rntviewer/src/render.cpp

internal
void accum_dt_ms(Delta_Time_Accum &accum, f32 dt)
{
	if (accum.count < accum.max) {
		assert(accum.start == 0);
		accum.base[accum.count++] = dt;
	} else {
		accum.base[accum.start++] = dt;
		if (accum.start == accum.max)
			accum.start = 0;
	}
}

internal
f32 calc_avg_dt_ms(const Delta_Time_Accum &accum)
{
	f32 res = 0;
	for (u16 idx = 0; idx < accum.count; ++idx)
		res += accum.base[idx];
	if (accum.count) res /= accum.count;
	return res;
}

internal
String8 to_pretty_size(Arena *arena, u64 bytes)
{
	if (bytes >= GiB(1)) return push_str8f(arena, "%.1f GiB", (f32)bytes / GiB(1));
	if (bytes >= MiB(1)) return push_str8f(arena, "%.1f MiB", (f32)bytes / MiB(1));
	if (bytes >= KiB(1)) return push_str8f(arena, "%.1f KiB", (f32)bytes / KiB(1));
	return push_str8f(arena, "%zu B", bytes);
}

internal
u32 mem_edit_bg_color_fn(const u8 *, u64 off, void *user_data)
{
  App_State *app = reinterpret_cast<App_State *>(user_data);
  const RNTuple_Data &rdata = app->rndata;
  const TFile_Data &tdata = app->tfile_data;
  u64 rblob_sz = rdata.rblob_header_size; // @Incomplete
  i64 hilite_cluster = app->viewer.highlight_cluster ? app->viewer.highlighted_cluster : -1;

  off += app->viewer.base_display_addr;

#define COL(c) (ImColor((c)[0], (c)[1], (c)[2]))
  // TFile start
  if (off <= tdata.root_file_header_size) return COL(app->viewer.col_tfile_header);
  if (tdata.rng_root_file_obj.start <= off && off < tdata.rng_root_file_obj.end()) return COL(app->viewer.col_tfile_obj);
  if (tdata.rng_root_file_info.start <= off && off < tdata.rng_root_file_info.end()) return COL(app->viewer.col_tfile_info);
  if (tdata.rng_root_file_free.start <= off && off < tdata.rng_root_file_free.end()) return COL(app->viewer.col_tfile_free);

  // Handle pages
  // fast case: `off` is in the same page info as previous `off`.
  if (app->last_pinfo->range.start < off && off < app->last_pinfo->range.end()) {
    if (hilite_cluster >= 0 && app->last_pinfo->cluster_id == (u64)hilite_cluster)
      return COL(app->viewer.col_highlight);
    if (off >= app->last_pinfo->range.end() - app->last_pinfo->checksum_size())
      return COL(app->viewer.col_checksum);
    return COL(app->viewer.col_page);
  }

  // still fast case: `off is in the next page info as the previous.
  if (app->last_pinfo->next) // don't check if it's checksum, since it's the first byte of the page
    app->last_pinfo = app->last_pinfo->next;

  if (app->last_pinfo && app->last_pinfo->range.start <= off && off < app->last_pinfo->range.end()) {
    if (hilite_cluster >= 0 && app->last_pinfo->cluster_id == (u64)hilite_cluster)
      return COL(app->viewer.col_highlight);
    if (off == app->last_pinfo->range.start)
      return COL(app->viewer.col_page_start);
    if (off >= app->last_pinfo->range.end() - app->last_pinfo->checksum_size())
      return COL(app->viewer.col_checksum);
    return COL(app->viewer.col_page);
  }

  if (rdata.rng_anchor_key.start <= off && off < rdata.rng_anchor_key.end()) return COL(app->viewer.col_key);
  if (rdata.rng_anchor.start <= off && off < rdata.rng_anchor.end() - 8)     return COL(app->viewer.col_anchor);
  if (rdata.rng_anchor.end() - 8 <= off && off < rdata.rng_anchor.end())     return COL(app->viewer.col_checksum);

  if (rdata.rng_header.start - rblob_sz <= off && off < rdata.rng_header.start) return COL(app->viewer.col_key);
  if (rdata.rng_header.start <= off && off < rdata.rng_header.end() - 8)        return COL(app->viewer.col_header);
  if (rdata.rng_header.end() - 8 <= off && off < rdata.rng_header.end())        return COL(app->viewer.col_checksum);

  if (rdata.rng_footer.start - rblob_sz <= off && off < rdata.rng_footer.start) return COL(app->viewer.col_key);
  if (rdata.rng_footer.start <= off && off < rdata.rng_footer.end() - 8)        return COL(app->viewer.col_footer);
  if (rdata.rng_footer.end() - 8 <= off && off < rdata.rng_footer.end())        return COL(app->viewer.col_checksum);

  if (rdata.rng_tkeys_list.start <= off && off < rdata.rng_tkeys_list.end())    return COL(app->viewer.col_tkeys_list);

