SDL_DisplayFormatAlpha(3SDL API ReferencSDL_DisplayFormatAlpha(3)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 sur-
face of the pixel format and colors of the video frame-
buffer 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
SDL Tue 11 Sep 2001, 2SDL_DisplayFormatAlpha(3)
