sdl2-hello-world/src/packages/game/main.c

#include <SDL.h>
#include <stdbool.h>
#include <stdio.h>

#include "IZ_action.h"
#include "IZ_app.h"

int main(int argc, char* args[]) {
	SDL_Window* window = NULL;
	SDL_Surface* screen_surface = NULL;
	IZ_App app;

	IZ_InitializeApp(&app);

	if (SDL_Init(
		SDL_INIT_VIDEO
		| SDL_INIT_GAMECONTROLLER
		| SDL_INIT_EVENTS
	) < 0) {
		printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
		return -1;
	}

	window = SDL_CreateWindow(
		APP_NAME,
		SDL_WINDOWPOS_CENTERED,
		SDL_WINDOWPOS_CENTERED,
		app.config.video.width,
		app.config.video.height,
		SDL_WINDOW_SHOWN
	);

	if (window == NULL) {
		printf("Window could not be created! SDL_Error: %s\n", SDL_GetError());
		return -2;
	}

	bool quit = false;
	SDL_Event e;
	screen_surface = SDL_GetWindowSurface(window);

	IZ_Action action = 0;
	while (!quit) {
		SDL_FillRect(screen_surface, NULL, SDL_MapRGB(screen_surface->format, 0x00, 0x00, 0x00));
		uint64_t ticks = SDL_GetTicks64();
		for (uint8_t i = 0; i < 64; i += 1) {
			const uint8_t column = (64 - i) % 32;
			const uint8_t row = i / 32;
			const uint64_t bitflag = (0x1lu << i);
			const uint8_t size = 4;
			if (ticks & bitflag) {
				SDL_FillRect(screen_surface, &(SDL_Rect) {
					column * size,
					app.config.video.height - ((row + 1) * size),
					size,
					size
					}, SDL_MapRGB(screen_surface->format, 0x00, 0xff, 0xff));
			}
		}

		while (SDL_PollEvent(&e) != 0) {
			if (e.type == SDL_QUIT) {
				quit = true;
			}

			for (uint8_t i = 0; i < CONTROLS; i += 1) {
				// TODO do same for gamepad
				if (e.key.keysym.sym == app.config.controls[0].keyboard[i]) {
					const uint16_t bitflag = (0x1 << i);
					if (e.type == SDL_KEYDOWN) {
						action |= bitflag;
					} else if (e.type == SDL_KEYUP) {
						action &= ~bitflag;
					}
				}
			}

			for (unsigned char i = 0; i < CONTROLS; i += 1) {
				const uint8_t column = i % 4;
				const uint8_t row = i / 4;
				const IZ_Action  bitflag = (0x1 << i);
				const uint8_t size = 4;
				if (action & bitflag) {
					SDL_FillRect(screen_surface, &(SDL_Rect) {
						column * size,
						row * size,
						size,
						size
					}, SDL_MapRGB(screen_surface->format, 0xff, 0xff, 0x00));
				}
			}

			SDL_UpdateWindowSurface(window);
		}
	}
	SDL_DestroyWindow(window);
	SDL_Quit();

	return 0;
}