Metrics: Show wire-frame mesh and approximate surface area when hovering ImDrawCmd. Amend aeb5795.

Internals: Added ImTriangleArea()

docs/CHANGELOG.txt

@@ -84,10 +84,11 @@ Other Changes:
 - Misc: Windows: Disabled win32 function by default when building with UWP. (#2892, #2895)
 - Misc: Using static_assert() when using C++11, instead of our own construct (avoid zealous Clang warnings).
 - Misc: Added IMGUI_DISABLE_FILE_FUNCTIONS/IMGUI_DISABLE_DEFAULT_FILE_FUNCTION to nullify or disable
-  default implementationof ImFileXXX functions linking with fopen/fclose/fread/fwrite. (#2734)
+  default implementation of ImFileXXX functions linking with fopen/fclose/fread/fwrite. (#2734)
 - Docs: Improved and moved FAQ to docs/FAQ.md so it can be readable on the web. [@ButternCream, @ocornut]
 - Docs: Added permanent redirect from https://www.dearimgui.org/faq to FAQ page.
 - Demo: Added simple item reordering demo in Widgets -> Drag and Drop section. (#2823, #143) [@rokups]
+- Metrics: Show wire-frame mesh and approximate surface area when hovering ImDrawCmd. [@ShironekoBen]
 - Metrics: Expose basic details of each window key/value state storage.
 - Examples: DX12: Using IDXGIDebug1::ReportLiveObjects() when DX12_ENABLE_DEBUG_LAYER is enabled.
 - Examples: Emscripten: Removed BINARYEN_TRAP_MODE=clamp from Makefile which was removed in Emscripten 1.39.0

imgui.cpp

@@ -45,7 +45,7 @@ CODE
 // [SECTION] FORWARD DECLARATIONS
 // [SECTION] CONTEXT AND MEMORY ALLOCATORS
 // [SECTION] MAIN USER FACING STRUCTURES (ImGuiStyle, ImGuiIO)
-// [SECTION] MISC HELPERS/UTILITIES (Maths, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geomtry, String, Format, Hash, File functions)
 // [SECTION] MISC HELPERS/UTILITIES (File functions)
 // [SECTION] MISC HELPERS/UTILITIES (ImText* functions)
 // [SECTION] MISC HELPERS/UTILITIES (Color functions)
@@ -1083,7 +1083,7 @@ void ImGuiIO::ClearInputCharacters()
 }
 
 //-----------------------------------------------------------------------------
-// [SECTION] MISC HELPERS/UTILITIES (Maths, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geometry, String, Format, Hash, File functions)
 //-----------------------------------------------------------------------------
 
 ImVec2 ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p)
@@ -9715,7 +9715,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
     static bool show_windows_rects = false;
     static int  show_windows_rect_type = WRT_WorkRect;
     static bool show_windows_begin_order = false;
-    static bool show_drawcmd_clip_rects = true;
+    static bool show_drawcmd_details = true;
 
     // Basic info
     ImGuiContext& g = *GImGui;
@@ -9766,7 +9766,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 return;
 
             if (window && !window->WasActive)
-                ImGui::Text("(Note: owning Window is inactive: DrawList is not being rendered!)");
+                ImGui::TextDisabled("Warning: owning Window is inactive. This DrawList is not being rendered!");
 
             unsigned int elem_offset = 0;
             for (const ImDrawCmd* pcmd = draw_list->CmdBuffer.begin(); pcmd < draw_list->CmdBuffer.end(); elem_offset += pcmd->ElemCount, pcmd++)
@@ -9780,73 +9780,51 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 }
 
