clicking on hovered page updates legend

src/mainloop.cpp

@@ -60,6 +60,21 @@ void monitor_key(GLFWwindow *window, u8 *key_state, i32 glfw_key, Input_Key key)
 	}
 }
 
+internal
+void monitor_mouse_btn(GLFWwindow *window, u8 *mouse_btn_state, i32 glfw_btn, Mouse_Button btn)
+{
+  u8 *state = &mouse_btn_state[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)
 {
@@ -75,6 +90,9 @@ void run_main_loop(GLFWwindow *window, Arena *arena, App_State &app)
 		delta_time_ms = time_since_prev_frame_us * 0.001f;
 		last_saved_time = frame_start;
 
+	  for (u32 i = 0; i < MOUSE_BTN_COUNT; ++i)
+	    app.user_input.mouse_btn_state[i] &= ~(MOUSE_BTN_STATE_JUST_PRESSED|MOUSE_BTN_STATE_JUST_RELEASED);
+
 		glfwPollEvents();
 
 		// Update window size
@@ -122,6 +140,10 @@ void run_main_loop(GLFWwindow *window, Arena *arena, App_State &app)
 			f64 mposx, mposy;
 			glfwGetCursorPos(window, &mposx, &mposy);
 
+		  u8 *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);
+
 			app.user_input.mouse_pos.x = static_cast<i32>(mposx);
 			app.user_input.mouse_pos.y = static_cast<i32>(mposy);
 		}

src/render.cpp

@@ -167,7 +167,7 @@ void viewer_jump_to(App_State &app, u64 addr)
 }
 
 internal
-void viewer_jump_to_page(App_State &app, u64 page_idx)
+Page_Info_Node *viewer_jump_to_page(App_State &app, u64 page_idx)
 {
   assert(app.rndata.n_pages > 0);
   page_idx = (page_idx + app.rndata.n_pages) % app.rndata.n_pages;
@@ -181,6 +181,8 @@ void viewer_jump_to_page(App_State &app, u64 page_idx)
 
   app.viewer.latest_page_gone_to = page_idx;
   viewer_jump_to(app, page->range.start);
+
+  return page;
 }
 
 internal
@@ -313,23 +315,24 @@ void update_and_render(Arena *arena, App_State &app, f32 delta_time_ms)
       ImGui::ColorEdit3("_Page Start", app.viewer.col_page_start, edit_flags);
       ImGui::SameLine(); 
       if (ImGui::Button("Page Start"))
-        viewer_jump_to_page(app, 0);
+        app.viewer.latest_page = viewer_jump_to_page(app, 0);
 
       ImGui::ColorEdit3("_Page", app.viewer.col_section[Sec_Page], edit_flags);
       ImGui::SameLine();
       if (ImGui::Button("Page"))
-        viewer_jump_to_page(app, app.viewer.latest_page_gone_to);
+        app.viewer.latest_page = viewer_jump_to_page(app, app.viewer.latest_page_gone_to);
       ImGui::SameLine();
       {
         const i64 step_fast_i64 = app.rndata.n_pages / 100;
         i64 page_to_go_to = app.viewer.latest_page_gone_to;
         ImGui::PushItemWidth(100.f);
         if (ImGui::InputScalar("##page_viewed", ImGuiDataType_S64, &page_to_go_to, &step_i64, &step_fast_i64, "%u", input_flags))
-          viewer_jump_to_page(app, page_to_go_to);
+          app.viewer.latest_page = viewer_jump_to_page(app, page_to_go_to);
         ImGui::PopItemWidth();
       }
       ImGui::SameLine();
-      ImGui::Text("%s", to_pretty_size(scratch.arena, app.rndata.tot_page_comp_size).c());
+      String8 this_page_width = app.viewer.latest_page ? push_str8f(scratch.arena, " (this page: %s)", to_pretty_size(scratch.arena, app.viewer.latest_page->range.len).c()) : str8("");
+      ImGui::Text("%s%s", to_pretty_size(scratch.arena, app.rndata.tot_page_comp_size).c(), this_page_width.c());
 
       ImGui::ColorEdit3("_Checksum", app.viewer.col_checksum, edit_flags);
       ImGui::SameLine(); 
@@ -394,6 +397,12 @@ void update_and_render(Arena *arena, App_State &app, f32 delta_time_ms)
           ImGui::TextColored(ImColor(0.5f, 0.5f, 0.5f), "(Hint: press Alt for single-field hover information)");
         imgui_render_string_tree(scratch.arena, hover_info.desc->head);
         app.viewer.hovered_range = hover_info.rng;
+
+        // Clicking on a page section will update the current page in the legend
+        if (hovered_section.id == Sec_Page && (app.user_input.mouse_btn_state[MOUSE_BTN_LEFT] & MOUSE_BTN_STATE_JUST_PRESSED)) {
+          u64 page_id = ((const Page_Info_Node *)hovered_section.info)->page_id;
+          app.viewer.latest_page = viewer_jump_to_page(app, page_id);
+        }
       } else {
         app.viewer.hovered_range = {};
       }

src/render.h

@@ -16,6 +16,8 @@ struct Viewer {
   b8 highlight_zstd_headers;
   u64 last_seen_zstd_header_start;
   
+  Page_Info_Node *latest_page;
+  
   u64 latest_page_gone_to;
   u64 latest_key_gone_to;
   u64 latest_checksum_gone_to;

src/rntuple.cpp

@@ -290,6 +290,7 @@ void gather_ntuple_metadata(Arena *arena, RMicroFileReader &reader, const RNTupl
     for (Page_Info_Node *pinfo = pinfo_head->next; pinfo; pinfo = pinfo->next) {
       assert(prev->range.end() <= pinfo->range.start);
       prev = pinfo;
+      pinfo->page_id = idx;
     
       if (pinfo->range.start != chunks_tail->range.end()) {
         // close current chunk and open new one

src/rntuple.h

@@ -18,6 +18,8 @@ struct Page_Info_Node {
   u32 cluster_id;
   b8 is_first_in_cluster;
 
+  u64 page_id;
+
   u8 bits_per_elem;
   String8 elem_type_name;
   String8 owner_field_name;

src/window.h

@@ -16,8 +16,21 @@ enum Key_State : u8 {
 	KEY_STATE_JUST_RELEASED = 0x4,
 };
 
+enum Mouse_Button {
+	MOUSE_BTN_LEFT,
+	MOUSE_BTN_RIGHT,
+	MOUSE_BTN_COUNT
+};
+
+enum Mouse_Button_State : u8 {
+  MOUSE_BTN_STATE_IS_DOWN = 0x1,
+  MOUSE_BTN_STATE_JUST_PRESSED = 0x2,
+  MOUSE_BTN_STATE_JUST_RELEASED = 0x4,
+};
+
 struct User_Input {
 	u8 key_state[KEY_COUNT];
+	u8 mouse_btn_state[MOUSE_BTN_COUNT];
 
 	struct { i32 x; i32 y; } mouse_pos;
 };