive online multiplayer games, please don't try posting here. We won't answer and you will be blocked. It doesn't matter if your question relates to said project. We've had too many of you and need to project our time and sanity.
+- Due to frequent abuse of this service from the aforementioned users, if your GitHub account is anonymous and was created five minutes ago please understand that your post will receive more scrutiny and incomplete questions will be harshly dismissed.
+
+If you have been using Dear ImGui for a while or have been using C/C++ for several years or have demonstrated good behavior here, it is ok to not fulfill every item to the letter. Those are guidelines and experienced users or members of the community will know which information is useful in a given context.
+
+## How to open a Pull Request
+
+- **Please understand that by submitting a PR you are also submitting a request for the maintainer to review your code and then take over its maintenance.** PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it. 
+- Many PRs are useful to demonstrate a need and a possible solution but aren't adequate for merging (causing other issues, not seeing other aspects of the big picture, etc.). In doubt, don't hesitate to push a PR because that is always the first step toward finding the mergeable solution! Even if a PR stays unmerged for a long time, its presence can be useful for other users and helps toward finding a general solution.
+- **When adding a feature,** please describe the usage context (how you intend to use it, why you need it, etc.). Be mindful of [The XY Problem](http://xyproblem.info/). 
+- **When fixing a warning or compilation problem,** please post the compiler log and specify the compiler version and platform you are using.
+- **Attach screenshots (or GIF/video) to clarify the context and demonstrate the feature at a glance.** You can drag pictures/files in the message edit box. Prefer the long-term longevity of GitHub attachments over 3rd party hosting (you can drag pictures into your post).
+- **Make sure your code follows the coding style already used in the codebase:** 4 spaces indentations (no tabs), `local_variable`, `FunctionName()`, `MemberName`, `// Text Comment`, `//CodeComment();`, C-style casts, etc.. We don't use modern C++ idioms and tend to use only a minimum of C++11 features. The applications under examples/ are generally less consistent because they sometimes try to mimic the coding style often adopted by a certain ecosystem (e.g. DirectX-related code tend to use the style of their sample). 
+- **Make sure you create a branch dedicated to the pull request**. In Git, 1 PR is associated to 1 branch. If you keep pushing to the same branch after you submitted the PR, your new commits will appear in the PR (we can still cherry-pick individual commits).
+
+Thank you for reading!
+
+## Copyright / Contributor License Agreement
+
+Any code you submit will become part of the repository and be distributed under the [Dear ImGui license](https://github.com/ocornut/imgui/blob/master/LICENSE.txt). By submitting code to the project you agree that the code is your work and that you can give it to the project.
+
+You also agree by submitting your code that you grant all transferrable rights to the code to the project maintainer, including for example re-licensing the code, modifying the code, and distributing it in source or binary forms. Specifically, this includes a requirement that you assign copyright to the project maintainer. For this reason, do not modify any copyright statements in files in any PRs.
+

third_party/imgui/docs/EXAMPLES.md

@@ -0,0 +1,246 @@
+_(You may browse this at https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md or view this file with any Markdown viewer)_
+
+## Dear ImGui: Examples
+
+**The [examples/](https://github.com/ocornut/imgui/blob/master/examples) folder example applications (standalone, ready-to-build) for variety of
+platforms and graphics APIs.** They all use standard backends from the [backends/](https://github.com/ocornut/imgui/blob/master/backends) folder (see [BACKENDS.md](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md)).
+
+The purpose of Examples is to showcase integration with backends, let you try Dear ImGui, and guide you toward
+integrating Dear ImGui in your own application/game/engine.
+**Once Dear ImGui is setup and running, run and refer to `ImGui::ShowDemoWindow()` in imgui_demo.cpp for usage of the end-user API.**
+
+You can find Windows binaries for some of those example applications at:
+  http://www.dearimgui.com/binaries
+
+
+### Getting Started
+
+Integration in a typical existing application, should take <20 lines when using standard backends.
+
+```cpp
+At initialization:
+  call ImGui::CreateContext()
+  call ImGui_ImplXXXX_Init() for each backend.
+
+At the beginning of your frame:
+  call ImGui_ImplXXXX_NewFrame() for each backend.
+  call ImGui::NewFrame()
+
+At the end of your frame:
+  call ImGui::Render()
+  call ImGui_ImplXXXX_RenderDrawData() for your Renderer backend.
+
+At shutdown:
+  call ImGui_ImplXXXX_Shutdown() for each backend.
+  call ImGui::DestroyContext()
+```
+
+Example (using [backends/imgui_impl_win32.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_win32.cpp) + [backends/imgui_impl_dx11.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp)):
+
+```cpp
+// Create a Dear ImGui context, setup some options
+ImGui::CreateContext();
+ImGuiIO& io = ImGui::GetIO();
+io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable some options
+
+// Initialize Platform + Renderer backends (here: using imgui_impl_win32.cpp + imgui_impl_dx11.cpp)
+ImGui_ImplWin32_Init(my_hwnd);
+ImGui_ImplDX11_Init(my_d3d_device, my_d3d_device_context);
+
+// Application main loop
+while (true)
+{
+    // Beginning of frame: update Renderer + Platform backend, start Dear ImGui frame
+    ImGui_ImplDX11_NewFrame();
+    ImGui_ImplWin32_NewFrame();
+    ImGui::NewFrame();
+
+    // Any application code here
+    ImGui::Text("Hello, world!");
+
+    // End of frame: render Dear ImGui
+    ImGui::Render();
+    ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+
+    // Swap
+    g_pSwapChain->Present(1, 0);
+}
+
+// Shutdown
+ImGui_ImplDX11_Shutdown();
+ImGui_ImplWin32_Shutdown();
+ImGui::DestroyContext();
+```
+
+Please read 'PROGRAMMER GUIDE' in imgui.cpp for notes on how to setup Dear ImGui in your codebase.
+Please read the comments and instruction at the top of each file.
+Please read FAQ at http://www.dearimgui.com/faq
+
+If you are using any of the backends provided here, you can add the backends/imgui_impl_xxxx(.cpp,.h)
+files to your project and use as-in. Each imgui_impl_xxxx.cpp file comes with its own individual
+Changelog, so if you want to update them later it will be easier to catch up with what changed.
+
+
+### Examples Applications
+
+[example_allegro5/](https://github.com/ocornut/imgui/blob/master/examples/example_allegro5/) <BR>
+Allegro 5 example. <BR>
+= main.cpp + imgui_impl_allegro5.cpp
+
+[example_android_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_android_opengl3/) <BR>
+Android + OpenGL3 (ES) example. <BR>
+= main.cpp + imgui_impl_android.cpp + imgui_impl_opengl3.cpp
+
+[example_apple_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_metal/) <BR>
+OSX & iOS + Metal example. <BR>
+= main.m + imgui_impl_osx.mm + imgui_impl_metal.mm <BR>
+It is based on the "cross-platform" game template provided with Xcode as of Xcode 9.
+(NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends.
+You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.)
+
+[example_apple_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_apple_opengl2/) <BR>
+OSX + OpenGL2 example. <BR>
+= main.mm + imgui_impl_osx.mm + imgui_impl_opengl2.cpp <BR>
+(NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends.
+ You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.)
+
+[example_emscripten_wgpu/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_wgpu/) <BR>
+Emcripten + GLFW + WebGPU example. <BR>
+= main.cpp + imgui_impl_glfw.cpp + imgui_impl_wgpu.cpp
+Note that the 'example_glfw_opengl3' and 'example_sdl2_opengl3' examples also supports Emscripten!
+
+[example_glfw_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_metal/) <BR>
+GLFW (Mac) + Metal example. <BR>
+= main.mm + imgui_impl_glfw.cpp + imgui_impl_metal.mm
+
+[example_glfw_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl2/) <BR>
+GLFW + OpenGL2 example (legacy, fixed pipeline). <BR>
+= main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp <BR>
+**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN GL or WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
+This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
+state, and might confuse your GPU driver. One star, not recommended.
+
+[example_glfw_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl3/) <BR>
+GLFW (Win32, Mac, Linux) + OpenGL3+/ES2/ES3 example (modern, programmable pipeline). <BR>
+= main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp <BR>
+This uses more modern GL calls and custom shaders.<BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
+
+[example_glfw_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/) <BR>
+GLFW (Win32, Mac, Linux) + Vulkan example. <BR>
+= main.cpp + imgui_impl_glfw.cpp + imgui_impl_vulkan.cpp <BR>
+This is quite long and tedious, because: Vulkan.
+For this example, the main.cpp file exceptionally use helpers function from imgui_impl_vulkan.h/cpp.
+
+[example_glut_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glut_opengl2/) <BR>
+GLUT (e.g., FreeGLUT on Linux/Windows, GLUT framework on OSX) + OpenGL2 example. <BR>
+= main.cpp + imgui_impl_glut.cpp + imgui_impl_opengl2.cpp <BR>
+Note that GLUT/FreeGLUT is largely obsolete software, prefer using GLFW or SDL.
+
+[example_null/](https://github.com/ocornut/imgui/blob/master/examples/example_null/) <BR>
+Null example, compile and link imgui, create context, run headless with no inputs and no graphics output. <BR>
+= main.cpp <BR>
+This is used to quickly test compilation of core imgui files in as many setups as possible.
+Because this application doesn't create a window nor a graphic context, there's no graphics output.
+
+[example_sdl2_directx11/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_directx11/) <BR>
+SDL2 + DirectX11 example, Windows only. <BR>
+= main.cpp + imgui_impl_sdl2.cpp + imgui_impl_dx11.cpp <BR>
+This to demonstrate usage of DirectX with SDL2.
+
+[example_sdl2_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_metal/) <BR>
+SDL2 + Metal example, Mac only. <BR>
+= main.mm + imgui_impl_sdl2.cpp + imgui_impl_metal.mm
+
+[example_sdl2_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_opengl2/) <BR>
+SDL2 (Win32, Mac, Linux etc.) + OpenGL example (legacy, fixed pipeline). <BR>
+= main.cpp + imgui_impl_sdl2.cpp + imgui_impl_opengl2.cpp <BR>
+**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING GL OR WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
+This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
+state, and might confuse your GPU driver. One star, not recommended.
+
+[example_sdl2_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_opengl3/) <BR>
+SDL2 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR>
+= main.cpp + imgui_impl_sdl2.cpp + imgui_impl_opengl3.cpp <BR>
+This uses more modern GL calls and custom shaders. <BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
+
+[example_sdl2_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_sdlrenderer/) <BR>
+SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer (most graphics backends are supported underneath) <BR>
+= main.cpp + imgui_impl_sdl2.cpp + imgui_impl_sdlrenderer.cpp <BR>
+This requires SDL 2.0.18+ (released November 2021) <BR>
+We do not really recommend using SDL_Renderer as it is a rather primitive API.
+
+[example_sdl2_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_vulkan/) <BR>
+SDL2 (Win32, Mac, Linux, etc.) + Vulkan example. <BR>
+= main.cpp + imgui_impl_sdl2.cpp + imgui_impl_vulkan.cpp <BR>
+This is quite long and tedious, because: Vulkan. <BR>
+For this example, the main.cpp file exceptionally use helpers function from imgui_impl_vulkan.h/cpp.
+
+[example_win32_directx9/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx9/) <BR>
+DirectX9 example, Windows only. <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_dx9.cpp
+
+[example_win32_directx10/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx10/) <BR>
+DirectX10 example, Windows only. <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_dx10.cpp
+
+[example_win32_directx11/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx11/) <BR>
+DirectX11 example, Windows only. <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_dx11.cpp
+
+[example_win32_directx12/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx12/) <BR>
+DirectX12 example, Windows only. <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_dx12.cpp <BR>
+This is quite long and tedious, because: DirectX12.
+
+[example_win32_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_opengl3/) <BR>
+Raw Windows + OpenGL3 + example (modern, programmable pipeline) <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_opengl3.cpp <BR>
+
+
+### Miscellaneous
+
+**Building**
+
+Unfortunately nowadays it is still tedious to create and maintain portable build files using external
+libraries (the kind we're using here to create a window and render 3D triangles) without relying on
+third party software and build systems. For most examples here we choose to provide:
+ - Makefiles for Linux/OSX
+ - Batch files for Visual Studio 2008+
+ - A .sln project file for Visual Studio 2012+
+ - Xcode project files for the Apple examples
+Please let us know if they don't work with your setup!
+You can probably just import the imgui_impl_xxx.cpp/.h files into your own codebase or compile those
+directly with a command-line compiler.
+
+If you are interested in using Cmake to build and links examples, see:
+  https://github.com/ocornut/imgui/pull/1713 and https://github.com/ocornut/imgui/pull/3027
+
+**About mouse cursor latency**
+
+Dear ImGui has no particular extra lag for most behaviors,
+e.g. the last value passed to 'io.AddMousePosEvent()' before NewFrame() will result in windows being moved
+to the right spot at the time of EndFrame()/Render(). At 60 FPS your experience should be pleasant.
+
+However, consider that OS mouse cursors are typically drawn through a very specific hardware accelerated
+path and will feel smoother than the majority of contents rendered via regular graphics API (including,
+but not limited to Dear ImGui windows). Because UI rendering and interaction happens on the same plane
+as the mouse, that disconnect may be jarring to particularly sensitive users.
+You may experiment with enabling the io.MouseDrawCursor flag to request Dear ImGui to draw a mouse cursor
+using the regular graphics API, to help you visualize the difference between a "hardware" cursor and a
+regularly rendered software cursor.
+However, rendering a mouse cursor at 60 FPS will feel sluggish so you likely won't want to enable that at
+all times. It might be beneficial for the user experience to switch to a software rendered cursor _only_
+when an interactive drag is in progress.
+
+Note that some setup or GPU drivers are likely to be causing extra display lag depending on their settings.
+If you feel that dragging windows feels laggy and you are not sure what the cause is: try to build a simple
+drawing a flat 2D shape directly under the mouse cursor!
+

