Backends: Metal4: Added Metal 4 backend. Added SDL3+Metal4 example. (#9458, #9451)

.github/workflows/build.yml

@@ -572,6 +572,9 @@ jobs:
     - name: Build macOS example_sdl2_metal
       run: make -C examples/example_sdl2_metal
 
+    - name: Build macOS example_sdl3_metal4
+      run: make -C examples/example_sdl3_metal4
+
     - name: Build macOS example_sdl2_opengl2
       run: make -C examples/example_sdl2_opengl2
       if: github.event_name == 'workflow_run'

.gitignore

@@ -72,6 +72,7 @@ examples/example_sdl2_opengl3/example_sdl2_opengl3
 examples/example_sdl2_sdlrenderer2/example_sdl2_sdlrenderer2
 examples/example_sdl2_vulkan/example_sdl2_vulkan
 examples/example_sdl3_metal/example_sdl3_metal
+examples/example_sdl3_metal4/example_sdl3_metal4
 examples/example_sdl3_opengl3/example_sdl3_opengl3
 examples/example_sdl3_sdlgpu3/example_sdl3_sdlgpu3
 examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3

backends/imgui_impl_metal4.h

@@ -1,8 +1,8 @@
-// dear imgui: Renderer Backend for Metal
+// dear imgui: Renderer Backend for Metal 4
 // This needs to be used along with a Platform Backend (e.g. OSX)
 
 // Implemented features:
-//  [X] Renderer: User texture binding. Use 'MTLTexture' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
+//  [X] Renderer: User texture binding. Use 'MTLTexture.gpuResourceID' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 
@@ -24,55 +24,31 @@
 
 #ifdef __OBJC__
 
-@class MTLRenderPassDescriptor;
-@protocol MTLDevice, MTLCommandBuffer, MTLRenderCommandEncoder;
+@class MTL4RenderPassDescriptor;
+@protocol MTLDevice, MTL4CommandBuffer, MTL4RenderCommandEncoder, MTL4CommandQueue;
 
+// framesInFlight must match the number of frames your application keeps in flight (e.g. the size of your own
+// command buffer/allocator ring). The backend uses it to size its own per-frame-in-flight resources (constant
+// buffer, vertex/index buffer cache) so the CPU never overwrites a slot the GPU may still be reading.
 // Follow "Getting Started" link and check examples/ folder to learn about using backends!
-IMGUI_IMPL_API bool ImGui_ImplMetal_Init(id<MTLDevice> device);
-IMGUI_IMPL_API void ImGui_ImplMetal_Shutdown();
-IMGUI_IMPL_API void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor);
-IMGUI_IMPL_API void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData,
-                                                   id<MTLCommandBuffer> commandBuffer,
-                                                   id<MTLRenderCommandEncoder> commandEncoder);
+IMGUI_IMPL_API bool ImGui_ImplMetal4_Init(id<MTLDevice> device, id<MTL4CommandQueue> commandQueue, int framesInFlight);
+IMGUI_IMPL_API void ImGui_ImplMetal4_Shutdown();
+// frameInFlightIndex must match the slot you use to index your own per-frame-in-flight resources
+// (e.g. the same index used to pick your command buffer/allocator), and must be < framesInFlight passed to Init().
+IMGUI_IMPL_API void ImGui_ImplMetal4_NewFrame(MTL4RenderPassDescriptor* renderPassDescriptor, int frameInFlightIndex);
+IMGUI_IMPL_API void ImGui_ImplMetal4_RenderDrawData(ImDrawData* drawData,
+                                                   id<MTL4CommandBuffer> commandBuffer,
+                                                   id<MTL4RenderCommandEncoder> commandEncoder);
 
 // Called by Init/NewFrame/Shutdown
-IMGUI_IMPL_API bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device);
-IMGUI_IMPL_API void ImGui_ImplMetal_DestroyDeviceObjects();
+IMGUI_IMPL_API bool ImGui_ImplMetal4_CreateDeviceObjects(id<MTLDevice> device);
+IMGUI_IMPL_API void ImGui_ImplMetal4_DestroyDeviceObjects();
 
 // (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
-IMGUI_IMPL_API void ImGui_ImplMetal_UpdateTexture(ImTextureData* tex);
+IMGUI_IMPL_API void ImGui_ImplMetal4_UpdateTexture(ImTextureData* tex);
 
 #endif
 
-//-----------------------------------------------------------------------------
-// C++ API
-//-----------------------------------------------------------------------------
-
-// Enable Metal C++ binding support with '#define IMGUI_IMPL_METAL_CPP' in your imconfig.h file
-// More info about using Metal from C++: https://developer.apple.com/metal/cpp/
-
-#ifdef IMGUI_IMPL_METAL_CPP
-#include <Metal/Metal.hpp>
-#ifndef __OBJC__
-
-// Follow "Getting Started" link and check examples/ folder to learn about using backends!
-IMGUI_IMPL_API bool ImGui_ImplMetal_Init(MTL::Device* device);
-IMGUI_IMPL_API void ImGui_ImplMetal_Shutdown();
-IMGUI_IMPL_API void ImGui_ImplMetal_NewFrame(MTL::RenderPassDescriptor* renderPassDescriptor);
-IMGUI_IMPL_API void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data,
-                                                   MTL::CommandBuffer* commandBuffer,
-                                                   MTL::RenderCommandEncoder* commandEncoder);
-
-// Called by Init/NewFrame/Shutdown
-IMGUI_IMPL_API bool ImGui_ImplMetal_CreateDeviceObjects(MTL::Device* device);
-IMGUI_IMPL_API void ImGui_ImplMetal_DestroyDeviceObjects();
-
-// (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = nullptr to handle this manually.
-IMGUI_IMPL_API void ImGui_ImplMetal_UpdateTexture(ImTextureData* tex);
-
-#endif
-#endif
-
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

examples/example_sdl3_metal4/Makefile

@@ -0,0 +1,48 @@
+#
+# You will need SDL3 (http://www.libsdl.org):
+#   brew install sdl3
+#
+
+#CXX = g++
+#CXX = clang++
+
+EXE = example_sdl3_metal4
+IMGUI_DIR = ../..
+SOURCES = main.mm
+SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
+SOURCES += $(IMGUI_DIR)/backends/imgui_impl_sdl3.cpp $(IMGUI_DIR)/backends/imgui_impl_metal4.mm
+OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
+
+LIBS = -framework Metal -framework MetalKit -framework Cocoa -framework IOKit -framework CoreVideo -framework QuartzCore
+LIBS += `pkg-config --libs sdl3`
+LIBS += -L/usr/local/lib -L/opt/local/lib
+
+CXXFLAGS += `pkg-config --cflags sdl3`
+CXXFLAGS += -I/usr/local/include -I/opt/local/include
+CXXFLAGS += -std=c++11 -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
+CXXFLAGS += -Wall -Wformat
+CFLAGS = $(CXXFLAGS)
+
+%.o:%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/backends/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:%.mm
+	$(CXX) $(CXXFLAGS) -ObjC++ -fobjc-weak -fobjc-arc -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/backends/%.mm
+	$(CXX) $(CXXFLAGS) -ObjC++ -fobjc-weak -fobjc-arc -c -o $@ $<
+
+all: $(EXE)
+	@echo Build complete
+
+$(EXE): $(OBJS)
+	$(CXX) -o $@ $^ $(CXXFLAGS) $(LIBS)
+
+clean:
+	rm -f $(EXE) $(OBJS)