[example/triangle] add simple *SDL3* app

example/triangle/src/main.cpp

@@ -1,7 +1,89 @@
+#include <SDL3/SDL.h>
+#include <SDL3/SDL_video.h>
+
 #include <cstdlib>
+#include <format>
+#include <functional>
+#include <iostream>
+
+template <typename Fn>
+struct scope_exit
+{
+public:
+    scope_exit(scope_exit const&) = delete;
+    scope_exit(scope_exit&&) = delete;
+    scope_exit& operator=(scope_exit const&) = delete;
+    scope_exit& operator=(scope_exit&&) = delete;
+
+    scope_exit(Fn&& f)
+        : fn{ std::forward<Fn&&>(f) }
+    {
+    }
+
+    ~scope_exit()
+    {
+        std::invoke(std::move(fn));
+    }
+
+private:
+    Fn fn;
+};
 
 int
 main()
 {
+    if (0 != SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS))
+    {
+        std::cout << std::format("SDL_Init failed with: '{}'", SDL_GetError()) << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto const destroy_sdl{ scope_exit([&]() { SDL_Quit(); }) };
+
+    auto* const window{ SDL_CreateWindow("probably triangle", 720, 480, SDL_WINDOW_VULKAN) };
+    if (!window)
+    {
+        std::cout << std::format("SDL_CreateWindow failed with: '{}'", SDL_GetError()) << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto const destroy_window{ scope_exit([&]() { SDL_DestroyWindow(window); }) };
+
+    auto* const renderer{ SDL_CreateRenderer(window, nullptr) };
+    if (!renderer)
+    {
+        std::cout << std::format("SDL_CreateRenderer failed with: '{}'", SDL_GetError()) << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto const destroy_renderer{ scope_exit([&]() { SDL_DestroyRenderer(renderer); }) };
+
+    if (0 != SDL_SetRenderDrawColor(renderer, 37, 5, 200, 255))
+    {
+        std::cout << std::format("SDL_SetRenderDrawColor failed with: '{}'", SDL_GetError()) << std::endl;
+        return EXIT_FAILURE;
+    }
+
+    bool running{ true };
+    while (running)
+    {
+        SDL_Event ev{};
+        while (SDL_PollEvent(&ev))
+        {
+            switch (ev.type)
+            {
+            case SDL_EVENT_QUIT:
+                running = false;
+            }
+        }
+
+        if (0 != SDL_RenderClear(renderer))
+        {
+            std::cout << std::format("SDL_RenderClear failed with: '{}'", SDL_GetError()) << std::endl;
+        }
+
+        if (0 != SDL_RenderPresent(renderer))
+        {
+            std::cout << std::format("SDL_RenderPresent failed with: '{}'", SDL_GetError()) << std::endl;
+        }
+    }
+
     return EXIT_SUCCESS;
 }