third_party/imgui/docs/FAQ.md

@@ -0,0 +1,706 @@
+# FAQ (Frequently Asked Questions)
+
+You may link to this document using short form:
+  https://www.dearimgui.com/faq
+or its real address:
+  https://github.com/ocornut/imgui/blob/master/docs/FAQ.md
+or view this file with any Markdown viewer.
+
+
+## Index
+
+| **Q&A: Basics** |
+:---------------------------------------------------------- |
+| [Where is the documentation?](#q-where-is-the-documentation) |
+| [What is this library called?](#q-what-is-this-library-called) |
+| [Which version should I get?](#q-which-version-should-i-get) |
+| **Q&A: Integration** |
+| **[How to get started?](#q-how-to-get-started)** |
+| **[How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?](#q-how-can-i-tell-whether-to-dispatch-mousekeyboard-to-dear-imgui-or-my-application)** |
+| [How can I enable keyboard or gamepad controls?](#q-how-can-i-enable-keyboard-or-gamepad-controls) |
+| [How can I use this on a machine without mouse, keyboard or screen? (input share, remote display)](#q-how-can-i-use-this-on-a-machine-without-mouse-keyboard-or-screen-input-share-remote-display) |
+| [I integrated Dear ImGui in my engine and little squares are showing instead of text...](#q-i-integrated-dear-imgui-in-my-engine-and-little-squares-are-showing-instead-of-text) |
+| [I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around...](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-clipping-or-disappearing-when-i-move-windows-around) |
+| [I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries...](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-displaying-outside-their-expected-windows-boundaries) |
+| **Q&A: Usage** |
+| **[About the ID Stack system..<br>Why is my widget not reacting when I click on it?<br>How can I have widgets with an empty label?<br>How can I have multiple widgets with the same label?<br>How can I have multiple windows with the same label?](#q-about-the-id-stack-system)** |
+| [How can I display an image? What is ImTextureID, how does it work?](#q-how-can-i-display-an-image-what-is-imtextureid-how-does-it-work)|
+| [How can I use maths operators with ImVec2?](#q-how-can-i-use-maths-operators-with-imvec2) |
+| [How can I use my own maths types instead of ImVec2/ImVec4?](#q-how-can-i-use-my-own-maths-types-instead-of-imvec2imvec4) |
+| [How can I interact with standard C++ types (such as std::string and std::vector)?](#q-how-can-i-interact-with-standard-c-types-such-as-stdstring-and-stdvector) |
+| [How can I display custom shapes? (using low-level ImDrawList API)](#q-how-can-i-display-custom-shapes-using-low-level-imdrawlist-api) |
+| **Q&A: Fonts, Text** |
+| [How should I handle DPI in my application?](#q-how-should-i-handle-dpi-in-my-application) |
+| [How can I load a different font than the default?](#q-how-can-i-load-a-different-font-than-the-default) |
+| [How can I easily use icons in my application?](#q-how-can-i-easily-use-icons-in-my-application) |
+| [How can I load multiple fonts?](#q-how-can-i-load-multiple-fonts) |
+| [How can I display and input non-Latin characters such as Chinese, Japanese, Korean, Cyrillic?](#q-how-can-i-display-and-input-non-latin-characters-such-as-chinese-japanese-korean-cyrillic) |
+| **Q&A: Concerns** |
+| [Who uses Dear ImGui?](#q-who-uses-dear-imgui) |
+| [Can you create elaborate/serious tools with Dear ImGui?](#q-can-you-create-elaborateserious-tools-with-dear-imgui)  |
+| [Can you reskin the look of Dear ImGui?](#q-can-you-reskin-the-look-of-dear-imgui) |
+| [Why using C++ (as opposed to C)?](#q-why-using-c-as-opposed-to-c) |
+| **Q&A: Community** |
+| [How can I help?](#q-how-can-i-help) |
+
+
+# Q&A: Basics
+
+### Q: Where is the documentation?
+
+**This library is poorly documented at the moment and expects the user to be acquainted with C/C++.**
+- The [Wiki](https://github.com/ocornut/imgui/wiki) is a hub to many resources and links.
+- Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the [examples/](https://github.com/ocornut/imgui/blob/master/examples/) folder to explain how to integrate Dear ImGui with your own engine/application. You can run those applications and explore them.
+- See demo code in [imgui_demo.cpp](https://github.com/ocornut/imgui/blob/master/imgui_demo.cpp) and particularly the `ImGui::ShowDemoWindow()` function. The demo covers most features of Dear ImGui, so you can read the code and see its output.
+- See documentation: [Backends](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md), [Examples](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md), [Fonts](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md).
+- See documentation and comments at the top of [imgui.cpp](https://github.com/ocornut/imgui/blob/master/imgui.cpp) + general API comments in [imgui.h](https://github.com/ocornut/imgui/blob/master/imgui.h).
+- The [Glossary](https://github.com/ocornut/imgui/wiki/Glossary) page may be useful.
+- The [Issues](https://github.com/ocornut/imgui/issues) and [Discussions](https://github.com/ocornut/imgui/discussions) sections can be searched for past questions and issues.
+- Your programming IDE is your friend, find the type or function declaration to find comments associated with it.
+- The `ImGui::ShowMetricsWindow()` function exposes lots of internal information and tools. Although it is primarily designed as a debugging tool, having access to that information tends to help understands concepts.
+
+##### [Return to Index](#index)
+
+---
+
+### Q. What is this library called?
+
+**This library is called Dear ImGui**. Please refer to it as Dear ImGui (not ImGui, not IMGUI).
+
+(The library misleadingly started its life in 2014 as "ImGui" due to the fact that I didn't give it a proper name when I released 1.0, and had no particular expectation that it would take off. However, the term IMGUI (immediate-mode graphical user interface) was coined before and is being used in variety of other situations e.g. Unity uses it own implementation of the IMGUI paradigm. To reduce the ambiguity without affecting existing code bases, I have decided in December 2015 a fully qualified name "Dear ImGui" for this library.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: Which version should I get?
+I occasionally tag [Releases](https://github.com/ocornut/imgui/releases) but it is generally safe and recommended to sync to master/latest. The library is fairly stable and regressions tend to be fixed fast when reported.
+
+You may use the [docking](https://github.com/ocornut/imgui/tree/docking) branch which includes:
+- [Docking features](https://github.com/ocornut/imgui/issues/2109)
+- [Multi-viewport features](https://github.com/ocornut/imgui/issues/1542)
+
+Many projects are using this branch and it is kept in sync with master regularly.
+
+##### [Return to Index](#index)
+
+----
+
+# Q&A: Integration
+
+### Q: How to get started?
+
+Read [EXAMPLES.md](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md). <BR>
+Read [BACKENDS.md](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md). <BR>
+Read `PROGRAMMER GUIDE` section of [imgui.cpp](https://github.com/ocornut/imgui/blob/master/imgui.cpp). <BR>
+The [Wiki](https://github.com/ocornut/imgui/wiki) is a hub to many resources and links.
+
+For first-time users having issues compiling/linking/running or issues loading fonts, please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions).
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?
+
+You can read the `io.WantCaptureMouse`, `io.WantCaptureKeyboard` and `io.WantTextInput` flags from the ImGuiIO structure.
+- When `io.WantCaptureMouse` is set, you need to discard/hide the mouse inputs from your underlying application.
+- When `io.WantCaptureKeyboard` is set, you need to discard/hide the keyboard inputs from your underlying application.
+- When `io.WantTextInput` is set, you can notify your OS/engine to popup an on-screen keyboard, if available (e.g. on a mobile phone, or console OS).
+
+Important: you should always pass your mouse/keyboard inputs to Dear ImGui, regardless of the value `io.WantCaptureMouse`/`io.WantCaptureKeyboard`. This is because e.g. we need to detect that you clicked in the void to unfocus its own windows, and other reasons.
+
+```cpp
+void MyLowLevelMouseButtonHandler(int button, bool down)
+{
+    // (1) ALWAYS forward mouse data to ImGui! This is automatic with default backends. With your own backend:
+    ImGuiIO& io = ImGui::GetIO();
+    io.AddMouseButtonEvent(button, down);
+
+    // (2) ONLY forward mouse data to your underlying app/game.
+    if (!io.WantCaptureMouse)
+        my_game->HandleMouseData(...);
+}
+```
+
+
+**Note:** The `io.WantCaptureMouse` is more correct that any manual attempt to "check if the mouse is hovering a window" (don't do that!). It handles mouse dragging correctly (both dragging that started over your application or over a Dear ImGui window) and handle e.g. popup and modal windows blocking inputs.
+
+**Note:** Those flags are updated by `ImGui::NewFrame()`. However it is generally more correct and easier that you poll flags from the previous frame, then submit your inputs, then call `NewFrame()`. If you attempt to do the opposite (which is generally harder) you are likely going to submit your inputs after `NewFrame()`, and therefore too late.
+
+**Note:** If you are using a touch device, you may find use for an early call to `UpdateHoveredWindowAndCaptureFlags()` to correctly dispatch your initial touch. We will work on better out-of-the-box touch support in the future.
+
+**Note:** Text input widget releases focus on the "KeyDown" event of the Return key, so the subsequent "KeyUp" event that your application receive will typically have `io.WantCaptureKeyboard == false`. Depending on your application logic it may or not be inconvenient to receive that KeyUp event. You might want to track which key-downs were targeted for Dear ImGui, e.g. with an array of bool, and filter out the corresponding key-ups.)
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I enable keyboard or gamepad controls?
+- The gamepad/keyboard navigation is fairly functional and keeps being improved. The initial focus was to support game controllers, but keyboard is becoming increasingly and decently usable. Gamepad support is particularly useful to use Dear ImGui on a game console (e.g. PS4, Switch, XB1) without a mouse connected!
+- Keyboard: set `io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard` to enable.
+- Gamepad: set `io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad` to enable (with a supporting backend).
+- See [Control Sheets for Gamepads](http://www.dearimgui.com/controls_sheets) (reference PNG/PSD for PS4, XB1, Switch gamepads).
+- See `USING GAMEPAD/KEYBOARD NAVIGATION CONTROLS` section of [imgui.cpp](https://github.com/ocornut/imgui/blob/master/imgui.cpp) for more details.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I use this on a machine without mouse, keyboard or screen? (input share, remote display)
+- You can share your computer mouse seamlessly with your console/tablet/phone using solutions such as [Synergy](https://symless.com/synergy)
+This is the preferred solution for developer productivity.
+In particular, the [micro-synergy-client repository](https://github.com/symless/micro-synergy-client) has simple
+and portable source code (uSynergy.c/.h) for a small embeddable client that you can use on any platform to connect
+to your host computer, based on the Synergy 1.x protocol. Make sure you download the Synergy 1 server on your computer.
+Console SDK also sometimes provide equivalent tooling or wrapper for Synergy-like protocols.
+- Game console users: consider emulating a mouse cursor with DualShock4 touch pad or a spare analog stick as a mouse-emulation fallback.
+- You may also use a third party solution such as [netImgui](https://github.com/sammyfreg/netImgui), [Remote ImGui](https://github.com/JordiRos/remoteimgui) or [imgui-ws](https://github.com/ggerganov/imgui-ws) which sends the vertices to render over the local network, allowing you to use Dear ImGui even on a screen-less machine. See [Wiki](https://github.com/ocornut/imgui/wiki) index for most details.
+- For touch inputs, you can increase the hit box of widgets (via the `style.TouchPadding` setting) to accommodate for the lack of precision of touch inputs, but it is recommended you use a mouse or gamepad to allow optimizing for screen real-estate and precision.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: I integrated Dear ImGui in my engine and little squares are showing instead of text...
+Your renderer is not using the font texture correctly or it hasn't been uploaded to the GPU.
+- If this happens using the standard backends: A) have you modified the font atlas after `ImGui_ImplXXX_NewFrame()`? B) maybe the texture failed to upload, which could happens if for some reason your texture is too big. Also see [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md).
+- If this happens with a custom backend: make sure you have uploaded the font texture to the GPU, that all shaders are rendering states are setup properly (e.g. texture is bound). Compare your code to existing backends and use a graphics debugger such as [RenderDoc](https://renderdoc.org) to debug your rendering states.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around...
+### Q: I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries...
+You are probably mishandling the clipping rectangles in your render function.
+Each draw command needs the triangle rendered using the clipping rectangle provided in the ImDrawCmd structure (`ImDrawCmd->CllipRect`).
+Rectangles provided by Dear ImGui are defined as
+`(x1=left,y1=top,x2=right,y2=bottom)`
+and **NOT** as
+`(x1,y1,width,height)`.
+Refer to rendering backends in the [backends/](https://github.com/ocornut/imgui/tree/master/backends) folder for references of how to handle the `ClipRect` field.
+For example, the [DirectX11 backend](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp) does this:
+```cpp
+// Project scissor/clipping rectangles into framebuffer space
+ImVec2 clip_off = draw_data->DisplayPos;
+ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+    continue;
+
+// Apply scissor/clipping rectangle
+const D3D11_RECT r = { (LONG)clip_min.x, (LONG)clip_min.y, (LONG)clip_max.x, (LONG)clip_max.y };
+ctx->RSSetScissorRects(1, &r);
+```
+
+##### [Return to Index](#index)
+
+---
+
+# Q&A: Usage
+
+### Q: About the ID Stack system...
+### Q: Why is my widget not reacting when I click on it?
+### Q: How can I have widgets with an empty label?
+### Q: How can I have multiple widgets with the same label?
+### Q: How can I have multiple windows with the same label?
+
+A primer on labels and the ID Stack...
+
+Dear ImGui internally needs to uniquely identify UI elements.
+Elements that are typically not clickable (such as calls to the Text functions) don't need an ID.
+Interactive widgets (such as calls to Button buttons) need a unique ID.
+
+**Unique IDs are used internally to track active widgets and occasionally associate state to widgets.<BR>
+Unique IDs are implicitly built from the hash of multiple elements that identify the "path" to the UI element.**
+
+Since Dear ImGui 1.85, you can use `Demo>Tools>Stack Tool` or call `ImGui::ShowStackToolWindow()`. The tool display intermediate values leading to the creation of a unique ID, making things easier to debug and understand.
+
+![Stack tool](https://user-images.githubusercontent.com/8225057/136235657-a0ea5665-dcd1-423f-9be6-dc3f8ced8f12.png)
+
+- Unique ID are often derived from a string label and at minimum scoped within their host window:
+```cpp
+Begin("MyWindow");
+Button("OK");          // Label = "OK",     ID = hash of ("MyWindow", "OK")
+Button("Cancel");      // Label = "Cancel", ID = hash of ("MyWindow", "Cancel")
+End();
+```
+- Other elements such as tree nodes, etc. also pushes to the ID stack:
+```cpp
+Begin("MyWindow");
+if (TreeNode("MyTreeNode"))
+{
+    Button("OK");      // Label = "OK",     ID = hash of ("MyWindow", "MyTreeNode", "OK")
+    TreePop();
+}
+End();
+```
+- Two items labeled "OK" in different windows or different tree locations won't collide:
+```cpp
+Begin("MyFirstWindow");
+Button("OK");          // Label = "OK",     ID = hash of ("MyFirstWindow", "OK")
+End();
+Begin("MyOtherWindow");
+Button("OK");          // Label = "OK",     ID = hash of ("MyOtherWindow", "OK")
+End();
+```
+
+- If you have a same ID twice in the same location, you'll have a conflict:
+```cpp
+Begin("MyWindow");
+Button("OK");
+Button("OK");      // ERROR: ID collision with the first button! Interacting with either button will trigger the first one.
+Button("");        // ERROR: ID collision with Begin("MyWindow")!
+End();
+```
+Fear not! This is easy to solve and there are many ways to solve it!
+
+- Solving ID conflict in a simple/local context:
+When passing a label you can optionally specify extra ID information within the string itself.
+Use "##" to pass a complement to the ID that won't be visible to the end-user.
+This helps solve the simple collision cases when you know e.g. at compilation time which items
+are going to be created:
+```cpp
+Begin("MyWindow");
+Button("Play");        // Label = "Play",   ID = hash of ("MyWindow", "Play")
+Button("Play##foo1");  // Label = "Play",   ID = hash of ("MyWindow", "Play##foo1")  // Different from other buttons
+Button("Play##foo2");  // Label = "Play",   ID = hash of ("MyWindow", "Play##foo2")  // Different from other buttons
+Button("##foo");       // Label = "",       ID = hash of ("MyWindow", "##foo")       // Different from window
+End();
+```
+- If you want to completely hide the label, but still need an ID:
+```cpp
+Checkbox("##On", &b);  // Label = "",       ID = hash of (..., "##On")   // No visible label, just a checkbox!
+```
+- Occasionally/rarely you might want to change a label while preserving a constant ID. This allows
+you to animate labels. For example, you may want to include varying information in a window title bar,
+but windows are uniquely identified by their ID. Use "###" to pass a label that isn't part of ID:
+```cpp
+Button("Hello###ID");  // Label = "Hello",  ID = hash of (..., "###ID")
+Button("World###ID");  // Label = "World",  ID = hash of (..., "###ID")  // Same ID, different label
+
+sprintf(buf, "My game (%f FPS)###MyGame", fps);
+Begin(buf);            // Variable title,   ID = hash of "MyGame"
+```
+- Solving ID conflict in a more general manner:
+Use `PushID()` / `PopID()` to create scopes and manipulate the ID stack, as to avoid ID conflicts
+within the same window. This is the most convenient way of distinguishing ID when iterating and
+creating many UI elements programmatically.
+You can push a pointer, a string, or an integer value into the ID stack.
+Remember that IDs are formed from the concatenation of _everything_ pushed into the ID stack.
+At each level of the stack, we store the seed used for items at this level of the ID stack.
+```cpp
+Begin("Window");
+for (int i = 0; i < 100; i++)
+{
+  PushID(i);           // Push i to the id tack
+  Button("Click");     // Label = "Click",  ID = hash of ("Window", i, "Click")
+  PopID();
+}
+for (int i = 0; i < 100; i++)
+{
+  MyObject* obj = Objects[i];
+  PushID(obj);
+  Button("Click");     // Label = "Click",  ID = hash of ("Window", obj pointer, "Click")
+  PopID();
+}
+for (int i = 0; i < 100; i++)
+{
+  MyObject* obj = Objects[i];
+  PushID(obj->Name);
+  Button("Click");     // Label = "Click",  ID = hash of ("Window", obj->Name, "Click")
+  PopID();
+}
+End();
+```
+- You can stack multiple prefixes into the ID stack:
+```cpp
+Button("Click");       // Label = "Click",  ID = hash of (..., "Click")
+PushID("node");
+  Button("Click");     // Label = "Click",  ID = hash of (..., "node", "Click")
+  PushID(my_ptr);
+    Button("Click");   // Label = "Click",  ID = hash of (..., "node", my_ptr, "Click")
+  PopID();
+PopID();
+```
+- Tree nodes implicitly create a scope for you by calling `PushID()`:
+```cpp
+Button("Click");       // Label = "Click",  ID = hash of (..., "Click")
+if (TreeNode("node"))  // <-- this function call will do a PushID() for you (unless instructed not to, with a special flag)
+{
+  Button("Click");     // Label = "Click",  ID = hash of (..., "node", "Click")
+  TreePop();
+}
+```
+
+When working with trees, IDs are used to preserve the open/close state of each tree node.
+Depending on your use cases you may want to use strings, indices, or pointers as ID.
+- e.g. when following a single pointer that may change over time, using a static string as ID
+will preserve your node open/closed state when the targeted object change.
+- e.g. when displaying a list of objects, using indices or pointers as ID will preserve the
+node open/closed state differently. See what makes more sense in your situation!
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I display an image? What is ImTextureID, how does it work?
+
+Short explanation:
+- Refer to [Image Loading and Displaying Examples](https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples) on the [Wiki](https://github.com/ocornut/imgui/wiki).
+- You may use functions such as `ImGui::Image()`, `ImGui::ImageButton()` or lower-level `ImDrawList::AddImage()` to emit draw calls that will use your own textures.
+- Actual textures are identified in a way that is up to the user/engine. Those identifiers are stored and passed as ImTextureID (void*) value.
+- Loading image files from the disk and turning them into a texture is not within the scope of Dear ImGui (for a good reason).
+
+**Please read documentations or tutorials on your graphics API to understand how to display textures on the screen before moving onward.**
+
+Long explanation:
+- Dear ImGui's job is to create "meshes", defined in a renderer-agnostic format made of draw commands and vertices. At the end of the frame, those meshes (ImDrawList) will be displayed by your rendering function. They are made up of textured polygons and the code to render them is generally fairly short (a few dozen lines). In the examples/ folder, we provide functions for popular graphics APIs (OpenGL, DirectX, etc.).
+- Each rendering function decides on a data type to represent "textures". The concept of what is a "texture" is entirely tied to your underlying engine/graphics API.
+ We carry the information to identify a "texture" in the ImTextureID type.
+ImTextureID is nothing more than a void*, aka 4/8 bytes worth of data: just enough to store one pointer or integer of your choice.
+Dear ImGui doesn't know or understand what you are storing in ImTextureID, it merely passes ImTextureID values until they reach your rendering function.
+- In the [examples/](https://github.com/ocornut/imgui/tree/master/examples) backends, for each graphics API we decided on a type that is likely to be a good representation for specifying an image from the end-user perspective. This is what the _examples_ rendering functions are using:
+```cpp
+OpenGL:
+- ImTextureID = GLuint
+- See ImGui_ImplOpenGL3_RenderDrawData() function in imgui_impl_opengl3.cpp
+```
+```cpp
+DirectX9:
+- ImTextureID = LPDIRECT3DTEXTURE9
+- See ImGui_ImplDX9_RenderDrawData() function in imgui_impl_dx9.cpp
+```
+```cpp
+DirectX11:
+- ImTextureID = ID3D11ShaderResourceView*
+- See ImGui_ImplDX11_RenderDrawData() function in imgui_impl_dx11.cpp
+```
+```cpp
+DirectX12:
+- ImTextureID = D3D12_GPU_DESCRIPTOR_HANDLE
+- See ImGui_ImplDX12_RenderDrawData() function in imgui_impl_dx12.cpp
+```
+For example, in the OpenGL example backend we store raw OpenGL texture identifier (GLuint) inside ImTextureID.
+Whereas in the DirectX11 example backend we store a pointer to ID3D11ShaderResourceView inside ImTextureID, which is a higher-level structure tying together both the texture and information about its format and how to read it.
+
+- If you have a custom engine built over e.g. OpenGL, instead of passing GLuint around you may decide to use a high-level data type to carry information about the texture as well as how to display it (shaders, etc.). The decision of what to use as ImTextureID can always be made better by knowing how your codebase is designed. If your engine has high-level data types for "textures" and "material" then you may want to use them.
+If you are starting with OpenGL or DirectX or Vulkan and haven't built much of a rendering engine over them, keeping the default ImTextureID representation suggested by the example backends is probably the best choice.
+(Advanced users may also decide to keep a low-level type in ImTextureID, use ImDrawList callback and pass information to their renderer)
+
+User code may do:
+```cpp
+// Cast our texture type to ImTextureID / void*
+MyTexture* texture = g_CoffeeTableTexture;
+ImGui::Image((void*)texture, ImVec2(texture->Width, texture->Height));
+```
+The renderer function called after ImGui::Render() will receive that same value that the user code passed:
+```cpp
+// Cast ImTextureID / void* stored in the draw command as our texture type
+MyTexture* texture = (MyTexture*)pcmd->GetTexID();
+MyEngineBindTexture2D(texture);
+```
+Once you understand this design, you will understand that loading image files and turning them into displayable textures is not within the scope of Dear ImGui.
+This is by design and is a good thing because it means your code has full control over your data types and how you display them.
+If you want to display an image file (e.g. PNG file) on the screen, please refer to documentation and tutorials for the graphics API you are using.
+
+Refer to [Image Loading and Displaying Examples](https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples) on the [Wiki](https://github.com/ocornut/imgui/wiki) to find simplified examples for loading textures with OpenGL, DirectX9 and DirectX11.
+
+C/C++ tip: a void* is pointer-sized storage. You may safely store any pointer or integer into it by casting your value to ImTextureID / void*, and vice-versa.
+Because both end-points (user code and rendering function) are under your control, you know exactly what is stored inside the ImTextureID / void*.
+Here are some examples:
+```cpp
+GLuint my_tex = XXX;
+void* my_void_ptr;
+my_void_ptr = (void*)(intptr_t)my_tex;                  // cast a GLuint into a void* (we don't take its address! we literally store the value inside the pointer)
+my_tex = (GLuint)(intptr_t)my_void_ptr;                 // cast a void* into a GLuint
+
+ID3D11ShaderResourceView* my_dx11_srv = XXX;
+void* my_void_ptr;
+my_void_ptr = (void*)my_dx11_srv;                       // cast a ID3D11ShaderResourceView* into an opaque void*
+my_dx11_srv = (ID3D11ShaderResourceView*)my_void_ptr;   // cast a void* into a ID3D11ShaderResourceView*
+```
+Finally, you may call `ImGui::ShowMetricsWindow()` to explore/visualize/understand how the ImDrawList are generated.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I use maths operators with ImVec2?
+
+We do not export maths operators by default in imgui.h in order to not conflict with the use of your own maths types and maths operators. As a convenience, you may use `#defne IMGUI_DEFINE_MATH_OPERATORS` + `#include "imgui.h"` to access our basic maths operators.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I use my own maths types instead of ImVec2/ImVec4?
+
+You can setup your [imconfig.h](https://github.com/ocornut/imgui/blob/master/imconfig.h) file with `IM_VEC2_CLASS_EXTRA`/`IM_VEC4_CLASS_EXTRA` macros to add implicit type conversions to our own maths types.
+This way you will be able to use your own types everywhere, e.g. passing `MyVector2` or `glm::vec2` to ImGui functions instead of `ImVec2`.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I interact with standard C++ types (such as std::string and std::vector)?
+- Being highly portable (backends/bindings for several languages, frameworks, programming styles, obscure or older platforms/compilers), and aiming for compatibility & performance suitable for every modern real-time game engine, Dear ImGui does not use any of std C++ types. We use raw types (e.g. char* instead of std::string) because they adapt to more use cases.
+- To use ImGui::InputText() with a std::string or any resizable string class, see [misc/cpp/imgui_stdlib.h](https://github.com/ocornut/imgui/blob/master/misc/cpp/imgui_stdlib.h).
+- To use combo boxes and list boxes with `std::vector` or any other data structure: the `BeginCombo()/EndCombo()` API
+lets you iterate and submit items yourself, so does the `ListBoxHeader()/ListBoxFooter()` API.
+Prefer using them over the old and awkward `Combo()/ListBox()` api.
+- Generally for most high-level types you should be able to access the underlying data type.
+You may write your own one-liner wrappers to facilitate user code (tip: add new functions in ImGui:: namespace from your code).
+- Dear ImGui applications often need to make intensive use of strings. It is expected that many of the strings you will pass
+to the API are raw literals (free in C/C++) or allocated in a manner that won't incur a large cost on your application.
+Please bear in mind that using `std::string` on applications with a large amount of UI may incur unsatisfactory performances.
+Modern implementations of `std::string` often include small-string optimization (which is often a local buffer) but those
+are not configurable and not the same across implementations.
+- If you are finding your UI traversal cost to be too large, make sure your string usage is not leading to an excessive amount
+of heap allocations. Consider using literals, statically sized buffers, and your own helper functions. A common pattern
+is that you will need to build lots of strings on the fly, and their maximum length can be easily scoped ahead.
+One possible implementation of a helper to facilitate printf-style building of strings: https://github.com/ocornut/Str
+This is a small helper where you can instance strings with configurable local buffers length. Many game engines will
+provide similar or better string helpers.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I display custom shapes? (using low-level ImDrawList API)
+
+- You can use the low-level `ImDrawList` api to render shapes within a window.
+```cpp
+ImGui::Begin("My shapes");
+
+ImDrawList* draw_list = ImGui::GetWindowDrawList();
+
+// Get the current ImGui cursor position
+ImVec2 p = ImGui::GetCursorScreenPos();
+
+// Draw a red circle
+draw_list->AddCircleFilled(ImVec2(p.x + 50, p.y + 50), 30.0f, IM_COL32(255, 0, 0, 255));
+
+// Draw a 3 pixel thick yellow line
+draw_list->AddLine(ImVec2(p.x, p.y), ImVec2(p.x + 100.0f, p.y + 100.0f), IM_COL32(255, 255, 0, 255), 3.0f);
+
+// Advance the ImGui cursor to claim space in the window (otherwise the window will appear small and needs to be resized)
+ImGui::Dummy(ImVec2(200, 200));
+
+ImGui::End();
+```
+![ImDrawList usage](https://raw.githubusercontent.com/wiki/ocornut/imgui/tutorials/CustomRendering01.png)
+
+- Refer to "Demo > Examples > Custom Rendering" in the demo window and read the code of `ShowExampleAppCustomRendering()` in `imgui_demo.cpp` from more examples.
+- To generate colors: you can use the macro `IM_COL32(255,255,255,255)` to generate them at compile time, or use `ImGui::GetColorU32(IM_COL32(255,255,255,255))` or `ImGui::GetColorU32(ImVec4(1.0f,1.0f,1.0f,1.0f))` to generate a color that is multiplied by the current value of `style.Alpha`.
+- Math operators: if you have setup `IM_VEC2_CLASS_EXTRA` in `imconfig.h` to bind your own math types, you can use your own math types and their natural operators instead of ImVec2. ImVec2 by default doesn't export any math operators in the public API. You may use `#define IMGUI_DEFINE_MATH_OPERATORS` `#include "imgui.h"` to use our math operators, but instead prefer using your own math library and set it up in `imconfig.h`.
+- You can use `ImGui::GetBackgroundDrawList()` or `ImGui::GetForegroundDrawList()` to access draw lists which will be displayed behind and over every other Dear ImGui window (one bg/fg drawlist per viewport). This is very convenient if you need to quickly display something on the screen that is not associated with a Dear ImGui window.
+- You can also create your own empty window and draw inside it. Call Begin() with the NoBackground | NoDecoration | NoSavedSettings | NoInputs flags (The `ImGuiWindowFlags_NoDecoration` flag itself is a shortcut for NoTitleBar | NoResize | NoScrollbar | NoCollapse). Then you can retrieve the ImDrawList* via `GetWindowDrawList()` and draw to it in any way you like.
+- You can create your own ImDrawList instance. You'll need to initialize them with `ImGui::GetDrawListSharedData()`, or create your own instancing `ImDrawListSharedData`, and then call your renderer function with your own ImDrawList or ImDrawData data.
+- Looking for fun? The [ImDrawList coding party 2020](https://github.com/ocornut/imgui/issues/3606) thread is full of "don't do this at home" extreme uses of the ImDrawList API.
+
+##### [Return to Index](#index)
+
+---
+
+# Q&A: Fonts, Text
+
+### Q: How should I handle DPI in my application?
+
+The short answer is: obtain the desired DPI scale, load your fonts resized with that scale (always round down fonts size to the nearest integer), and scale your Style structure accordingly using `style.ScaleAllSizes()`.
+
+Your application may want to detect DPI change and reload the fonts and reset style between frames.
+
+Your ui code  should avoid using hardcoded constants for size and positioning. Prefer to express values as multiple of reference values such as `ImGui::GetFontSize()` or `ImGui::GetFrameHeight()`. So e.g. instead of seeing a hardcoded height of 500 for a given item/window, you may want to use `30*ImGui::GetFontSize()` instead.
+
+Down the line Dear ImGui will provide a variety of standardized reference values to facilitate using this.
+
+Applications in the `examples/` folder are not DPI aware partly because they are unable to load a custom font from the file-system (may change that in the future).
+
+The reason DPI is not auto-magically solved in stock examples is that we don't yet have a satisfying solution for the "multi-dpi" problem (using the `docking` branch: when multiple viewport windows are over multiple monitors using different DPI scales). The current way to handle this on the application side is:
+- Create and maintain one font atlas per active DPI scale (e.g. by iterating `platform_io.Monitors[]` before `NewFrame()`).
+- Hook `platform_io.OnChangedViewport()` to detect when a `Begin()` call makes a Dear ImGui window change monitor (and therefore DPI).
+- In the hook: swap atlas, swap style with correctly sized one, and remap the current font from one atlas to the other (you may need to maintain a remapping table of your fonts at varying DPI scales).
+
+This approach is relatively easy and functional but comes with two issues:
+- It's not possibly to reliably size or position a window ahead of `Begin()` without knowing on which monitor it'll land.
+- Style override may be lost during the `Begin()` call crossing monitor boundaries. You may need to do some custom scaling mumbo-jumbo if you want your `OnChangedViewport()` handler to preserve style overrides.
+
+Please note that if you are not using multi-viewports with multi-monitors using different DPI scales, you can ignore that and use the simpler technique recommended at the top.
+    
+On Windows, in addition to scaling the font size (make sure to round to an integer) and using `style.ScaleAllSizes()`, you will need to inform Windows that your application is DPI aware. If this is not done, Windows will scale the application window and the UI text will be blurry. Potential solutions to indicate DPI awareness on Windows are:
+
+- For SDL: the flag `SDL_WINDOW_ALLOW_HIGHDPI` needs to be passed to `SDL_CreateWindow()``.
+- For GLFW: this is done automatically.
+- For other Windows projects with other backends, or wrapper projects:
+  - We provide a `ImGui_ImplWin32_EnableDpiAwareness()` helper method in the Win32 backend.
+  - Use an [application manifest file](https://learn.microsoft.com/en-us/windows/win32/hidpi/setting-the-default-dpi-awareness-for-a-process) to set the `<dpiAware>` property.
+
+### Q: How can I load a different font than the default?
+Use the font atlas to load the TTF/OTF file you want:
+
+```cpp
+ImGuiIO& io = ImGui::GetIO();
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels);
+io.Fonts->GetTexDataAsRGBA32() or GetTexDataAsAlpha8()
+```
+
+Default is ProggyClean.ttf, monospace, rendered at size 13, embedded in dear imgui's source code.
+
+(Tip: monospace fonts are convenient because they allow to facilitate horizontal alignment directly at the string level.)
+
+(Read the [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) file for more details about font loading.)
+
+New programmers: remember that in C/C++ and most programming languages if you want to use a
+backslash \ within a string literal, you need to write it double backslash "\\":
+
+```cpp
+io.Fonts->AddFontFromFileTTF("MyFolder\MyFont.ttf", size);  // WRONG (you are escaping the M here!)
+io.Fonts->AddFontFromFileTTF("MyFolder\\MyFont.ttf", size); // CORRECT (Windows only)
+io.Fonts->AddFontFromFileTTF("MyFolder/MyFont.ttf", size);  // ALSO CORRECT
+```
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I easily use icons in my application?
+The most convenient and practical way is to merge an icon font such as FontAwesome inside your
+main font. Then you can refer to icons within your strings.
+You may want to see `ImFontConfig::GlyphMinAdvanceX` to make your icon look monospace to facilitate alignment.
+(Read the [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) file for more details about icons font loading.)
+With some extra effort, you may use colorful icons by registering custom rectangle space inside the font atlas,
+and copying your own graphics data into it. See docs/FONTS.md about using the AddCustomRectFontGlyph API.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I load multiple fonts?
+Use the font atlas to pack them into a single texture:
+(Read the [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) file and the code in ImFontAtlas for more details.)
+
+```cpp
+ImGuiIO& io = ImGui::GetIO();
+ImFont* font0 = io.Fonts->AddFontDefault();
+ImFont* font1 = io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels);
+ImFont* font2 = io.Fonts->AddFontFromFileTTF("myfontfile2.ttf", size_in_pixels);
+io.Fonts->GetTexDataAsRGBA32() or GetTexDataAsAlpha8()
+// the first loaded font gets used by default
+// use ImGui::PushFont()/ImGui::PopFont() to change the font at runtime
+
+// Options
+ImFontConfig config;
+config.OversampleH = 2;
+config.OversampleV = 1;
+config.GlyphOffset.y -= 1.0f;      // Move everything by 1 pixel up
+config.GlyphExtraSpacing.x = 1.0f; // Increase spacing between characters
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_pixels, &config);
+
+// Combine multiple fonts into one (e.g. for icon fonts)
+static ImWchar ranges[] = { 0xf000, 0xf3ff, 0 };
+ImFontConfig config;
+config.MergeMode = true;
+io.Fonts->AddFontDefault();
+io.Fonts->AddFontFromFileTTF("fontawesome-webfont.ttf", 16.0f, &config, ranges); // Merge icon font
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_pixels, nullptr, &config, io.Fonts->GetGlyphRangesJapanese()); // Merge japanese glyphs
+```
+
+##### [Return to Index](#index)
+
+---
+
+### Q: How can I display and input non-Latin characters such as Chinese, Japanese, Korean, Cyrillic?
+When loading a font, pass custom Unicode ranges to specify the glyphs to load.
+
+```cpp
+// Add default Japanese ranges
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels, nullptr, io.Fonts->GetGlyphRangesJapanese());
+
+// Or create your own custom ranges (e.g. for a game you can feed your entire game script and only build the characters the game need)
+ImVector<ImWchar> ranges;
+ImFontGlyphRangesBuilder builder;
+builder.AddText("Hello world");                        // Add a string (here "Hello world" contains 7 unique characters)
+builder.AddChar(0x7262);                               // Add a specific character
+builder.AddRanges(io.Fonts->GetGlyphRangesJapanese()); // Add one of the default ranges
+builder.BuildRanges(&ranges);                          // Build the final result (ordered ranges with all the unique characters submitted)
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", 16.0f, nullptr, ranges.Data);
+```
+
+All your strings need to use UTF-8 encoding. In C++11 you can encode a string literal in UTF-8
+by using the u8"hello" syntax. Specifying literal in your source code using a local code page
+(such as CP-923 for Japanese or CP-1251 for Cyrillic) will NOT work!
+Otherwise, you can convert yourself to UTF-8 or load text data from a file already saved as UTF-8.
+
+Text input: it is up to your application to pass the right character code by calling `io.AddInputCharacter()`.
+The applications in examples/ are doing that.
+Windows: you can use the WM_CHAR or WM_UNICHAR or WM_IME_CHAR message (depending if your app is built using Unicode or MultiByte mode).
+You may also use `MultiByteToWideChar()` or `ToUnicode()` to retrieve Unicode codepoints from MultiByte characters or keyboard state.
+Windows: if your language is relying on an Input Method Editor (IME), you can write your HWND to ImGui::GetMainViewport()->PlatformHandleRaw
+for the default implementation of io.SetPlatformImeDataFn() to set your Microsoft IME position correctly.
+
+##### [Return to Index](#index)
+
+---
+
+# Q&A: Concerns
+
+### Q: Who uses Dear ImGui?
+
+You may take a look at:
+
+- [Quotes](https://github.com/ocornut/imgui/wiki/Quotes)
+- [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui)
+- [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors)
+- [Gallery](https://github.com/ocornut/imgui/issues/5886)
+
+##### [Return to Index](#index)
+
+---
+
+### Q: Can you create elaborate/serious tools with Dear ImGui?
+
+Yes. People have written game editors, data browsers, debuggers, profilers, and all sorts of non-trivial tools with the library. In my experience, the simplicity of the API is very empowering. Your UI runs close to your live data. Make the tools always-on and everybody in the team will be inclined to create new tools (as opposed to more "offline" UI toolkits where only a fraction of your team effectively creates tools). The list of sponsors below is also an indicator that serious game teams have been using the library.
+
+Dear ImGui is very programmer centric and the immediate-mode GUI paradigm might require you to readjust some habits before you can realize its full potential. Dear ImGui is about making things that are simple, efficient, and powerful.
+
+Dear ImGui is built to be efficient and scalable toward the needs for AAA-quality applications running all day. The IMGUI paradigm offers different opportunities for optimization than the more typical RMGUI paradigm.
+
+##### [Return to Index](#index)
+
+---
+
+### Q: Can you reskin the look of Dear ImGui?
+
+Somewhat. You can alter the look of the interface to some degree: changing colors, sizes, padding, rounding, and fonts. However, as Dear ImGui is designed and optimized to create debug tools, the amount of skinning you can apply is limited. There is only so much you can stray away from the default look and feel of the interface. Dear ImGui is NOT designed to create a user interface for games, although with ingenious use of the low-level API you can do it.
+
+A reasonably skinned application may look like (screenshot from [#2529](https://github.com/ocornut/imgui/issues/2529#issuecomment-524281119)):
+![minipars](https://user-images.githubusercontent.com/314805/63589441-d9794f00-c5b1-11e9-8d96-cfc1b93702f7.png)
+
+##### [Return to Index](#index)
+
+---
+
+### Q: Why using C++ (as opposed to C)?
+
+Dear ImGui takes advantage of a few C++ language features for convenience but nothing anywhere Boost insanity/quagmire. Dear ImGui doesn't use any C++ header file. Dear ImGui uses a very small subset of C++11 features. In particular, function overloading and default parameters are used to make the API easier to use and code terser. Doing so I believe the API is sitting on a sweet spot and giving up on those features would make the API more cumbersome. Other features such as namespace, constructors, and templates (in the case of the ImVector<> class) are also relied on as a convenience.
+
+There is an auto-generated [c-api for Dear ImGui (cimgui)](https://github.com/cimgui/cimgui) by Sonoro1234 and Stephan Dilly. It is designed for creating bindings to other languages. If possible, I would suggest using your target language functionalities to try replicating the function overloading and default parameters used in C++ else the API may be harder to use. Also see [Bindings](https://github.com/ocornut/imgui/wiki/Bindings) for various third-party bindings.
+
+##### [Return to Index](#index)
+
+---
+
+# Q&A: Community
+
+### Q: How can I help?
+- Businesses: please reach out to `contact AT dearimgui.com` if you work in a place using Dear ImGui! We can discuss ways for your company to fund development via invoiced technical support, maintenance, or sponsoring contacts. This is among the most useful thing you can do for Dear ImGui. With increased funding, we can hire more people to work on this project.
+- Individuals: you can support continued maintenance and development via PayPal donations. See [README](https://github.com/ocornut/imgui/blob/master/docs/README.md).
+- If you are experienced with Dear ImGui and C++, look at [GitHub Issues](https://github.com/ocornut/imgui/issues), [GitHub Discussions](https://github.com/ocornut/imgui/discussions), the [Wiki](https://github.com/ocornut/imgui/wiki), read [docs/TODO.txt](https://github.com/ocornut/imgui/blob/master/docs/TODO.txt), and see how you want to help and can help!
+- Disclose your usage of Dear ImGui via a dev blog post, a tweet, a screenshot, a mention somewhere, etc.
+You may post screenshots or links in the [gallery threads](https://github.com/ocornut/imgui/issues/5886). Visuals are ideal as they inspire other programmers. Disclosing your use of Dear ImGui helps the library grow credibility, and helps other teams and programmers with taking decisions.
+- If you have issues or if you need to hack into the library, even if you don't expect any support it is useful that you share your issues or sometimes incomplete PR.
+
+##### [Return to Index](#index)
+

