1 files changed, 131 insertions, 0 deletions
diff --git a/in_practice/breakout/linux.c b/in_practice/breakout/linux.c
new file mode 100644
index 0000000..2150ed9
--- /dev/null
+++ b/in_practice/breakout/linux.c
@@ -0,0 +1,131 @@
+#include "game.h"
+#include "sys.h"
+
+#include <SDL3/SDL.h>
+#include <GL/glew.h>
+
+#define DEBUG 1
+
+typedef struct {
+	SDL_Window *window;
+	i32 width;
+	i32 height;
+	SDL_Renderer *renderer;
+	u64 last_counter;
+	f32 dt;
+} sdl_context_t;
+
+static sdl_context_t init_sdl(i32 width, i32 height, i32 debug)
+{
+	sdl_context_t ctx = {0};
+	ctx.width = width;
+	ctx.height = height;
+	SDL_Init(SDL_INIT_VIDEO);
+	u64 flags = SDL_WINDOW_OPENGL;
+	SDL_CreateWindowAndRenderer("breakout", ctx.width, ctx.height, flags, &ctx.window, &ctx.renderer);
+	if (debug)
+		SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
+	SDL_GLContext glctx = SDL_GL_CreateContext(ctx.window);
+	SDL_GL_MakeCurrent(ctx.window, glctx);
+	SDL_GL_SetSwapInterval(0);
+	ctx.last_counter = SDL_GetPerformanceCounter();
+	glewInit();
+	return ctx;
+}
+
+static void process_sdl_key(input_t *input, i32 scancode, i32 pressed)
+{
+	switch (scancode) {
+	case SDL_SCANCODE_ESCAPE:
+		input->escape.current = pressed;
+		break;
+	case SDL_SCANCODE_RIGHT:
+		input->right.current = pressed;
+		break;
+	case SDL_SCANCODE_LEFT:
+		input->left.current = pressed;
+		break;
+	case SDL_SCANCODE_SPACE:
+		input->space.current = pressed;
+		break;
+	default:
+		break;
+	}
+}
+
+static void process_sdl_events(game_t *game)
+{
+	SDL_Event event;
+	while (SDL_PollEvent(&event)) {
+		switch (event.type) {
+		case SDL_EVENT_KEY_DOWN:
+		case SDL_EVENT_KEY_UP:
+			process_sdl_key(&game->input, event.key.scancode, event.key.down);
+		default:
+			break;
+		}
+	}
+}
+
+static f32 get_elapsed(u64 last_counter)
+{
+	u64 frequency = SDL_GetPerformanceFrequency();
+	u64 current_counter = SDL_GetPerformanceCounter();
+	return (f32)(current_counter - last_counter) / (f32)frequency;
+}
+
+static void lock_framerate_sdl(sdl_context_t *ctx, i32 fps)
+{
+	f32 elapsed = get_elapsed(ctx->last_counter) * 1000.0f;
+	f32 target = 1000.0f / (f32)fps;
+	f32 sleep = target - elapsed;
+	if (sleep > 0)
+		SDL_Delay((u32)sleep);
+	do {
+		elapsed = get_elapsed(ctx->last_counter) * 1000.0f;
+	} while (elapsed < target);
+	ctx->dt = get_elapsed(ctx->last_counter);
+	ctx->last_counter = SDL_GetPerformanceCounter();
+}
+
+static void fps_info(f32 dt, i32 again)
+{
+	static f32 time = 0;
+	static i32 lastsec = 0;
+	static f32 sumdt = 0;
+	static i32 sumfps = 0;
+	static f32 frame_count = 0;
+	time += dt;
+	sumdt += dt;
+	sumfps += (i32)(1.0f / dt);
+	frame_count++;
+	i32 sec = (i32)time;
+	if (sec != 0 && sec % again == 0) {
+		if (lastsec != sec) {
+			f32 mean_dt = sumdt / frame_count;
+			f32 mean_fps = sumfps / frame_count;
+			info("time: %d dt: %f fps: %f", sec, mean_dt, mean_fps);
+			lastsec = sec;
+			sumdt = 0;
+			sumfps = 0;
+			frame_count = 0;
+		}
+	}
+}
+
+i32 main(void)
+{
+	sdl_context_t ctx = init_sdl(1600, 800, DEBUG);
+	game_t game = init_game(ctx.width, ctx.height);
+	while (game.running) {
+		process_sdl_events(&game);
+		process_input(&game);
+		update_game(&game, ctx.dt);
+		update_input(&game.input);
+		lock_framerate_sdl(&ctx, 60);
+		fps_info(ctx.dt, 10);
+		render_game(game);
+		SDL_GL_SwapWindow(ctx.window);
+	}
+	return 0;
+}