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;
	}

	screen_surface = SDL_GetWindowSurface(window);

	bool quit = false;
	SDL_Event e;

	while (true) {
		uint64_t ticks = SDL_GetTicks64();

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

			// Handle joystick events
			for (uint8_t current_player = 0; current_player < PLAYERS; current_player += 1) {
				if (e.type == SDL_JOYDEVICEADDED) {
					if (SDL_NumJoysticks() <= PLAYERS && !app.assigned_joysticks[current_player]) {
						app.assigned_joysticks[current_player] = SDL_JoystickOpen(e.jdevice.which);
					}
				}

				if (e.type == SDL_JOYDEVICEREMOVED) {
					if (
						app.assigned_joysticks[current_player]
						&& SDL_JoystickInstanceID(app.assigned_joysticks[current_player]) == e.jdevice.which
					) {
						app.assigned_joysticks[current_player] = NULL;
					}
				}

				if (e.type == SDL_JOYAXISMOTION) {
					if (e.jaxis.axis == 0 || e.jaxis.axis == 3) {
						app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_RIGHT);
						app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_LEFT);
						if (e.jaxis.value > app.config.input.gamepad_axis_threshold) {
							app.actions[current_player] |= (0x1 << IZ_ACTION_INDEX_RIGHT);
						} else if (e.jaxis.value <= -app.config.input.gamepad_axis_threshold) {
							app.actions[current_player] |= (0x1 << IZ_ACTION_INDEX_LEFT);
						}
					}
					if (e.jaxis.axis == 1 || e.jaxis.axis == 4) {
						app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_UP);
						app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_DOWN);
						if (e.jaxis.value > app.config.input.gamepad_axis_threshold) {
							app.actions[current_player] |= (0x1 << IZ_ACTION_INDEX_DOWN);
						} else if (e.jaxis.value <= -app.config.input.gamepad_axis_threshold) {
							app.actions[current_player] |= (0x1 << IZ_ACTION_INDEX_UP);
						}
					}
				}

				if (e.type == SDL_JOYHATMOTION) {
					app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_UP);
					app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_RIGHT);
					app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_DOWN);
					app.actions[current_player] &= ~(0x1 << IZ_ACTION_INDEX_LEFT);
					if (e.jhat.value != 0) {
						app.actions[current_player] |= e.jhat.value;
					}
				}
			}

			// Handle keyboard events
			for (uint8_t current_player = 0; current_player < PLAYERS; current_player += 1) {
				for (uint8_t i = 0; i < CONTROLS; i += 1) {
					if (e.key.keysym.sym == app.config.controls[current_player].keyboard[i]) {
						const uint16_t bitflag = (0x1 << i);
						if (e.type == SDL_KEYDOWN) {
							app.actions[current_player] |= bitflag;
						} else if (e.type == SDL_KEYUP) {
							app.actions[current_player] &= ~bitflag;
						}
					}

					if (i >= 4) {
						if (e.jbutton.button == app.config.controls[current_player].gamepad[i]) {
							const uint16_t bitflag = (0x1 << i);
							if (e.type == SDL_JOYBUTTONDOWN) {
								app.actions[current_player] |= bitflag;
							} else if (e.type == SDL_JOYBUTTONUP) {
								app.actions[current_player] &= ~bitflag;
							}
						}
					}
				}
			}
		}

		if (quit) {
			break;
		}

		if (ticks - app.video_update_at > 1000 / app.config.video.max_fps) {
			// Update window
			SDL_FillRect(screen_surface, NULL, SDL_MapRGB(screen_surface->format, 0x00, 0x00, 0x00));

			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));
				}
			}

			for (uint8_t current_player = 0; current_player < PLAYERS; current_player += 1) {
				for (uint8_t 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 (app.actions[current_player] & bitflag) {
						SDL_FillRect(screen_surface, &(SDL_Rect) {
							column * size,
							row * size,
							size,
							size
						}, SDL_MapRGB(screen_surface->format, 0xff, 0xff, 0x00));
					}
				}
			}
			SDL_UpdateWindowSurface(window);

			app.video_update_at = ticks;
		}
	}
	SDL_DestroyWindow(window);
	SDL_Quit();

	return 0;
}