Metrics, Demo: moved font details display to metrics code. (#4171)

docs/CHANGELOG.txt

@@ -36,6 +36,9 @@ HOW TO UPDATE?
 -----------------------------------------------------------------------
 
 Other Changes:
+- Demo: Fixed requirement in 1.83 to link with imgui_demo.cpp if IMGUI_DISABLE_METRICS_WINDOW is not set. (#4171)
+  Normally the right way to disable compiling the demo is to set IMGUI_DISABLE_DEMO_WINDOWS, but we want to avoid
+  implying that the file is required.
 - Backends: OpenGL3: Handle GL_CLIP_ORIGIN on <4.5 contexts if "GL_ARB_clip_control" extension is detected. (#4170, #3998)
 
 

imgui.cpp

@@ -11280,6 +11280,25 @@ void ImGui::ShowMetricsWindow(bool* p_open)
     End();
 }
 
+// [DEBUG] List fonts in a font atlas and display its texture
+void ImGui::ShowFontAtlas(ImFontAtlas* atlas)
+{
+    for (int i = 0; i < atlas->Fonts.Size; i++)
+    {
+        ImFont* font = atlas->Fonts[i];
+        PushID(font);
+        DebugNodeFont(font);
+        PopID();
+    }
+    if (TreeNode("Atlas texture", "Atlas texture (%dx%d pixels)", atlas->TexWidth, atlas->TexHeight))
+    {
+        ImVec4 tint_col = ImVec4(1.0f, 1.0f, 1.0f, 1.0f);
+        ImVec4 border_col = ImVec4(1.0f, 1.0f, 1.0f, 0.5f);
+        Image(atlas->TexID, ImVec2((float)atlas->TexWidth, (float)atlas->TexHeight), ImVec2(0.0f, 0.0f), ImVec2(1.0f, 1.0f), tint_col, border_col);
+        TreePop();
+    }
+}
+
 // [DEBUG] Display contents of Columns
 void ImGui::DebugNodeColumns(ImGuiOldColumns* columns)
 {
@@ -11414,6 +11433,101 @@ void ImGui::DebugNodeDrawCmdShowMeshAndBoundingBox(ImDrawList* out_draw_list, co
     out_draw_list->Flags = backup_flags;
 }
 
