void PutPixel(SDL_Surface *surf, int x, int y, Uint32 pixel)
{
   //This function replaces the pixel on x,y position with color: pixel
   int bpp = surf->format->BytesPerPixel;
   Uint8 *p = (Uint8 *)surf->pixels + y * surf->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;
   }
}




Uint32 GetPixel(SDL_Surface *surf, int x, int y)
{
   //This function returns pixels color
   int bpp = surf->format->BytesPerPixel;
   Uint8 *p = (Uint8 *)surf->pixels + y * surf->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;
   }
}