sdl.cpp

#include <SDL.h> // include SDL header

int main(int argc, char* argv[])
{
    SDL_Surface *screen; // even with SDL2, we can still bring ancient code back
    SDL_Window *window;
    SDL_Surface *image;

    SDL_Init(SDL_INIT_VIDEO); // init video

    // create the window like normal
    window = SDL_CreateWindow("SDL2 Example", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);

    // but instead of creating a renderer, we can draw directly to the screen
    screen = SDL_GetWindowSurface(window);

    int format = screen->format->format;

    printf("%d %d %d %d\n", SDL_PIXELTYPE(format), SDL_PIXELORDER(format), SDL_PIXELLAYOUT(format), SDL_BITSPERPIXEL(format));
    printf("%d %d %d %d\n", SDL_BYTESPERPIXEL(format), SDL_ISPIXELFORMAT_INDEXED(format), SDL_ISPIXELFORMAT_ALPHA(format), SDL_ISPIXELFORMAT_FOURCC(format));

    printf("blend mode result: %d\n", SDL_SetSurfaceBlendMode(screen, SDL_BLENDMODE_BLEND));

    SDL_Surface *surface;
    Uint32 rmask, gmask, bmask, amask;

    /* SDL interprets each pixel as a 32-bit number, so our masks must depend
       on the endianness (byte order) of the machine */
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
    rmask = 0xff000000;
    gmask = 0x00ff0000;
    bmask = 0x0000ff00;
    amask = 0x000000ff;
#else
    rmask = 0x000000ff;
    gmask = 0x0000ff00;
    bmask = 0x00ff0000;
    amask = 0xff000000;
#endif

    surface = SDL_CreateRGBSurface(0, 100, 100, 32,
                                   rmask, gmask, bmask, amask);
    if(surface == NULL) {
      fprintf(stderr, "CreateRGBSurface failed: %s\n", SDL_GetError());
      exit(1);
    }


    SDL_FillRect(surface, NULL, SDL_MapRGBA(surface->format, 255, 0, 0, 128));


    SDL_BlitSurface(surface, NULL, screen, NULL);




    // let's just show some classic code for reference
    //    image = SDL_LoadBMP("box.bmp"); // loads image
    //    SDL_BlitSurface(image, NULL, screen, NULL); // blit it to the screen
    //    SDL_FreeSurface(image);


    // this works just like SDL_Flip() in SDL 1.2
    SDL_UpdateWindowSurface(window);

    // show image for 2 seconds
    SDL_Delay(4000);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}