                 ImDrawIdx* idx_buffer = (draw_list->IdxBuffer.Size > 0) ? draw_list->IdxBuffer.Data : NULL;
-
-                // Calculate approximate coverage area (touched pixel count)
-                // This will be in pixels squared as long there's no post-scaling happening to the ImGui output
-                // Optionally also draw all the polys in the list in wireframe when hovering over 
-
-                float total_area = 0.0f;
-
-                for (unsigned int base_idx = elem_offset; base_idx < (elem_offset + pcmd->ElemCount); base_idx += 3)
-                {
-                    ImVec2 triangles_pos[3];
-                    for (int n = 0; n < 3; n++)
-                    {
-                        int vtx_i = idx_buffer ? idx_buffer[base_idx + n] : (base_idx + n);
-                        ImDrawVert& v = draw_list->VtxBuffer[vtx_i];
-                        triangles_pos[n] = v.pos;                            
-                    }
-
-                    // Calculate triangle area and accumulate
-
-                    float area = abs((triangles_pos[0].x * (triangles_pos[1].y - triangles_pos[2].y)) +
-                                 (triangles_pos[1].x * (triangles_pos[2].y - triangles_pos[0].y)) +
-                                 (triangles_pos[2].x * (triangles_pos[0].y - triangles_pos[1].y))) * 0.5f;
-
-                    total_area += area;
-                }
-
                 char buf[300];
-                ImFormatString(buf, IM_ARRAYSIZE(buf), "Draw %4d triangles, tex 0x%p, area %.0fpx^2, clip_rect (%4.0f,%4.0f)-(%4.0f,%4.0f)",
+                ImFormatString(buf, IM_ARRAYSIZE(buf), "DrawCmd: %4d triangles, Tex 0x%p, ClipRect (%4.0f,%4.0f)-(%4.0f,%4.0f)",
-                    pcmd->ElemCount/3, (void*)(intptr_t)pcmd->TextureId, total_area,
+                    pcmd->ElemCount/3, (void*)(intptr_t)pcmd->TextureId,
                     pcmd->ClipRect.x, pcmd->ClipRect.y, pcmd->ClipRect.z, pcmd->ClipRect.w);
                 bool pcmd_node_open = ImGui::TreeNode((void*)(pcmd - draw_list->CmdBuffer.begin()), "%s", buf);
-                if (show_drawcmd_clip_rects && fg_draw_list && ImGui::IsItemHovered())
+                if (show_drawcmd_details && fg_draw_list && ImGui::IsItemHovered())
                 {
                     ImRect clip_rect = pcmd->ClipRect;
                     ImRect vtxs_rect;
                     for (unsigned int i = elem_offset; i < elem_offset + (int)pcmd->ElemCount; i++)
                         vtxs_rect.Add(draw_list->VtxBuffer[idx_buffer ? idx_buffer[i] : i].pos);
-                    clip_rect.Floor(); fg_draw_list->AddRect(clip_rect.Min, clip_rect.Max, IM_COL32(255,0,255,255));
+                    fg_draw_list->AddRect(ImFloor(clip_rect.Min), ImFloor(clip_rect.Max), IM_COL32(255,0,255,255));
-                    vtxs_rect.Floor(); fg_draw_list->AddRect(vtxs_rect.Min, vtxs_rect.Max, IM_COL32(255,255,0,255));
+                    fg_draw_list->AddRect(ImFloor(vtxs_rect.Min), ImFloor(vtxs_rect.Max), IM_COL32(255,255,0,255));
                 }
                 if (!pcmd_node_open)
                     continue;
 
-                // Display vertex information summary. Hover to get all triangles drawn in wireframe
+                // Calculate approximate coverage area (touched pixel count)
-                ImFormatString(buf, IM_ARRAYSIZE(buf), "ElemCount: %d, ElemCount/3: %d, VtxOffset: +%d, IdxOffset: +%d", pcmd->ElemCount, pcmd->ElemCount/3, pcmd->VtxOffset, pcmd->IdxOffset);
+                // This will be in pixels squared as long there's no post-scaling happening to the renderer output.
-                ImGui::Selectable(buf, false);
+                float total_area = 0.0f;
-
+                for (unsigned int base_idx = elem_offset; base_idx < (elem_offset + pcmd->ElemCount); base_idx += 3)
-                if (fg_draw_list && ImGui::IsItemHovered())
                 {
-                    // Draw wireframe version of everything
+                    ImVec2 triangle[3];
+                    for (int n = 0; n < 3; n++)
+                        triangle[n] = draw_list->VtxBuffer[idx_buffer ? idx_buffer[base_idx + n] : (base_idx + n)].pos;
+                    total_area += ImTriangleArea(triangle[0], triangle[1], triangle[2]);
+                }
 