+// [DEBUG] Display details for a single font, called by ShowStyleEditor().
+void ImGui::DebugNodeFont(ImFont* font)
+{
+    bool opened = TreeNode(font, "Font: \"%s\"\n%.2f px, %d glyphs, %d file(s)",
+        font->ConfigData ? font->ConfigData[0].Name : "", font->FontSize, font->Glyphs.Size, font->ConfigDataCount);
+    SameLine();
+    if (SmallButton("Set as default"))
+        GetIO().FontDefault = font;
+    if (!opened)
+        return;
+
+    // Display preview text
+    PushFont(font);
+    Text("The quick brown fox jumps over the lazy dog");
+    PopFont();
+
+    // Display details
+    SetNextItemWidth(GetFontSize() * 8);
+    DragFloat("Font scale", &font->Scale, 0.005f, 0.3f, 2.0f, "%.1f");
+    SameLine(); MetricsHelpMarker(
+        "Note than the default embedded font is NOT meant to be scaled.\n\n"
+        "Font are currently rendered into bitmaps at a given size at the time of building the atlas. "
+        "You may oversample them to get some flexibility with scaling. "
+        "You can also render at multiple sizes and select which one to use at runtime.\n\n"
+        "(Glimmer of hope: the atlas system will be rewritten in the future to make scaling more flexible.)");
+    Text("Ascent: %f, Descent: %f, Height: %f", font->Ascent, font->Descent, font->Ascent - font->Descent);
+    Text("Fallback character: '%c' (U+%04X)", font->FallbackChar, font->FallbackChar);
+    Text("Ellipsis character: '%c' (U+%04X)", font->EllipsisChar, font->EllipsisChar);
+    const int surface_sqrt = (int)ImSqrt((float)font->MetricsTotalSurface);
+    Text("Texture Area: about %d px ~%dx%d px", font->MetricsTotalSurface, surface_sqrt, surface_sqrt);
+    for (int config_i = 0; config_i < font->ConfigDataCount; config_i++)
+        if (font->ConfigData)
+            if (const ImFontConfig* cfg = &font->ConfigData[config_i])
+                BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d, Offset: (%.1f,%.1f)",
+                    config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH, cfg->GlyphOffset.x, cfg->GlyphOffset.y);
+
+    // Display all glyphs of the fonts in separate pages of 256 characters
+    if (TreeNode("Glyphs", "Glyphs (%d)", font->Glyphs.Size))
+    {
+        ImDrawList* draw_list = GetWindowDrawList();
+        const ImU32 glyph_col = GetColorU32(ImGuiCol_Text);
+        const float cell_size = font->FontSize * 1;
+        const float cell_spacing = GetStyle().ItemSpacing.y;
+        for (unsigned int base = 0; base <= IM_UNICODE_CODEPOINT_MAX; base += 256)
+        {
+            // Skip ahead if a large bunch of glyphs are not present in the font (test in chunks of 4k)
+            // This is only a small optimization to reduce the number of iterations when IM_UNICODE_MAX_CODEPOINT
+            // is large // (if ImWchar==ImWchar32 we will do at least about 272 queries here)
+            if (!(base & 4095) && font->IsGlyphRangeUnused(base, base + 4095))
+            {
+                base += 4096 - 256;
+                continue;
+            }
+
+            int count = 0;
+            for (unsigned int n = 0; n < 256; n++)
+                if (font->FindGlyphNoFallback((ImWchar)(base + n)))
+                    count++;
+            if (count <= 0)
+                continue;
+            if (!TreeNode((void*)(intptr_t)base, "U+%04X..U+%04X (%d %s)", base, base + 255, count, count > 1 ? "glyphs" : "glyph"))
+                continue;
+
+            // Draw a 16x16 grid of glyphs
+            ImVec2 base_pos = GetCursorScreenPos();
+            for (unsigned int n = 0; n < 256; n++)
+            {
+                // We use ImFont::RenderChar as a shortcut because we don't have UTF-8 conversion functions
+                // available here and thus cannot easily generate a zero-terminated UTF-8 encoded string.
+                ImVec2 cell_p1(base_pos.x + (n % 16) * (cell_size + cell_spacing), base_pos.y + (n / 16) * (cell_size + cell_spacing));
+                ImVec2 cell_p2(cell_p1.x + cell_size, cell_p1.y + cell_size);
+                const ImFontGlyph* glyph = font->FindGlyphNoFallback((ImWchar)(base + n));
+                draw_list->AddRect(cell_p1, cell_p2, glyph ? IM_COL32(255, 255, 255, 100) : IM_COL32(255, 255, 255, 50));
+                if (glyph)
+                    font->RenderChar(draw_list, cell_size, cell_p1, glyph_col, (ImWchar)(base + n));
+                if (glyph && IsMouseHoveringRect(cell_p1, cell_p2))
+                {
+                    BeginTooltip();
+                    Text("Codepoint: U+%04X", base + n);
+                    Separator();
+                    Text("Visible: %d", glyph->Visible);
+                    Text("AdvanceX: %.1f", glyph->AdvanceX);
+                    Text("Pos: (%.2f,%.2f)->(%.2f,%.2f)", glyph->X0, glyph->Y0, glyph->X1, glyph->Y1);
+                    Text("UV: (%.3f,%.3f)->(%.3f,%.3f)", glyph->U0, glyph->V0, glyph->U1, glyph->V1);
+                    EndTooltip();
+                }
+            }
+            Dummy(ImVec2((cell_size + cell_spacing) * 16, (cell_size + cell_spacing) * 16));
+            TreePop();
+        }
+        TreePop();
+    }
+    TreePop();
+}
+
 // [DEBUG] Display contents of ImGuiStorage
 void ImGui::DebugNodeStorage(ImGuiStorage* storage, const char* label)
 {
@@ -11564,9 +11678,11 @@ void ImGui::DebugNodeWindowsList(ImVector<ImGuiWindow*>* windows, const char* la
 #else
 
