.TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 

.SH "NAME"

SDL_DisplayFormatAlpha \- Convert a surface to the display format

.SH "SYNOPSIS"

.PP

\fB#include "SDL\&.h"

.sp

\fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR);

.SH "DESCRIPTION"

.PP

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 \fISDL_ConvertSurface\fR

.PP

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\&.

.PP

This function can be used to convert a colourkey to an alpha channel, if the \fBSDL_SRCCOLORKEY\fP 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\&.

.SH "RETURN VALUE"

.PP

If the conversion fails or runs out of memory, it returns \fBNULL\fR

.SH "SEE ALSO"

.PP

\fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR

...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01