+                // Display vertex information summary. Hover to get all triangles drawn in wire-frame
+                ImFormatString(buf, IM_ARRAYSIZE(buf), "Mesh: ElemCount: %d, VtxOffset: +%d, IdxOffset: +%d, Area: ~%0.f px", pcmd->ElemCount, pcmd->VtxOffset, pcmd->IdxOffset, total_area);
+                ImGui::Selectable(buf);
+                if (fg_draw_list && ImGui::IsItemHovered() && show_drawcmd_details)
+                {
+                    // Draw wire-frame version of everything
                     ImDrawListFlags backup_flags = fg_draw_list->Flags;
-                    fg_draw_list->Flags &= ~ImDrawListFlags_AntiAliasedLines; // Disable AA on triangle outlines at is more readable for very large and thin triangles.
+                    fg_draw_list->Flags &= ~ImDrawListFlags_AntiAliasedLines; // Disable AA on triangle outlines is more readable for very large and thin triangles.
-
+                    ImRect clip_rect = pcmd->ClipRect;
+                    fg_draw_list->AddRect(ImFloor(clip_rect.Min), ImFloor(clip_rect.Max), IM_COL32(255, 0, 255, 255));
                     for (unsigned int base_idx = elem_offset; base_idx < (elem_offset + pcmd->ElemCount); base_idx += 3)
                     {
-                        ImVec2 triangles_pos[3];
+                        ImVec2 triangle[3];
                         for (int n = 0; n < 3; n++)
-                        {
+                            triangle[n] = draw_list->VtxBuffer[idx_buffer ? idx_buffer[base_idx + n] : (base_idx + n)].pos;
-                            int vtx_i = idx_buffer ? idx_buffer[base_idx + n] : (base_idx + n);
+                        fg_draw_list->AddPolyline(triangle, 3, IM_COL32(255, 255, 0, 255), true, 1.0f);
-                            ImDrawVert& v = draw_list->VtxBuffer[vtx_i];
-                            triangles_pos[n] = v.pos;
-                        }
-
-                        fg_draw_list->AddPolyline(triangles_pos, 3, IM_COL32(255, 255, 0, 255), true, 1.0f);
                     }
-
                     fg_draw_list->Flags = backup_flags;
                 }
 
@@ -9856,22 +9834,21 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                     for (int prim = clipper.DisplayStart, idx_i = elem_offset + clipper.DisplayStart*3; prim < clipper.DisplayEnd; prim++)
                     {
                         char *buf_p = buf, *buf_end = buf + IM_ARRAYSIZE(buf);
-                        ImVec2 triangles_pos[3];
+                        ImVec2 triangle[3];
                         for (int n = 0; n < 3; n++, idx_i++)
                         {
-                            int vtx_i = idx_buffer ? idx_buffer[idx_i] : idx_i;
+                            ImDrawVert& v = draw_list->VtxBuffer[idx_buffer ? idx_buffer[idx_i] : idx_i];
-                            ImDrawVert& v = draw_list->VtxBuffer[vtx_i];
+                            triangle[n] = v.pos;
-                            triangles_pos[n] = v.pos;
                             buf_p += ImFormatString(buf_p, buf_end - buf_p, "%s %04d: pos (%8.2f,%8.2f), uv (%.6f,%.6f), col %08X\n",
-                                (n == 0) ? "elem" : "    ", idx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col);
+                                (n == 0) ? "Vert:" : "     ", idx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col);
                         }
 
                         ImGui::Selectable(buf, false);
                         if (fg_draw_list && ImGui::IsItemHovered())
                         {
                             ImDrawListFlags backup_flags = fg_draw_list->Flags;
-                            fg_draw_list->Flags &= ~ImDrawListFlags_AntiAliasedLines; // Disable AA on triangle outlines at is more readable for very large and thin triangles.
+                            fg_draw_list->Flags &= ~ImDrawListFlags_AntiAliasedLines; // Disable AA on triangle outlines is more readable for very large and thin triangles.
-                            fg_draw_list->AddPolyline(triangles_pos, 3, IM_COL32(255,255,0,255), true, 1.0f);
+                            fg_draw_list->AddPolyline(triangle, 3, IM_COL32(255,255,0,255), true, 1.0f);
                             fg_draw_list->Flags = backup_flags;
                         }
                     }
@@ -10058,7 +10035,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             }
             ImGui::Unindent();
         }
-        ImGui::Checkbox("Show clipping rectangle when hovering ImDrawCmd node", &show_drawcmd_clip_rects);
+        ImGui::Checkbox("Show details when hovering ImDrawCmd node", &show_drawcmd_details);
         ImGui::TreePop();
     }
 

