Backends: SDL_Renderer2/3: Use endian-dependent RGBA32 texture format, to match SDL_Color. (ocornut#8327)

Daniel K. O. (dkosmari) · ocornut · commit aa23f3801b74 · 2025-01-18T17:26:36.000+01:00
diff --git a/backends/imgui_impl_sdlrenderer2.cpp b/backends/imgui_impl_sdlrenderer2.cpp
@@ -21,6 +21,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer2_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-05-14: *BREAKING CHANGE* ImGui_ImplSDLRenderer3_RenderDrawData() requires SDL_Renderer* passed as parameter.
 //  2023-05-30: Renamed imgui_impl_sdlrenderer.h/.cpp to imgui_impl_sdlrenderer2.h/.cpp to accommodate for upcoming SDL3.
@@ -228,7 +229,7 @@ bool ImGui_ImplSDLRenderer2_CreateFontsTexture()
 
     // Upload texture to graphics system
     // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
-    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_RGBA32, SDL_TEXTUREACCESS_STATIC, width, height);
     if (bd->FontTexture == nullptr)
     {
         SDL_Log("error creating texture");
diff --git a/backends/imgui_impl_sdlrenderer3.cpp b/backends/imgui_impl_sdlrenderer3.cpp
@@ -23,6 +23,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer3_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-07-01: Update for SDL3 api changes: SDL_RenderGeometryRaw() uint32 version was removed (SDL#9009).
 //  2024-05-14: *BREAKING CHANGE* ImGui_ImplSDLRenderer3_RenderDrawData() requires SDL_Renderer* passed as parameter.
@@ -247,7 +248,7 @@ bool ImGui_ImplSDLRenderer3_CreateFontsTexture()
 
     // Upload texture to graphics system
     // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
-    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_RGBA32, SDL_TEXTUREACCESS_STATIC, width, height);
     if (bd->FontTexture == nullptr)
     {
         SDL_Log("error creating texture");
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
@@ -60,6 +60,8 @@ Other changes:
   vkAcquireNextImageKHR() or vkQueuePresentKHR(). (#7825, #7831) [@NostraMagister]
 - Backends: SDLGPU3: Exposed ImGui_ImplSDLGPU3_CreateDeviceObjects()/_DestroyDeviceObjects().
   Removed return value from ImGui_ImplSDLGPU3_CreateFontsTexture(). (#8163, #7998, #7988)
+- Backends: SDL_Renderer2/3: Use endian-dependent RGBA32 texture format, to match
+  SDL_Color. (#8327) [@dkosmari]
 - Backends: DirectX12: Texture upload use the command queue provided in
   ImGui_ImplDX12_InitInfo instead of creating its own.
 
