switch to SDL3 (no cmake fetch, just find_package)

examples/webgpu/triangle/platform/platform_sdl3.cpp

@@ -0,0 +1,95 @@
+// platform_sdl3.cpp — SDL3 windowing backend for the WebGPU example
+#include "platform.h"   // webgpu/webgpu.h first
+
+#define SDL_MAIN_HANDLED    // we don't want SDL_main
+#include <SDL3/SDL.h>
+
+#ifdef __APPLE__
+#  include <SDL3/SDL_metal.h>
+#endif
+
+#include <chrono>
+#include <cstdio>
+
+static SDL_Window* sWin = nullptr;
+static std::chrono::steady_clock::time_point sStartTime;
+#ifdef __APPLE__
+static SDL_MetalView sMetalView = nullptr;
+#endif
+
+bool platformInit(int width, int height, const char* title) {
+    if (!SDL_Init(SDL_INIT_VIDEO)) {
+        fprintf(stderr, "ERROR: SDL_Init failed: %s\n", SDL_GetError());
+        return false;
+    }
+
+    SDL_WindowFlags flags = 0;
+#ifdef __APPLE__
+    flags |= SDL_WINDOW_METAL;
+#endif
+
+    sWin = SDL_CreateWindow(title, width, height, flags);
+    if (!sWin) {
+        fprintf(stderr, "ERROR: SDL_CreateWindow failed: %s\n", SDL_GetError());
+        SDL_Quit();
+        return false;
+    }
+    SDL_SetWindowPosition(sWin, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+
+    sStartTime = std::chrono::steady_clock::now();
+    return true;
+}
+
+WGPUSurface platformCreateSurface(WGPUInstance instance) {
+    WGPUSurfaceDescriptor desc = {};
+    SDL_PropertiesID props = SDL_GetWindowProperties(sWin);
+
+#if defined(__APPLE__)
+    sMetalView = SDL_Metal_CreateView(sWin);
+    if (!sMetalView) {
+        fprintf(stderr, "ERROR: SDL_Metal_CreateView failed\n");
+        return nullptr;
+    }
+    WGPUSurfaceSourceMetalLayer metalDesc = {};
+    metalDesc.chain.sType = WGPUSType_SurfaceSourceMetalLayer;
+    metalDesc.layer       = SDL_Metal_GetLayer(sMetalView);
+    desc.nextInChain      = &metalDesc.chain;
+#elif defined(_WIN32)
+    WGPUSurfaceSourceWindowsHWND hwndDesc = {};
+    hwndDesc.chain.sType = WGPUSType_SurfaceSourceWindowsHWND;
+    hwndDesc.hinstance   = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_WIN32_INSTANCE_POINTER, nullptr);
+    hwndDesc.hwnd        = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_WIN32_HWND_POINTER, nullptr);
+    desc.nextInChain     = &hwndDesc.chain;
+#else   // Linux / X11
+    WGPUSurfaceSourceXlibWindow x11Desc = {};
+    x11Desc.chain.sType = WGPUSType_SurfaceSourceXlibWindow;
+    x11Desc.display     = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_X11_DISPLAY_POINTER, nullptr);
+    x11Desc.window      = (uint32_t)SDL_GetNumberProperty(props, SDL_PROP_WINDOW_X11_WINDOW_NUMBER, 0);
+    desc.nextInChain    = &x11Desc.chain;
+#endif
+
+    return wgpuInstanceCreateSurface(instance, &desc);
+}
+
+double platformGetTime() {
+    return std::chrono::duration<double>(
+        std::chrono::steady_clock::now() - sStartTime).count();
+}
+
+void platformRunLoop(void (*render)(), void (*shutdown)()) {
+    bool running = true;
+    while (running) {
+        SDL_Event e;
+        while (SDL_PollEvent(&e)) {
+            if (e.type == SDL_EVENT_QUIT) running = false;
+            if (e.type == SDL_EVENT_KEY_DOWN && e.key.key == SDLK_ESCAPE) running = false;
+        }
+        if (running) render();
+    }
+    shutdown();
+#ifdef __APPLE__
+    SDL_Metal_DestroyView(sMetalView);
+#endif
+    SDL_DestroyWindow(sWin);
+    SDL_Quit();
+}