third_party/imgui/docs/FONTS.md

@@ -0,0 +1,401 @@
+_(You may browse this at https://github.com/ocornut/imgui/blob/master/docs/FONTS.md or view this file with any Markdown viewer)_
+
+## Dear ImGui: Using Fonts
+
+The code in imgui.cpp embeds a copy of 'ProggyClean.ttf' (by Tristan Grimmer),
+a 13 pixels high, pixel-perfect font used by default. We embed it in the source code so you can use Dear ImGui without any file system access. ProggyClean does not scale smoothly, therefore it is recommended that you load your own file when using Dear ImGui in an application aiming to look nice and wanting to support multiple resolutions.
+
+You may also load external .TTF/.OTF files.
+In the [misc/fonts/](https://github.com/ocornut/imgui/tree/master/misc/fonts) folder you can find a few suggested fonts, provided as a convenience.
+
+**Also read the FAQ:** https://www.dearimgui.com/faq (there is a Fonts section!)
+
+## Index
+- [Readme First](#readme-first)
+- [How should I handle DPI in my application?](#how-should-i-handle-dpi-in-my-application)
+- [Fonts Loading Instructions](#font-loading-instructions)
+- [Using Icon Fonts](#using-icon-fonts)
+- [Using FreeType Rasterizer (imgui_freetype)](#using-freetype-rasterizer-imgui_freetype)
+- [Using Colorful Glyphs/Emojis](#using-colorful-glyphsemojis)
+- [Using Custom Glyph Ranges](#using-custom-glyph-ranges)
+- [Using Custom Colorful Icons](#using-custom-colorful-icons)
+- [Using Font Data Embedded In Source Code](#using-font-data-embedded-in-source-code)
+- [About filenames](#about-filenames)
+- [Credits/Licenses For Fonts Included In Repository](#creditslicenses-for-fonts-included-in-repository)
+- [Font Links](#font-links)
+
+---------------------------------------
+ ## Readme First
+
+- You can use the `Metrics/Debugger` window (available in `Demo>Tools`) to browse your fonts and understand what's going on if you have an issue. You can also reach it in `Demo->Tools->Style Editor->Fonts`. The same information are also available in the Style Editor under Fonts.
+
+![Fonts debugging](https://user-images.githubusercontent.com/8225057/135429892-0e41ef8d-33c5-4991-bcf6-f997a0bcfd6b.png)
+
+- You can use the `UTF-8 Encoding viewer` in `Metrics/Debugger` to verify the content of your UTF-8 strings. From C/C++ code, you can call `ImGui::DebugTextEncoding("my string");` function to verify that your UTF-8 encoding is correct.
+
+![UTF-8 Encoding viewer](https://user-images.githubusercontent.com/8225057/166505963-8a0d7899-8ee8-4558-abb2-1ae523dc02f9.png)
+
+- All loaded fonts glyphs are rendered into a single texture atlas ahead of time. Calling either of `io.Fonts->GetTexDataAsAlpha8()`, `io.Fonts->GetTexDataAsRGBA32()` or `io.Fonts->Build()` will build the atlas.
+
+- Make sure your font ranges data are persistent (available during the calls to `GetTexDataAsAlpha8()`/`GetTexDataAsRGBA32()/`Build()`.
+
+- Use C++11 u8"my text" syntax to encode literal strings as UTF-8. e.g.:
+```cpp
+u8"hello"
+u8"こんにちは"   // this will be encoded as UTF-8
+```
+
+##### [Return to Index](#index)
+
+## How should I handle DPI in my application?
+
+See [FAQ entry](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-how-should-i-handle-dpi-in-my-application).
+
+##### [Return to Index](#index)
+
+
+## Font Loading Instructions
+
+**Load default font:**
+```cpp
+ImGuiIO& io = ImGui::GetIO();
+io.Fonts->AddFontDefault();
+```
+
+
+**Load .TTF/.OTF file with:**
+```cpp
+ImGuiIO& io = ImGui::GetIO();
+io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
+```
+If you get an assert stating "Could not load font file!", your font filename is likely incorrect. Read "[About filenames](#about-filenames)" carefully.
+
+
+**Load multiple fonts:**
+```cpp
+// Init
+ImGuiIO& io = ImGui::GetIO();
+ImFont* font1 = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
+ImFont* font2 = io.Fonts->AddFontFromFileTTF("anotherfont.otf", size_pixels);
+```
+```cpp
+// In application loop: select font at runtime
+ImGui::Text("Hello"); // use the default font (which is the first loaded font)
+ImGui::PushFont(font2);
+ImGui::Text("Hello with another font");
+ImGui::PopFont();
+```
+
+
+**For advanced options create a ImFontConfig structure and pass it to the AddFont() function (it will be copied internally):**
+```cpp
+ImFontConfig config;
+config.OversampleH = 2;
+config.OversampleV = 1;
+config.GlyphExtraSpacing.x = 1.0f;
+ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, &config);
+```
+
+
+**Combine multiple fonts into one:**
+```cpp
+// Load a first font
+ImFont* font = io.Fonts->AddFontDefault();
+
+// Add character ranges and merge into the previous font
+// The ranges array is not copied by the AddFont* functions and is used lazily
+// so ensure it is available at the time of building or calling GetTexDataAsRGBA32().
+static const ImWchar icons_ranges[] = { 0xf000, 0xf3ff, 0 }; // Will not be copied by AddFont* so keep in scope.
+ImFontConfig config;
+config.MergeMode = true;
+io.Fonts->AddFontFromFileTTF("DroidSans.ttf", 18.0f, &config, io.Fonts->GetGlyphRangesJapanese()); // Merge into first font
+io.Fonts->AddFontFromFileTTF("fontawesome-webfont.ttf", 18.0f, &config, icons_ranges);             // Merge into first font
+io.Fonts->Build();
+```
+
+**Add a fourth parameter to bake specific font ranges only:**
+
+```cpp
+// Basic Latin, Extended Latin
+io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, nullptr, io.Fonts->GetGlyphRangesDefault());
+
+// Default + Selection of 2500 Ideographs used by Simplified Chinese
+io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, nullptr, io.Fonts->GetGlyphRangesChineseSimplifiedCommon());
+
+// Default + Hiragana, Katakana, Half-Width, Selection of 1946 Ideographs
+io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, nullptr, io.Fonts->GetGlyphRangesJapanese());
+```
+See [Using Custom Glyph Ranges](#using-custom-glyph-ranges) section to create your own ranges.
+
+
+**Example loading and using a Japanese font:**
+
+```cpp
+ImGuiIO& io = ImGui::GetIO();
+io.Fonts->AddFontFromFileTTF("NotoSansCJKjp-Medium.otf", 20.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
+```
+```cpp
+ImGui::Text(u8"こんにちは！テスト %d", 123);
+if (ImGui::Button(u8"ロード"))
+{
+    // do stuff
+}
+ImGui::InputText("string", buf, IM_ARRAYSIZE(buf));
+ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
+```
+
+![sample code output](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v160/code_sample_02_jp.png)
+<br>_(settings: Dark style (left), Light style (right) / Font: NotoSansCJKjp-Medium, 20px / Rounding: 5)_
+
+**Font Atlas too large?**
+
+- If you have very large number of glyphs or multiple fonts, the texture may become too big for your graphics API. The typical result of failing to upload a texture is if every glyph appears as a white rectangle.
+- Mind the fact that some graphics drivers have texture size limitation. If you are building a PC application, mind the fact that your users may use hardware with lower limitations than yours.
+
+Some solutions:
+
+1. Reduce glyphs ranges by calculating them from source localization data.
+   You can use the `ImFontGlyphRangesBuilder` for this purpose and rebuilding your atlas between frames when new characters are needed. This will be the biggest win!
+2. You may reduce oversampling, e.g. `font_config.OversampleH = 2`, this will largely reduce your texture size.
+   Note that while OversampleH = 2 looks visibly very close to 3 in most situations, with OversampleH = 1 the quality drop will be noticeable.
+3. Set `io.Fonts.TexDesiredWidth` to specify a texture width to minimize texture height (see comment in `ImFontAtlas::Build()` function).
+4. Set `io.Fonts.Flags |= ImFontAtlasFlags_NoPowerOfTwoHeight;` to disable rounding the texture height to the next power of two.
+5. Read about oversampling [here](https://github.com/nothings/stb/blob/master/tests/oversample).
+6. To support the extended range of unicode beyond 0xFFFF (e.g. emoticons, dingbats, symbols, shapes, ancient languages, etc...) add `#define IMGUI_USE_WCHAR32`in your `imconfig.h`.
+
+##### [Return to Index](#index)
+
+## Using Icon Fonts
+
+Using an icon font (such as [FontAwesome](http://fontawesome.io) or [OpenFontIcons](https://github.com/traverseda/OpenFontIcons)) is an easy and practical way to use icons in your Dear ImGui application.
+A common pattern is to merge the icon font within your main font, so you can embed icons directly from your strings without having to change fonts back and forth.
+
+To refer to the icon UTF-8 codepoints from your C++ code, you may use those headers files created by Juliette Foucaut: https://github.com/juliettef/IconFontCppHeaders.
+
+So you can use `ICON_FA_SEARCH` as a string that will render as a "Search" icon.
+
+Example Setup:
+```cpp
+// Merge icons into default tool font
+#include "IconsFontAwesome.h"
+ImGuiIO& io = ImGui::GetIO();
+io.Fonts->AddFontDefault();
+
+ImFontConfig config;
+config.MergeMode = true;
+config.GlyphMinAdvanceX = 13.0f; // Use if you want to make the icon monospaced
+static const ImWchar icon_ranges[] = { ICON_MIN_FA, ICON_MAX_FA, 0 };
+io.Fonts->AddFontFromFileTTF("fonts/fontawesome-webfont.ttf", 13.0f, &config, icon_ranges);
+```
+Example Usage:
+```cpp
+// Usage, e.g.
+ImGui::Text("%s among %d items", ICON_FA_SEARCH, count);
+ImGui::Button(ICON_FA_SEARCH " Search");
+// C string _literals_ can be concatenated at compilation time, e.g. "hello" " world"
+// ICON_FA_SEARCH is defined as a string literal so this is the same as "A" "B" becoming "AB"
+```
+See Links below for other icons fonts and related tools.
+
+Here's an application using icons ("Avoyd", https://www.avoyd.com):
+![avoyd](https://user-images.githubusercontent.com/8225057/81696852-c15d9e80-9464-11ea-9cab-2a4d4fc84396.jpg)
+
+##### [Return to Index](#index)
+
+## Using FreeType Rasterizer (imgui_freetype)
+
+- Dear ImGui uses imstb\_truetype.h to rasterize fonts (with optional oversampling). This technique and its implementation are not ideal for fonts rendered at small sizes, which may appear a little blurry or hard to read.
+- There is an implementation of the ImFontAtlas builder using FreeType that you can use in the [misc/freetype/](https://github.com/ocornut/imgui/tree/master/misc/freetype) folder.
+- FreeType supports auto-hinting which tends to improve the readability of small fonts.
+- Read documentation in the [misc/freetype/](https://github.com/ocornut/imgui/tree/master/misc/freetype) folder.
+- Correct sRGB space blending will have an important effect on your font rendering quality.
+
+##### [Return to Index](#index)
+
+## Using Colorful Glyphs/Emojis
+
+- Rendering of colored emojis is only supported by imgui_freetype with FreeType 2.10+.
+- You will need to load fonts with the `ImGuiFreeTypeBuilderFlags_LoadColor` flag.
+- Emojis are frequently encoded in upper Unicode layers (character codes >0x10000) and will need dear imgui compiled with `IMGUI_USE_WCHAR32`.
+- Not all types of color fonts are supported by FreeType at the moment.
+- Stateful Unicode features such as skin tone modifiers are not supported by the text renderer.
+
+![colored glyphs](https://user-images.githubusercontent.com/8225057/106171241-9dc4ba80-6191-11eb-8a69-ca1467b206d1.png)
+
+```cpp
+io.Fonts->AddFontFromFileTTF("../../../imgui_dev/data/fonts/NotoSans-Regular.ttf", 16.0f);
+static ImWchar ranges[] = { 0x1, 0x1FFFF, 0 };
+static ImFontConfig cfg;
+cfg.OversampleH = cfg.OversampleV = 1;
+cfg.MergeMode = true;
+cfg.FontBuilderFlags |= ImGuiFreeTypeBuilderFlags_LoadColor;
+io.Fonts->AddFontFromFileTTF("C:\\Windows\\Fonts\\seguiemj.ttf", 16.0f, &cfg, ranges);
+```
+
+##### [Return to Index](#index)
+
+## Using Custom Glyph Ranges
+
+You can use the `ImFontGlyphRangesBuilder` helper to create glyph ranges based on text input. For example: for a game where your script is known, if you can feed your entire script to it and only build the characters the game needs.
+```cpp
+ImVector<ImWchar> ranges;
+ImFontGlyphRangesBuilder builder;
+builder.AddText("Hello world");                        // Add a string (here "Hello world" contains 7 unique characters)
+builder.AddChar(0x7262);                               // Add a specific character
+builder.AddRanges(io.Fonts->GetGlyphRangesJapanese()); // Add one of the default ranges
+builder.BuildRanges(&ranges);                          // Build the final result (ordered ranges with all the unique characters submitted)
+
+io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels, nullptr, ranges.Data);
+io.Fonts->Build();                                     // Build the atlas while 'ranges' is still in scope and not deleted.
+```
+
+##### [Return to Index](#index)
+
+## Using Custom Colorful Icons
+
+As an alternative to rendering colorful glyphs using imgui_freetype with `ImGuiFreeTypeBuilderFlags_LoadColor`, you may allocate your own space in the texture atlas and write yourself into it. **(This is a BETA api, use if you are familiar with dear imgui and with your rendering backend)**
+
+- You can use the `ImFontAtlas::AddCustomRect()` and `ImFontAtlas::AddCustomRectFontGlyph()` api to register rectangles that will be packed into the font atlas texture. Register them before building the atlas, then call Build()`.
+- You can then use `ImFontAtlas::GetCustomRectByIndex(int)` to query the position/size of your rectangle within the texture, and blit/copy any graphics data of your choice into those rectangles.
+- This API is beta because it is likely to change in order to support multi-dpi (multiple viewports on multiple monitors with varying DPI scale).
+
+#### Pseudo-code:
+```cpp
+// Add font, then register two custom 13x13 rectangles mapped to glyph 'a' and 'b' of this font
+ImFont* font = io.Fonts->AddFontDefault();
+int rect_ids[2];
+rect_ids[0] = io.Fonts->AddCustomRectFontGlyph(font, 'a', 13, 13, 13+1);
+rect_ids[1] = io.Fonts->AddCustomRectFontGlyph(font, 'b', 13, 13, 13+1);
+
+// Build atlas
+io.Fonts->Build();
+
+// Retrieve texture in RGBA format
+unsigned char* tex_pixels = nullptr;
+int tex_width, tex_height;
+io.Fonts->GetTexDataAsRGBA32(&tex_pixels, &tex_width, &tex_height);
+
+for (int rect_n = 0; rect_n < IM_ARRAYSIZE(rect_ids); rect_n++)
+{
+    int rect_id = rect_ids[rect_n];
+    if (const ImFontAtlasCustomRect* rect = io.Fonts->GetCustomRectByIndex(rect_id))
+    {
+        // Fill the custom rectangle with red pixels (in reality you would draw/copy your bitmap data here!)
+        for (int y = 0; y < rect->Height; y++)
+        {
+            ImU32* p = (ImU32*)tex_pixels + (rect->Y + y) * tex_width + (rect->X);
+            for (int x = rect->Width; x > 0; x--)
+                *p++ = IM_COL32(255, 0, 0, 255);
+        }
+    }
+}
+```
+
+##### [Return to Index](#index)
+
+## Using Font Data Embedded In Source Code
+
+- Compile and use [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) to create a compressed C style array that you can embed in source code.
+- See the documentation in [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) for instructions on how to use the tool.
+- You may find a precompiled version binary_to_compressed_c.exe for Windows inside the demo binaries package (see [README](https://github.com/ocornut/imgui/blob/master/docs/README.md)).
+- The tool can optionally output Base85 encoding to reduce the size of _source code_ but the read-only arrays in the actual binary will be about 20% bigger.
+
+Then load the font with:
+```cpp
+ImFont* font = io.Fonts->AddFontFromMemoryCompressedTTF(compressed_data, compressed_data_size, size_pixels, ...);
+```
+or
+```cpp
+ImFont* font = io.Fonts->AddFontFromMemoryCompressedBase85TTF(compressed_data_base85, size_pixels, ...);
+```
+
+##### [Return to Index](#index)
+
+## About filenames
+
+**Please note that many new C/C++ users have issues loading their files _because the filename they provide is wrong_.**
+
+Two things to watch for:
+- Make sure your IDE/debugger settings starts your executable from the right working directory. In Visual Studio you can change your working directory in project `Properties > General > Debugging > Working Directory`. People assume that their execution will start from the root folder of the project, where by default it often starts from the folder where object or executable files are stored.
+```cpp
+// Relative filename depends on your Working Directory when running your program!
+io.Fonts->AddFontFromFileTTF("MyImage01.jpg", ...);
+
+// Load from the parent folder of your Working Directory
+io.Fonts->AddFontFromFileTTF("../MyImage01.jpg", ...);
+```
+- In C/C++ and most programming languages if you want to use a backslash `\` within a string literal, you need to write it double backslash `\\`. At it happens, Windows uses backslashes as a path separator, so be mindful.
+```cpp
+io.Fonts->AddFontFromFileTTF("MyFiles\MyImage01.jpg", ...);   // This is INCORRECT!!
+io.Fonts->AddFontFromFileTTF("MyFiles\\MyImage01.jpg", ...);  // This is CORRECT
+```
+In some situations, you may also use `/` path separator under Windows.
+
+##### [Return to Index](#index)
+
+## Credits/Licenses For Fonts Included In Repository
+
+Some fonts files are available in the `misc/fonts/` folder:
+
+**Roboto-Medium.ttf**, by Christian Robetson
+<br>Apache License 2.0
+<br>https://fonts.google.com/specimen/Roboto
+
+**Cousine-Regular.ttf**, by Steve Matteson
+<br>Digitized data copyright (c) 2010 Google Corporation.
+<br>Licensed under the SIL Open Font License, Version 1.1
+<br>https://fonts.google.com/specimen/Cousine
+
+**DroidSans.ttf**, by Steve Matteson
+<br>Apache License 2.0
+<br>https://www.fontsquirrel.com/fonts/droid-sans
+
+**ProggyClean.ttf**, by Tristan Grimmer
+<br>MIT License
+<br>(recommended loading setting: Size = 13.0, GlyphOffset.y = +1)
+<br>http://www.proggyfonts.net/
+
+**ProggyTiny.ttf**, by Tristan Grimmer
+<br>MIT License
+<br>(recommended loading setting: Size = 10.0, GlyphOffset.y = +1)
+<br>http://www.proggyfonts.net/
+
+**Karla-Regular.ttf**, by Jonathan Pinhorn
+<br>SIL OPEN FONT LICENSE Version 1.1
+
+##### [Return to Index](#index)
+
+## Font Links
+
+#### ICON FONTS
+
+- C/C++ header for icon fonts (#define with code points to use in source code string literals) https://github.com/juliettef/IconFontCppHeaders
+- FontAwesome https://fortawesome.github.io/Font-Awesome
+- OpenFontIcons https://github.com/traverseda/OpenFontIcons
+- Google Icon Fonts https://design.google.com/icons/
+- Kenney Icon Font (Game Controller Icons) https://github.com/nicodinh/kenney-icon-font
+- IcoMoon - Custom Icon font builder https://icomoon.io/app
+
+#### REGULAR FONTS
+
+- Google Noto Fonts (worldwide languages) https://www.google.com/get/noto/
+- Open Sans Fonts https://fonts.google.com/specimen/Open+Sans
+- (Japanese) M+ fonts by Coji Morishita http://mplus-fonts.sourceforge.jp/mplus-outline-fonts/index-en.html
+
+#### MONOSPACE FONTS
+
+Pixel Perfect:
+- Proggy Fonts, by Tristan Grimmer http://www.proggyfonts.net or http://upperbounds.net
+- Sweet16, Sweet16 Mono, by Martin Sedlak (Latin + Supplemental + Extended A) https://github.com/kmar/Sweet16Font (also include an .inl file to use directly in dear imgui.)
+
+Regular:
+- Google Noto Mono Fonts https://www.google.com/get/noto/
+- Typefaces for source code beautification https://github.com/chrissimpkins/codeface
+- Programmation fonts http://s9w.github.io/font_compare/
+- Inconsolata http://www.levien.com/type/myfonts/inconsolata.html
+- Adobe Source Code Pro: Monospaced font family for ui & coding environments https://github.com/adobe-fonts/source-code-pro
+- Monospace/Fixed Width Programmer's Fonts http://www.lowing.org/fonts/
+
+Or use Arial Unicode or other Unicode fonts provided with Windows for full characters coverage (not sure of their licensing).
+
+##### [Return to Index](#index)