  // @Speed
  for (u64 cg_idx = 0; cg_idx < rdata.n_cluster_groups; ++cg_idx) {
    Cluster_Group_Info &cg_info = rdata.cluster_groups[cg_idx];
    if (cg_info.rng_page_list.start -rblob_sz <= off && off < cg_info.rng_page_list.start) return COL(app->viewer.col_page_list);
    if (cg_info.rng_page_list.start <= off && off < cg_info.rng_page_list.end() - 8)       return COL(app->viewer.col_page_list);
    if (cg_info.rng_page_list.end() - 8 <= off && off < cg_info.rng_page_list.end())       return COL(app->viewer.col_checksum);
  }

  // Slow page group lookup, ideally only done once per render when last_pinfo is invalid.
  for (Page_Info_Chunk *chunk = rdata.page_chunks; chunk; chunk = chunk->next) {
    if (chunk->range.start - rblob_sz <= off && off < chunk->range.start) return COL(app->viewer.col_key);
    if (chunk->range.start <= off && off < chunk->range.end()) {
      for (u64 group_idx = chunk->first_group; group_idx < rdata.n_page_groups; ++group_idx) {
        const Page_Info_Group &group = rdata.page_groups[group_idx];
        if (off < group.range.start || off >= group.range.end())
          continue;

        for (Page_Info_Node *pinfo = group.first; pinfo; pinfo = pinfo->next) {
          if (pinfo->range.start <= off && off < pinfo->range.end()) {
            app->last_pinfo = pinfo;
            if (hilite_cluster >= 0 && pinfo->cluster_id == (u64)hilite_cluster) return COL(app->viewer.col_highlight);
            if (pinfo->range.start == off)                                       return COL(app->viewer.col_page_start);
            if (off >= pinfo->range.end() - pinfo->checksum_size())              return COL(app->viewer.col_checksum);
            return COL(app->viewer.col_page);
          }
        }
      }

      fprintf(stderr, "Offset 0x%lX is in chunk 0x%lX - 0x%lX, but found in no page_info range!\n", 
              off, chunk->range.start, chunk->range.end());
      assert(false);
    }
  }
#undef COL

  return IM_COL32(0, 0, 0, 0);
}

internal
MemoryEditor make_memory_editor(App_State &app)
{
  MemoryEditor mem_edit;
  mem_edit.Cols = 32;
  mem_edit.OptShowDataPreview = true;
  // Do nothing on write.
  // Note that we don't use ReadOnly = true because that disables selecting bytes
  mem_edit.WriteFn = [] (ImU8*, size_t, ImU8) {};
  mem_edit.BgColorFn = mem_edit_bg_color_fn;
  mem_edit.BgColorFnUserData = &app;
  return mem_edit;
}

internal
void make_viewer(App_State &app)
{
  Viewer viewer {};
  viewer.mem_edit = make_memory_editor(app);

#define COL(c, r, g, b) viewer.c[0] = r/255.0, viewer.c[1] = g/255.0, viewer.c[2] = b/255.0
  COL(col_anchor, 150, 150, 0);
  COL(col_header, 150, 0, 50);
  COL(col_footer, 50, 0, 150);
  COL(col_key,    0, 100, 50);
  COL(col_tfile_header,  90, 90, 90);
  COL(col_tfile_obj,  120, 120, 120);
  COL(col_tfile_info, 95, 76, 76);
  COL(col_tfile_free, 60, 60, 90);
  COL(col_page,   125, 0, 125);
  COL(col_page_start, 200, 0, 200);
  COL(col_checksum, 134, 65, 25);
  COL(col_page_list, 60, 110, 120);
  COL(col_tkeys_list, 100, 140, 100);
  COL(col_highlight, 190, 190, 190);
#undef COL

  app.viewer = viewer;
}

internal
void viewer_jump_to(Viewer &viewer, u64 addr)
{
  viewer.base_display_addr = addr;
  viewer.mem_edit.GotoAddr = 0;
}

internal
void 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;
  
