06-Moving-Text.c

#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <SDL2/SDL_render.h>
#include <SDL2/SDL_ttf.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define WINDOW_TITLE "06 Moving Text"
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
#define IMAGE_FLAGS IMG_INIT_PNG
#define TEXT_SIZE 80

struct Game {
    SDL_Window *window;
    SDL_Renderer *renderer;
    SDL_Texture *background;
    TTF_Font *text_font;
    SDL_Color text_color;
    SDL_Rect text_rect;
    SDL_Texture *text_image;
    int text_xvel;
    int text_yvel;
};

void game_cleanup(struct Game *game, int exit_status);
bool load_media(struct Game *game);
bool sdl_initialize(struct Game *game);
void text_update(struct Game *game);

int main() {
    struct Game game = {
        .window = NULL,
        .renderer = NULL,
        .background = NULL,
        .text_font = NULL,
        .text_color = {255, 255, 255, 255},
        .text_rect = {100, 0, 0, 0},
        .text_image = NULL,
        .text_xvel = 3,
        .text_yvel = 3,
    };

    if (sdl_initialize(&game)) {
        game_cleanup(&game, EXIT_FAILURE);
    }

    if (load_media(&game)) {
        game_cleanup(&game, EXIT_FAILURE);
    }

    while (true) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            switch (event.type) {
            case SDL_QUIT:
                game_cleanup(&game, EXIT_SUCCESS);
                break;
            case SDL_KEYDOWN:
                switch (event.key.keysym.scancode) {
                case SDL_SCANCODE_ESCAPE:
                    game_cleanup(&game, EXIT_SUCCESS);
                    break;
                case SDL_SCANCODE_SPACE:
                    SDL_SetRenderDrawColor(game.renderer, rand() % 256,
                                           rand() % 256, rand() % 256, 255);
                    break;
                default:
                    break;
                }
            default:
                break;
            }
        }

        text_update(&game);

        SDL_RenderClear(game.renderer);

        SDL_RenderCopy(game.renderer, game.background, NULL, NULL);

        SDL_RenderCopy(game.renderer, game.text_image, NULL, &game.text_rect);

        SDL_RenderPresent(game.renderer);

        SDL_Delay(16);
    }

    game_cleanup(&game, EXIT_SUCCESS);

    return 0;
}

void game_cleanup(struct Game *game, int exit_status) {
    SDL_DestroyTexture(game->text_image);
    TTF_CloseFont(game->text_font);
    SDL_DestroyTexture(game->background);
    SDL_DestroyRenderer(game->renderer);
    SDL_DestroyWindow(game->window);
    TTF_Quit();
    IMG_Quit();
    SDL_Quit();
    exit(exit_status);
}

bool sdl_initialize(struct Game *game) {
    if (SDL_Init(SDL_INIT_EVERYTHING)) {
        fprintf(stderr, "Error initializing SDL: %s\n", SDL_GetError());
        return true;
    }

    int img_init = IMG_Init(IMAGE_FLAGS);
    if ((img_init & IMAGE_FLAGS) != IMAGE_FLAGS) {
        fprintf(stderr, "Error initializing SDL_image: %s\n", IMG_GetError());
        return true;
    }

    if (TTF_Init()) {
        fprintf(stderr, "Error initializing SDL_ttf: %s\n", IMG_GetError());
        return true;
    }

    game->window = SDL_CreateWindow(WINDOW_TITLE, SDL_WINDOWPOS_CENTERED,
                                    SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH,
                                    SCREEN_HEIGHT, 0);
    if (!game->window) {
        fprintf(stderr, "Error creating window: %s\n", SDL_GetError());
        return true;
    }

    game->renderer = SDL_CreateRenderer(game->window, -1, 0);
    if (!game->renderer) {
        fprintf(stderr, "Error creating renderer: %s\n", SDL_GetError());
        return true;
    }

    srand((unsigned)time(NULL));

    return false;
}

bool load_media(struct Game *game) {
    game->background = IMG_LoadTexture(game->renderer, "images/background.png");
    if (!game->background) {
        fprintf(stderr, "Error creating Texture: %s\n", IMG_GetError());
        return true;
    }

    game->text_font = TTF_OpenFont("fonts/freesansbold.ttf", TEXT_SIZE);
    if (!game->text_font) {
        fprintf(stderr, "Error creating Font: %s\n", TTF_GetError());
        return true;
    }

    SDL_Surface *surface =
        TTF_RenderText_Blended(game->text_font, "SDL", game->text_color);
    if (!surface) {
        fprintf(stderr, "Error creating Surface: %s\n", SDL_GetError());
        return true;
    }
    game->text_rect.w = surface->w;
    game->text_rect.h = surface->h;
    game->text_image = SDL_CreateTextureFromSurface(game->renderer, surface);
    SDL_FreeSurface(surface);
    if (!game->text_image) {
        fprintf(stderr, "Error creating Texture: %s\n", SDL_GetError());
        return true;
    }

    return false;
}

void text_update(struct Game *game) {
    game->text_rect.x += game->text_xvel;
    game->text_rect.y += game->text_yvel;
    if (game->text_rect.x + game->text_rect.w > SCREEN_WIDTH) {
        game->text_xvel = -3;
    }
    if (game->text_rect.x < 0) {
        game->text_xvel = 3;
    }
    if (game->text_rect.y + game->text_rect.h > SCREEN_HEIGHT) {
        game->text_yvel = -3;
    }
    if (game->text_rect.y < 0) {
        game->text_yvel = 3;
    }
}