third_party/imgui/docs/README.md

@@ -0,0 +1,214 @@
+Dear ImGui
+=====
+
+<center><b><i>"Give someone state and they'll have a bug one day, but teach them how to represent state in two separate locations that have to be kept in sync and they'll have bugs for a lifetime."</i></b></center> <a href="https://twitter.com/rygorous/status/1507178315886444544">-ryg</a>
+
+----
+
+[![Build Status](https://github.com/ocornut/imgui/workflows/build/badge.svg)](https://github.com/ocornut/imgui/actions?workflow=build) [![Static Analysis Status](https://github.com/ocornut/imgui/workflows/static-analysis/badge.svg)](https://github.com/ocornut/imgui/actions?workflow=static-analysis) [![Tests Status](https://github.com/ocornut/imgui_test_engine/workflows/tests/badge.svg)](https://github.com/ocornut/imgui_test_engine/actions?workflow=tests)
+
+<sub>(This library is available under a free and permissive license, but needs financial support to sustain its continued improvements. In addition to maintenance and stability there are many desirable features yet to be added. If your company is using Dear ImGui, please consider reaching out.)</sub>
+
+Businesses: support continued development and maintenance via invoiced sponsoring/support contracts:
+<br>&nbsp;&nbsp;_E-mail: contact @ dearimgui dot com_
+<br>Individuals: support continued development and maintenance [here](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=WGHNC6MBFLZ2S). Also see [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors) page.
+
+| [The Pitch](#the-pitch) - [Usage](#usage) - [How it works](#how-it-works) - [Releases & Changelogs](#releases--changelogs) - [Demo](#demo) - [Integration](#integration) |
+:----------------------------------------------------------: |
+| [Gallery](#gallery) - [Support, FAQ](#support-frequently-asked-questions-faq) -  [How to help](#how-to-help) - [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors) - [Credits](#credits) - [License](#license) |
+| [Wiki](https://github.com/ocornut/imgui/wiki) - [Languages & frameworks backends/bindings](https://github.com/ocornut/imgui/wiki/Bindings) - [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) - [User quotes](https://github.com/ocornut/imgui/wiki/Quotes) |
+
+### The Pitch
+
+Dear ImGui is a **bloat-free graphical user interface library for C++**. It outputs optimized vertex buffers that you can render anytime in your 3D-pipeline-enabled application. It is fast, portable, renderer agnostic, and self-contained (no external dependencies).
+
+Dear ImGui is designed to **enable fast iterations** and to **empower programmers** to create **content creation tools and visualization / debug tools** (as opposed to UI for the average end-user). It favors simplicity and productivity toward this goal and lacks certain features commonly found in more high-level libraries.
+
+Dear ImGui is particularly suited to integration in game engines (for tooling), real-time 3D applications, fullscreen applications, embedded applications, or any applications on console platforms where operating system features are non-standard.
+
+ - Minimize state synchronization.
+ - Minimize state storage on user side.
+ - Minimize setup and maintenance.
+ - Easy to use to create dynamic UI which are the reflection of a dynamic data set.
+ - Easy to use to create code-driven and data-driven tools.
+ - Easy to use to create ad hoc short-lived tools and long-lived, more elaborate tools.
+ - Easy to hack and improve.
+ - Portable, minimize dependencies, run on target (consoles, phones, etc.).
+ - Efficient runtime and memory consumption.
+ - Battle-tested, used by [many major actors in the game industry](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui).
+
+### Usage
+
+**The core of Dear ImGui is self-contained within a few platform-agnostic files** which you can easily compile in your application/engine. They are all the files in the root folder of the repository (imgui*.cpp, imgui*.h). **No specific build process is required**. You can add the .cpp files into your existing project.
+
+**Backends for a variety of graphics API and rendering platforms** are provided in the [backends/](https://github.com/ocornut/imgui/tree/master/backends) folder, along with example applications in the [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder. See the [Integration](#integration) section of this document for details. You may also create your own backend. Anywhere where you can render textured triangles, you can render Dear ImGui.
+
+After Dear ImGui is set up in your application, you can use it from \_anywhere\_ in your program loop:
+```cpp
+ImGui::Text("Hello, world %d", 123);
+if (ImGui::Button("Save"))
+    MySaveFunction();
+ImGui::InputText("string", buf, IM_ARRAYSIZE(buf));
+ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
+```
+![sample code output (dark, segoeui font, freetype)](https://user-images.githubusercontent.com/8225057/191050833-b7ecf528-bfae-4a9f-ac1b-f3d83437a2f4.png)
+![sample code output (light, segoeui font, freetype)](https://user-images.githubusercontent.com/8225057/191050838-8742efd4-504d-4334-a9a2-e756d15bc2ab.png)
+
+```cpp
+// Create a window called "My First Tool", with a menu bar.
+ImGui::Begin("My First Tool", &my_tool_active, ImGuiWindowFlags_MenuBar);
+if (ImGui::BeginMenuBar())
+{
+    if (ImGui::BeginMenu("File"))
+    {
+        if (ImGui::MenuItem("Open..", "Ctrl+O")) { /* Do stuff */ }
+        if (ImGui::MenuItem("Save", "Ctrl+S"))   { /* Do stuff */ }
+        if (ImGui::MenuItem("Close", "Ctrl+W"))  { my_tool_active = false; }
+        ImGui::EndMenu();
+    }
+    ImGui::EndMenuBar();
+}
+
+// Edit a color stored as 4 floats
+ImGui::ColorEdit4("Color", my_color);
+
+// Generate samples and plot them
+float samples[100];
+for (int n = 0; n < 100; n++)
+    samples[n] = sinf(n * 0.2f + ImGui::GetTime() * 1.5f);
+ImGui::PlotLines("Samples", samples, 100);
+
+// Display contents in a scrolling region
+ImGui::TextColored(ImVec4(1,1,0,1), "Important Stuff");
+ImGui::BeginChild("Scrolling");
+for (int n = 0; n < 50; n++)
+    ImGui::Text("%04d: Some text", n);
+ImGui::EndChild();
+ImGui::End();
+```
+![my_first_tool_v188](https://user-images.githubusercontent.com/8225057/191055698-690a5651-458f-4856-b5a9-e8cc95c543e2.gif)
+
+Dear ImGui allows you to **create elaborate tools** as well as very short-lived ones. On the extreme side of short-livedness: using the Edit&Continue (hot code reload) feature of modern compilers you can add a few widgets to tweak variables while your application is running, and remove the code a minute later! Dear ImGui is not just for tweaking values. You can use it to trace a running algorithm by just emitting text commands. You can use it along with your own reflection data to browse your dataset live. You can use it to expose the internals of a subsystem in your engine, to create a logger, an inspection tool, a profiler, a debugger, an entire game-making editor/framework, etc.
+
+### How it works
+
+Check out the Wiki's [About the IMGUI paradigm](https://github.com/ocornut/imgui/wiki#about-the-imgui-paradigm) section if you want to understand the core principles behind the IMGUI paradigm. An IMGUI tries to minimize superfluous state duplication, state synchronization, and state retention from the user's point of view. It is less error-prone (less code and fewer bugs) than traditional retained-mode interfaces, and lends itself to creating dynamic user interfaces.
+
+Dear ImGui outputs vertex buffers and command lists that you can easily render in your application. The number of draw calls and state changes required to render them is fairly small. Because Dear ImGui doesn't know or touch graphics state directly, you can call its functions  anywhere in your code (e.g. in the middle of a running algorithm, or in the middle of your own rendering process). Refer to the sample applications in the examples/ folder for instructions on how to integrate Dear ImGui with your existing codebase.
+
+_A common misunderstanding is to mistake immediate mode GUI for immediate mode rendering, which usually implies hammering your driver/GPU with a bunch of inefficient draw calls and state changes as the GUI functions are called. This is NOT what Dear ImGui does. Dear ImGui outputs vertex buffers and a small list of draw calls batches. It never touches your GPU directly. The draw call batches are decently optimal and you can render them later, in your app or even remotely._
+
+### Releases & Changelogs
+
+See [Releases](https://github.com/ocornut/imgui/releases) page for decorated Changelogs.
+Reading the changelogs is a good way to keep up to date with the things Dear ImGui has to offer, and maybe will give you ideas of some features that you've been ignoring until now!
+
+### Demo
+
+Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. [Here's how the demo looks](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
+
+You should be able to build the examples from sources. If you don't, let us know! If you want to have a quick look at some Dear ImGui features, you can download Windows binaries of the demo app here:
+- [imgui-demo-binaries-20220504.zip](https://www.dearimgui.com/binaries/imgui-demo-binaries-20220504.zip) (Windows, 1.88 WIP, built 2022/05/04, master) or [older binaries](https://www.dearimgui.com/binaries).
+
+The demo applications are not DPI aware so expect some blurriness on a 4K screen. For DPI awareness in your application, you can load/reload your font at a different scale and scale your style with `style.ScaleAllSizes()` (see [FAQ](https://www.dearimgui.com/faq)).
+
+### Integration
+
+On most platforms and when using C++, **you should be able to use a combination of the [imgui_impl_xxxx](https://github.com/ocornut/imgui/tree/master/backends) backends without modification** (e.g. `imgui_impl_win32.cpp` + `imgui_impl_dx11.cpp`). If your engine supports multiple platforms, consider using more imgui_impl_xxxx files instead of rewriting them: this will be less work for you, and you can get Dear ImGui running immediately. You can _later_ decide to rewrite a custom backend using your custom engine functions if you wish so.
+
+Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that. If you are an experienced programmer at ease with those concepts, it should take you less than two hours to integrate Dear ImGui into your custom engine. **Make sure to spend time reading the [FAQ](https://www.dearimgui.com/faq), comments, and the examples applications!**
+
+Officially maintained backends/bindings (in repository):
+- Renderers: DirectX9, DirectX10, DirectX11, DirectX12, Metal, OpenGL/ES/ES2, SDL_Renderer, Vulkan, WebGPU.
+- Platforms: GLFW, SDL2, Win32, Glut, OSX, Android.
+- Frameworks: Allegro5, Emscripten.
+
+[Third-party backends/bindings](https://github.com/ocornut/imgui/wiki/Bindings) wiki page:
+- Languages: C, C# and: Beef, ChaiScript, Crystal, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lobster, Lua, Odin, Pascal, PureBasic, Python, Ruby, Rust, Swift...
+- Frameworks: AGS/Adventure Game Studio, Amethyst, Blender, bsf, Cinder, Cocos2d-x, Diligent Engine, Flexium, GML/Game Maker Studio2, GLEQ, Godot, GTK3+OpenGL3, Irrlicht Engine, LÖVE+LUA, Magnum, Monogame, NanoRT, nCine, Nim Game Lib, Nintendo 3DS & Switch (homebrew), Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, SDL_Renderer, SFML, Sokol, Unity, Unreal Engine 4, vtk, VulkanHpp, VulkanSceneGraph, Win32 GDI, WxWidgets.
+- Many bindings are auto-generated (by good old [cimgui](https://github.com/cimgui/cimgui) or newer/experimental [dear_bindings](https://github.com/dearimgui/dear_bindings)), you can use their metadata output to generate bindings for other languages.
+
+[Useful Extensions/Widgets](https://github.com/ocornut/imgui/wiki/Useful-Extensions) wiki page:
+- Automation/testing, Text editors, node editors, timeline editors, plotting, software renderers, remote network access, memory editors, gizmos, etc. One of the most notable and well supported extension is [ImPlot](https://github.com/epezent/implot).
+
+Also see [Wiki](https://github.com/ocornut/imgui/wiki) for more links and ideas.
+
+### Gallery
+
+For more user-submitted screenshots of projects using Dear ImGui, check out the [Gallery Threads](https://github.com/ocornut/imgui/issues/5886)!
+
+For a list of third-party widgets and extensions, check out the [Useful Extensions/Widgets](https://github.com/ocornut/imgui/wiki/Useful-Extensions) wiki page.
+
+|  |  |
+|--|--|
+| Custom engine [erhe](https://github.com/tksuoran/erhe) (docking branch)<BR>[![erhe](https://user-images.githubusercontent.com/8225057/190203358-6988b846-0686-480e-8663-1311fbd18abd.jpg)](https://user-images.githubusercontent.com/994606/147875067-a848991e-2ad2-4fd3-bf71-4aeb8a547bcf.png) | Custom engine for [Wonder Boy: The Dragon's Trap](http://www.TheDragonsTrap.com) (2017)<BR>[![the dragon's trap](https://user-images.githubusercontent.com/8225057/190203379-57fcb80e-4aec-4fec-959e-17ddd3cd71e5.jpg)](https://cloud.githubusercontent.com/assets/8225057/20628927/33e14cac-b329-11e6-80f6-9524e93b048a.png) |
+| Custom engine (untitled)<BR>[![editor white](https://user-images.githubusercontent.com/8225057/190203393-c5ac9f22-b900-4d1e-bfeb-6027c63e3d92.jpg)](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v160/editor_white.png) | Tracy Profiler ([github](https://github.com/wolfpld/tracy))<BR>[![tracy profiler](https://user-images.githubusercontent.com/8225057/190203401-7b595f6e-607c-44d3-97ea-4c2673244dfb.jpg)](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v176/tracy_profiler.png) |
+
+### Support, Frequently Asked Questions (FAQ)
+
+See: [Frequently Asked Questions (FAQ)](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md) where common questions are answered.
+
+See: [Wiki](https://github.com/ocornut/imgui/wiki) for many links, references, articles.
+
+See: [Articles about the IMGUI paradigm](https://github.com/ocornut/imgui/wiki#about-the-imgui-paradigm) to read/learn about the Immediate Mode GUI paradigm.
+
+See: [Upcoming Changes](https://github.com/ocornut/imgui/wiki/Upcoming-Changes).
+
+See: [Dear ImGui Test Engine + Test Suite](https://github.com/ocornut/imgui_test_engine) for Automation & Testing.
+
+Getting started? For first-time users having issues compiling/linking/running or issues loading fonts, please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions). For other questions, bug reports, requests, feedback, you may post on [GitHub Issues](https://github.com/ocornut/imgui/issues). Please read and fill the New Issue template carefully.
+
+Private support is available for paying business customers (E-mail: _contact @ dearimgui dot com_).
+
+**Which version should I get?**
+
+We occasionally tag [Releases](https://github.com/ocornut/imgui/releases) (with nice releases notes) but it is generally safe and recommended to sync to master/latest. The library is fairly stable and regressions tend to be fixed fast when reported. Advanced users may want to use the `docking` branch with [Multi-Viewport](https://github.com/ocornut/imgui/issues/1542) and [Docking](https://github.com/ocornut/imgui/issues/2109) features. This branch is kept in sync with master regularly.
+
+**Who uses Dear ImGui?**
+
+See the [Quotes](https://github.com/ocornut/imgui/wiki/Quotes), [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors), and [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages for an idea of who is using Dear ImGui. Please add your game/software if you can! Also, see the [Gallery Threads](https://github.com/ocornut/imgui/issues/5886)!
+
+How to help
+-----------
+
+**How can I help?**
+
+- See [GitHub Forum/Issues](https://github.com/ocornut/imgui/issues) and [GitHub Discussions](https://github.com/ocornut/imgui/discussions).
+- You may help with development and submit pull requests! Please understand that by submitting a PR you are also submitting a request for the maintainer to review your code and then take over its maintenance forever. PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it.
+- See [Help wanted](https://github.com/ocornut/imgui/wiki/Help-Wanted) on the [Wiki](https://github.com/ocornut/imgui/wiki/) for some more ideas.
+- Have your company financially support this project with invoiced sponsoring/support contracts or by buying a license for [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine) (please reach out: contact at dearimgui dot com).
+
+Sponsors
+--------
+
+Ongoing Dear ImGui development is and has been financially supported by users and private sponsors.
+<BR>Please see the **[detailed list of current and past Dear ImGui supporters](https://github.com/ocornut/imgui/wiki/Sponsors)** for details.
+<BR>From November 2014 to December 2019, ongoing development has also been financially supported by its users on Patreon and through individual donations.
+
+**THANK YOU to all past and present supporters for helping to keep this project alive and thriving!**
+
+Dear ImGui is using software and services provided free of charge for open source projects:
+- [PVS-Studio](https://www.viva64.com/en/b/0570/) for static analysis.
+- [GitHub actions](https://github.com/features/actions) for continuous integration systems.
+- [OpenCppCoverage](https://github.com/OpenCppCoverage/OpenCppCoverage) for code coverage analysis.
+
+Credits
+-------
+
+Developed by [Omar Cornut](https://www.miracleworld.net) and every direct or indirect [contributors](https://github.com/ocornut/imgui/graphs/contributors) to the GitHub. The early version of this library was developed with the support of [Media Molecule](https://www.mediamolecule.com) and first used internally on the game [Tearaway](https://tearaway.mediamolecule.com) (PS Vita).
+
+Recurring contributors (2022): Omar Cornut [@ocornut](https://github.com/ocornut), Rokas Kupstys [@rokups](https://github.com/rokups) (a good portion of work on automation system and regression tests now available in [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine)).
+
+Sponsoring, support contracts and other B2B transactions are hosted and handled by [Disco Hello](https://www.discohello.com).
+
+Omar: "I first discovered the IMGUI paradigm at [Q-Games](https://www.q-games.com) where Atman Binstock had dropped his own simple implementation in the codebase, which I spent quite some time improving and thinking about. It turned out that Atman was exposed to the concept directly by working with Casey. When I moved to Media Molecule I rewrote a new library trying to overcome the flaws and limitations of the first one I've worked with. It became this library and since then I have spent an unreasonable amount of time iterating and improving it."
+
+Embeds [ProggyClean.ttf](http://upperbounds.net) font by Tristan Grimmer (MIT license).
+<br>Embeds [stb_textedit.h, stb_truetype.h, stb_rect_pack.h](https://github.com/nothings/stb/) by Sean Barrett (public domain).
+
+Inspiration, feedback, and testing for early versions: Casey Muratori, Atman Binstock, Mikko Mononen, Emmanuel Briney, Stefan Kamoda, Anton Mikhailov, Matt Willis. Also thank you to everyone posting feedback, questions and patches on GitHub.
+
+License
+-------
+
+Dear ImGui is licensed under the MIT License, see [LICENSE.txt](https://github.com/ocornut/imgui/blob/master/LICENSE.txt) for more information.

third_party/imgui/docs/TODO.txt

@@ -0,0 +1,370 @@
+dear imgui
+ISSUES & TODO LIST
+
+Issue numbers (#) refer to GitHub issues listed at https://github.com/ocornut/imgui/issues/XXXX
+This list is not well maintained, most of the work happens on GitHub nowadays.
+The list below consist mostly of ideas noted down before they are requested/discussed by users (at which point they usually exist on the github issue tracker).
+It's mostly a bunch of personal notes, probably incomplete. Feel free to query if you have any questions.
+
+ - doc/test: add a proper documentation+regression testing system (#435)
+ - doc/test: checklist app to verify backends/integration of imgui (test inputs, rendering, callback, etc.).
+ - doc/tips: tips of the day: website? applet in imgui_club?
+ - doc/wiki: work on the wiki https://github.com/ocornut/imgui/wiki
+
+ - window: preserve/restore relative focus ordering (persistent or not), and e.g. of multiple reappearing windows (#2304) -> also see docking reference to same #.
+ - window: calling SetNextWindowSize() every frame with <= 0 doesn't do anything, may be useful to allow (particularly when used for a single axis). (#690)
+ - window: add a way for very transient windows (non-saved, temporary overlay over hundreds of objects) to "clean" up from the global window list. perhaps a lightweight explicit cleanup pass.
+ - window: auto-fit feedback loop when user relies on any dynamic layout (window width multiplier, column) appears weird to end-user. clarify.
+ - window: begin with *p_open == false could return false.
+ - window: get size/pos helpers given names (see discussion in #249)
+ - window: when window is very small, prioritize resize button over close button.
+ - window: double-clicking on title bar to minimize isn't consistent, perhaps move to single-click on left-most collapse icon?
+ - window: expose contents size. (#1045)
+ - window: using SetWindowPos() inside Begin() and moving the window with the mouse reacts a very ugly glitch. We should just defer the SetWindowPos() call.
+ - window: GetWindowSize() returns (0,0) when not calculated? (#1045)
+ - window: investigate better auto-positioning for new windows.
+ - window: top most window flag? more z-order contrl? (#2574)
+ - window/size: manually triggered auto-fit (double-click on grip) shouldn't resize window down to viewport size?
+ - window/size: how to allow to e.g. auto-size vertically to fit contents, but be horizontally resizable? Assuming SetNextWindowSize() is modified to treat -1.0f on each axis as "keep as-is" (would be good but might break erroneous code): Problem is UpdateWindowManualResize() and lots of code treat (window->AutoFitFramesX > 0 || window->AutoFitFramesY > 0) together.
+ - window/opt: freeze window flag: if not focused/hovered, return false, render with previous ImDrawList. and/or reduce refresh rate. -> this may require enforcing that it is illegal to submit contents if Begin returns false.
+ - window/child: background options for child windows, border option (disable rounding).
+ - window/child: allow resizing of child windows (possibly given min/max for each axis?.)
+ - window/child: allow SetNextWindowContentSize() to work on child windows.
+ - window/clipping: some form of clipping when DisplaySize (or corresponding viewport) is zero.
+ - window/tabbing: add a way to signify that a window or docked window requires attention (e.g. blinking title bar).
+ - window/id_stack: add e.g. window->GetIDFromPath() with support for leading / and ../ (#1390, #331)
+ ! scrolling: exposing horizontal scrolling with Shift+Wheel even when scrollbar is disabled expose lots of issues (#2424, #1463)
+ - scrolling: while holding down a scrollbar, try to keep the same contents visible (at least while not moving mouse)
+ - scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet.
+ - scrolling: forward mouse wheel scrolling to parent window when at the edge of scrolling limits? (useful for listbox,tables?)
+ - scrolling/clipping: separator on the initial position of a window is not visible (cursorpos.y <= clippos.y). (2017-08-20: can't repro)
+ - scrolling/style: shadows on scrollable areas to denote that there is more contents (see e.g. DaVinci Resolve ui)
+
+ - drawdata: make it easy to deep-copy (or swap?) a full ImDrawData so user can easily save that data if they use threaded rendering. (e.g. #2646)
+ ! drawlist: add CalcTextSize() func to facilitate consistent code from user pov (currently need to use ImGui or ImFont alternatives!)
+ - drawlist: maintaining bounding box per command would allow to merge draw command when clipping isn't relied on (typical non-scrolling window or non-overflowing column would merge with previous command). (WIP branch)
+ - drawlist: primitives/helpers to manipulate vertices post submission, so e.g. a quad/rect can be resized to fit later submitted content, _without_ using the ChannelSplit api
+ - drawlist: make it easier to toggle AA per primitive, so we can use e.g. non-AA fill + AA borders more naturally
+ - drawlist: non-AA strokes have gaps between points (#593, #288), glitch especially on RenderCheckmark() and ColorPicker4().
+ - drawlist: rendering: provide a way for imgui to output to a single/global vertex buffer, re-order indices only at the end of the frame (ref: https://gist.github.com/floooh/10388a0afbe08fce9e617d8aefa7d302)
+ - drawlist: callback: add an extra void* in ImDrawCallback to allow passing render-local data to the callback (would break API).
+ - drawlist: AddRect vs AddLine position confusing (#2441)
+ - drawlist/opt: store rounded corners in texture to use 1 quad per corner (filled and wireframe) to lower the cost of rounding. (#1962)
+ - drawlist/opt: AddRect() axis aligned pixel aligned (no-aa) could use 8 triangles instead of 16 and no normal calculation.
+ - drawlist/opt: thick AA line could be doable in same number of triangles as 1.0 AA line by storing gradient+full color in atlas.
+
+ - main: IsItemHovered() info stored in a stack? so that 'if TreeNode() { Text; TreePop; } if IsHovered' return the hover state of the TreeNode?
+
+ - widgets: display mode: widget-label, label-widget (aligned on column or using fixed size), label-newline-tab-widget etc. (#395)
+ - widgets: clean up widgets internal toward exposing everything and stabilizing imgui_internals.h.
+ - widgets: add always-allow-overlap mode. This should perhaps be the default? one problem is that highlight after mouse-wheel scrolling gets deferred, makes scrolling more flickery.
+ - widgets: start exposing PushItemFlag() and ImGuiItemFlags
+ - widgets: alignment options in style (e.g. center Selectable, Right-Align within Button, etc.) #1260
+ - widgets: activate by identifier (trigger button, focus given id)
+ - widgets: a way to represent "mixed" values, so e.g. all values replaced with *, including check-boxes, colors, etc. with support for multi-components widgets (e.g. SliderFloat3, make only "Y" mixed) (#2644)
+ - widgets: checkbox: checkbox with custom glyph inside frame.
+ - widgets: coloredit: keep reporting as active when picker is on?
+ - widgets: group/scalarn functions: expose more per-component information. e.g. store NextItemData.ComponentIdx set by scalarn function, groups can expose them back somehow.
+ - selectable: using (size.x == 0.0f) and (SelectableTextAlign.x > 0.0f) followed by SameLine() is currently not supported.
+ - selectable: generic BeginSelectable()/EndSelectable() mechanism. (work out alongside range-select branch)
+ - selectable: a way to visualize partial/mixed selection (e.g. parent tree node has children with mixed selection)
+
+ - input text: clean up the mess caused by converting UTF-8 <> wchar. the code is rather inefficient right now and super fragile. (WIP branch)
+ - input text: preserve scrolling when unfocused?
+ - input text: reorganize event handling, allow CharFilter to modify buffers, allow multiple events? (#541)
+ - input text: expose CursorPos in char filter event (#816)
+ - input text: try usage idiom of using InputText with data only exposed through get/set accessors, without extraneous copy/alloc. (#3009)
+ - input text: access public fields via a non-callback API e.g. InputTextGetState("xxx") that may return nullptr if not active (available in internals)
+ - input text: flag to disable live update of the user buffer (also applies to float/int text input) (#701)
+ - input text: hover tooltip could show unclamped text
+ - input text: support for INSERT key to toggle overwrite mode. currently disabled because stb_textedit behavior is unsatisfactory on multi-line. (#2863)
+ - input text: option to Tab after an Enter validation.
+ - input text: add ImGuiInputTextFlags_EnterToApply? (off #218)
+ - input text: easier ways to update buffer (from source char*) while owned. preserve some sort of cursor position for multi-line text.
+ - input text: add flag (e.g. ImGuiInputTextFlags_EscapeClearsBuffer) to clear instead of revert. what to do with focus? (also see #2890)
+ - input text: add discard flag (e.g. ImGuiInputTextFlags_DiscardActiveBuffer) or make it easier to clear active focus for text replacement during edition (#725)
+ - input text: display bug when clicking a drag/slider after an input text in a different window has all-selected text (order dependent). actually a very old bug but no one appears to have noticed it.
+ - input text: allow centering/positioning text so that ctrl+clicking Drag or Slider keeps the textual value at the same pixel position.
+ - input text: decorrelate display layout from inputs with custom template - e.g. what's the easiest way to implement a nice IP/Mac address input editor?
+ - input text: global callback system so user can plug in an expression evaluator easily. (#1691)
+ - input text: force scroll to end or scroll to a given line/contents (so user can implement a log or a search feature)
+ - input text: a way to preview completion (e.g. disabled text completing from the cursor)
+ - input text: a side bar that could e.g. preview where errors are. probably left to the user to draw but we'd need to give them the info there.
+ - input text: a way for the user to provide syntax coloring.
+ - input text: Shift+TAB with ImGuiInputTextFlags_AllowTabInput could eat preceding blanks, up to tab_count.
+ - input text multi-line: don't directly call AddText() which does an unnecessary vertex reserve for character count prior to clipping. and/or more line-based clipping to AddText(). and/or reorganize TextUnformatted/RenderText for more efficiency for large text (e.g TextUnformatted could clip and log separately, etc).
+ - input text multi-line: support for copy/cut without selection (copy/cut current line?)
+ - input text multi-line: line numbers? status bar? (follow up on #200)
+ - input text multi-line: behave better when user changes input buffer while editing is active (even though it is illegal behavior). namely, the change of buffer can create a scrollbar glitch (#725)
+ - input text multi-line: better horizontal scrolling support (#383, #1224)
+ - input text multi-line: single call to AddText() should be coarse clipped on InputTextEx() end.
+ - input number: optional range min/max for Input*() functions
+ - input number: holding [-]/[+] buttons could increase the step speed non-linearly (or user-controlled)
+ - input number: use mouse wheel to step up/down
+
+ - layout: helper or a way to express ImGui::SameLine(ImGui::GetCursorStartPos().x + ImGui::CalcItemWidth() + ImGui::GetStyle().ItemInnerSpacing.x); in a simpler manner.
+ - layout, font: horizontal tab support, A) text mode: forward only tabs (e.g. every 4 characters/N pixels from pos x1), B) manual mode: explicit tab stops acting as mini columns, no clipping (for menu items, many kind of uses, also vaguely relate to #267, #395)
+ - layout: horizontal layout helper (#97)
+ - layout: horizontal flow until no space left (#404)
+ - layout: more generic alignment state (left/right/centered) for single items?
+ - layout: clean up the InputFloatN/SliderFloatN/ColorEdit4 layout code. item width should include frame padding.
+ - layout: vertical alignment of mixed height items (e.g. buttons) within a same line (#1284)
+ - layout: null layout mode were items are not rendered but user can query GetItemRectMin()/Max/Size.
+ - layout: (R&D) local multi-pass layout mode.
+ - layout: (R&D) bind authored layout data (created by an off-line tool), items fetch their pos/size at submission, self-optimize data structures to stable linear access.
+
+ - tables: see https://github.com/ocornut/imgui/issues/2957#issuecomment-569726095
+
+ - group: BeginGroup() needs a border option. (~#1496)
+ - group: IsHovered() after EndGroup() covers whole AABB rather than the intersection of individual items. Is that desirable?
+ - group: merge deactivation/activation within same group (fwd WasEdited flag). (#2550)
+
+!- color: the color conversion helpers/types are a mess and needs sorting out.
+ - color: (api breaking) ImGui::ColorConvertXXX functions should be loose ImColorConvertXX to match imgui_internals.h
+
+ - plot: full featured plot/graph api w/ scrolling, zooming etc. all bell & whistle. why not!
+ - plot: PlotLines() should use the polygon-stroke facilities, less vertices (currently issues with averaging normals)
+ - plot: make it easier for user to draw extra stuff into the graph (e.g: draw basis, highlight certain points, 2d plots, multiple plots)
+ - plot: "smooth" automatic scale over time, user give an input 0.0(full user scale) 1.0(full derived from value)
+ - plot: option/feature: draw the zero line
+ - plot: option/feature: draw grid, vertical markers
+ - plot: option/feature: draw unit
+ - plot: add a helper e.g. Plot(char* label, float value, float time_span=2.0f) that stores values and Plot them for you - probably another function name. and/or automatically allow to plot ANY displayed value (more reliance on stable ID)
+
+ - clipper: ability to disable the clipping through a simple flag/bool.
+ - clipper: ability to run without knowing full count in advance.
+ - clipper: horizontal clipping support. (#2580)
+
+ - separator: expose flags (#759)
+ - separator: take indent into consideration (optional)
+ - separator: width, thickness, centering (#1643)
+ - splitter: formalize the splitter idiom into an official api (we want to handle n-way split) (#319)
+
+ - dock: merge docking branch (#2109)
+
+ - tabs: "there is currently a problem because TabItem() will try to submit their own tooltip after 0.50 second, and this will have the effect of making your tooltip flicker once." -> tooltip priority work (WIP branch)
+ - tabs: make EndTabBar fail if users doesn't respect BeginTabBar return value, for consistency/future-proofing.
+ - tabs: persistent order/focus in BeginTabBar() api (#261, #351)
+ - tabs: TabItem could honor SetNextItemWidth()?
+ - tabs: explicit api (even if internal) to cleanly manipulate tab order.
+ - tabs: Mouse wheel over tab bar could scroll? (with shift?) (#2702)
+
+ - image/image button: misalignment on padded/bordered button?
+ - image/image button: parameters are confusing, image() has tint_col,border_col whereas imagebutton() has bg_col/tint_col. Even thou they are different parameters ordering could be more consistent. can we fix that?
+ - image button: not taking an explicit id can be problematic. (#2464, #1390)
+ - slider/drag: ctrl+click when format doesn't include a % character.. disable? display underlying value in default format? (see TempInputTextScalar)
+ - slider: allow using the [-]/[+] buttons used by InputFloat()/InputInt()
+ - slider: initial absolute click is imprecise. change to relative movement slider (same as scrollbar). (#1946)
+ - slider: add dragging-based widgets to edit values with mouse (on 2 axises), saving screen real-estate.
+ - slider: tint background based on value (e.g. v_min -> v_max, or use 0.0f either side of the sign)
+ - slider: relative dragging? + precision dragging
+ - slider: step option (#1183)
+ - slider: style: fill % of the bar instead of positioning a drag.
+ - knob: rotating knob widget (#942)
+ - drag float: support for reversed drags (min > max) (removed is_locked, also see fdc526e)
+ - drag float: up/down axis
+ - drag float: power != 0.0f with current value being outside the range keeps the value stuck.
+ - drag float: added leeway on edge (e.g. a few invisible steps past the clamp limits)
+
+ - combo: use clipper.
+ - combo: flag for BeginCombo to not return true when unchanged (#1182)
+ - combo: a way/helper to customize the combo preview (#1658) -> experimental BeginComboPreview()
+ - combo/listbox: keyboard control. need InputText-like non-active focus + key handling. considering keyboard for custom listbox (pr #203)
+ - listbox: multiple selection (WIP range-select branch)
+ - listbox: unselect option (#1208)
+ - listbox: make it easier/more natural to implement range-select (need some sort of info/ref about the last clicked/focused item that user can translate to an index?) (WIP range-select branch)
+ - listbox: user may want to initial scroll to focus on the one selected value?
+ - listbox: disable capturing mouse wheel if the listbox has no scrolling. (#1681)
+ - listbox: scrolling should track modified selection.
+ - listbox: future api should allow to enable horizontal scrolling (#2510)
+
+!- popups/menus: clarify usage of popups id, how MenuItem/Selectable closing parent popups affects the ID, etc. this is quite fishy needs improvement! (#331, #402)
+ - modals: make modal title bar blink when trying to click outside the modal
+ - modals: technically speaking, we could make Begin() with ImGuiWindowFlags_Modal work without involving popup. May help untangle a few things, as modals are more like regular windows than popups.
+ - popups: if the popup functions took explicit ImGuiID it would allow the user to manage the scope of those ID. (#331)
+ - popups: clicking outside (to close popup) and holding shouldn't drag window below.
+ - popups: add variant using global identifier similar to Begin/End (#402)
+ - popups: border options. richer api like BeginChild() perhaps? (#197)
+ - popups/modals: although it is sometimes convenient that popups/modals lifetime is owned by imgui, we could also a bool-owned-by-user api as long as Begin() return value testing is enforced.
+
+ - tooltip: drag and drop with tooltip near monitor edges lose/changes its last direction instead of locking one. The drag and drop tooltip should always follow without changing direction.
+ - tooltip: allow to set the width of a tooltip to allow TextWrapped() etc. while keeping the height automatic.
+ - tooltip: tooltips with delay timers? or general timer policy? (instantaneous vs timed): IsItemHovered() with timer + implicit aabb-id for items with no ID. (#1485) (WIP branch)
+ - tooltip: drag tooltip hovering over source widget with IsItemHovered/SetTooltip flickers (WIP branch)
+
+ - status-bar: add a per-window status bar helper similar to what menu-bar does. generalize concept of layer0 rect in window (can make _MenuBar window flag obsolete too).
+ - shortcuts: local-style shortcut api, e.g. parse "&Save"
+ - shortcuts,menus: global-style shortcut api e.g. "Save (CTRL+S)" -> explicit flag for recursing into closed menu
+ - shortcuts: programmatically access shortcuts "Focus("&Save"))
+ - menus: menu-bar: main menu-bar could affect clamping of windows position (~ akin to modifying DisplayMin)
+ - menus: hovering from menu to menu on a menu-bar has 1 frame without any menu, which is a little annoying. ideally either 0 either longer.
+ - menus: could merge draw call in most cases (how about storing an optional aabb in ImDrawCmd to move the burden of merging in a single spot).
+ - menus: would be nice if the Selectable() supported horizontal alignment (must be given the equivalent of WorkRect.Max.x matching the position of the shortcut column)
+
+ - tree node: add treenode/treepush int variants? not there because (void*) cast from int warns on some platforms/settings?
+ - tree node: try to apply scrolling at time of TreePop() if node was just opened and end of node is past scrolling limits?
+ - tree node / selectable render mismatch which is visible if you use them both next to each other (e.g. cf. property viewer)
+ - tree node: tweak color scheme to distinguish headers from selected tree node (#581)
+ - tree node: leaf/non-leaf highlight mismatch.
+ - tree node: flag to disable formatting and/or detect "%s"
+ - tree node/opt: could avoid formatting when clipped (flag assuming we don't care about width/height, assume single line height? format only %s/%c to be able to count height?)
+
+ - settings: write more decent code to allow saving/loading new fields: columns, selected tree nodes?
+ - settings: api for per-tool simple persistent data (bool,int,float,columns sizes,etc.) in .ini file (#437)
+ - settings/persistence: helpers to make TreeNodeBehavior persist (even during dev!) - may need to store some semantic and/or data type in ImGuiStoragePair
+
+ - style: better default styles. (#707)
+ - style: PushStyleVar: allow direct access to individual float X/Y elements.
+ - style: add a highlighted text color (for headers, etc.)
+ - style: border types: out-screen, in-screen, etc. (#447)
+ - style: add window shadow (fading away from the window. Paint-style calculation of vertices alpha after drawlist would be easier)
+ - style: a concept of "compact style" that the end-user can easily rely on (e.g. PushStyleCompact()?) that maps to other settings? avoid implementing duplicate helpers such as SmallCheckbox(), etc.
+ - style: try to make PushStyleVar() more robust to incorrect parameters (to be more friendly to edit & continues situation).
+ - style: global scale setting.
+ - style: FramePadding could be different for up vs down (#584)
+ - style: WindowPadding needs to be EVEN as the 0.5 multiplier used on this value probably have a subtle effect on clip rectangle
+ - style: have a more global HSV setter (e.g. alter hue on all elements). consider replacing active/hovered by offset in HSV space? (#438, #707, #1223)
+ - style: gradients fill (#1223) ~ 2 bg colors for each fill? tricky with rounded shapes and using textures for corners.
+ - style editor: color child window height expressed in multiple of line height.
+
+ - log: improve logging of ArrowButton, ListBox, TabItem
+ - log: carry on indent / tree depth when opening a child window
+ - log: enabling log ends up pushing and growing vertices buffers because we don't distinguish layout vs render clipping
+ - log: have more control over the log scope (e.g. stop logging when leaving current tree node scope)
+ - log: be able to log anything (e.g. right-click on a window/tree-node, shows context menu? log into tty/file/clipboard)
+ - log: let user copy any window content to clipboard easily (CTRL+C on windows? while moving it? context menu?). code is commented because it fails with multiple Begin/End pairs.
+ - log: obsolete LogButtons().... (was: LogButtons() options for specifying depth and/or hiding depth slider)
+
+ - filters: set a current filter that certains items (e.g. tree node) can automatically query to hide themselves
+ - filters: handle wild-cards (with implicit leading/trailing *), reg-exprs
+ - filters: fuzzy matches (may use code at blog.forrestthewoods.com/4cffeed33fdb)
+
+ - drag and drop: focus drag target window on hold (even without open)
+ - drag and drop: releasing a drop shows the "..." tooltip for one frame - since e13e598 (#1725)
+ - drag and drop: drag source on a group object (would need e.g. an invisible button covering group in EndGroup) https://twitter.com/paniq/status/1121446364909535233
+ - drag and drop: have some way to know when a drag begin from BeginDragDropSource() pov. (see 2018/01/11 post in #143)
+ - drag and drop: allow preview tooltip to be submitted from a different place than the drag source. (#1725)
+ - drag and drop: allow using with other mouse buttons (where activeid won't be set). (#1637)
+ - drag and drop: make it easier and provide a demo to have tooltip both are source and target site, with a more detailed one on target site (tooltip ordering problem)
+ - drag and drop: demo with reordering nodes (in a list, or a tree node). (#143)
+ - drag and drop: test integrating with os drag and drop (make it easy to do a naive WM_DROPFILE integration)
+ - drag and drop: allow for multiple payload types. (#143)
+ - drag and drop: make payload optional? payload promise? (see 2018/01/11 post in #143)
+ - drag and drop: (#143) "both an in-process pointer and a promise to generate a serialized version, for whether the drag ends inside or outside the same process"
+ - drag and drop: feedback when hovering a region blocked by modal (mouse cursor "NO"?)
+
+ - markup: simple markup language for color change? (#902, #3130)
+
+ - text: selectable text (for copy) as a generic feature (ItemFlags?)
+ - text: proper alignment options in imgui_internal.h
+ - text: provided a framed text helper, e.g. https://pastebin.com/1Laxy8bT
+ - text: refactor TextUnformatted (or underlying function) to more explicitly request if we need width measurement or not
+ - text/layout/tabs: \t pulling position from base pos + step, or offset array (e.g. could be used in text edit, menus for simple icon+text alignment, etc.)
+ - text link/url button: underlined. should api expose an ID or use text contents as ID? which colors enum to use?
+ - text/wrapped: should be a more first-class citizen, e.g. wrapped text within a Selectable with known width.
+ - text/wrapped: custom separator for text wrapping. (#3002)
+ - text/wrapped: figure out better way to use TextWrapped() in an always auto-resize context (tooltip, etc.) (#249)
+
+ - font: arbitrary line spacing. (#2945)
+ - font: MergeMode: flags to select overwriting or not (this is now very easy with refactored ImFontAtlasBuildWithStbTruetype)
+ - font: free the Alpha buffer if user only requested RGBA.
+!- font: better CalcTextSizeA() API, at least for simple use cases. current one is horrible (perhaps have simple vs extended versions).
+ - font: for the purpose of RenderTextEllipsis(), it might be useful that CalcTextSizeA() can ignore the trailing padding?
+ - font: a CalcTextHeight() helper could run faster than CalcTextSize().y
+ - font: enforce monospace through ImFontConfig (for icons?) + create dual ImFont output from same input, reusing rasterized data but with different glyphs/AdvanceX
+ - font: finish CustomRectRegister() to allow mapping Unicode codepoint to custom texture data
+ - font: remove ID from CustomRect registration, it seems unnecessary!
+ - font: make it easier to submit own bitmap font (same texture, another texture?). (#2127, #2575)
+ - font: PushFontSize API (#1018)
+ - font: MemoryTTF taking ownership confusing/not obvious, maybe default should be opposite?
+ - font: storing MinAdvanceX per font would allow us to skip calculating line width (under a threshold of character count) in loops looking for block width
+ - font/demo: add tools to show glyphs used by a text blob, display U16 value, list missing glyphs.
+ - font/demo: demonstrate use of ImFontGlyphRangesBuilder.
+ - font/atlas: add a missing Glyphs.reserve()
+ - font/atlas: incremental updates
+ - font/atlas: dynamic font atlas to avoid baking huge ranges into bitmap and make scaling easier.
+ - font/draw: vertical and/or rotated text renderer (#705) - vertical is easier clipping wise
+ - font/draw: need to be able to specify wrap start position.
+ - font/draw: better reserve policy for large horizontal block of text (shouldn't reserve for all clipped lines). also see #3349.
+ - font/draw: fix for drawing 16k+ visible characters in same call.
+ - font/draw: underline, squiggle line rendering helpers.
+ - font: optimization: for monospace font (like the default one) we can trim IndexXAdvance as long as trailing value is == FallbackXAdvance (need to make sure TAB is still correct), would save on cache line.
+ - font: add support for kerning, probably optional. A) perhaps default to (32..128)^2 matrix ~ 9K entries = 36KB, then hash for non-ascii?. B) or sparse lookup into per-char list?
+ - font: add a simpler CalcTextSizeA() api? current one ok but not welcome if user needs to call it directly (without going through ImGui::CalcTextSize)
+ - font: fix AddRemapChar() to work before atlas  has been built.
+ - font: (api breaking) remove "TTF" from symbol names. also because it now supports OTF.
+ - font/opt: Considering storing standalone AdvanceX table as 16-bit fixed point integer?
+ - font/opt: Glyph currently 40 bytes (2+9*4). Consider storing UV as 16-bits integer? (->32 bytes). X0/Y0/X1/Y1 as 16 fixed-point integers? Or X0/Y0 as float and X1/Y1 as fixed8_8?
+
+ - nav: some features such as PageUp/Down/Home/End should probably work without ImGuiConfigFlags_NavEnableKeyboard? (where do we draw the line? how about CTRL+Tab)
+ ! nav: never clear NavId on some setup (e.g. gamepad centric)
+ - nav: there's currently no way to completely clear focus with the keyboard. depending on patterns used by the application to dispatch inputs, it may be desirable.
+ - nav: code to focus child-window on restoring NavId appears to have issue: e.g. when focus change is implicit because of window closure.
+ - nav: Home/End behavior when navigable item is not fully visible at the edge of scrolling? should be backtrack to keep item into view?
+ - nav: NavScrollToBringItemIntoView() with item bigger than view should focus top-right? Repro: using Nav in "About Window"
+ - nav: wrap around logic to allow e.g. grid based layout (pressing NavRight on the right-most element would go to the next row, etc.). see internal's NavMoveRequestTryWrapping().
+ - nav: patterns to make it possible for arrows key to update selection (see JustMovedTo in range_select branch)
+ - nav: restore/find nearest NavId when current one disappear (e.g. pressed a button that disappear, or perhaps auto restoring when current button change name)
+ - nav: SetItemDefaultFocus() level of priority, so widget like Selectable when inside a popup could claim a low-priority default focus on the first selected iem
+ - nav: NavFlattened: init requests don't work properly on flattened siblings.
+ - nav: NavFlattened: pageup/pagedown/home/end don't work properly on flattened siblings.
+ - nav: NavFlattened: ESC on a flattened child should select something.
+ - nav: NavFlattened: broken: in typical usage scenario, the items of a fully clipped child are currently not considered to enter into a NavFlattened child.
+ - nav: NavFlattened: cannot access menu-bar of a flattened child window with Alt/menu key (not a very common use case..).
+ - nav: simulate right-click or context activation? (SHIFT+F10, keyboard Menu key?)
+ - nav/popup: esc/enter default behavior for popups, e.g. be able to mark an "ok" or "cancel" button that would get triggered by those keys, default validation button, etc.
+ - nav/treenode: left within a tree node block as a fallback (ImGuiTreeNodeFlags_NavLeftJumpsBackHere by default?)
+ - nav/menus: pressing left-right on a vertically clipped menu bar tends to jump to the collapse/close buttons.
+ - nav/menus: allow pressing Menu to leave a sub-menu.
+ - nav/menus: a way to access the main menu bar with Alt? (currently needs CTRL+TAB) or last focused window menu bar?
+ - nav/menus: when using the main menu bar, even though we restore focus after, the underlying window loses its title bar highlight during menu manipulation. could we prevent it?
+ - nav/menus: main menu bar currently cannot restore a nullptr focus. Could save NavWindow at the time of being focused, similarly to what popup do?
+ - nav/menus: Alt,Up could open the first menu (e.g. "File") currently it tends to nav into the window/collapse menu. Do do that we would need custom transition?
+ - nav/windowing: configure fade-in/fade-out delay on Ctrl+Tab?
+ - nav/windowing: when CTRL+Tab/windowing is active, the HoveredWindow detection doesn't take account of the window display re-ordering.
+ - nav/windowing: Resizing window will currently fail with certain types of resizing constraints/callback applied
+ - focus: preserve ActiveId/focus stack state, e.g. when opening a menu and close it, previously selected InputText() focus gets restored (#622)
+
+ - inputs: we need an explicit flag about whether the platform window is focused, to be able to distinguish focused key releases vs alt-tabbing all release behaviors.
+ - inputs: support track pad style scrolling & slider edit.
+ - inputs/io: backspace and arrows in the context of a text input could use system repeat rate.
+ - inputs/io: clarify/standardize/expose repeat rate and repeat delays (#1808)
+ - inputs/scrolling: support for smooth scrolling (#2462, #2569)
+
+ - misc: idle: expose "woken up" boolean (set by inputs) and/or animation time (for cursor blink) for backend to be able stop refreshing easily.
+ - misc: idle: if cursor blink if the _only_ visible animation, core imgui could rewrite vertex alpha to avoid CPU pass on ImGui:: calls.
+ - misc: idle: if cursor blink if the _only_ visible animation, could even expose a dirty rectangle that optionally can be leverage by some app to render in a smaller viewport, getting rid of much pixel shading cost.
+ - misc: no way to run a root-most GetID() with ImGui:: api since there's always a Debug window in the stack. (mentioned in #2960)
+ - misc: make the ImGuiCond values linear (non-power-of-two). internal storage for ImGuiWindow can use integers to combine into flags (Why?)
+ - misc: PushItemFlag(): add a flag to disable keyboard capture when used with mouse? (#1682)
+ - misc: use more size_t in public api?
+ - misc: possible compile-time support for string view/range instead of char* would e.g. facilitate usage with Rust (#683, #3038, WIP string_view branch)
+ - misc: possible compile-time support for wchar_t instead of char*?
+
+ - demo: demonstrate using PushStyleVar() in more details.
+ - demo: add vertical separator demo
+ - demo: add virtual scrolling example?
+ - demo: demonstrate Plot offset
+ - demo: window size constraint: square demo is broken when resizing from edges (#1975), would need to rework the callback system to solve this
+
+ - examples: window minimize, maximize (#583)
+ - examples: provide a zero frame-rate/idle example.
+ - examples: dx11/dx12: try to use new swapchain blit models (#2970)
+ - backends: report it better when not able to create texture?
+ - backends: apple: example_apple should be using modern GL3.
+ - backends: glfw: could go idle when minimized? if (glfwGetWindowAttrib(window, GLFW_ICONIFIED)) { glfwWaitEvents(); continue; } // issue: DeltaTime will be super high on resume, perhaps provide a way to let impl know (#440)
+ - backends: opengl: rename imgui_impl_opengl2 to impl_opengl_legacy and imgui_impl_opengl3 to imgui_impl_opengl? (#1900)
+ - backends: opengl: could use a single vertex buffer and glBufferSubData for uploads?
+ - backends: opengl: explicitly disable GL_STENCIL_TEST in bindings.
+ - backends: vulkan: viewport: support for synchronized swapping of multiple swap chains.
+ - backends: bgfx: https://gist.github.com/RichardGale/6e2b74bc42b3005e08397236e4be0fd0
+ - backends: emscriptem: with refactored examples, we could provide a direct imgui_impl_emscripten platform layer (see eg. https://github.com/floooh/sokol-samples/blob/master/html5/imgui-emsc.cc#L42)
+
+ - bindings: ways to use clang ast dump to generate bindings or helpers for bindings? (e.g. clang++ -Xclang -ast-dump=json imgui.h) (WIP project "dear-bindings" still private)
+
+ - optimization: replace vsnprintf with stb_printf? using IMGUI_USE_STB_SPRINTF. (#1038 + needed for string_view)
+ - optimization: add clipping for multi-component widgets (SliderFloatX, ColorEditX, etc.). one problem is that nav branch can't easily clip parent group when there is a move request.
+ - optimization: add a flag to disable most of rendering, for the case where the user expect to skip it (#335)
+ - optimization: fully covered window (covered by another with non-translucent bg + WindowRounding worth of padding) may want to clip rendering.
+ - optimization: use another hash function than crc32, e.g. FNV1a
+ - optimization: turn some the various stack vectors into statically-sized arrays

