From 8403c49484d7962fdd7395de090716a6f2dd9cef Mon Sep 17 00:00:00 2001 From: Shi Yan Date: Tue, 22 Jul 2025 18:28:12 -0500 Subject: [PATCH] Examples: SDL3+Metal: Added example. (#8827, #8825) --- examples/example_sdl3_metal/Makefile | 48 +++++++ examples/example_sdl3_metal/main.mm | 188 +++++++++++++++++++++++++++ 2 files changed, 236 insertions(+) create mode 100644 examples/example_sdl3_metal/Makefile create mode 100644 examples/example_sdl3_metal/main.mm diff --git a/examples/example_sdl3_metal/Makefile b/examples/example_sdl3_metal/Makefile new file mode 100644 index 000000000..9093ae133 --- /dev/null +++ b/examples/example_sdl3_metal/Makefile @@ -0,0 +1,48 @@ +# +# You will need SDL3 (http://www.libsdl.org): +# brew install sdl3 +# + +#CXX = g++ +#CXX = clang++ + +EXE = example_sdl3_metal +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_metal.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) diff --git a/examples/example_sdl3_metal/main.mm b/examples/example_sdl3_metal/main.mm new file mode 100644 index 000000000..b847cbed4 --- /dev/null +++ b/examples/example_sdl3_metal/main.mm @@ -0,0 +1,188 @@ +// Dear ImGui: standalone example application for SDL3 + Metal +// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.) + +// Learn about Dear ImGui: +// - FAQ https://dearimgui.com/faq +// - Getting Started https://dearimgui.com/getting-started +// - Documentation https://dearimgui.com/docs (same as your local docs/ folder). +// - Introduction, links and more at the top of imgui.cpp + +#include "imgui.h" +#include "imgui_impl_sdl3.h" +#include "imgui_impl_metal.h" +#include +#include + +#import +#import + +int main(int, char**) +{ + // Setup SDL + // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function] + if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD)) + { + printf("Error: SDL_Init(): %s\n", SDL_GetError()); + return -1; + } + + float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay()); + SDL_WindowFlags window_flags = SDL_WINDOW_METAL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY; + SDL_Window *window = SDL_CreateWindow("Dear ImGui SDL3+SDL_GPU example", (int)(1280 * main_scale), (int)(720 * main_scale), window_flags); + if (window == nullptr) + { + printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError()); + return -1; + } + SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED); + SDL_ShowWindow(window); + + // Setup Dear ImGui context + IMGUI_CHECKVERSION(); + ImGui::CreateContext(); + ImGuiIO& io = ImGui::GetIO(); (void)io; + io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls + io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls + + // Setup Dear ImGui style + ImGui::StyleColorsDark(); + //ImGui::StyleColorsLight(); + + // Setup scaling + ImGuiStyle& style = ImGui::GetStyle(); + style.ScaleAllSizes(main_scale); // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again) + style.FontScaleDpi = main_scale; // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose) + + // Setup Platform/Renderer backends + // Create Metal device BEFORE creating the view/layer + id metalDevice = MTLCreateSystemDefaultDevice(); + if (!metalDevice) + { + printf("Error: failed to create Metal device.\n"); + SDL_DestroyWindow(window); + SDL_Quit(); + return -1; + } + + SDL_MetalView view = SDL_Metal_CreateView(window); + CAMetalLayer* layer = (__bridge CAMetalLayer*)SDL_Metal_GetLayer(view); + layer.device = metalDevice; + layer.pixelFormat = MTLPixelFormatBGRA8Unorm; + ImGui_ImplMetal_Init(layer.device); + + ImGui_ImplSDL3_InitForMetal(window); + + id commandQueue = [layer.device newCommandQueue]; + MTLRenderPassDescriptor* renderPassDescriptor = [MTLRenderPassDescriptor new]; + + // Our state + bool show_demo_window = true; + bool show_another_window = false; + float clear_color[4] = {0.45f, 0.55f, 0.60f, 1.00f}; + + // Main loop + bool done = false; + while (!done) + { + @autoreleasepool + { + // Poll and handle events (inputs, window resize, etc.) + // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs. + // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data. + // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data. + // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags. + SDL_Event event; + while (SDL_PollEvent(&event)) + { + ImGui_ImplSDL3_ProcessEvent(&event); + if (event.type == SDL_EVENT_QUIT) + done = true; + if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window)) + done = true; + } + + // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function] + if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED) + { + SDL_Delay(10); + continue; + } + + int width, height; + SDL_GetWindowSizeInPixels(window, &width, &height); + + layer.drawableSize = CGSizeMake(width, height); + id drawable = [layer nextDrawable]; + + id commandBuffer = [commandQueue commandBuffer]; + renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0] * clear_color[3], clear_color[1] * clear_color[3], clear_color[2] * clear_color[3], clear_color[3]); + renderPassDescriptor.colorAttachments[0].texture = drawable.texture; + renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear; + renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore; + id renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor]; + [renderEncoder pushDebugGroup:@"ImGui demo"]; + + // Start the Dear ImGui frame + ImGui_ImplMetal_NewFrame(renderPassDescriptor); + ImGui_ImplSDL3_NewFrame(); + ImGui::NewFrame(); + + // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!). + if (show_demo_window) + ImGui::ShowDemoWindow(&show_demo_window); + + // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window. + { + static float f = 0.0f; + static int counter = 0; + + ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it. + + ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too) + ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state + ImGui::Checkbox("Another Window", &show_another_window); + + ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f + ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color + + if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated) + counter++; + ImGui::SameLine(); + ImGui::Text("counter = %d", counter); + + ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate); + ImGui::End(); + } + + // 3. Show another simple window. + if (show_another_window) + { + ImGui::Begin("Another Window", &show_another_window); // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked) + ImGui::Text("Hello from another window!"); + if (ImGui::Button("Close Me")) + show_another_window = false; + ImGui::End(); + } + + // Rendering + ImGui::Render(); + ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder); + + [renderEncoder popDebugGroup]; + [renderEncoder endEncoding]; + + [commandBuffer presentDrawable:drawable]; + [commandBuffer commit]; + } + } + + // Cleanup + ImGui_ImplMetal_Shutdown(); + ImGui_ImplSDL3_Shutdown(); + ImGui::DestroyContext(); + + SDL_DestroyWindow(window); + SDL_Quit(); + + return 0; +}