  // @Speed
  Page_Info_Node *page = app.rndata.pages;
  for (u64 i = 0; i < page_idx; ++i) {
    page = page->next;    
    assert(page);
  }

  app.viewer.latest_page_gone_to = page_idx;
  viewer_jump_to(app.viewer, page->range.start);
}

internal
void viewer_jump_to_page_list(App_State &app, u64 page_list_idx)
{
  assert(app.rndata.n_cluster_groups > 0);
  page_list_idx = (page_list_idx + app.rndata.n_cluster_groups) % app.rndata.n_cluster_groups;
  
  Cluster_Group_Info &cg_info = app.rndata.cluster_groups[page_list_idx];

  app.viewer.latest_page_list_gone_to = page_list_idx;
  viewer_jump_to(app.viewer, cg_info.rng_page_list.start);
}

internal
void viewer_jump_to_cluster(App_State &app, u64 cluster_idx)
{
  assert(app.rndata.n_clusters > 0);
  cluster_idx = (cluster_idx + app.rndata.n_clusters) % app.rndata.n_clusters;

  // @Speed: this is slow! Consider an acceleration structure, or maybe we can reuse
  // Page_Info_Groups + binary search? (depends on whether cluster_idx are sorted)
  Page_Info_Node *page = app.rndata.pages;
  for (u64 i = 0; i < app.rndata.n_pages; ++i) {
    if (page->cluster_id == cluster_idx)
      break;
    page = page->next;    
    assert(page);
  }

  app.viewer.highlighted_cluster = cluster_idx;
  viewer_jump_to(app.viewer, page->range.start);
}

internal
void update_and_render(Arena *arena, App_State &app, f32 delta_time_ms)
{
  accum_dt_ms(app.delta_time_accum, delta_time_ms);
  
  ImGui::SetNextWindowPos({ 0, 0 });
  ImGui::SetNextWindowSize({ (f32)app.win_data.width, (f32)app.win_data.height });

  Temp scratch = scratch_begin(&arena, 1);
  defer { scratch_end(scratch); };

  const auto main_win_flags = ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoDecoration;
  if (ImGui::Begin("main", nullptr, main_win_flags)) {
        
    String8 ntpl_desc = rntuple_description(scratch.arena, app.rndata);
    ImGui::Text("RNTuple '%s' (%s) from file \"%s\"", app.ntpl_name.c(), ntpl_desc.c(), app.inspected_file.name.c());

    // Draw stats
    {
      ImGui::SameLine();

      f32 avg_dt = calc_avg_dt_ms(app.delta_time_accum);

      String8 mem_used = to_pretty_size(scratch.arena, arena->mem_used);
      String8 mem_peak = to_pretty_size(scratch.arena, arena->mem_peak_used);
      String8 stat_txt = push_str8f(scratch.arena, "mem used: %s (peak: %s) | avg dt: %.1f", 
                                    mem_used.c(), mem_peak.c(), avg_dt);

      f32 pos_x = (ImGui::GetCursorPosX() + ImGui::GetColumnWidth() - ImGui::CalcTextSize(stat_txt.c()).x 
        - ImGui::GetScrollX() - 2 * ImGui::GetStyle().ItemSpacing.x);
      if (pos_x > ImGui::GetCursorPosX())
        ImGui::SetCursorPosX(pos_x);

      ImGui::Text("%s", stat_txt.c());
    }

    ImGui::Separator();

    // Draw main content
    {
      const i64 step_i64 = 1;

      ImGui::BeginTable("Hex View", 2, ImGuiTableFlags_Resizable);

      ImGui::TableNextColumn();

      assert(app.viewer.base_display_addr < app.inspected_file.size);
      void *content = app.inspected_file.mem + app.viewer.base_display_addr;
      u64 content_size = app.inspected_file.size - app.viewer.base_display_addr;
      app.last_pinfo = &invalid_pinfo;
      app.viewer.mem_edit.DrawContents(content, content_size, app.viewer.base_display_addr);

      ImGui::TableNextColumn();
      ImGuiColorEditFlags flags =  ImGuiColorEditFlags_NoInputs|ImGuiColorEditFlags_NoLabel;

      ImGui::ColorEdit3("_TFile Header",   app.viewer.col_tfile_header,  flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TFile Header"))   viewer_jump_to(app.viewer, 0);