third_party/imgui/imconfig.h

@@ -0,0 +1,122 @@
+//-----------------------------------------------------------------------------
+// COMPILE-TIME OPTIONS FOR DEAR IMGUI
+// Runtime options (clipboard callbacks, enabling various features, etc.) can generally be set via the ImGuiIO structure.
+// You can use ImGui::SetAllocatorFunctions() before calling ImGui::CreateContext() to rewire memory allocation functions.
+//-----------------------------------------------------------------------------
+// A) You may edit imconfig.h (and not overwrite it when updating Dear ImGui, or maintain a patch/rebased branch with your modifications to it)
+// B) or '#define IMGUI_USER_CONFIG "my_imgui_config.h"' in your project and then add directives in your own file without touching this template.
+//-----------------------------------------------------------------------------
+// You need to make sure that configuration settings are defined consistently _everywhere_ Dear ImGui is used, which include the imgui*.cpp
+// files but also _any_ of your code that uses Dear ImGui. This is because some compile-time options have an affect on data structures.
+// Defining those options in imconfig.h will ensure every compilation unit gets to see the same data structure layouts.
+// Call IMGUI_CHECKVERSION() from your .cpp files to verify that the data structures your files are using are matching the ones imgui.cpp is using.
+//-----------------------------------------------------------------------------
+
+#pragma once
+
+//---- Define assertion handler. Defaults to calling assert().
+// If your macro uses multiple statements, make sure is enclosed in a 'do { .. } while (0)' block so it can be used as a single statement.
+//#define IM_ASSERT(_EXPR)  MyAssert(_EXPR)
+//#define IM_ASSERT(_EXPR)  ((void)(_EXPR))     // Disable asserts
+
+//---- Define attributes of all API symbols declarations, e.g. for DLL under Windows
+// Using Dear ImGui via a shared library is not recommended, because of function call overhead and because we don't guarantee backward nor forward ABI compatibility.
+// DLL users: heaps and globals are not shared across DLL boundaries! You will need to call SetCurrentContext() + SetAllocatorFunctions()
+// for each static/DLL boundary you are calling from. Read "Context and Memory Allocators" section of imgui.cpp for more details.
+//#define IMGUI_API __declspec( dllexport )
+//#define IMGUI_API __declspec( dllimport )
+
+//---- Don't define obsolete functions/enums/behaviors. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names.
+//#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+//#define IMGUI_DISABLE_OBSOLETE_KEYIO                      // 1.87: disable legacy io.KeyMap[]+io.KeysDown[] in favor io.AddKeyEvent(). This will be folded into IMGUI_DISABLE_OBSOLETE_FUNCTIONS in a few versions.
+
+//---- Disable all of Dear ImGui or don't implement standard windows/tools.
+// It is very strongly recommended to NOT disable the demo windows and debug tool during development. They are extremely useful in day to day work. Please read comments in imgui_demo.cpp.
+//#define IMGUI_DISABLE                                     // Disable everything: all headers and source files will be empty.
+//#define IMGUI_DISABLE_DEMO_WINDOWS                        // Disable demo windows: ShowDemoWindow()/ShowStyleEditor() will be empty.
+//#define IMGUI_DISABLE_DEBUG_TOOLS                         // Disable metrics/debugger and other debug tools: ShowMetricsWindow(), ShowDebugLogWindow() and ShowStackToolWindow() will be empty (this was called IMGUI_DISABLE_METRICS_WINDOW before 1.88).
+
+//---- Don't implement some functions to reduce linkage requirements.
+//#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc. (user32.lib/.a, kernel32.lib/.a)
+//#define IMGUI_ENABLE_WIN32_DEFAULT_IME_FUNCTIONS          // [Win32] [Default with Visual Studio] Implement default IME handler (require imm32.lib/.a, auto-link for Visual Studio, -limm32 on command-line for MinGW)
+//#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // [Win32] [Default with non-Visual Studio compilers] Don't implement default IME handler (won't require imm32.lib/.a)
+//#define IMGUI_DISABLE_WIN32_FUNCTIONS                     // [Win32] Won't use and link with any Win32 function (clipboard, ime).
+//#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS      // [OSX] Implement default OSX clipboard handler (need to link with '-framework ApplicationServices', this is why this is not the default).
+//#define IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS            // Don't implement ImFormatString/ImFormatStringV so you can implement them yourself (e.g. if you don't want to link with vsnprintf)
+//#define IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS              // Don't implement ImFabs/ImSqrt/ImPow/ImFmod/ImCos/ImSin/ImAcos/ImAtan2 so you can implement them yourself.
+//#define IMGUI_DISABLE_FILE_FUNCTIONS                      // Don't implement ImFileOpen/ImFileClose/ImFileRead/ImFileWrite and ImFileHandle at all (replace them with dummies)
+//#define IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS              // Don't implement ImFileOpen/ImFileClose/ImFileRead/ImFileWrite and ImFileHandle so you can implement them yourself if you don't want to link with fopen/fclose/fread/fwrite. This will also disable the LogToTTY() function.
+//#define IMGUI_DISABLE_DEFAULT_ALLOCATORS                  // Don't implement default allocators calling malloc()/free() to avoid linking with them. You will need to call ImGui::SetAllocatorFunctions().
+//#define IMGUI_DISABLE_SSE                                 // Disable use of SSE intrinsics even if available
+
+//---- Include imgui_user.h at the end of imgui.h as a convenience
+//#define IMGUI_INCLUDE_IMGUI_USER_H
+
+//---- Pack colors to BGRA8 instead of RGBA8 (to avoid converting from one to another)
+//#define IMGUI_USE_BGRA_PACKED_COLOR
+
+//---- Use 32-bit for ImWchar (default is 16-bit) to support unicode planes 1-16. (e.g. point beyond 0xFFFF like emoticons, dingbats, symbols, shapes, ancient languages, etc...)
+//#define IMGUI_USE_WCHAR32
+
+//---- Avoid multiple STB libraries implementations, or redefine path/filenames to prioritize another version
+// By default the embedded implementations are declared static and not available outside of Dear ImGui sources files.
+//#define IMGUI_STB_TRUETYPE_FILENAME   "my_folder/stb_truetype.h"
+//#define IMGUI_STB_RECT_PACK_FILENAME  "my_folder/stb_rect_pack.h"
+//#define IMGUI_STB_SPRINTF_FILENAME    "my_folder/stb_sprintf.h"    // only used if enabled
+//#define IMGUI_DISABLE_STB_TRUETYPE_IMPLEMENTATION
+//#define IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
+
+//---- Use stb_sprintf.h for a faster implementation of vsnprintf instead of the one from libc (unless IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS is defined)
+// Compatibility checks of arguments and formats done by clang and GCC will be disabled in order to support the extra formats provided by stb_sprintf.h.
+//#define IMGUI_USE_STB_SPRINTF
+
+//---- Use FreeType to build and rasterize the font atlas (instead of stb_truetype which is embedded by default in Dear ImGui)
+// Requires FreeType headers to be available in the include path. Requires program to be compiled with 'misc/freetype/imgui_freetype.cpp' (in this repository) + the FreeType library (not provided).
+// On Windows you may use vcpkg with 'vcpkg install freetype --triplet=x64-windows' + 'vcpkg integrate install'.
+//#define IMGUI_ENABLE_FREETYPE
+
+//---- Use stb_truetype to build and rasterize the font atlas (default)
+// The only purpose of this define is if you want force compilation of the stb_truetype backend ALONG with the FreeType backend.
+//#define IMGUI_ENABLE_STB_TRUETYPE
+
+//---- Define constructor and implicit cast operators to convert back<>forth between your math types and ImVec2/ImVec4.
+// This will be inlined as part of ImVec2 and ImVec4 class declarations.
+/*
+#define IM_VEC2_CLASS_EXTRA                                                     \
+        constexpr ImVec2(const MyVec2& f) : x(f.x), y(f.y) {}                   \
+        operator MyVec2() const { return MyVec2(x,y); }
+
+#define IM_VEC4_CLASS_EXTRA                                                     \
+        constexpr ImVec4(const MyVec4& f) : x(f.x), y(f.y), z(f.z), w(f.w) {}   \
+        operator MyVec4() const { return MyVec4(x,y,z,w); }
+*/
+//---- ...Or use Dear ImGui's own very basic math operators.
+//#define IMGUI_DEFINE_MATH_OPERATORS
+
+//---- Use 32-bit vertex indices (default is 16-bit) is one way to allow large meshes with more than 64K vertices.
+// Your renderer backend will need to support it (most example renderer backends support both 16/32-bit indices).
+// Another way to allow large meshes while keeping 16-bit indices is to handle ImDrawCmd::VtxOffset in your renderer.
+// Read about ImGuiBackendFlags_RendererHasVtxOffset for details.
+//#define ImDrawIdx unsigned int
+
+//---- Override ImDrawCallback signature (will need to modify renderer backends accordingly)
+//struct ImDrawList;
+//struct ImDrawCmd;
+//typedef void (*MyImDrawCallback)(const ImDrawList* draw_list, const ImDrawCmd* cmd, void* my_renderer_user_data);
+//#define ImDrawCallback MyImDrawCallback
+
+//---- Debug Tools: Macro to break in Debugger
+// (use 'Metrics->Tools->Item Picker' to pick widgets with the mouse and break into them for easy debugging.)
+//#define IM_DEBUG_BREAK  IM_ASSERT(0)
+//#define IM_DEBUG_BREAK  __debugbreak()
+
+//---- Debug Tools: Enable slower asserts
+//#define IMGUI_DEBUG_PARANOID
+
+//---- Tip: You can add extra functions within the ImGui:: namespace, here or in your own headers files.
+/*
+namespace ImGui
+{
+    void MyFunction(const char* name, const MyMatrix44& v);
+}
+*/

