NAME

       SDL_SetColorKey - Sets the color key (transparent pixel) in a blittable surface and RLE acceleration.

SYNOPSIS

       #include "SDL.h"

       int SDL_SetColorKey(SDL_Surface *surface, Uint32 flag, Uint32 key);

DESCRIPTION

        Sets  the  color  key  (transparent  pixel)  in  a  blittable  surface  and enables or disables RLE blit
       acceleration.

       RLE acceleration can substantially speed up blitting of images with large horizontal runs of  transparent
       pixels  (i.e., pixels that match the key value). The key must be of the same pixel format as the surface,
       SDL_MapRGB is often useful for obtaining an acceptable value.

       If flag is SDL_SRCCOLORKEY then key is the transparent pixel value in the source image of a blit.

       If flag is OR'd with SDL_RLEACCEL then the surface will be draw using RLE acceleration  when  drawn  with
       SDL_BlitSurface. The surface will actually be encoded for RLE acceleration the first time SDL_BlitSurface
       or SDL_DisplayFormat is called on the surface.

       If flag is 0, this function clears any current color key.

RETURN VALUE

       This function returns 0, or -1 if there was an error.

SEE ALSO

       SDL_BlitSurface, SDL_DisplayFormat, SDL_MapRGB, SDL_SetAlpha