imgui_demo.cpp

@@ -3421,7 +3421,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                     ImGui::Text("Fallback character: '%c' (U+%04X)", font->FallbackChar, font->FallbackChar);
                     ImGui::Text("Ellipsis character: '%c' (U+%04X)", font->EllipsisChar, font->EllipsisChar);
                     const float surface_sqrt = sqrtf((float)font->MetricsTotalSurface);
-                    ImGui::Text("Texture surface: %d pixels (approx) ~ %dx%d", font->MetricsTotalSurface, (int)surface_sqrt, (int)surface_sqrt);
+                    ImGui::Text("Texture Area: about %d px ~%dx%d px", font->MetricsTotalSurface, (int)surface_sqrt, (int)surface_sqrt);
                     for (int config_i = 0; config_i < font->ConfigDataCount; config_i++)
                         if (const ImFontConfig* cfg = &font->ConfigData[config_i])
                             ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d", config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH);

imgui_internal.h

@@ -194,11 +194,11 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 //-----------------------------------------------------------------------------
 // - Helpers: Misc
 // - Helpers: Bit manipulation
-// - Helpers: Geometry
 // - Helpers: String, Formatting
 // - Helpers: UTF-8 <> wchar conversions
 // - Helpers: ImVec2/ImVec4 operators
 // - Helpers: Maths
+// - Helpers: Geometry
 // - Helper: ImBoolVector
 // - Helper: ImPool<>
 // - Helper: ImChunkStream<>
@@ -216,13 +216,6 @@ static inline ImU32     ImHash(const void* data, int size, ImU32 seed = 0) { ret
 static inline bool      ImIsPowerOfTwo(int v)           { return v != 0 && (v & (v - 1)) == 0; }
 static inline int       ImUpperPowerOfTwo(int v)        { v--; v |= v >> 1; v |= v >> 2; v |= v >> 4; v |= v >> 8; v |= v >> 16; v++; return v; }
 
-// Helpers: Geometry
-IMGUI_API ImVec2        ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p);
-IMGUI_API bool          ImTriangleContainsPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
-IMGUI_API ImVec2        ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
-IMGUI_API void          ImTriangleBarycentricCoords(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p, float& out_u, float& out_v, float& out_w);
-IMGUI_API ImGuiDir      ImGetDirQuadrantFromDelta(float dx, float dy);
-
 // Helpers: String, Formatting
 IMGUI_API int           ImStricmp(const char* str1, const char* str2);
 IMGUI_API int           ImStrnicmp(const char* str1, const char* str2, size_t count);
@@ -343,6 +336,14 @@ static inline ImVec2 ImRotate(const ImVec2& v, float cos_a, float sin_a)
 static inline float  ImLinearSweep(float current, float target, float speed)    { if (current < target) return ImMin(current + speed, target); if (current > target) return ImMax(current - speed, target); return current; }
 static inline ImVec2 ImMul(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y); }
 
+// Helpers: Geometry
+IMGUI_API ImVec2     ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p);
+IMGUI_API bool       ImTriangleContainsPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
+IMGUI_API ImVec2     ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
+IMGUI_API void       ImTriangleBarycentricCoords(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p, float& out_u, float& out_v, float& out_w);
+inline float         ImTriangleArea(const ImVec2& a, const ImVec2& b, const ImVec2& c) { return ImFabs((a.x * (b.y - c.y)) + (b.x * (c.y - a.y)) + (c.x * (a.y - b.y))) * 0.5f; }
+IMGUI_API ImGuiDir   ImGetDirQuadrantFromDelta(float dx, float dy);
+
 // Helper: ImBoolVector
 // Store 1-bit per value. Note that Resize() currently clears the whole vector.
 struct IMGUI_API ImBoolVector