third_party/imgui/imstb_rectpack.h

@@ -0,0 +1,627 @@
+// [DEAR IMGUI]
+// This is a slightly modified version of stb_rect_pack.h 1.01.
+// Grep for [DEAR IMGUI] to find the changes.
+// 
+// stb_rect_pack.h - v1.01 - public domain - rectangle packing
+// Sean Barrett 2014
+//
+// Useful for e.g. packing rectangular textures into an atlas.
+// Does not do rotation.
+//
+// Before #including,
+//
+//    #define STB_RECT_PACK_IMPLEMENTATION
+//
+// in the file that you want to have the implementation.
+//
+// Not necessarily the awesomest packing method, but better than
+// the totally naive one in stb_truetype (which is primarily what
+// this is meant to replace).
+//
+// Has only had a few tests run, may have issues.
+//
+// More docs to come.
+//
+// No memory allocations; uses qsort() and assert() from stdlib.
+// Can override those by defining STBRP_SORT and STBRP_ASSERT.
+//
+// This library currently uses the Skyline Bottom-Left algorithm.
+//
+// Please note: better rectangle packers are welcome! Please
+// implement them to the same API, but with a different init
+// function.
+//
+// Credits
+//
+//  Library
+//    Sean Barrett
+//  Minor features
+//    Martins Mozeiko
+//    github:IntellectualKitty
+//
+//  Bugfixes / warning fixes
+//    Jeremy Jaussaud
+//    Fabian Giesen
+//
+// Version history:
+//
+//     1.01  (2021-07-11)  always use large rect mode, expose STBRP__MAXVAL in public section
+//     1.00  (2019-02-25)  avoid small space waste; gracefully fail too-wide rectangles
+//     0.99  (2019-02-07)  warning fixes
+//     0.11  (2017-03-03)  return packing success/fail result
+//     0.10  (2016-10-25)  remove cast-away-const to avoid warnings
+//     0.09  (2016-08-27)  fix compiler warnings
+//     0.08  (2015-09-13)  really fix bug with empty rects (w=0 or h=0)
+//     0.07  (2015-09-13)  fix bug with empty rects (w=0 or h=0)
+//     0.06  (2015-04-15)  added STBRP_SORT to allow replacing qsort
+//     0.05:  added STBRP_ASSERT to allow replacing assert
+//     0.04:  fixed minor bug in STBRP_LARGE_RECTS support
+//     0.01:  initial release
+//
+// LICENSE
+//
+//   See end of file for license information.
+
+//////////////////////////////////////////////////////////////////////////////
+//
+//       INCLUDE SECTION
+//
+
+#ifndef STB_INCLUDE_STB_RECT_PACK_H
+#define STB_INCLUDE_STB_RECT_PACK_H
+
+#define STB_RECT_PACK_VERSION  1
+
+#ifdef STBRP_STATIC
+#define STBRP_DEF static
+#else
+#define STBRP_DEF extern
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct stbrp_context stbrp_context;
+typedef struct stbrp_node    stbrp_node;
+typedef struct stbrp_rect    stbrp_rect;
+
+typedef int            stbrp_coord;
+
+#define STBRP__MAXVAL  0x7fffffff
+// Mostly for internal use, but this is the maximum supported coordinate value.
+
+STBRP_DEF int stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects);
+// Assign packed locations to rectangles. The rectangles are of type
+// 'stbrp_rect' defined below, stored in the array 'rects', and there
+// are 'num_rects' many of them.
+//
+// Rectangles which are successfully packed have the 'was_packed' flag
+// set to a non-zero value and 'x' and 'y' store the minimum location
+// on each axis (i.e. bottom-left in cartesian coordinates, top-left
+// if you imagine y increasing downwards). Rectangles which do not fit
+// have the 'was_packed' flag set to 0.
+//
+// You should not try to access the 'rects' array from another thread
+// while this function is running, as the function temporarily reorders
+// the array while it executes.
+//
+// To pack into another rectangle, you need to call stbrp_init_target
+// again. To continue packing into the same rectangle, you can call
+// this function again. Calling this multiple times with multiple rect
+// arrays will probably produce worse packing results than calling it
+// a single time with the full rectangle array, but the option is
+// available.
+//
+// The function returns 1 if all of the rectangles were successfully
+// packed and 0 otherwise.
+
+struct stbrp_rect
+{
+   // reserved for your use:
+   int            id;
+
+   // input:
+   stbrp_coord    w, h;
+
+   // output:
+   stbrp_coord    x, y;
+   int            was_packed;  // non-zero if valid packing
+
+}; // 16 bytes, nominally
+
+
+STBRP_DEF void stbrp_init_target (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes);
+// Initialize a rectangle packer to:
+//    pack a rectangle that is 'width' by 'height' in dimensions
+//    using temporary storage provided by the array 'nodes', which is 'num_nodes' long
+//
+// You must call this function every time you start packing into a new target.
+//
+// There is no "shutdown" function. The 'nodes' memory must stay valid for
+// the following stbrp_pack_rects() call (or calls), but can be freed after
+// the call (or calls) finish.
+//
+// Note: to guarantee best results, either:
+//       1. make sure 'num_nodes' >= 'width'
+//   or  2. call stbrp_allow_out_of_mem() defined below with 'allow_out_of_mem = 1'
+//
+// If you don't do either of the above things, widths will be quantized to multiples
+// of small integers to guarantee the algorithm doesn't run out of temporary storage.
+//
+// If you do #2, then the non-quantized algorithm will be used, but the algorithm
+// may run out of temporary storage and be unable to pack some rectangles.
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem (stbrp_context *context, int allow_out_of_mem);
+// Optionally call this function after init but before doing any packing to
+// change the handling of the out-of-temp-memory scenario, described above.
+// If you call init again, this will be reset to the default (false).
+
+
+STBRP_DEF void stbrp_setup_heuristic (stbrp_context *context, int heuristic);
+// Optionally select which packing heuristic the library should use. Different
+// heuristics will produce better/worse results for different data sets.
+// If you call init again, this will be reset to the default.
+
+enum
+{
+   STBRP_HEURISTIC_Skyline_default=0,
+   STBRP_HEURISTIC_Skyline_BL_sortHeight = STBRP_HEURISTIC_Skyline_default,
+   STBRP_HEURISTIC_Skyline_BF_sortHeight
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// the details of the following structures don't matter to you, but they must
+// be visible so you can handle the memory allocations for them
+
+struct stbrp_node
+{
+   stbrp_coord  x,y;
+   stbrp_node  *next;
+};
+
+struct stbrp_context
+{
+   int width;
+   int height;
+   int align;
+   int init_mode;
+   int heuristic;
+   int num_nodes;
+   stbrp_node *active_head;
+   stbrp_node *free_head;
+   stbrp_node extra[2]; // we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2'
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+//     IMPLEMENTATION SECTION
+//
+
+#ifdef STB_RECT_PACK_IMPLEMENTATION
+#ifndef STBRP_SORT
+#include <stdlib.h>
+#define STBRP_SORT qsort
+#endif
+
+#ifndef STBRP_ASSERT
+#include <assert.h>
+#define STBRP_ASSERT assert
+#endif
+
+#ifdef _MSC_VER
+#define STBRP__NOTUSED(v)  (void)(v)
+#define STBRP__CDECL       __cdecl
+#else
+#define STBRP__NOTUSED(v)  (void)sizeof(v)
+#define STBRP__CDECL
+#endif
+
+enum
+{
+   STBRP__INIT_skyline = 1
+};
+
+STBRP_DEF void stbrp_setup_heuristic(stbrp_context *context, int heuristic)
+{
+   switch (context->init_mode) {
+      case STBRP__INIT_skyline:
+         STBRP_ASSERT(heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight || heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight);
+         context->heuristic = heuristic;
+         break;
+      default:
+         STBRP_ASSERT(0);
+   }
+}
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem(stbrp_context *context, int allow_out_of_mem)
+{
+   if (allow_out_of_mem)
+      // if it's ok to run out of memory, then don't bother aligning them;
+      // this gives better packing, but may fail due to OOM (even though
+      // the rectangles easily fit). @TODO a smarter approach would be to only
+      // quantize once we've hit OOM, then we could get rid of this parameter.
+      context->align = 1;
+   else {
+      // if it's not ok to run out of memory, then quantize the widths
+      // so that num_nodes is always enough nodes.
+      //
+      // I.e. num_nodes * align >= width
+      //                  align >= width / num_nodes
+      //                  align = ceil(width/num_nodes)
+
+      context->align = (context->width + context->num_nodes-1) / context->num_nodes;
+   }
+}
+
+STBRP_DEF void stbrp_init_target(stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes)
+{
+   int i;
+
+   for (i=0; i < num_nodes-1; ++i)
+      nodes[i].next = &nodes[i+1];
+   nodes[i].next = NULL;
+   context->init_mode = STBRP__INIT_skyline;
+   context->heuristic = STBRP_HEURISTIC_Skyline_default;
+   context->free_head = &nodes[0];
+   context->active_head = &context->extra[0];
+   context->width = width;
+   context->height = height;
+   context->num_nodes = num_nodes;
+   stbrp_setup_allow_out_of_mem(context, 0);
+
+   // node 0 is the full width, node 1 is the sentinel (lets us not store width explicitly)
+   context->extra[0].x = 0;
+   context->extra[0].y = 0;
+   context->extra[0].next = &context->extra[1];
+   context->extra[1].x = (stbrp_coord) width;
+   context->extra[1].y = (1<<30);
+   context->extra[1].next = NULL;
+}
+
+// find minimum y position if it starts at x1
+static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0, int width, int *pwaste)
+{
+   stbrp_node *node = first;
+   int x1 = x0 + width;
+   int min_y, visited_width, waste_area;
+
+   STBRP__NOTUSED(c);
+
+   STBRP_ASSERT(first->x <= x0);
+
+   #if 0
+   // skip in case we're past the node
+   while (node->next->x <= x0)
+      ++node;
+   #else
+   STBRP_ASSERT(node->next->x > x0); // we ended up handling this in the caller for efficiency
+   #endif
+
+   STBRP_ASSERT(node->x <= x0);
+
+   min_y = 0;
+   waste_area = 0;
+   visited_width = 0;
+   while (node->x < x1) {
+      if (node->y > min_y) {
+         // raise min_y higher.
+         // we've accounted for all waste up to min_y,
+         // but we'll now add more waste for everything we've visted
+         waste_area += visited_width * (node->y - min_y);
+         min_y = node->y;
+         // the first time through, visited_width might be reduced
+         if (node->x < x0)
+            visited_width += node->next->x - x0;
+         else
+            visited_width += node->next->x - node->x;
+      } else {
+         // add waste area
+         int under_width = node->next->x - node->x;
+         if (under_width + visited_width > width)
+            under_width = width - visited_width;
+         waste_area += under_width * (min_y - node->y);
+         visited_width += under_width;
+      }
+      node = node->next;
+   }
+
+   *pwaste = waste_area;
+   return min_y;
+}
+
+typedef struct
+{
+   int x,y;
+   stbrp_node **prev_link;
+} stbrp__findresult;
+
+static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int width, int height)
+{
+   int best_waste = (1<<30), best_x, best_y = (1 << 30);
+   stbrp__findresult fr;
+   stbrp_node **prev, *node, *tail, **best = NULL;
+
+   // align to multiple of c->align
+   width = (width + c->align - 1);
+   width -= width % c->align;
+   STBRP_ASSERT(width % c->align == 0);
+
+   // if it can't possibly fit, bail immediately
+   if (width > c->width || height > c->height) {
+      fr.prev_link = NULL;
+      fr.x = fr.y = 0;
+      return fr;
+   }
+
+   node = c->active_head;
+   prev = &c->active_head;
+   while (node->x + width <= c->width) {
+      int y,waste;
+      y = stbrp__skyline_find_min_y(c, node, node->x, width, &waste);
+      if (c->heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight) { // actually just want to test BL
+         // bottom left
+         if (y < best_y) {
+            best_y = y;
+            best = prev;
+         }
+      } else {
+         // best-fit
+         if (y + height <= c->height) {
+            // can only use it if it first vertically
+            if (y < best_y || (y == best_y && waste < best_waste)) {
+               best_y = y;
+               best_waste = waste;
+               best = prev;
+            }
+         }
+      }
+      prev = &node->next;
+      node = node->next;
+   }
+
+   best_x = (best == NULL) ? 0 : (*best)->x;
+
+   // if doing best-fit (BF), we also have to try aligning right edge to each node position
+   //
+   // e.g, if fitting
+   //
+   //     ____________________
+   //    |____________________|
+   //
+   //            into
+   //
+   //   |                         |
+   //   |             ____________|
+   //   |____________|
+   //
+   // then right-aligned reduces waste, but bottom-left BL is always chooses left-aligned
+   //
+   // This makes BF take about 2x the time
+
+   if (c->heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight) {
+      tail = c->active_head;
+      node = c->active_head;
+      prev = &c->active_head;
+      // find first node that's admissible
+      while (tail->x < width)
+         tail = tail->next;
+      while (tail) {
+         int xpos = tail->x - width;
+         int y,waste;
+         STBRP_ASSERT(xpos >= 0);
+         // find the left position that matches this
+         while (node->next->x <= xpos) {
+            prev = &node->next;
+            node = node->next;
+         }
+         STBRP_ASSERT(node->next->x > xpos && node->x <= xpos);
+         y = stbrp__skyline_find_min_y(c, node, xpos, width, &waste);
+         if (y + height <= c->height) {
+            if (y <= best_y) {
+               if (y < best_y || waste < best_waste || (waste==best_waste && xpos < best_x)) {
+                  best_x = xpos;
+                  //STBRP_ASSERT(y <= best_y); [DEAR IMGUI]
+                  best_y = y;
+                  best_waste = waste;
+                  best = prev;
+               }
+            }
+         }
+         tail = tail->next;
+      }
+   }
+
+   fr.prev_link = best;
+   fr.x = best_x;
+   fr.y = best_y;
+   return fr;
+}
+
+static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, int width, int height)
+{
+   // find best position according to heuristic
+   stbrp__findresult res = stbrp__skyline_find_best_pos(context, width, height);
+   stbrp_node *node, *cur;
+
+   // bail if:
+   //    1. it failed
+   //    2. the best node doesn't fit (we don't always check this)
+   //    3. we're out of memory
+   if (res.prev_link == NULL || res.y + height > context->height || context->free_head == NULL) {
+      res.prev_link = NULL;
+      return res;
+   }
+
+   // on success, create new node
+   node = context->free_head;
+   node->x = (stbrp_coord) res.x;
+   node->y = (stbrp_coord) (res.y + height);
+
+   context->free_head = node->next;
+
+   // insert the new node into the right starting point, and
+   // let 'cur' point to the remaining nodes needing to be
+   // stiched back in
+
+   cur = *res.prev_link;
+   if (cur->x < res.x) {
+      // preserve the existing one, so start testing with the next one
+      stbrp_node *next = cur->next;
+      cur->next = node;
+      cur = next;
+   } else {
+      *res.prev_link = node;
+   }
+
+   // from here, traverse cur and free the nodes, until we get to one
+   // that shouldn't be freed
+   while (cur->next && cur->next->x <= res.x + width) {
+      stbrp_node *next = cur->next;
+      // move the current node to the free list
+      cur->next = context->free_head;
+      context->free_head = cur;
+      cur = next;
+   }
+
+   // stitch the list back in
+   node->next = cur;
+
+   if (cur->x < res.x + width)
+      cur->x = (stbrp_coord) (res.x + width);
+
+#ifdef _DEBUG
+   cur = context->active_head;
+   while (cur->x < context->width) {
+      STBRP_ASSERT(cur->x < cur->next->x);
+      cur = cur->next;
+   }
+   STBRP_ASSERT(cur->next == NULL);
+
+   {
+      int count=0;
+      cur = context->active_head;
+      while (cur) {
+         cur = cur->next;
+         ++count;
+      }
+      cur = context->free_head;
+      while (cur) {
+         cur = cur->next;
+         ++count;
+      }
+      STBRP_ASSERT(count == context->num_nodes+2);
+   }
+#endif
+
+   return res;
+}
+
+static int STBRP__CDECL rect_height_compare(const void *a, const void *b)
+{
+   const stbrp_rect *p = (const stbrp_rect *) a;
+   const stbrp_rect *q = (const stbrp_rect *) b;
+   if (p->h > q->h)
+      return -1;
+   if (p->h < q->h)
+      return  1;
+   return (p->w > q->w) ? -1 : (p->w < q->w);
+}
+
+static int STBRP__CDECL rect_original_order(const void *a, const void *b)
+{
+   const stbrp_rect *p = (const stbrp_rect *) a;
+   const stbrp_rect *q = (const stbrp_rect *) b;
+   return (p->was_packed < q->was_packed) ? -1 : (p->was_packed > q->was_packed);
+}
+
+STBRP_DEF int stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int num_rects)
+{
+   int i, all_rects_packed = 1;
+
+   // we use the 'was_packed' field internally to allow sorting/unsorting
+   for (i=0; i < num_rects; ++i) {
+      rects[i].was_packed = i;
+   }
+
+   // sort according to heuristic
+   STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_height_compare);
+
+   for (i=0; i < num_rects; ++i) {
+      if (rects[i].w == 0 || rects[i].h == 0) {
+         rects[i].x = rects[i].y = 0;  // empty rect needs no space
+      } else {
+         stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h);
+         if (fr.prev_link) {
+            rects[i].x = (stbrp_coord) fr.x;
+            rects[i].y = (stbrp_coord) fr.y;
+         } else {
+            rects[i].x = rects[i].y = STBRP__MAXVAL;
+         }
+      }
+   }
+
+   // unsort
+   STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_original_order);
+
+   // set was_packed flags and all_rects_packed status
+   for (i=0; i < num_rects; ++i) {
+      rects[i].was_packed = !(rects[i].x == STBRP__MAXVAL && rects[i].y == STBRP__MAXVAL);
+      if (!rects[i].was_packed)
+         all_rects_packed = 0;
+   }
+
+   // return the all_rects_packed status
+   return all_rects_packed;
+}
+#endif
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/

third_party/imgui/misc/README.txt

@@ -0,0 +1,23 @@
+
+misc/cpp/
+  InputText() wrappers for C++ standard library (STL) type: std::string.
+  This is also an example of how you may wrap your own similar types.
+
+misc/debuggers/
+  Helper files for popular debuggers.
+  With the .natvis file, types like ImVector<> will be displayed nicely in Visual Studio debugger.
+
+misc/fonts/
+  Fonts loading/merging instructions (e.g. How to handle glyph ranges, how to merge icons fonts).
+  Command line tool "binary_to_compressed_c" to create compressed arrays to embed data in source code.
+  Suggested fonts and links.
+
+misc/freetype/
+  Font atlas builder/rasterizer using FreeType instead of stb_truetype.
+  Benefit from better FreeType rasterization, in particular for small fonts.
+
+misc/single_file/
+  Single-file header stub.
+  We use this to validate compiling all *.cpp files in a same compilation unit.
+  Users of that technique (also called "Unity builds") can generally provide this themselves,
+  so we don't really recommend you use this in your projects.

third_party/imgui/misc/cpp/README.txt

@@ -0,0 +1,13 @@
+
+imgui_stdlib.h + imgui_stdlib.cpp
+  InputText() wrappers for C++ standard library (STL) type: std::string.
+  This is also an example of how you may wrap your own similar types.
+
+imgui_scoped.h
+  [Experimental, not currently in main repository]
+  Additional header file with some RAII-style wrappers for common Dear ImGui functions.
+  Try by merging: https://github.com/ocornut/imgui/pull/2197
+  Discuss at: https://github.com/ocornut/imgui/issues/2096
+
+See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+  https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness

third_party/imgui/misc/cpp/imgui_stdlib.cpp

@@ -0,0 +1,75 @@
+// dear imgui: wrappers for C++ standard library (STL) types (std::string, etc.)
+// This is also an example of how you may wrap your own similar types.
+
+// Changelog:
+// - v0.10: Initial version. Added InputText() / InputTextMultiline() calls with std::string
+
+// See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+//   https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness
+
+#include "imgui.h"
+#include "imgui_stdlib.h"
+
+struct InputTextCallback_UserData
+{
+    std::string*            Str;
+    ImGuiInputTextCallback  ChainCallback;
+    void*                   ChainCallbackUserData;
+};
+
+static int InputTextCallback(ImGuiInputTextCallbackData* data)
+{
+    InputTextCallback_UserData* user_data = (InputTextCallback_UserData*)data->UserData;
+    if (data->EventFlag == ImGuiInputTextFlags_CallbackResize)
+    {
+        // Resize string callback
+        // If for some reason we refuse the new length (BufTextLen) and/or capacity (BufSize) we need to set them back to what we want.
+        std::string* str = user_data->Str;
+        IM_ASSERT(data->Buf == str->c_str());
+        str->resize(data->BufTextLen);
+        data->Buf = (char*)str->c_str();
+    }
+    else if (user_data->ChainCallback)
+    {
+        // Forward to user callback, if any
+        data->UserData = user_data->ChainCallbackUserData;
+        return user_data->ChainCallback(data);
+    }
+    return 0;
+}
+
+bool ImGui::InputText(const char* label, std::string* str, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputText(label, (char*)str->c_str(), str->capacity() + 1, flags, InputTextCallback, &cb_user_data);
+}
+
+bool ImGui::InputTextMultiline(const char* label, std::string* str, const ImVec2& size, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputTextMultiline(label, (char*)str->c_str(), str->capacity() + 1, size, flags, InputTextCallback, &cb_user_data);
+}
+
+bool ImGui::InputTextWithHint(const char* label, const char* hint, std::string* str, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputTextWithHint(label, hint, (char*)str->c_str(), str->capacity() + 1, flags, InputTextCallback, &cb_user_data);
+}

third_party/imgui/misc/cpp/imgui_stdlib.h

@@ -0,0 +1,21 @@
+// dear imgui: wrappers for C++ standard library (STL) types (std::string, etc.)
+// This is also an example of how you may wrap your own similar types.
+
+// Changelog:
+// - v0.10: Initial version. Added InputText() / InputTextMultiline() calls with std::string
+
+// See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+//   https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness
+
+#pragma once
+
+#include <string>
+
+namespace ImGui
+{
+    // ImGui::InputText() with std::string
+    // Because text input needs dynamic resizing, we need to setup a callback to grow the capacity
+    IMGUI_API bool  InputText(const char* label, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextMultiline(const char* label, std::string* str, const ImVec2& size = ImVec2(0, 0), ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextWithHint(const char* label, const char* hint, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+}

third_party/imgui/misc/debuggers/README.txt

@@ -0,0 +1,16 @@
+
+HELPER FILES FOR POPULAR DEBUGGERS
+
+imgui.gdb
+    GDB: disable stepping into trivial functions.
+    (read comments inside file for details)
+
+imgui.natstepfilter
+    Visual Studio Debugger: disable stepping into trivial functions.
+    (read comments inside file for details)
+
+imgui.natvis
+    Visual Studio Debugger: describe Dear ImGui types for better display.
+    With this, types like ImVector<> will be displayed nicely in the debugger.
+    (read comments inside file for details)
+

third_party/imgui/misc/debuggers/imgui.gdb

@@ -0,0 +1,12 @@
+# GDB configuration to aid debugging experience
+
+# To enable these customizations edit $HOME/.gdbinit (or ./.gdbinit if local gdbinit is enabled) and add:
+#   add-auto-load-safe-path /path/to/imgui.gdb
+#   source /path/to/imgui.gdb
+#
+# More Information at:
+#   * https://sourceware.org/gdb/current/onlinedocs/gdb/gdbinit-man.html
+#   * https://sourceware.org/gdb/current/onlinedocs/gdb/Init-File-in-the-Current-Directory.html#Init-File-in-the-Current-Directory
+
+# Disable stepping into trivial functions
+skip -rfunction Im(Vec2|Vec4|Strv|Vector|Span)::.+

third_party/imgui/misc/debuggers/imgui.natstepfilter

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+.natstepfilter file for Visual Studio debugger.
+Purpose: instruct debugger to skip some functions when using StepInto (F11)
+
+Since Visual Studio 2022 version 17.6 Preview 2 (currently available as a "Preview" build on March 14, 2023)
+It is possible to add the .natstepfilter file to your project file and it will automatically be used.
+(https://developercommunity.visualstudio.com/t/allow-natstepfilter-and-natjmc-to-be-included-as-p/561718)
+
+For older Visual Studio version prior to 2022 17.6 Preview 2:
+* copy in %USERPROFILE%\Documents\Visual Studio XXXX\Visualizers (current user)
+* or copy in %VsInstallDirectory%\Common7\Packages\Debugger\Visualizers (all users)
+If you have multiple VS version installed, the version that matters is the one you are using the IDE/debugger
+of (not the compiling toolset). This is supported since Visual Studio 2012.
+
+More information at: https://docs.microsoft.com/en-us/visualstudio/debugger/just-my-code?view=vs-2019#BKMK_C___Just_My_Code
+-->
+
+<StepFilter xmlns="http://schemas.microsoft.com/vstudio/debugger/natstepfilter/2010">
+
+    <!-- Disable stepping into trivial functions -->
+    <Function>
+        <Name>(ImVec2|ImVec4|ImStrv)::.+</Name>
+        <Action>NoStepInto</Action>
+    </Function>
+    <Function>
+        <Name>(ImVector|ImSpan).*::operator.+</Name>
+        <Action>NoStepInto</Action>
+    </Function>
+
+</StepFilter>

third_party/imgui/misc/debuggers/imgui.natvis

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+.natvis file for Visual Studio debugger.
+Purpose: provide nicer views on data types used by Dear ImGui.
+
+To enable:
+* include file in your VS project (most recommended: not intrusive and always kept up to date!)
+* or copy in %USERPROFILE%\Documents\Visual Studio XXXX\Visualizers (current user)
+* or copy in %VsInstallDirectory%\Common7\Packages\Debugger\Visualizers (all users)
+
+More information at: https://docs.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects?view=vs-2019
+-->
+
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+
+<Type Name="ImVector&lt;*&gt;">
+  <DisplayString>{{Size={Size} Capacity={Capacity}}}</DisplayString>
+  <Expand>
+    <ArrayItems>
+      <Size>Size</Size>
+      <ValuePointer>Data</ValuePointer>
+    </ArrayItems>
+  </Expand>
+</Type>
+
+<Type Name="ImSpan&lt;*&gt;">
+  <DisplayString>{{Size={DataEnd-Data} }}</DisplayString>
+  <Expand>
+    <ArrayItems>
+      <Size>DataEnd-Data</Size>
+      <ValuePointer>Data</ValuePointer>
+    </ArrayItems>
+  </Expand>
+</Type>
+
+<Type Name="ImVec2">
+  <DisplayString>{{x={x,g} y={y,g}}}</DisplayString>
+</Type>
+
+<Type Name="ImVec4">
+  <DisplayString>{{x={x,g} y={y,g} z={z,g} w={w,g}}}</DisplayString>
+</Type>
+
+<Type Name="ImRect">
+  <DisplayString>{{Min=({Min.x,g} {Min.y,g}) Max=({Max.x,g} {Max.y,g}) Size=({Max.x-Min.x,g} {Max.y-Min.y,g})}}</DisplayString>
+  <Expand>
+    <Item Name="Min">Min</Item>
+    <Item Name="Max">Max</Item>
+    <Item Name="[Width]">Max.x - Min.x</Item>
+    <Item Name="[Height]">Max.y - Min.y</Item>
+  </Expand>
+</Type>
+
+<Type Name="ImGuiWindow">
+  <DisplayString>{{Name {Name,s} Active {(Active||WasActive)?1:0,d} Child {(Flags &amp; 0x01000000)?1:0,d} Popup {(Flags &amp; 0x04000000)?1:0,d} Hidden {(Hidden)?1:0,d}}</DisplayString>
+</Type>
+
+</AutoVisualizer>

