-extern SDL_Surface* screen;
-
-/* 'Stolen' from the SDL documentation.
- * Return the pixel value at (x, y)
- * NOTE: The surface must be locked before calling this!
- */
-Uint32 getpixel(SDL_Surface *surface, int x, int y)
-{
- int bpp = surface->format->BytesPerPixel;
- /* Here p is the address to the pixel we want to retrieve */
- Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
-
- switch(bpp) {
- case 1:
- return *p;
-
- case 2:
- return *(Uint16 *)p;
-
- case 3:
- if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
- return p[0] << 16 | p[1] << 8 | p[2];
- else
- return p[0] | p[1] << 8 | p[2] << 16;
-
- case 4:
- return *(Uint32 *)p;
-
- default:
- return 0; /* shouldn't happen, but avoids warnings */
- }
-}
-
-/* 'Stolen' from the SDL documentation.
- * Set the pixel at (x, y) to the given value
- * NOTE: The surface must be locked before calling this!
- */
-void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
-{
- int bpp = surface->format->BytesPerPixel;
- /* Here p is the address to the pixel we want to set */
- Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
-
- switch(bpp) {
- case 1:
- *p = pixel;
- break;
-
- case 2:
- *(Uint16 *)p = pixel;
- break;
-
- case 3:
- if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
- {
- p[0] = (pixel >> 16) & 0xff;
- p[1] = (pixel >> 8) & 0xff;
- p[2] = pixel & 0xff;
- }
- else
- {
- p[0] = pixel & 0xff;
- p[1] = (pixel >> 8) & 0xff;
- p[2] = (pixel >> 16) & 0xff;
- }
- break;
-
- case 4:
- *(Uint32 *)p = pixel;
- break;
-
- default:
- assert(false);
- }
-}
-
-/* Draw a single pixel on the screen. */
-void drawpixel(int x, int y, Uint32 pixel)
-{
- /* Lock the screen for direct access to the pixels */
- if ( SDL_MUSTLOCK(screen) )
- {
- if ( SDL_LockSurface(screen) < 0 )
- {
- fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError());
- return;
- }
- }
-
- if(!(x < 0 || y < 0 || x > SCREEN_WIDTH || y > SCREEN_HEIGHT))
- putpixel(screen, x, y, pixel);
-
- if ( SDL_MUSTLOCK(screen) )
- {
- SDL_UnlockSurface(screen);
- }
- /* Update just the part of the display that we've changed */
- SDL_UpdateRect(screen, x, y, 1, 1);
-}
-
-/* --- FILL A RECT --- */