Misc: Made IMGUI_CHECKVERSION() macro also check for matching size of ImDrawIdx.

docs/CHANGELOG.txt

@@ -91,6 +91,7 @@ Other Changes:
   angles, also faster to output. (#2518) [@rmitton]
 - Misc: Added IM_MALLOC/IM_FREE macros mimicking IM_NEW/IM_DELETE so user doesn't need to revert
   to using the ImGui::MemAlloc()/MemFree() calls directly.
+- Misc: Made IMGUI_CHECKVERSION() macro also check for matching size of ImDrawIdx.
 - Metrics: Added "Show windows rectangles" tool to visualize the different rectangles.
 - Demo: Improved trees in columns demo.
 - Examples: OpenGL: Added a dummy GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized

imgui.cpp

@@ -3039,9 +3039,12 @@ void ImGui::SetCurrentContext(ImGuiContext* ctx)
 #endif
 }
 
-// Helper function to verify that the type sizes are matching between the calling file's compilation unit and imgui.cpp's compilation unit
+// Helper function to verify ABI compatibility between caller code and compiled version of Dear ImGui.
-// If the user has inconsistent compilation settings, imgui configuration #define, packing pragma, etc. you may see different structures from what imgui.cpp sees which is highly problematic.
+// Verify that the type sizes are matching between the calling file's compilation unit and imgui.cpp's compilation unit
-bool ImGui::DebugCheckVersionAndDataLayout(const char* version, size_t sz_io, size_t sz_style, size_t sz_vec2, size_t sz_vec4, size_t sz_vert)
+// If the user has inconsistent compilation settings, imgui configuration #define, packing pragma, etc. your user code
+// may see different structures thanwhat imgui.cpp sees, which is problematic.
+// We usually require settings to be in imconfig.h to make sure that they are accessible to all compilation units involved with Dear ImGui.
+bool ImGui::DebugCheckVersionAndDataLayout(const char* version, size_t sz_io, size_t sz_style, size_t sz_vec2, size_t sz_vec4, size_t sz_vert, size_t sz_idx)
 {
     bool error = false;
     if (strcmp(version, IMGUI_VERSION)!=0) { error = true; IM_ASSERT(strcmp(version,IMGUI_VERSION)==0 && "Mismatched version string!");  }
@@ -3050,6 +3053,7 @@ bool ImGui::DebugCheckVersionAndDataLayout(const char* version, size_t sz_io, si
     if (sz_vec2  != sizeof(ImVec2))        { error = true; IM_ASSERT(sz_vec2  == sizeof(ImVec2)       && "Mismatched struct layout!"); }
     if (sz_vec4  != sizeof(ImVec4))        { error = true; IM_ASSERT(sz_vec4  == sizeof(ImVec4)       && "Mismatched struct layout!"); }
     if (sz_vert  != sizeof(ImDrawVert))    { error = true; IM_ASSERT(sz_vert  == sizeof(ImDrawVert)   && "Mismatched struct layout!"); }
+    if (sz_idx   != sizeof(ImDrawIdx))     { error = true; IM_ASSERT(sz_idx   == sizeof(ImDrawIdx)    && "Mismatched struct layout!"); }
     return !error;
 }
 

imgui.h

@@ -48,7 +48,7 @@ Index of this file:
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.70 WIP"
 #define IMGUI_VERSION_NUM           16991
-#define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert))
+#define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 
 // Define attributes of all API symbols declarations (e.g. for DLL under Windows)
 // IMGUI_API is used for core imgui functions, IMGUI_IMPL_API is used for the default bindings files (imgui_impl_xxx.h)
@@ -207,7 +207,7 @@ namespace ImGui
     IMGUI_API void          DestroyContext(ImGuiContext* ctx = NULL);   // NULL = destroy current context
     IMGUI_API ImGuiContext* GetCurrentContext();
     IMGUI_API void          SetCurrentContext(ImGuiContext* ctx);
-    IMGUI_API bool          DebugCheckVersionAndDataLayout(const char* version_str, size_t sz_io, size_t sz_style, size_t sz_vec2, size_t sz_vec4, size_t sz_drawvert);
+    IMGUI_API bool          DebugCheckVersionAndDataLayout(const char* version_str, size_t sz_io, size_t sz_style, size_t sz_vec2, size_t sz_vec4, size_t sz_drawvert, size_t sz_drawidx);
 
     // Main
     IMGUI_API ImGuiIO&      GetIO();                                    // access the IO structure (mouse/keyboard/gamepad inputs, time, various configuration options/flags)