third_party/imgui/misc/fonts/binary_to_compressed_c.cpp

@@ -0,0 +1,388 @@
+// dear imgui
+// (binary_to_compressed_c.cpp)
+// Helper tool to turn a file into a C array, if you want to embed font data in your source code.
+
+// The data is first compressed with stb_compress() to reduce source code size,
+// then encoded in Base85 to fit in a string so we can fit roughly 4 bytes of compressed data into 5 bytes of source code (suggested by @mmalex)
+// (If we used 32-bit constants it would require take 11 bytes of source code to encode 4 bytes, and be endianness dependent)
+// Note that even with compression, the output array is likely to be bigger than the binary file..
+// Load compressed TTF fonts with ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF()
+
+// Build with, e.g:
+//   # cl.exe binary_to_compressed_c.cpp
+//   # g++ binary_to_compressed_c.cpp
+//   # clang++ binary_to_compressed_c.cpp
+// You can also find a precompiled Windows binary in the binary/demo package available from https://github.com/ocornut/imgui
+
+// Usage:
+//   binary_to_compressed_c.exe [-base85] [-nocompress] [-nostatic] <inputfile> <symbolname>
+// Usage example:
+//   # binary_to_compressed_c.exe myfont.ttf MyFont > myfont.cpp
+//   # binary_to_compressed_c.exe -base85 myfont.ttf MyFont > myfont.cpp
+
+#define _CRT_SECURE_NO_WARNINGS
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+// stb_compress* from stb.h - declaration
+typedef unsigned int stb_uint;
+typedef unsigned char stb_uchar;
+stb_uint stb_compress(stb_uchar* out, stb_uchar* in, stb_uint len);
+
+static bool binary_to_compressed_c(const char* filename, const char* symbol, bool use_base85_encoding, bool use_compression, bool use_static);
+
+int main(int argc, char** argv)
+{
+    if (argc < 3)
+    {
+        printf("Syntax: %s [-base85] [-nocompress] [-nostatic] <inputfile> <symbolname>\n", argv[0]);
+        return 0;
+    }
+
+    int argn = 1;
+    bool use_base85_encoding = false;
+    bool use_compression = true;
+    bool use_static = true;
+    while (argn < (argc - 2) && argv[argn][0] == '-')
+    {
+        if (strcmp(argv[argn], "-base85") == 0) { use_base85_encoding = true; argn++; }
+        else if (strcmp(argv[argn], "-nocompress") == 0) { use_compression = false; argn++; }
+        else if (strcmp(argv[argn], "-nostatic") == 0) { use_static = false; argn++; }
+        else
+        {
+            fprintf(stderr, "Unknown argument: '%s'\n", argv[argn]);
+            return 1;
+        }
+    }
+
+    bool ret = binary_to_compressed_c(argv[argn], argv[argn + 1], use_base85_encoding, use_compression, use_static);
+    if (!ret)
+        fprintf(stderr, "Error opening or reading file: '%s'\n", argv[argn]);
+    return ret ? 0 : 1;
+}
+
+char Encode85Byte(unsigned int x)
+{
+    x = (x % 85) + 35;
+    return (char)((x >= '\\') ? x + 1 : x);
+}
+
+bool binary_to_compressed_c(const char* filename, const char* symbol, bool use_base85_encoding, bool use_compression, bool use_static)
+{
+    // Read file
+    FILE* f = fopen(filename, "rb");
+    if (!f) return false;
+    int data_sz;
+    if (fseek(f, 0, SEEK_END) || (data_sz = (int)ftell(f)) == -1 || fseek(f, 0, SEEK_SET)) { fclose(f); return false; }
+    char* data = new char[data_sz + 4];
+    if (fread(data, 1, data_sz, f) != (size_t)data_sz) { fclose(f); delete[] data; return false; }
+    memset((void*)(((char*)data) + data_sz), 0, 4);
+    fclose(f);
+
+    // Compress
+    int maxlen = data_sz + 512 + (data_sz >> 2) + sizeof(int); // total guess
+    char* compressed = use_compression ? new char[maxlen] : data;
+    int compressed_sz = use_compression ? stb_compress((stb_uchar*)compressed, (stb_uchar*)data, data_sz) : data_sz;
+    if (use_compression)
+        memset(compressed + compressed_sz, 0, maxlen - compressed_sz);
+
+    // Output as Base85 encoded
+    FILE* out = stdout;
+    fprintf(out, "// File: '%s' (%d bytes)\n", filename, (int)data_sz);
+    fprintf(out, "// Exported using binary_to_compressed_c.cpp\n");
+    const char* static_str = use_static ? "static " : "";
+    const char* compressed_str = use_compression ? "compressed_" : "";
+    if (use_base85_encoding)
+    {
+        fprintf(out, "%sconst char %s_%sdata_base85[%d+1] =\n    \"", static_str, symbol, compressed_str, (int)((compressed_sz + 3) / 4)*5);
+        char prev_c = 0;
+        for (int src_i = 0; src_i < compressed_sz; src_i += 4)
+        {
+            // This is made a little more complicated by the fact that ??X sequences are interpreted as trigraphs by old C/C++ compilers. So we need to escape pairs of ??.
+            unsigned int d = *(unsigned int*)(compressed + src_i);
+            for (unsigned int n5 = 0; n5 < 5; n5++, d /= 85)
+            {
+                char c = Encode85Byte(d);
+                fprintf(out, (c == '?' && prev_c == '?') ? "\\%c" : "%c", c);
+                prev_c = c;
+            }
+            if ((src_i % 112) == 112 - 4)
+                fprintf(out, "\"\n    \"");
+        }
+        fprintf(out, "\";\n\n");
+    }
+    else
+    {
+        fprintf(out, "%sconst unsigned int %s_%ssize = %d;\n", static_str, symbol, compressed_str, (int)compressed_sz);
+        fprintf(out, "%sconst unsigned int %s_%sdata[%d/4] =\n{", static_str, symbol, compressed_str, (int)((compressed_sz + 3) / 4)*4);
+        int column = 0;
+        for (int i = 0; i < compressed_sz; i += 4)
+        {
+            unsigned int d = *(unsigned int*)(compressed + i);
+            if ((column++ % 12) == 0)
+                fprintf(out, "\n    0x%08x, ", d);
+            else
+                fprintf(out, "0x%08x, ", d);
+        }
+        fprintf(out, "\n};\n\n");
+    }
+
+    // Cleanup
+    delete[] data;
+    if (use_compression)
+        delete[] compressed;
+    return true;
+}
+
+// stb_compress* from stb.h - definition
+
+////////////////////           compressor         ///////////////////////
+
+static stb_uint stb_adler32(stb_uint adler32, stb_uchar *buffer, stb_uint buflen)
+{
+    const unsigned long ADLER_MOD = 65521;
+    unsigned long s1 = adler32 & 0xffff, s2 = adler32 >> 16;
+    unsigned long blocklen, i;
+
+    blocklen = buflen % 5552;
+    while (buflen) {
+        for (i=0; i + 7 < blocklen; i += 8) {
+            s1 += buffer[0], s2 += s1;
+            s1 += buffer[1], s2 += s1;
+            s1 += buffer[2], s2 += s1;
+            s1 += buffer[3], s2 += s1;
+            s1 += buffer[4], s2 += s1;
+            s1 += buffer[5], s2 += s1;
+            s1 += buffer[6], s2 += s1;
+            s1 += buffer[7], s2 += s1;
+
+            buffer += 8;
+        }
+
+        for (; i < blocklen; ++i)
+            s1 += *buffer++, s2 += s1;
+
+        s1 %= ADLER_MOD, s2 %= ADLER_MOD;
+        buflen -= blocklen;
+        blocklen = 5552;
+    }
+    return (s2 << 16) + s1;
+}
+
+static unsigned int stb_matchlen(stb_uchar *m1, stb_uchar *m2, stb_uint maxlen)
+{
+    stb_uint i;
+    for (i=0; i < maxlen; ++i)
+        if (m1[i] != m2[i]) return i;
+    return i;
+}
+
+// simple implementation that just takes the source data in a big block
+
+static stb_uchar *stb__out;
+static FILE      *stb__outfile;
+static stb_uint   stb__outbytes;
+
+static void stb__write(unsigned char v)
+{
+    fputc(v, stb__outfile);
+    ++stb__outbytes;
+}
+
+//#define stb_out(v)    (stb__out ? *stb__out++ = (stb_uchar) (v) : stb__write((stb_uchar) (v)))
+#define stb_out(v)    do { if (stb__out) *stb__out++ = (stb_uchar) (v); else stb__write((stb_uchar) (v)); } while (0)
+
+static void stb_out2(stb_uint v) { stb_out(v >> 8); stb_out(v); }
+static void stb_out3(stb_uint v) { stb_out(v >> 16); stb_out(v >> 8); stb_out(v); }
+static void stb_out4(stb_uint v) { stb_out(v >> 24); stb_out(v >> 16); stb_out(v >> 8 ); stb_out(v); }
+
+static void outliterals(stb_uchar *in, int numlit)
+{
+    while (numlit > 65536) {
+        outliterals(in,65536);
+        in     += 65536;
+        numlit -= 65536;
+    }
+
+    if      (numlit ==     0)    ;
+    else if (numlit <=    32)    stb_out (0x000020 + numlit-1);
+    else if (numlit <=  2048)    stb_out2(0x000800 + numlit-1);
+    else /*  numlit <= 65536) */ stb_out3(0x070000 + numlit-1);
+
+    if (stb__out) {
+        memcpy(stb__out,in,numlit);
+        stb__out += numlit;
+    } else
+        fwrite(in, 1, numlit, stb__outfile);
+}
+
+static int stb__window = 0x40000; // 256K
+
+static int stb_not_crap(int best, int dist)
+{
+    return   ((best > 2  &&  dist <= 0x00100)
+        || (best > 5  &&  dist <= 0x04000)
+        || (best > 7  &&  dist <= 0x80000));
+}
+
+static  stb_uint stb__hashsize = 32768;
+
+// note that you can play with the hashing functions all you
+// want without needing to change the decompressor
+#define stb__hc(q,h,c)      (((h) << 7) + ((h) >> 25) + q[c])
+#define stb__hc2(q,h,c,d)   (((h) << 14) + ((h) >> 18) + (q[c] << 7) + q[d])
+#define stb__hc3(q,c,d,e)   ((q[c] << 14) + (q[d] << 7) + q[e])
+
+static unsigned int stb__running_adler;
+
+static int stb_compress_chunk(stb_uchar *history,
+    stb_uchar *start,
+    stb_uchar *end,
+    int length,
+    int *pending_literals,
+    stb_uchar **chash,
+    stb_uint mask)
+{
+    (void)history;
+    int window = stb__window;
+    stb_uint match_max;
+    stb_uchar *lit_start = start - *pending_literals;
+    stb_uchar *q = start;
+
+#define STB__SCRAMBLE(h)   (((h) + ((h) >> 16)) & mask)
+
+    // stop short of the end so we don't scan off the end doing
+    // the hashing; this means we won't compress the last few bytes
+    // unless they were part of something longer
+    while (q < start+length && q+12 < end) {
+        int m;
+        stb_uint h1,h2,h3,h4, h;
+        stb_uchar *t;
+        int best = 2, dist=0;
+
+        if (q+65536 > end)
+            match_max = (stb_uint)(end-q);
+        else
+            match_max = 65536;
+
+#define stb__nc(b,d)  ((d) <= window && ((b) > 9 || stb_not_crap((int)(b),(int)(d))))
+
+#define STB__TRY(t,p)  /* avoid retrying a match we already tried */ \
+    if (p ? dist != (int)(q-t) : 1)                             \
+    if ((m = stb_matchlen(t, q, match_max)) > best)     \
+    if (stb__nc(m,q-(t)))                                \
+    best = m, dist = (int)(q - (t))
+
+        // rather than search for all matches, only try 4 candidate locations,
+        // chosen based on 4 different hash functions of different lengths.
+        // this strategy is inspired by LZO; hashing is unrolled here using the
+        // 'hc' macro
+        h = stb__hc3(q,0, 1, 2); h1 = STB__SCRAMBLE(h);
+        t = chash[h1]; if (t) STB__TRY(t,0);
+        h = stb__hc2(q,h, 3, 4); h2 = STB__SCRAMBLE(h);
+        h = stb__hc2(q,h, 5, 6);        t = chash[h2]; if (t) STB__TRY(t,1);
+        h = stb__hc2(q,h, 7, 8); h3 = STB__SCRAMBLE(h);
+        h = stb__hc2(q,h, 9,10);        t = chash[h3]; if (t) STB__TRY(t,1);
+        h = stb__hc2(q,h,11,12); h4 = STB__SCRAMBLE(h);
+        t = chash[h4]; if (t) STB__TRY(t,1);
+
+        // because we use a shared hash table, can only update it
+        // _after_ we've probed all of them
+        chash[h1] = chash[h2] = chash[h3] = chash[h4] = q;
+
+        if (best > 2)
+            assert(dist > 0);
+
+        // see if our best match qualifies
+        if (best < 3) { // fast path literals
+            ++q;
+        } else if (best > 2  &&  best <= 0x80    &&  dist <= 0x100) {
+            outliterals(lit_start, (int)(q-lit_start)); lit_start = (q += best);
+            stb_out(0x80 + best-1);
+            stb_out(dist-1);
+        } else if (best > 5  &&  best <= 0x100   &&  dist <= 0x4000) {
+            outliterals(lit_start, (int)(q-lit_start)); lit_start = (q += best);
+            stb_out2(0x4000 + dist-1);
+            stb_out(best-1);
+        } else if (best > 7  &&  best <= 0x100   &&  dist <= 0x80000) {
+            outliterals(lit_start, (int)(q-lit_start)); lit_start = (q += best);
+            stb_out3(0x180000 + dist-1);
+            stb_out(best-1);
+        } else if (best > 8  &&  best <= 0x10000 &&  dist <= 0x80000) {
+            outliterals(lit_start, (int)(q-lit_start)); lit_start = (q += best);
+            stb_out3(0x100000 + dist-1);
+            stb_out2(best-1);
+        } else if (best > 9                      &&  dist <= 0x1000000) {
+            if (best > 65536) best = 65536;
+            outliterals(lit_start, (int)(q-lit_start)); lit_start = (q += best);
+            if (best <= 0x100) {
+                stb_out(0x06);
+                stb_out3(dist-1);
+                stb_out(best-1);
+            } else {
+                stb_out(0x04);
+                stb_out3(dist-1);
+                stb_out2(best-1);
+            }
+        } else {  // fallback literals if no match was a balanced tradeoff
+            ++q;
+        }
+    }
+
+    // if we didn't get all the way, add the rest to literals
+    if (q-start < length)
+        q = start+length;
+
+    // the literals are everything from lit_start to q
+    *pending_literals = (int)(q - lit_start);
+
+    stb__running_adler = stb_adler32(stb__running_adler, start, (stb_uint)(q - start));
+    return (int)(q - start);
+}
+
+static int stb_compress_inner(stb_uchar *input, stb_uint length)
+{
+    int literals = 0;
+    stb_uint len,i;
+
+    stb_uchar **chash;
+    chash = (stb_uchar**) malloc(stb__hashsize * sizeof(stb_uchar*));
+    if (chash == nullptr) return 0; // failure
+    for (i=0; i < stb__hashsize; ++i)
+        chash[i] = nullptr;
+
+    // stream signature
+    stb_out(0x57); stb_out(0xbc);
+    stb_out2(0);
+
+    stb_out4(0);       // 64-bit length requires 32-bit leading 0
+    stb_out4(length);
+    stb_out4(stb__window);
+
+    stb__running_adler = 1;
+
+    len = stb_compress_chunk(input, input, input+length, length, &literals, chash, stb__hashsize-1);
+    assert(len == length);
+
+    outliterals(input+length - literals, literals);
+
+    free(chash);
+
+    stb_out2(0x05fa); // end opcode
+
+    stb_out4(stb__running_adler);
+
+    return 1; // success
+}
+
+stb_uint stb_compress(stb_uchar *out, stb_uchar *input, stb_uint length)
+{
+    stb__out = out;
+    stb__outfile = nullptr;
+
+    stb_compress_inner(input, length);
+
+    return (stb_uint)(stb__out - out);
+}

third_party/imgui/misc/freetype/README.md

@@ -0,0 +1,37 @@
+# imgui_freetype
+
+Build font atlases using FreeType instead of stb_truetype (which is the default font rasterizer).
+<br>by @vuhdo, @mikesart, @ocornut.
+
+### Usage
+
+1. Get latest FreeType binaries or build yourself (under Windows you may use vcpkg with `vcpkg install freetype --triplet=x64-windows`, `vcpkg integrate install`).
+2. Add imgui_freetype.h/cpp alongside your project files.
+3. Add `#define IMGUI_ENABLE_FREETYPE` in your [imconfig.h](https://github.com/ocornut/imgui/blob/master/imconfig.h) file
+
+### About Gamma Correct Blending
+
+FreeType assumes blending in linear space rather than gamma space.
+See FreeType note for [FT_Render_Glyph](https://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Render_Glyph).
+For correct results you need to be using sRGB and convert to linear space in the pixel shader output.
+The default Dear ImGui styles will be impacted by this change (alpha values will need tweaking).
+
+### Testbed for toying with settings (for developers)
+
+See https://gist.github.com/ocornut/b3a9ecf13502fd818799a452969649ad
+
+### Known issues
+
+- Oversampling settins are ignored but also not so much necessary with the higher quality rendering.
+
+### Comparison
+
+Small, thin anti-aliased fonts typically benefit a lot from FreeType's hinting:
+![comparing_font_rasterizers](https://user-images.githubusercontent.com/8225057/107550178-fef87f00-6bd0-11eb-8d09-e2edb2f0ccfc.gif)
+
+### Colorful glyphs/emojis
+
+You can use the `ImGuiFreeTypeBuilderFlags_LoadColor` flag to load certain colorful glyphs. See the
+["Using Colorful Glyphs/Emojis"](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md#using-colorful-glyphsemojis) section of FONTS.md.
+
+![colored glyphs](https://user-images.githubusercontent.com/8225057/106171241-9dc4ba80-6191-11eb-8a69-ca1467b206d1.png)