 void ImGui::ShowMetricsWindow(bool*) {}
+void ImGui::ShowFontAtlas(ImFontAtlas*) {}
 void ImGui::DebugNodeColumns(ImGuiOldColumns*) {}
 void ImGui::DebugNodeDrawList(ImGuiWindow*, const ImDrawList*, const char*) {}
 void ImGui::DebugNodeDrawCmdShowMeshAndBoundingBox(ImDrawList*, const ImDrawList*, const ImDrawCmd*, bool, bool) {}
+void ImGui::DebugNodeFont(ImFont*) {}
 void ImGui::DebugNodeStorage(ImGuiStorage*, const char*) {}
 void ImGui::DebugNodeTabBar(ImGuiTabBar*, const char*) {}
 void ImGui::DebugNodeWindow(ImGuiWindow*, const char*) {}

imgui_demo.cpp

@@ -54,7 +54,6 @@ Index of this file:
 // - sub section: ShowDemoWindowTables()
 // - sub section: ShowDemoWindowMisc()
 // [SECTION] About Window / ShowAboutWindow()
-// [SECTION] Font Viewer / ShowFontAtlas()
 // [SECTION] Style Editor / ShowStyleEditor()
 // [SECTION] Example App: Main Menu Bar / ShowExampleAppMainMenuBar()
 // [SECTION] Example App: Debug Console / ShowExampleAppConsole()
@@ -5744,15 +5743,15 @@ void ImGui::ShowAboutWindow(bool* p_open)
 }
 
 //-----------------------------------------------------------------------------
-// [SECTION] Font viewer / ShowFontAtlas()
+// [SECTION] Style Editor / ShowStyleEditor()
 //-----------------------------------------------------------------------------
 // - ShowFontSelector()
-// - ShowFont()
+// - ShowStyleSelector()
-// - ShowFontAtlas()
+// - ShowStyleEditor()
 //-----------------------------------------------------------------------------
 
-// This isn't worth putting in public API but we want Metrics to use it
+// Forward declare ShowFontAtlas() which isn't worth putting in public API yet
-namespace ImGui { void ShowFontAtlas(ImFontAtlas* atlas); }
+namespace ImGui { IMGUI_API void ShowFontAtlas(ImFontAtlas* atlas); }
 
 // Demo helper function to select among loaded fonts.
 // Here we use the regular BeginCombo()/EndCombo() api which is more the more flexible one.
@@ -5780,124 +5779,6 @@ void ImGui::ShowFontSelector(const char* label)
         "- If you need to add/remove fonts at runtime (e.g. for DPI change), do it before calling NewFrame().");
 }
 
