#include <stdlib.h>
#include "SDL.h"

#define SCREEN_WIDTH (640)
#define SCREEN_HEIGHT (480)

SDL_Surface *screen;

/*
 * From http://www.libsdl.org/intro.en/usingvideo.html
 */
void
putpixel(unsigned x, unsigned y, Uint8 R, Uint8 G, Uint8 B)
{
    Uint32 color = SDL_MapRGB(screen->format, R, G, B);

    if ( SDL_MUSTLOCK(screen) ) {
        if ( SDL_LockSurface(screen) < 0 ) {
            return;
        }
    }
    switch (screen->format->BytesPerPixel) {
        case 1: { /* Assuming 8-bpp */
            Uint8 *bufp;

            bufp = (Uint8 *)screen->pixels + y*screen->pitch + x;
            *bufp = color;
        }
        break;

        case 2: { /* Probably 15-bpp or 16-bpp */
            Uint16 *bufp;

            bufp = (Uint16 *)screen->pixels + y*screen->pitch/2 + x;
            *bufp = color;
        }
        break;

        case 3: { /* Slow 24-bpp mode, usually not used */
            Uint8 *bufp;

            bufp = (Uint8 *)screen->pixels + y*screen->pitch + x;
            *(bufp+screen->format->Rshift/8) = R;
            *(bufp+screen->format->Gshift/8) = G;
            *(bufp+screen->format->Bshift/8) = B;
        }
        break;

        case 4: { /* Probably 32-bpp */
            Uint32 *bufp;

            bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
            *bufp = color;
        }
        break;
    }
    if ( SDL_MUSTLOCK(screen) ) {
        SDL_UnlockSurface(screen);
    }
    SDL_UpdateRect(screen, x, y, 1, 1);
}

int
init_video(char doublebuf, char fullscreen)
{
	Uint32 flags = 0;
	if (doublebuf)
		flags |= doublebuf;
	if (fullscreen)
		flags |= SDL_FULLSCREEN;
	if (SDL_Init(SDL_INIT_VIDEO) != 0) {
		fprintf(stderr, "Unable to initialize SDL: %s\n", SDL_GetError());
		return 0;
	}
	atexit(SDL_Quit);
	screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 16, flags);
	if (screen == NULL) {
		fprintf(stderr, "Unable to set video mode: %s\n", SDL_GetError());
		return 0;
	}
	SDL_WM_SetCaption("Window Title", "Icon Title");
	return 1;
}