third_party/imgui/misc/freetype/imgui_freetype.cpp

@@ -0,0 +1,797 @@
+// dear imgui: FreeType font builder (used as a replacement for the stb_truetype builder)
+// (code)
+
+// Get the latest version at https://github.com/ocornut/imgui/tree/master/misc/freetype
+// Original code by @vuhdo (Aleksei Skriabin). Improvements by @mikesart. Maintained since 2019 by @ocornut.
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2023/01/04: fixed a packing issue which in some occurrences would prevent large amount of glyphs from being packed correctly.
+//  2021/08/23: fixed crash when FT_Render_Glyph() fails to render a glyph and returns NULL.
+//  2021/03/05: added ImGuiFreeTypeBuilderFlags_Bitmap to load bitmap glyphs.
+//  2021/03/02: set 'atlas->TexPixelsUseColors = true' to help some backends with deciding of a prefered texture format.
+//  2021/01/28: added support for color-layered glyphs via ImGuiFreeTypeBuilderFlags_LoadColor (require Freetype 2.10+).
+//  2021/01/26: simplified integration by using '#define IMGUI_ENABLE_FREETYPE'.
+//              renamed ImGuiFreeType::XXX flags to ImGuiFreeTypeBuilderFlags_XXX for consistency with other API. removed ImGuiFreeType::BuildFontAtlas().
+//  2020/06/04: fix for rare case where FT_Get_Char_Index() succeed but FT_Load_Glyph() fails.
+//  2019/02/09: added RasterizerFlags::Monochrome flag to disable font anti-aliasing (combine with ::MonoHinting for best results!)
+//  2019/01/15: added support for imgui allocators + added FreeType only override function SetAllocatorFunctions().
+//  2019/01/10: re-factored to match big update in STB builder. fixed texture height waste. fixed redundant glyphs when merging. support for glyph padding.
+//  2018/06/08: added support for ImFontConfig::GlyphMinAdvanceX, GlyphMaxAdvanceX.
+//  2018/02/04: moved to main imgui repository (away from http://www.github.com/ocornut/imgui_club)
+//  2018/01/22: fix for addition of ImFontAtlas::TexUvscale member.
+//  2017/10/22: minor inconsequential change to match change in master (removed an unnecessary statement).
+//  2017/09/26: fixes for imgui internal changes.
+//  2017/08/26: cleanup, optimizations, support for ImFontConfig::RasterizerFlags, ImFontConfig::RasterizerMultiply.
+//  2017/08/16: imported from https://github.com/Vuhdo/imgui_freetype into http://www.github.com/ocornut/imgui_club, updated for latest changes in ImFontAtlas, minor tweaks.
+
+// About Gamma Correct Blending:
+// - FreeType assumes blending in linear space rather than gamma space.
+// - See https://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Render_Glyph
+// - For correct results you need to be using sRGB and convert to linear space in the pixel shader output.
+// - The default dear imgui styles will be impacted by this change (alpha values will need tweaking).
+
+// FIXME: cfg.OversampleH, OversampleV are not supported (but perhaps not so necessary with this rasterizer).
+
+#include "imgui_freetype.h"
+#include "imgui_internal.h"     // ImMin,ImMax,ImFontAtlasBuild*,
+#include <stdint.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H          // <freetype/freetype.h>
+#include FT_MODULE_H            // <freetype/ftmodapi.h>
+#include FT_GLYPH_H             // <freetype/ftglyph.h>
+#include FT_SYNTHESIS_H         // <freetype/ftsynth.h>
+
+#ifdef _MSC_VER
+#pragma warning (push)
+#pragma warning (disable: 4505)     // unreferenced local function has been removed (stb stuff)
+#pragma warning (disable: 26812)    // [Static Analyzer] The enum type 'xxx' is unscoped. Prefer 'enum class' over 'enum' (Enum.3).
+#endif
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wpragmas"                  // warning: unknown option after '#pragma GCC diagnostic' kind
+#pragma GCC diagnostic ignored "-Wunused-function"          // warning: 'xxxx' defined but not used
+#pragma GCC diagnostic ignored "-Wsubobject-linkage"        // warning: 'xxxx' has a field 'xxxx' whose type uses the anonymous namespace
+#endif
+
+//-------------------------------------------------------------------------
+// Data
+//-------------------------------------------------------------------------
+
+// Default memory allocators
+static void* ImGuiFreeTypeDefaultAllocFunc(size_t size, void* user_data) { IM_UNUSED(user_data); return IM_ALLOC(size); }
+static void  ImGuiFreeTypeDefaultFreeFunc(void* ptr, void* user_data) { IM_UNUSED(user_data); IM_FREE(ptr); }
+
+// Current memory allocators
+static void* (*GImGuiFreeTypeAllocFunc)(size_t size, void* user_data) = ImGuiFreeTypeDefaultAllocFunc;
+static void  (*GImGuiFreeTypeFreeFunc)(void* ptr, void* user_data) = ImGuiFreeTypeDefaultFreeFunc;
+static void* GImGuiFreeTypeAllocatorUserData = nullptr;
+
+//-------------------------------------------------------------------------
+// Code
+//-------------------------------------------------------------------------
+
+namespace
+{
+    // Glyph metrics:
+    // --------------
+    //
+    //                       xmin                     xmax
+    //                        |                         |
+    //                        |<-------- width -------->|
+    //                        |                         |
+    //              |         +-------------------------+----------------- ymax
+    //              |         |    ggggggggg   ggggg    |     ^        ^
+    //              |         |   g:::::::::ggg::::g    |     |        |
+    //              |         |  g:::::::::::::::::g    |     |        |
+    //              |         | g::::::ggggg::::::gg    |     |        |
+    //              |         | g:::::g     g:::::g     |     |        |
+    //    offsetX  -|-------->| g:::::g     g:::::g     |  offsetY     |
+    //              |         | g:::::g     g:::::g     |     |        |
+    //              |         | g::::::g    g:::::g     |     |        |
+    //              |         | g:::::::ggggg:::::g     |     |        |
+    //              |         |  g::::::::::::::::g     |     |      height
+    //              |         |   gg::::::::::::::g     |     |        |
+    //  baseline ---*---------|---- gggggggg::::::g-----*--------      |
+    //            / |         |             g:::::g     |              |
+    //     origin   |         | gggggg      g:::::g     |              |
+    //              |         | g:::::gg   gg:::::g     |              |
+    //              |         |  g::::::ggg:::::::g     |              |
+    //              |         |   gg:::::::::::::g      |              |
+    //              |         |     ggg::::::ggg        |              |
+    //              |         |         gggggg          |              v
+    //              |         +-------------------------+----------------- ymin
+    //              |                                   |
+    //              |------------- advanceX ----------->|
+
+    // A structure that describe a glyph.
+    struct GlyphInfo
+    {
+        int         Width;              // Glyph's width in pixels.
+        int         Height;             // Glyph's height in pixels.
+        FT_Int      OffsetX;            // The distance from the origin ("pen position") to the left of the glyph.
+        FT_Int      OffsetY;            // The distance from the origin to the top of the glyph. This is usually a value < 0.
+        float       AdvanceX;           // The distance from the origin to the origin of the next glyph. This is usually a value > 0.
+        bool        IsColored;          // The glyph is colored
+    };
+
+    // Font parameters and metrics.
+    struct FontInfo
+    {
+        uint32_t    PixelHeight;        // Size this font was generated with.
+        float       Ascender;           // The pixel extents above the baseline in pixels (typically positive).
+        float       Descender;          // The extents below the baseline in pixels (typically negative).
+        float       LineSpacing;        // The baseline-to-baseline distance. Note that it usually is larger than the sum of the ascender and descender taken as absolute values. There is also no guarantee that no glyphs extend above or below subsequent baselines when using this distance. Think of it as a value the designer of the font finds appropriate.
+        float       LineGap;            // The spacing in pixels between one row's descent and the next row's ascent.
+        float       MaxAdvanceWidth;    // This field gives the maximum horizontal cursor advance for all glyphs in the font.
+    };
+
+    // FreeType glyph rasterizer.
+    // NB: No ctor/dtor, explicitly call Init()/Shutdown()
+    struct FreeTypeFont
+    {
+        bool                    InitFont(FT_Library ft_library, const ImFontConfig& cfg, unsigned int extra_user_flags); // Initialize from an external data buffer. Doesn't copy data, and you must ensure it stays valid up to this object lifetime.
+        void                    CloseFont();
+        void                    SetPixelHeight(int pixel_height); // Change font pixel size. All following calls to RasterizeGlyph() will use this size
+        const FT_Glyph_Metrics* LoadGlyph(uint32_t in_codepoint);
+        const FT_Bitmap*        RenderGlyphAndGetInfo(GlyphInfo* out_glyph_info);
+        void                    BlitGlyph(const FT_Bitmap* ft_bitmap, uint32_t* dst, uint32_t dst_pitch, unsigned char* multiply_table = nullptr);
+        ~FreeTypeFont()         { CloseFont(); }
+
+        // [Internals]
+        FontInfo        Info;               // Font descriptor of the current font.
+        FT_Face         Face;
+        unsigned int    UserFlags;          // = ImFontConfig::RasterizerFlags
+        FT_Int32        LoadFlags;
+        FT_Render_Mode  RenderMode;
+    };
+
+    // From SDL_ttf: Handy routines for converting from fixed point
+    #define FT_CEIL(X)  (((X + 63) & -64) / 64)
+
+    bool FreeTypeFont::InitFont(FT_Library ft_library, const ImFontConfig& cfg, unsigned int extra_font_builder_flags)
+    {
+        FT_Error error = FT_New_Memory_Face(ft_library, (uint8_t*)cfg.FontData, (uint32_t)cfg.FontDataSize, (uint32_t)cfg.FontNo, &Face);
+        if (error != 0)
+            return false;
+        error = FT_Select_Charmap(Face, FT_ENCODING_UNICODE);
+        if (error != 0)
+            return false;
+
+        // Convert to FreeType flags (NB: Bold and Oblique are processed separately)
+        UserFlags = cfg.FontBuilderFlags | extra_font_builder_flags;
+
+        LoadFlags = 0;
+        if ((UserFlags & ImGuiFreeTypeBuilderFlags_Bitmap) == 0)
+            LoadFlags |= FT_LOAD_NO_BITMAP;
+
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_NoHinting)
+            LoadFlags |= FT_LOAD_NO_HINTING;
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_NoAutoHint)
+            LoadFlags |= FT_LOAD_NO_AUTOHINT;
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_ForceAutoHint)
+            LoadFlags |= FT_LOAD_FORCE_AUTOHINT;
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_LightHinting)
+            LoadFlags |= FT_LOAD_TARGET_LIGHT;
+        else if (UserFlags & ImGuiFreeTypeBuilderFlags_MonoHinting)
+            LoadFlags |= FT_LOAD_TARGET_MONO;
+        else
+            LoadFlags |= FT_LOAD_TARGET_NORMAL;
+
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_Monochrome)
+            RenderMode = FT_RENDER_MODE_MONO;
+        else
+            RenderMode = FT_RENDER_MODE_NORMAL;
+
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_LoadColor)
+            LoadFlags |= FT_LOAD_COLOR;
+
+        memset(&Info, 0, sizeof(Info));
+        SetPixelHeight((uint32_t)cfg.SizePixels);
+
+        return true;
+    }
+
+    void FreeTypeFont::CloseFont()
+    {
+        if (Face)
+        {
+            FT_Done_Face(Face);
+            Face = nullptr;
+        }
+    }
+
+    void FreeTypeFont::SetPixelHeight(int pixel_height)
+    {
+        // Vuhdo: I'm not sure how to deal with font sizes properly. As far as I understand, currently ImGui assumes that the 'pixel_height'
+        // is a maximum height of an any given glyph, i.e. it's the sum of font's ascender and descender. Seems strange to me.
+        // NB: FT_Set_Pixel_Sizes() doesn't seem to get us the same result.
+        FT_Size_RequestRec req;
+        req.type = (UserFlags & ImGuiFreeTypeBuilderFlags_Bitmap) ? FT_SIZE_REQUEST_TYPE_NOMINAL : FT_SIZE_REQUEST_TYPE_REAL_DIM;
+        req.width = 0;
+        req.height = (uint32_t)pixel_height * 64;
+        req.horiResolution = 0;
+        req.vertResolution = 0;
+        FT_Request_Size(Face, &req);
+
+        // Update font info
+        FT_Size_Metrics metrics = Face->size->metrics;
+        Info.PixelHeight = (uint32_t)pixel_height;
+        Info.Ascender = (float)FT_CEIL(metrics.ascender);
+        Info.Descender = (float)FT_CEIL(metrics.descender);
+        Info.LineSpacing = (float)FT_CEIL(metrics.height);
+        Info.LineGap = (float)FT_CEIL(metrics.height - metrics.ascender + metrics.descender);
+        Info.MaxAdvanceWidth = (float)FT_CEIL(metrics.max_advance);
+    }
+
+    const FT_Glyph_Metrics* FreeTypeFont::LoadGlyph(uint32_t codepoint)
+    {
+        uint32_t glyph_index = FT_Get_Char_Index(Face, codepoint);
+        if (glyph_index == 0)
+            return nullptr;
+
+		// If this crash for you: FreeType 2.11.0 has a crash bug on some bitmap/colored fonts.
+		// - https://gitlab.freedesktop.org/freetype/freetype/-/issues/1076
+		// - https://github.com/ocornut/imgui/issues/4567
+		// - https://github.com/ocornut/imgui/issues/4566
+		// You can use FreeType 2.10, or the patched version of 2.11.0 in VcPkg, or probably any upcoming FreeType version.
+        FT_Error error = FT_Load_Glyph(Face, glyph_index, LoadFlags);
+        if (error)
+            return nullptr;
+
+        // Need an outline for this to work
+        FT_GlyphSlot slot = Face->glyph;
+        IM_ASSERT(slot->format == FT_GLYPH_FORMAT_OUTLINE || slot->format == FT_GLYPH_FORMAT_BITMAP);
+
+        // Apply convenience transform (this is not picking from real "Bold"/"Italic" fonts! Merely applying FreeType helper transform. Oblique == Slanting)
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_Bold)
+            FT_GlyphSlot_Embolden(slot);
+        if (UserFlags & ImGuiFreeTypeBuilderFlags_Oblique)
+        {
+            FT_GlyphSlot_Oblique(slot);
+            //FT_BBox bbox;
+            //FT_Outline_Get_BBox(&slot->outline, &bbox);
+            //slot->metrics.width = bbox.xMax - bbox.xMin;
+            //slot->metrics.height = bbox.yMax - bbox.yMin;
+        }
+
+        return &slot->metrics;
+    }
+
+    const FT_Bitmap* FreeTypeFont::RenderGlyphAndGetInfo(GlyphInfo* out_glyph_info)
+    {
+        FT_GlyphSlot slot = Face->glyph;
+        FT_Error error = FT_Render_Glyph(slot, RenderMode);
+        if (error != 0)
+            return nullptr;
+
+        FT_Bitmap* ft_bitmap = &Face->glyph->bitmap;
+        out_glyph_info->Width = (int)ft_bitmap->width;
+        out_glyph_info->Height = (int)ft_bitmap->rows;
+        out_glyph_info->OffsetX = Face->glyph->bitmap_left;
+        out_glyph_info->OffsetY = -Face->glyph->bitmap_top;
+        out_glyph_info->AdvanceX = (float)FT_CEIL(slot->advance.x);
+        out_glyph_info->IsColored = (ft_bitmap->pixel_mode == FT_PIXEL_MODE_BGRA);
+
+        return ft_bitmap;
+    }
+
+    void FreeTypeFont::BlitGlyph(const FT_Bitmap* ft_bitmap, uint32_t* dst, uint32_t dst_pitch, unsigned char* multiply_table)
+    {
+        IM_ASSERT(ft_bitmap != nullptr);
+        const uint32_t w = ft_bitmap->width;
+        const uint32_t h = ft_bitmap->rows;
+        const uint8_t* src = ft_bitmap->buffer;
+        const uint32_t src_pitch = ft_bitmap->pitch;
+
+        switch (ft_bitmap->pixel_mode)
+        {
+        case FT_PIXEL_MODE_GRAY: // Grayscale image, 1 byte per pixel.
+            {
+                if (multiply_table == nullptr)
+                {
+                    for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
+                        for (uint32_t x = 0; x < w; x++)
+                            dst[x] = IM_COL32(255, 255, 255, src[x]);
+                }
+                else
+                {
+                    for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
+                        for (uint32_t x = 0; x < w; x++)
+                            dst[x] = IM_COL32(255, 255, 255, multiply_table[src[x]]);
+                }
+                break;
+            }
+        case FT_PIXEL_MODE_MONO: // Monochrome image, 1 bit per pixel. The bits in each byte are ordered from MSB to LSB.
+            {
+                uint8_t color0 = multiply_table ? multiply_table[0] : 0;
+                uint8_t color1 = multiply_table ? multiply_table[255] : 255;
+                for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
+                {
+                    uint8_t bits = 0;
+                    const uint8_t* bits_ptr = src;
+                    for (uint32_t x = 0; x < w; x++, bits <<= 1)
+                    {
+                        if ((x & 7) == 0)
+                            bits = *bits_ptr++;
+                        dst[x] = IM_COL32(255, 255, 255, (bits & 0x80) ? color1 : color0);
+                    }
+                }
+                break;
+            }
+        case FT_PIXEL_MODE_BGRA:
+            {
+                // FIXME: Converting pre-multiplied alpha to straight. Doesn't smell good.
+                #define DE_MULTIPLY(color, alpha) (ImU32)(255.0f * (float)color / (float)alpha + 0.5f)
+                if (multiply_table == nullptr)
+                {
+                    for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
+                        for (uint32_t x = 0; x < w; x++)
+                        {
+                            uint8_t r = src[x * 4 + 2], g = src[x * 4 + 1], b = src[x * 4], a = src[x * 4 + 3];
+                            dst[x] = IM_COL32(DE_MULTIPLY(r, a), DE_MULTIPLY(g, a), DE_MULTIPLY(b, a), a);
+                        }
+                }
+                else
+                {
+                    for (uint32_t y = 0; y < h; y++, src += src_pitch, dst += dst_pitch)
+                    {
+                        for (uint32_t x = 0; x < w; x++)
+                        {
+                            uint8_t r = src[x * 4 + 2], g = src[x * 4 + 1], b = src[x * 4], a = src[x * 4 + 3];
+                            dst[x] = IM_COL32(multiply_table[DE_MULTIPLY(r, a)], multiply_table[DE_MULTIPLY(g, a)], multiply_table[DE_MULTIPLY(b, a)], multiply_table[a]);
+                        }
+                    }
+                }
+                #undef DE_MULTIPLY
+                break;
+            }
+        default:
+            IM_ASSERT(0 && "FreeTypeFont::BlitGlyph(): Unknown bitmap pixel mode!");
+        }
+    }
+} // namespace
+
+#ifndef STB_RECT_PACK_IMPLEMENTATION                        // in case the user already have an implementation in the _same_ compilation unit (e.g. unity builds)
+#ifndef IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
+#define STBRP_ASSERT(x)     do { IM_ASSERT(x); } while (0)
+#define STBRP_STATIC
+#define STB_RECT_PACK_IMPLEMENTATION
+#endif
+#ifdef IMGUI_STB_RECT_PACK_FILENAME
+#include IMGUI_STB_RECT_PACK_FILENAME
+#else
+#include "imstb_rectpack.h"
+#endif
+#endif
+
+struct ImFontBuildSrcGlyphFT
+{
+    GlyphInfo           Info;
+    uint32_t            Codepoint;
+    unsigned int*       BitmapData;         // Point within one of the dst_tmp_bitmap_buffers[] array
+
+    ImFontBuildSrcGlyphFT() { memset((void*)this, 0, sizeof(*this)); }
+};
+
+struct ImFontBuildSrcDataFT
+{
+    FreeTypeFont        Font;
+    stbrp_rect*         Rects;              // Rectangle to pack. We first fill in their size and the packer will give us their position.
+    const ImWchar*      SrcRanges;          // Ranges as requested by user (user is allowed to request too much, e.g. 0x0020..0xFFFF)
+    int                 DstIndex;           // Index into atlas->Fonts[] and dst_tmp_array[]
+    int                 GlyphsHighest;      // Highest requested codepoint
+    int                 GlyphsCount;        // Glyph count (excluding missing glyphs and glyphs already set by an earlier source font)
+    ImBitVector         GlyphsSet;          // Glyph bit map (random access, 1-bit per codepoint. This will be a maximum of 8KB)
+    ImVector<ImFontBuildSrcGlyphFT>   GlyphsList;
+};
+
+// Temporary data for one destination ImFont* (multiple source fonts can be merged into one destination ImFont)
+struct ImFontBuildDstDataFT
+{
+    int                 SrcCount;           // Number of source fonts targeting this destination font.
+    int                 GlyphsHighest;
+    int                 GlyphsCount;
+    ImBitVector         GlyphsSet;          // This is used to resolve collision when multiple sources are merged into a same destination font.
+};
+
+bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, unsigned int extra_flags)
+{
+    IM_ASSERT(atlas->ConfigData.Size > 0);
+
+    ImFontAtlasBuildInit(atlas);
+
+    // Clear atlas
+    atlas->TexID = (ImTextureID)nullptr;
+    atlas->TexWidth = atlas->TexHeight = 0;
+    atlas->TexUvScale = ImVec2(0.0f, 0.0f);
+    atlas->TexUvWhitePixel = ImVec2(0.0f, 0.0f);
+    atlas->ClearTexData();
+
+    // Temporary storage for building
+    bool src_load_color = false;
+    ImVector<ImFontBuildSrcDataFT> src_tmp_array;
+    ImVector<ImFontBuildDstDataFT> dst_tmp_array;
+    src_tmp_array.resize(atlas->ConfigData.Size);
+    dst_tmp_array.resize(atlas->Fonts.Size);
+    memset((void*)src_tmp_array.Data, 0, (size_t)src_tmp_array.size_in_bytes());
+    memset((void*)dst_tmp_array.Data, 0, (size_t)dst_tmp_array.size_in_bytes());
+
+    // 1. Initialize font loading structure, check font data validity
+    for (int src_i = 0; src_i < atlas->ConfigData.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        FreeTypeFont& font_face = src_tmp.Font;
+        IM_ASSERT(cfg.DstFont && (!cfg.DstFont->IsLoaded() || cfg.DstFont->ContainerAtlas == atlas));
+
+        // Find index from cfg.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
+        src_tmp.DstIndex = -1;
+        for (int output_i = 0; output_i < atlas->Fonts.Size && src_tmp.DstIndex == -1; output_i++)
+            if (cfg.DstFont == atlas->Fonts[output_i])
+                src_tmp.DstIndex = output_i;
+        IM_ASSERT(src_tmp.DstIndex != -1); // cfg.DstFont not pointing within atlas->Fonts[] array?
+        if (src_tmp.DstIndex == -1)
+            return false;
+
+        // Load font
+        if (!font_face.InitFont(ft_library, cfg, extra_flags))
+            return false;
+
+        // Measure highest codepoints
+        src_load_color |= (cfg.FontBuilderFlags & ImGuiFreeTypeBuilderFlags_LoadColor) != 0;
+        ImFontBuildDstDataFT& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
+        src_tmp.SrcRanges = cfg.GlyphRanges ? cfg.GlyphRanges : atlas->GetGlyphRangesDefault();
+        for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
+        {
+            // Check for valid range. This may also help detect *some* dangling pointers, because a common
+            // user error is to setup ImFontConfig::GlyphRanges with a pointer to data that isn't persistent.
+            IM_ASSERT(src_range[0] <= src_range[1]);
+            src_tmp.GlyphsHighest = ImMax(src_tmp.GlyphsHighest, (int)src_range[1]);
+        }
+        dst_tmp.SrcCount++;
+        dst_tmp.GlyphsHighest = ImMax(dst_tmp.GlyphsHighest, src_tmp.GlyphsHighest);
+    }
+
+    // 2. For every requested codepoint, check for their presence in the font data, and handle redundancy or overlaps between source fonts to avoid unused glyphs.
+    int total_glyphs_count = 0;
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        ImFontBuildDstDataFT& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
+        src_tmp.GlyphsSet.Create(src_tmp.GlyphsHighest + 1);
+        if (dst_tmp.GlyphsSet.Storage.empty())
+            dst_tmp.GlyphsSet.Create(dst_tmp.GlyphsHighest + 1);
+
+        for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
+            for (int codepoint = src_range[0]; codepoint <= (int)src_range[1]; codepoint++)
+            {
+                if (dst_tmp.GlyphsSet.TestBit(codepoint))    // Don't overwrite existing glyphs. We could make this an option (e.g. MergeOverwrite)
+                    continue;
+                uint32_t glyph_index = FT_Get_Char_Index(src_tmp.Font.Face, codepoint); // It is actually in the font? (FIXME-OPT: We are not storing the glyph_index..)
+                if (glyph_index == 0)
+                    continue;
+
+                // Add to avail set/counters
+                src_tmp.GlyphsCount++;
+                dst_tmp.GlyphsCount++;
+                src_tmp.GlyphsSet.SetBit(codepoint);
+                dst_tmp.GlyphsSet.SetBit(codepoint);
+                total_glyphs_count++;
+            }
+    }
+
+    // 3. Unpack our bit map into a flat list (we now have all the Unicode points that we know are requested _and_ available _and_ not overlapping another)
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        src_tmp.GlyphsList.reserve(src_tmp.GlyphsCount);
+
+        IM_ASSERT(sizeof(src_tmp.GlyphsSet.Storage.Data[0]) == sizeof(ImU32));
+        const ImU32* it_begin = src_tmp.GlyphsSet.Storage.begin();
+        const ImU32* it_end = src_tmp.GlyphsSet.Storage.end();
+        for (const ImU32* it = it_begin; it < it_end; it++)
+            if (ImU32 entries_32 = *it)
+                for (ImU32 bit_n = 0; bit_n < 32; bit_n++)
+                    if (entries_32 & ((ImU32)1 << bit_n))
+                    {
+                        ImFontBuildSrcGlyphFT src_glyph;
+                        src_glyph.Codepoint = (ImWchar)(((it - it_begin) << 5) + bit_n);
+                        //src_glyph.GlyphIndex = 0; // FIXME-OPT: We had this info in the previous step and lost it..
+                        src_tmp.GlyphsList.push_back(src_glyph);
+                    }
+        src_tmp.GlyphsSet.Clear();
+        IM_ASSERT(src_tmp.GlyphsList.Size == src_tmp.GlyphsCount);
+    }
+    for (int dst_i = 0; dst_i < dst_tmp_array.Size; dst_i++)
+        dst_tmp_array[dst_i].GlyphsSet.Clear();
+    dst_tmp_array.clear();
+
+    // Allocate packing character data and flag packed characters buffer as non-packed (x0=y0=x1=y1=0)
+    // (We technically don't need to zero-clear buf_rects, but let's do it for the sake of sanity)
+    ImVector<stbrp_rect> buf_rects;
+    buf_rects.resize(total_glyphs_count);
+    memset(buf_rects.Data, 0, (size_t)buf_rects.size_in_bytes());
+
+    // Allocate temporary rasterization data buffers.
+    // We could not find a way to retrieve accurate glyph size without rendering them.
+    // (e.g. slot->metrics->width not always matching bitmap->width, especially considering the Oblique transform)
+    // We allocate in chunks of 256 KB to not waste too much extra memory ahead. Hopefully users of FreeType won't mind the temporary allocations.
+    const int BITMAP_BUFFERS_CHUNK_SIZE = 256 * 1024;
+    int buf_bitmap_current_used_bytes = 0;
+    ImVector<unsigned char*> buf_bitmap_buffers;
+    buf_bitmap_buffers.push_back((unsigned char*)IM_ALLOC(BITMAP_BUFFERS_CHUNK_SIZE));
+
+    // 4. Gather glyphs sizes so we can pack them in our virtual canvas.
+    // 8. Render/rasterize font characters into the texture
+    int total_surface = 0;
+    int buf_rects_out_n = 0;
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        src_tmp.Rects = &buf_rects[buf_rects_out_n];
+        buf_rects_out_n += src_tmp.GlyphsCount;
+
+        // Compute multiply table if requested
+        const bool multiply_enabled = (cfg.RasterizerMultiply != 1.0f);
+        unsigned char multiply_table[256];
+        if (multiply_enabled)
+            ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, cfg.RasterizerMultiply);
+
+        // Gather the sizes of all rectangles we will need to pack
+        const int padding = atlas->TexGlyphPadding;
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsList.Size; glyph_i++)
+        {
+            ImFontBuildSrcGlyphFT& src_glyph = src_tmp.GlyphsList[glyph_i];
+
+            const FT_Glyph_Metrics* metrics = src_tmp.Font.LoadGlyph(src_glyph.Codepoint);
+            if (metrics == nullptr)
+                continue;
+
+            // Render glyph into a bitmap (currently held by FreeType)
+            const FT_Bitmap* ft_bitmap = src_tmp.Font.RenderGlyphAndGetInfo(&src_glyph.Info);
+            if (ft_bitmap == nullptr)
+                continue;
+
+            // Allocate new temporary chunk if needed
+            const int bitmap_size_in_bytes = src_glyph.Info.Width * src_glyph.Info.Height * 4;
+            if (buf_bitmap_current_used_bytes + bitmap_size_in_bytes > BITMAP_BUFFERS_CHUNK_SIZE)
+            {
+                buf_bitmap_current_used_bytes = 0;
+                buf_bitmap_buffers.push_back((unsigned char*)IM_ALLOC(BITMAP_BUFFERS_CHUNK_SIZE));
+            }
+            IM_ASSERT(buf_bitmap_current_used_bytes + bitmap_size_in_bytes <= BITMAP_BUFFERS_CHUNK_SIZE); // We could probably allocate custom-sized buffer instead.
+
+            // Blit rasterized pixels to our temporary buffer and keep a pointer to it.
+            src_glyph.BitmapData = (unsigned int*)(buf_bitmap_buffers.back() + buf_bitmap_current_used_bytes);
+            buf_bitmap_current_used_bytes += bitmap_size_in_bytes;
+            src_tmp.Font.BlitGlyph(ft_bitmap, src_glyph.BitmapData, src_glyph.Info.Width, multiply_enabled ? multiply_table : nullptr);
+
+            src_tmp.Rects[glyph_i].w = (stbrp_coord)(src_glyph.Info.Width + padding);
+            src_tmp.Rects[glyph_i].h = (stbrp_coord)(src_glyph.Info.Height + padding);
+            total_surface += src_tmp.Rects[glyph_i].w * src_tmp.Rects[glyph_i].h;
+        }
+    }
+
+    // We need a width for the skyline algorithm, any width!
+    // The exact width doesn't really matter much, but some API/GPU have texture size limitations and increasing width can decrease height.
+    // User can override TexDesiredWidth and TexGlyphPadding if they wish, otherwise we use a simple heuristic to select the width based on expected surface.
+    const int surface_sqrt = (int)ImSqrt((float)total_surface) + 1;
+    atlas->TexHeight = 0;
+    if (atlas->TexDesiredWidth > 0)
+        atlas->TexWidth = atlas->TexDesiredWidth;
+    else
+        atlas->TexWidth = (surface_sqrt >= 4096 * 0.7f) ? 4096 : (surface_sqrt >= 2048 * 0.7f) ? 2048 : (surface_sqrt >= 1024 * 0.7f) ? 1024 : 512;
+
+    // 5. Start packing
+    // Pack our extra data rectangles first, so it will be on the upper-left corner of our texture (UV will have small values).
+    const int TEX_HEIGHT_MAX = 1024 * 32;
+    const int num_nodes_for_packing_algorithm = atlas->TexWidth - atlas->TexGlyphPadding;
+    ImVector<stbrp_node> pack_nodes;
+    pack_nodes.resize(num_nodes_for_packing_algorithm);
+    stbrp_context pack_context;
+    stbrp_init_target(&pack_context, atlas->TexWidth - atlas->TexGlyphPadding, TEX_HEIGHT_MAX - atlas->TexGlyphPadding, pack_nodes.Data, pack_nodes.Size);
+    ImFontAtlasBuildPackCustomRects(atlas, &pack_context);
+
+    // 6. Pack each source font. No rendering yet, we are working with rectangles in an infinitely tall texture at this point.
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        stbrp_pack_rects(&pack_context, src_tmp.Rects, src_tmp.GlyphsCount);
+
+        // Extend texture height and mark missing glyphs as non-packed so we won't render them.
+        // FIXME: We are not handling packing failure here (would happen if we got off TEX_HEIGHT_MAX or if a single if larger than TexWidth?)
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
+            if (src_tmp.Rects[glyph_i].was_packed)
+                atlas->TexHeight = ImMax(atlas->TexHeight, src_tmp.Rects[glyph_i].y + src_tmp.Rects[glyph_i].h);
+    }
+
+    // 7. Allocate texture
+    atlas->TexHeight = (atlas->Flags & ImFontAtlasFlags_NoPowerOfTwoHeight) ? (atlas->TexHeight + 1) : ImUpperPowerOfTwo(atlas->TexHeight);
+    atlas->TexUvScale = ImVec2(1.0f / atlas->TexWidth, 1.0f / atlas->TexHeight);
+    if (src_load_color)
+    {
+        size_t tex_size = (size_t)atlas->TexWidth * atlas->TexHeight * 4;
+        atlas->TexPixelsRGBA32 = (unsigned int*)IM_ALLOC(tex_size);
+        memset(atlas->TexPixelsRGBA32, 0, tex_size);
+    }
+    else
+    {
+        size_t tex_size = (size_t)atlas->TexWidth * atlas->TexHeight * 1;
+        atlas->TexPixelsAlpha8 = (unsigned char*)IM_ALLOC(tex_size);
+        memset(atlas->TexPixelsAlpha8, 0, tex_size);
+    }
+
+    // 8. Copy rasterized font characters back into the main texture
+    // 9. Setup ImFont and glyphs for runtime
+    bool tex_use_colors = false;
+    for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
+    {
+        ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
+        if (src_tmp.GlyphsCount == 0)
+            continue;
+
+        // When merging fonts with MergeMode=true:
+        // - We can have multiple input fonts writing into a same destination font.
+        // - dst_font->ConfigData is != from cfg which is our source configuration.
+        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        ImFont* dst_font = cfg.DstFont;
+
+        const float ascent = src_tmp.Font.Info.Ascender;
+        const float descent = src_tmp.Font.Info.Descender;
+        ImFontAtlasBuildSetupFont(atlas, dst_font, &cfg, ascent, descent);
+        const float font_off_x = cfg.GlyphOffset.x;
+        const float font_off_y = cfg.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
+
+        const int padding = atlas->TexGlyphPadding;
+        for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
+        {
+            ImFontBuildSrcGlyphFT& src_glyph = src_tmp.GlyphsList[glyph_i];
+            stbrp_rect& pack_rect = src_tmp.Rects[glyph_i];
+            IM_ASSERT(pack_rect.was_packed);
+            if (pack_rect.w == 0 && pack_rect.h == 0)
+                continue;
+
+            GlyphInfo& info = src_glyph.Info;
+            IM_ASSERT(info.Width + padding <= pack_rect.w);
+            IM_ASSERT(info.Height + padding <= pack_rect.h);
+            const int tx = pack_rect.x + padding;
+            const int ty = pack_rect.y + padding;
+
+            // Register glyph
+            float x0 = info.OffsetX + font_off_x;
+            float y0 = info.OffsetY + font_off_y;
+            float x1 = x0 + info.Width;
+            float y1 = y0 + info.Height;
+            float u0 = (tx) / (float)atlas->TexWidth;
+            float v0 = (ty) / (float)atlas->TexHeight;
+            float u1 = (tx + info.Width) / (float)atlas->TexWidth;
+            float v1 = (ty + info.Height) / (float)atlas->TexHeight;
+            dst_font->AddGlyph(&cfg, (ImWchar)src_glyph.Codepoint, x0, y0, x1, y1, u0, v0, u1, v1, info.AdvanceX);
+
+            ImFontGlyph* dst_glyph = &dst_font->Glyphs.back();
+            IM_ASSERT(dst_glyph->Codepoint == src_glyph.Codepoint);
+            if (src_glyph.Info.IsColored)
+                dst_glyph->Colored = tex_use_colors = true;
+
+            // Blit from temporary buffer to final texture
+            size_t blit_src_stride = (size_t)src_glyph.Info.Width;
+            size_t blit_dst_stride = (size_t)atlas->TexWidth;
+            unsigned int* blit_src = src_glyph.BitmapData;
+            if (atlas->TexPixelsAlpha8 != nullptr)
+            {
+                unsigned char* blit_dst = atlas->TexPixelsAlpha8 + (ty * blit_dst_stride) + tx;
+                for (int y = 0; y < info.Height; y++, blit_dst += blit_dst_stride, blit_src += blit_src_stride)
+                    for (int x = 0; x < info.Width; x++)
+                        blit_dst[x] = (unsigned char)((blit_src[x] >> IM_COL32_A_SHIFT) & 0xFF);
+            }
+            else
+            {
+                unsigned int* blit_dst = atlas->TexPixelsRGBA32 + (ty * blit_dst_stride) + tx;
+                for (int y = 0; y < info.Height; y++, blit_dst += blit_dst_stride, blit_src += blit_src_stride)
+                    for (int x = 0; x < info.Width; x++)
+                        blit_dst[x] = blit_src[x];
+            }
+        }
+
+        src_tmp.Rects = nullptr;
+    }
+    atlas->TexPixelsUseColors = tex_use_colors;
+
+    // Cleanup
+    for (int buf_i = 0; buf_i < buf_bitmap_buffers.Size; buf_i++)
+        IM_FREE(buf_bitmap_buffers[buf_i]);
+    src_tmp_array.clear_destruct();
+
+    ImFontAtlasBuildFinish(atlas);
+
+    return true;
+}
+
+// FreeType memory allocation callbacks
+static void* FreeType_Alloc(FT_Memory /*memory*/, long size)
+{
+    return GImGuiFreeTypeAllocFunc((size_t)size, GImGuiFreeTypeAllocatorUserData);
+}
+
+static void FreeType_Free(FT_Memory /*memory*/, void* block)
+{
+    GImGuiFreeTypeFreeFunc(block, GImGuiFreeTypeAllocatorUserData);
+}
+
+static void* FreeType_Realloc(FT_Memory /*memory*/, long cur_size, long new_size, void* block)
+{
+    // Implement realloc() as we don't ask user to provide it.
+    if (block == nullptr)
+        return GImGuiFreeTypeAllocFunc((size_t)new_size, GImGuiFreeTypeAllocatorUserData);
+
+    if (new_size == 0)
+    {
+        GImGuiFreeTypeFreeFunc(block, GImGuiFreeTypeAllocatorUserData);
+        return nullptr;
+    }
+
+    if (new_size > cur_size)
+    {
+        void* new_block = GImGuiFreeTypeAllocFunc((size_t)new_size, GImGuiFreeTypeAllocatorUserData);
+        memcpy(new_block, block, (size_t)cur_size);
+        GImGuiFreeTypeFreeFunc(block, GImGuiFreeTypeAllocatorUserData);
+        return new_block;
+    }
+
+    return block;
+}
+
+static bool ImFontAtlasBuildWithFreeType(ImFontAtlas* atlas)
+{
+    // FreeType memory management: https://www.freetype.org/freetype2/docs/design/design-4.html
+    FT_MemoryRec_ memory_rec = {};
+    memory_rec.user = nullptr;
+    memory_rec.alloc = &FreeType_Alloc;
+    memory_rec.free = &FreeType_Free;
+    memory_rec.realloc = &FreeType_Realloc;
+
+    // https://www.freetype.org/freetype2/docs/reference/ft2-module_management.html#FT_New_Library
+    FT_Library ft_library;
+    FT_Error error = FT_New_Library(&memory_rec, &ft_library);
+    if (error != 0)
+        return false;
+
+    // If you don't call FT_Add_Default_Modules() the rest of code may work, but FreeType won't use our custom allocator.
+    FT_Add_Default_Modules(ft_library);
+
+    bool ret = ImFontAtlasBuildWithFreeTypeEx(ft_library, atlas, atlas->FontBuilderFlags);
+    FT_Done_Library(ft_library);
+
+    return ret;
+}
+
+const ImFontBuilderIO* ImGuiFreeType::GetBuilderForFreeType()
+{
+    static ImFontBuilderIO io;
+    io.FontBuilder_Build = ImFontAtlasBuildWithFreeType;
+    return &io;
+}
+
+void ImGuiFreeType::SetAllocatorFunctions(void* (*alloc_func)(size_t sz, void* user_data), void (*free_func)(void* ptr, void* user_data), void* user_data)
+{
+    GImGuiFreeTypeAllocFunc = alloc_func;
+    GImGuiFreeTypeFreeFunc = free_func;
+    GImGuiFreeTypeAllocatorUserData = user_data;
+}
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
+#ifdef _MSC_VER
+#pragma warning (pop)
+#endif

third_party/imgui/misc/freetype/imgui_freetype.h

@@ -0,0 +1,50 @@
+// dear imgui: FreeType font builder (used as a replacement for the stb_truetype builder)
+// (headers)
+
+#pragma once
+
+#include "imgui.h"      // IMGUI_API
+
+// Forward declarations
+struct ImFontAtlas;
+struct ImFontBuilderIO;
+
+// Hinting greatly impacts visuals (and glyph sizes).
+// - By default, hinting is enabled and the font's native hinter is preferred over the auto-hinter.
+// - When disabled, FreeType generates blurrier glyphs, more or less matches the stb_truetype.h
+// - The Default hinting mode usually looks good, but may distort glyphs in an unusual way.
+// - The Light hinting mode generates fuzzier glyphs but better matches Microsoft's rasterizer.
+// You can set those flags globaly in ImFontAtlas::FontBuilderFlags
+// You can set those flags on a per font basis in ImFontConfig::FontBuilderFlags
+enum ImGuiFreeTypeBuilderFlags
+{
+    ImGuiFreeTypeBuilderFlags_NoHinting     = 1 << 0,   // Disable hinting. This generally generates 'blurrier' bitmap glyphs when the glyph are rendered in any of the anti-aliased modes.
+    ImGuiFreeTypeBuilderFlags_NoAutoHint    = 1 << 1,   // Disable auto-hinter.
+    ImGuiFreeTypeBuilderFlags_ForceAutoHint = 1 << 2,   // Indicates that the auto-hinter is preferred over the font's native hinter.
+    ImGuiFreeTypeBuilderFlags_LightHinting  = 1 << 3,   // A lighter hinting algorithm for gray-level modes. Many generated glyphs are fuzzier but better resemble their original shape. This is achieved by snapping glyphs to the pixel grid only vertically (Y-axis), as is done by Microsoft's ClearType and Adobe's proprietary font renderer. This preserves inter-glyph spacing in horizontal text.
+    ImGuiFreeTypeBuilderFlags_MonoHinting   = 1 << 4,   // Strong hinting algorithm that should only be used for monochrome output.
+    ImGuiFreeTypeBuilderFlags_Bold          = 1 << 5,   // Styling: Should we artificially embolden the font?
+    ImGuiFreeTypeBuilderFlags_Oblique       = 1 << 6,   // Styling: Should we slant the font, emulating italic style?
+    ImGuiFreeTypeBuilderFlags_Monochrome    = 1 << 7,   // Disable anti-aliasing. Combine this with MonoHinting for best results!
+    ImGuiFreeTypeBuilderFlags_LoadColor     = 1 << 8,   // Enable FreeType color-layered glyphs
+    ImGuiFreeTypeBuilderFlags_Bitmap        = 1 << 9    // Enable FreeType bitmap glyphs
+};
+
+namespace ImGuiFreeType
+{
+    // This is automatically assigned when using '#define IMGUI_ENABLE_FREETYPE'.
+    // If you need to dynamically select between multiple builders:
+    // - you can manually assign this builder with 'atlas->FontBuilderIO = ImGuiFreeType::GetBuilderForFreeType()'
+    // - prefer deep-copying this into your own ImFontBuilderIO instance if you use hot-reloading that messes up static data.
+    IMGUI_API const ImFontBuilderIO*    GetBuilderForFreeType();
+
+    // Override allocators. By default ImGuiFreeType will use IM_ALLOC()/IM_FREE()
+    // However, as FreeType does lots of allocations we provide a way for the user to redirect it to a separate memory heap if desired.
+    IMGUI_API void                      SetAllocatorFunctions(void* (*alloc_func)(size_t sz, void* user_data), void (*free_func)(void* ptr, void* user_data), void* user_data = nullptr);
+
+    // Obsolete names (will be removed soon)
+    // Prefer using '#define IMGUI_ENABLE_FREETYPE'
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    static inline bool BuildFontAtlas(ImFontAtlas* atlas, unsigned int flags = 0) { atlas->FontBuilderIO = GetBuilderForFreeType(); atlas->FontBuilderFlags = flags; return atlas->Build(); }
+#endif
+}

third_party/imgui/misc/single_file/imgui_single_file.h

@@ -0,0 +1,29 @@
+// dear imgui: single-file wrapper include
+// We use this to validate compiling all *.cpp files in a same compilation unit.
+// Users of that technique (also called "Unity builds") can generally provide this themselves,
+// so we don't really recommend you use this in your projects.
+
+// Do this:
+//    #define IMGUI_IMPLEMENTATION
+// Before you include this file in *one* C++ file to create the implementation.
+// Using this in your project will leak the contents of imgui_internal.h and ImVec2 operators in this compilation unit.
+
+#ifdef IMGUI_IMPLEMENTATION
+#define IMGUI_DEFINE_MATH_OPERATORS
+#endif
+
+#include "../../imgui.h"
+#ifdef IMGUI_ENABLE_FREETYPE
+#include "../../misc/freetype/imgui_freetype.h"
+#endif
+
+#ifdef IMGUI_IMPLEMENTATION
+#include "../../imgui.cpp"
+#include "../../imgui_demo.cpp"
+#include "../../imgui_draw.cpp"
+#include "../../imgui_tables.cpp"
+#include "../../imgui_widgets.cpp"
+#ifdef IMGUI_ENABLE_FREETYPE
+#include "../../misc/freetype/imgui_freetype.cpp"
+#endif
+#endif