docs/man3/SDL_DisplayFormatAlpha.3
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parent 3351 8e0182c236d8
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     1 .TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
       
     2 .SH "NAME"
       
     3 SDL_DisplayFormatAlpha \- Convert a surface to the display format
       
     4 .SH "SYNOPSIS"
       
     5 .PP
       
     6 \fB#include "SDL\&.h"
       
     7 .sp
       
     8 \fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR);
       
     9 .SH "DESCRIPTION"
       
    10 .PP
       
    11 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
       
    12 .PP
       
    13 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\&.
       
    14 .PP
       
    15 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\&.
       
    16 .SH "RETURN VALUE"
       
    17 .PP
       
    18 If the conversion fails or runs out of memory, it returns \fBNULL\fR
       
    19 .SH "SEE ALSO"
       
    20 .PP
       
    21 \fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR
       
    22 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01