-// [Internal] Display details for a single font, called by ShowStyleEditor().
-static void ShowFont(ImFont* font)
-{
-    ImGuiIO& io = ImGui::GetIO();
-    ImGuiStyle& style = ImGui::GetStyle();
-    bool font_details_opened = ImGui::TreeNode(font, "Font: \"%s\"\n%.2f px, %d glyphs, %d file(s)",
-        font->ConfigData ? font->ConfigData[0].Name : "", font->FontSize, font->Glyphs.Size, font->ConfigDataCount);
-    ImGui::SameLine(); if (ImGui::SmallButton("Set as default")) { io.FontDefault = font; }
-    if (!font_details_opened)
-        return;
-
-    // Display preview text
-    ImGui::PushFont(font);
-    ImGui::Text("The quick brown fox jumps over the lazy dog");
-    ImGui::PopFont();
-
-    // Display details
-    ImGui::SetNextItemWidth(ImGui::GetFontSize() * 8);
-    ImGui::DragFloat("Font scale", &font->Scale, 0.005f, 0.3f, 2.0f, "%.1f");   // Scale only this font
-    ImGui::SameLine(); HelpMarker(
-        "Note than the default embedded font is NOT meant to be scaled.\n\n"
-        "Font are currently rendered into bitmaps at a given size at the time of building the atlas. "
-        "You may oversample them to get some flexibility with scaling. "
-        "You can also render at multiple sizes and select which one to use at runtime.\n\n"
-        "(Glimmer of hope: the atlas system will be rewritten in the future to make scaling more flexible.)");
-    ImGui::Text("Ascent: %f, Descent: %f, Height: %f", font->Ascent, font->Descent, font->Ascent - font->Descent);
-    ImGui::Text("Fallback character: '%c' (U+%04X)", font->FallbackChar, font->FallbackChar);
-    ImGui::Text("Ellipsis character: '%c' (U+%04X)", font->EllipsisChar, font->EllipsisChar);
-    const int surface_sqrt = (int)sqrtf((float)font->MetricsTotalSurface);
-    ImGui::Text("Texture Area: about %d px ~%dx%d px", font->MetricsTotalSurface, surface_sqrt, surface_sqrt);
-    for (int config_i = 0; config_i < font->ConfigDataCount; config_i++)
-        if (font->ConfigData)
-            if (const ImFontConfig* cfg = &font->ConfigData[config_i])
-                ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d, Offset: (%.1f,%.1f)",
-                    config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH, cfg->GlyphOffset.x, cfg->GlyphOffset.y);
-
-    // Display all glyphs of the fonts in separate pages of 256 characters
-    if (ImGui::TreeNode("Glyphs", "Glyphs (%d)", font->Glyphs.Size))
-    {
-        const ImU32 glyph_col = ImGui::GetColorU32(ImGuiCol_Text);
-        for (unsigned int base = 0; base <= IM_UNICODE_CODEPOINT_MAX; base += 256)
-        {
-            // Skip ahead if a large bunch of glyphs are not present in the font (test in chunks of 4k)
-            // This is only a small optimization to reduce the number of iterations when IM_UNICODE_MAX_CODEPOINT
-            // is large // (if ImWchar==ImWchar32 we will do at least about 272 queries here)
-            if (!(base & 4095) && font->IsGlyphRangeUnused(base, base + 4095))
-            {
-                base += 4096 - 256;
-                continue;
-            }
-
-            int count = 0;
-            for (unsigned int n = 0; n < 256; n++)
-                if (font->FindGlyphNoFallback((ImWchar)(base + n)))
-                    count++;
-            if (count <= 0)
-                continue;
-            if (!ImGui::TreeNode((void*)(intptr_t)base, "U+%04X..U+%04X (%d %s)", base, base + 255, count, count > 1 ? "glyphs" : "glyph"))
-                continue;
-            float cell_size = font->FontSize * 1;
-            float cell_spacing = style.ItemSpacing.y;
-            ImVec2 base_pos = ImGui::GetCursorScreenPos();
-            ImDrawList* draw_list = ImGui::GetWindowDrawList();
-            for (unsigned int n = 0; n < 256; n++)
-            {
-                // We use ImFont::RenderChar as a shortcut because we don't have UTF-8 conversion functions
-                // available here and thus cannot easily generate a zero-terminated UTF-8 encoded string.
-                ImVec2 cell_p1(base_pos.x + (n % 16) * (cell_size + cell_spacing), base_pos.y + (n / 16) * (cell_size + cell_spacing));
-                ImVec2 cell_p2(cell_p1.x + cell_size, cell_p1.y + cell_size);
-                const ImFontGlyph* glyph = font->FindGlyphNoFallback((ImWchar)(base + n));
-                draw_list->AddRect(cell_p1, cell_p2, glyph ? IM_COL32(255, 255, 255, 100) : IM_COL32(255, 255, 255, 50));
-                if (glyph)
-                    font->RenderChar(draw_list, cell_size, cell_p1, glyph_col, (ImWchar)(base + n));
-                if (glyph && ImGui::IsMouseHoveringRect(cell_p1, cell_p2))
-                {
-                    ImGui::BeginTooltip();
-                    ImGui::Text("Codepoint: U+%04X", base + n);
-                    ImGui::Separator();
-                    ImGui::Text("Visible: %d", glyph->Visible);
-                    ImGui::Text("AdvanceX: %.1f", glyph->AdvanceX);
-                    ImGui::Text("Pos: (%.2f,%.2f)->(%.2f,%.2f)", glyph->X0, glyph->Y0, glyph->X1, glyph->Y1);
-                    ImGui::Text("UV: (%.3f,%.3f)->(%.3f,%.3f)", glyph->U0, glyph->V0, glyph->U1, glyph->V1);
-                    ImGui::EndTooltip();
-                }
-            }
-            ImGui::Dummy(ImVec2((cell_size + cell_spacing) * 16, (cell_size + cell_spacing) * 16));
-            ImGui::TreePop();
-        }
-        ImGui::TreePop();
-    }
-    ImGui::TreePop();
-}
-
-void ImGui::ShowFontAtlas(ImFontAtlas* atlas)
-{
-    for (int i = 0; i < atlas->Fonts.Size; i++)
-    {
-        ImFont* font = atlas->Fonts[i];
-        ImGui::PushID(font);
-        ShowFont(font);
-        ImGui::PopID();
-    }
-    if (ImGui::TreeNode("Atlas texture", "Atlas texture (%dx%d pixels)", atlas->TexWidth, atlas->TexHeight))
-    {
-        ImVec4 tint_col = ImVec4(1.0f, 1.0f, 1.0f, 1.0f);
-        ImVec4 border_col = ImVec4(1.0f, 1.0f, 1.0f, 0.5f);
-        ImGui::Image(atlas->TexID, ImVec2((float)atlas->TexWidth, (float)atlas->TexHeight), ImVec2(0, 0), ImVec2(1, 1), tint_col, border_col);
-        ImGui::TreePop();
-    }
-}
-
-//-----------------------------------------------------------------------------
-// [SECTION] Style Editor / ShowStyleEditor()
-//-----------------------------------------------------------------------------
-// - ShowStyleSelector()
-// - ShowStyleEditor()
-//-----------------------------------------------------------------------------
-
 // Demo helper function to select among default colors. See ShowStyleEditor() for more advanced options.
 // Here we use the simplified Combo() api that packs items into a single literal string.
 // Useful for quick combo boxes where the choices are known locally.

