NAME

       SDL_DisplayFormatAlpha - Convert a surface to the display format

SYNOPSIS

       #include "SDL.h"

       SDL_Surface *SDL_DisplayFormatAlpha(SDL_Surface *surface);

DESCRIPTION

       This  function  takes  a  surface  and  copies it to a new surface of the pixel format and
       colors of the video framebuffer plus an alpha channel, suitable for fast blitting onto the
       display surface. It calls SDL_ConvertSurface

       If  you want to take advantage of hardware colorkey or alpha blit acceleration, you should
       set the colorkey and alpha value before calling this function.

       This  function  can  be  used  to  convert  a  colourkey  to  an  alpha  channel,  if  the
       SDL_SRCCOLORKEY flag is set on the surface. The generated surface will then be transparent
       (alpha=0) where the pixels match the colourkey, and opaque (alpha=255) elsewhere.

RETURN VALUE

       If the conversion fails or runs out of memory, it returns NULL

SEE ALSO

       SDL_ConvertSurface, SDL_SetAlpha, SDL_SetColorKey, SDL_DisplayFormat, SDL_Surface