SDL_SetColorKey

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SDL Library Documentation
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SDL_SetColorKey

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
  
  
    
    
      
        
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