imgui_internal.h

@@ -2613,9 +2613,11 @@ namespace ImGui
     inline void             DebugDrawItemRect(ImU32 col = IM_COL32(255,0,0,255))    { ImGuiContext& g = *GImGui; ImGuiWindow* window = g.CurrentWindow; GetForegroundDrawList(window)->AddRect(window->DC.LastItemRect.Min, window->DC.LastItemRect.Max, col); }
     inline void             DebugStartItemPicker()                                  { ImGuiContext& g = *GImGui; g.DebugItemPickerActive = true; }
 
+    IMGUI_API void          ShowFontAtlas(ImFontAtlas* atlas);
     IMGUI_API void          DebugNodeColumns(ImGuiOldColumns* columns);
     IMGUI_API void          DebugNodeDrawList(ImGuiWindow* window, const ImDrawList* draw_list, const char* label);
     IMGUI_API void          DebugNodeDrawCmdShowMeshAndBoundingBox(ImDrawList* out_draw_list, const ImDrawList* draw_list, const ImDrawCmd* draw_cmd, bool show_mesh, bool show_aabb);
+    IMGUI_API void          DebugNodeFont(ImFont* font);
     IMGUI_API void          DebugNodeStorage(ImGuiStorage* storage, const char* label);
     IMGUI_API void          DebugNodeTabBar(ImGuiTabBar* tab_bar, const char* label);
     IMGUI_API void          DebugNodeTable(ImGuiTable* table);