basic random walk with fancy out_ptr

main.cpp

@@ -4,12 +4,29 @@
 
 #include <memory>
 #include <print>
+#include <random>
 
 template <auto sdl_destroyfunc>
 using sdl_deleter_t = decltype([](auto* ptr) { sdl_destroyfunc(ptr); });
 
-using window_t = std::unique_ptr<SDL_Window, sdl_deleter_t<SDL_DestroyWindow>>;
+template <class SDLT, auto sdl_destroyfunc>
-using surface_t = std::unique_ptr<SDL_Surface, sdl_deleter_t<SDL_FreeSurface>>;
+using sdl_wrapper_t = std::unique_ptr<SDLT, sdl_deleter_t<sdl_destroyfunc>>;
+
+using window_t = sdl_wrapper_t<SDL_Window, SDL_DestroyWindow>;
+using surface_t = sdl_wrapper_t<SDL_Surface, SDL_FreeSurface>;
+using renderer_t = sdl_wrapper_t<SDL_Renderer, SDL_DestroyRenderer>;
+
+struct Point {
+	int x;
+	int y;
+};
+
+auto operator+(Point a, Point b) {
+	return Point{.x = a.x + b.x, .y = a.y + b.y};
+}
+
+constexpr int width = 3440;
+constexpr int height = 1440;
 
 int main() {
 	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
@@ -18,10 +35,15 @@ int main() {
 	}
 
 	{
-		auto window = window_t{SDL_CreateWindow(
+		renderer_t renderer;
-			"SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+		window_t window;
-			1024, 512, SDL_WINDOW_SHOWN
+		SDL_CreateWindowAndRenderer(
-		)};
+			width, height, SDL_WINDOW_SHOWN | SDL_WINDOW_FULLSCREEN,
+			std::out_ptr(window), std::out_ptr(renderer)
+		);
+		SDL_SetRenderDrawColor(renderer.get(), 0, 0, 0, 0);
+		SDL_RenderClear(renderer.get());
+		SDL_SetRenderDrawColor(renderer.get(), 255, 0, 0, 255);
 
 		if (!window) {
 			std::println(
@@ -32,12 +54,32 @@ int main() {
 
 		auto surface = surface_t{SDL_GetWindowSurface(window.get())};
 
+		auto point = Point{.x = width / 2, .y = height / 2};
+		const Point directions[] = {
+			{.x = -1, .y = 0},
+			{.x = 1, .y = 0},
+			{.x = 0, .y = -1},
+			{.x = 0, .y = 1}
+		};
+
+		std::mt19937_64 rne(std::random_device{}());
+		std::uniform_int_distribution<int> dist(0, 3);
+
 		SDL_Event e;
 		bool quit = false;
 		while (!quit) {
 			while (SDL_PollEvent(&e)) {
 				if (e.type == SDL_QUIT) { quit = true; }
 			}
+			SDL_RenderDrawPoint(renderer.get(), point.x, point.y);
+			Point newpoint;
+			do {
+				newpoint = point + directions[dist(rne)];
+			} while (newpoint.x < 0 or newpoint.x >= width or newpoint.y < 0 or
+			         newpoint.y >= height);
+			point = newpoint;
+
+			SDL_RenderPresent(renderer.get());
 		}
 	}