      ImGui::ColorEdit3("_TFile Object",   app.viewer.col_tfile_obj,  flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TFile Object"))   viewer_jump_to(app.viewer, app.tfile_data.rng_root_file_obj.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.tfile_data.rng_root_file_obj.len).c());

      ImGui::ColorEdit3("_TFile Info",   app.viewer.col_tfile_info,  flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TFile Info"))   viewer_jump_to(app.viewer, app.tfile_data.rng_root_file_info.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.tfile_data.rng_root_file_info.len).c());

      ImGui::ColorEdit3("_TFile FreeList",   app.viewer.col_tfile_free,  flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TFile FreeList"))   viewer_jump_to(app.viewer, app.tfile_data.rng_root_file_free.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.tfile_data.rng_root_file_free.len).c());

      ImGui::ColorEdit3("_RNTuple Anchor", app.viewer.col_anchor, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("RNTuple Anchor")) viewer_jump_to(app.viewer, app.rndata.rng_anchor.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.rndata.rng_anchor.len).c());

      ImGui::ColorEdit3("_RNTuple Header", app.viewer.col_header, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("RNTuple Header")) viewer_jump_to(app.viewer, app.rndata.rng_header.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.rndata.rng_header.len).c());

      ImGui::ColorEdit3("_RNTuple Footer", app.viewer.col_footer, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("RNTuple Footer")) viewer_jump_to(app.viewer, app.rndata.rng_footer.start);
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.rndata.rng_footer.len).c());

      ImGui::ColorEdit3("_TKey Header",    app.viewer.col_key,    flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TKey Header"))    {} // TODO jump to next key

      ImGui::ColorEdit3("_Page Start", app.viewer.col_page_start, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("Page Start"))     viewer_jump_to_page(app, 0);

      ImGui::ColorEdit3("_Page", app.viewer.col_page, flags);
      ImGui::SameLine();
      if (ImGui::Button("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"))
          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_size).c());

      ImGui::ColorEdit3("_Checksum", app.viewer.col_checksum, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("Checksum")) {} // TODO jump to next checksum

      ImGui::ColorEdit3("_Page List", app.viewer.col_page_list, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("Page List"))      viewer_jump_to_page_list(app, app.viewer.latest_page_list_gone_to);
      ImGui::SameLine();
      {
        i64 page_list_to_go_to = app.viewer.latest_page_list_gone_to;
        ImGui::PushItemWidth(80.f);
        if (ImGui::InputScalar("##page_list_viewed", ImGuiDataType_S64, &page_list_to_go_to, &step_i64, nullptr, "%u"))
          viewer_jump_to_page_list(app, page_list_to_go_to);
        ImGui::PopItemWidth();
      }
      ImGui::SameLine(); 
      ImGui::Text("%s", to_pretty_size(scratch.arena, app.rndata.tot_page_list_size).c());

      ImGui::ColorEdit3("_TKey List", app.viewer.col_tkeys_list, flags);
      ImGui::SameLine(); 
      if (ImGui::Button("TKey List"))      viewer_jump_to(app.viewer, app.rndata.rng_tkeys_list.start);

      // -------------------------------
      ImGui::Separator();
      String8 root_version_str = push_str8f(scratch.arena, "%u.%u.%u", 
                                            app.tfile_data.root_version_major,
                                            app.tfile_data.root_version_minor,
                                            app.tfile_data.root_version_patch);
      ImGui::Text("ROOT version: %s", root_version_str.c());
      ImGui::Text("TFile compression: %u", app.tfile_data.compression);
      ImGui::Text("Num pages: %lu", app.rndata.n_pages);
      ImGui::Text("Num elements: %lu", app.rndata.n_elems);

      {
        const i64 step_fast_i64 = app.rndata.n_clusters / 100;
        i64 cluster_to_highlight = app.viewer.highlighted_cluster;
        ImGui::PushItemWidth(100.f);
        if (ImGui::InputScalar("##highlighted_cluster", ImGuiDataType_S64, &cluster_to_highlight, &step_i64, &step_fast_i64, "%u")) {
          viewer_jump_to_cluster(app, cluster_to_highlight);
        }
        ImGui::PopItemWidth();
        ImGui::SameLine();
        ImGui::Checkbox("Highlight cluster", &app.viewer.highlight_cluster);
      }

      ImGui::EndTable();
    }

    ImGui::End();
  }
}