Backends: SDLRenderer2/3: expose selected state in ImGui_ImplXXXX_RenderState structures during render loop. (#6969, #5834, #7468, #3590 + #7616)

backends/imgui_impl_sdlrenderer2.cpp

@@ -10,6 +10,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -20,6 +21,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  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.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -140,12 +142,20 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     SDL_RenderGetViewport(renderer, &old.Viewport);
     SDL_RenderGetClipRect(renderer, &old.ClipRect);
 
+    // Setup desired state
+    ImGui_ImplSDLRenderer2_SetupRenderState(renderer);
+
+    // Setup render state structure (for callbacks and custom texture bindings)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    ImGui_ImplSDLRenderer2_RenderState render_state;
+    render_state.Renderer = renderer;
+    platform_io.Renderer_RenderState = &render_state;
+
 	// Will project scissor/clipping rectangles into framebuffer space
 	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
 	ImVec2 clip_scale = render_scale;
 
     // Render command lists
-    ImGui_ImplSDLRenderer2_SetupRenderState(renderer);
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* draw_list = draw_data->CmdLists[n];
@@ -198,6 +208,7 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
             }
         }
     }
+    platform_io.Renderer_RenderState = NULL;
 
     // Restore modified SDL_Renderer state
     SDL_RenderSetViewport(renderer, &old.Viewport);

backends/imgui_impl_sdlrenderer2.h

@@ -10,6 +10,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -37,4 +38,12 @@ IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_DestroyFontsTexture();
 IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer2_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_DestroyDeviceObjects();
 
+// [BETA] Selected render state data shared with callbacks.
+// This is temporarily stored in GetPlatformIO().Renderer_RenderState during the ImGui_ImplSDLRenderer2_RenderDrawData() call.
+// (Please open an issue if you feel you need access to more data)
+struct ImGui_ImplSDLRenderer2_RenderState
+{
+    SDL_Renderer*       Renderer;
+};
+
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdlrenderer3.cpp

@@ -12,6 +12,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -22,6 +23,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  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.
 //  2024-02-12: Amend to query SDL_RenderViewportSet() and restore viewport accordingly.
@@ -163,12 +165,20 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     SDL_GetRenderViewport(renderer, &old.Viewport);
     SDL_GetRenderClipRect(renderer, &old.ClipRect);
 
+    // Setup desired state
+    ImGui_ImplSDLRenderer3_SetupRenderState(renderer);
+
+    // Setup render state structure (for callbacks and custom texture bindings)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    ImGui_ImplSDLRenderer3_RenderState render_state;
+    render_state.Renderer = renderer;
+    platform_io.Renderer_RenderState = &render_state;
+
 	// Will project scissor/clipping rectangles into framebuffer space
 	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
 	ImVec2 clip_scale = render_scale;
 
     // Render command lists
-    ImGui_ImplSDLRenderer3_SetupRenderState(renderer);
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* draw_list = draw_data->CmdLists[n];
@@ -217,6 +227,7 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
             }
         }
     }
+    platform_io.Renderer_RenderState = NULL;
 
     // Restore modified SDL_Renderer state
     SDL_SetRenderViewport(renderer, old.ViewportEnabled ? &old.Viewport : nullptr);

backends/imgui_impl_sdlrenderer3.h

@@ -12,6 +12,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -39,4 +40,12 @@ IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_DestroyFontsTexture();
 IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer3_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_DestroyDeviceObjects();
 
+// [BETA] Selected render state data shared with callbacks.
+// This is temporarily stored in GetPlatformIO().Renderer_RenderState during the ImGui_ImplSDLRenderer3_RenderDrawData() call.
+// (Please open an issue if you feel you need access to more data)
+struct ImGui_ImplSDLRenderer3_RenderState
+{
+    SDL_Renderer*       Renderer;
+};
+
 #endif // #ifndef IMGUI_DISABLE

docs/CHANGELOG.txt

@@ -63,8 +63,8 @@ Other changes:
 - Tables: fixed initial auto-sizing issue with synched-instances. (#8045, #7218)
 - InputText: fixed an issue with not declaring ownership of Delete/Backspace/Arrow keys,
   preventing use of external shortcuts not guarded by an ActiveId check. (#8048) [@geertbleyen]
-- Backends: DX11, DX12, Vulkan, WGPU: expose selected state in ImGui_ImplXXXX_RenderState.
+- Backends: DX11, DX12, SDLRenderer2/3. Vulkan, WGPU: expose selected state in
-  structure during render loop. (#6969, #5834, #7468, #3590)
+  ImGui_ImplXXXX_RenderState structures during render loop. (#6969, #5834, #7468, #3590)
 - Backends: DX9, DX10, DX11, DX12, OpenGL, Vulkan, WGPU: Changed default texture sampler
   to Clamp instead of Repeat/Wrap. (#7468, #7511, #5999, #5502, #7230)