docs/man3/SDL_SetColorKey.3
author Sam Lantinga <slouken@libsdl.org>
Wed, 08 Mar 2006 18:30:12 +0000
changeset 1486 9d77fc9d0ace
parent 181 e5bc29de3f0a
child 2283 546f7c1eb755
permissions -rw-r--r--
Re-added C runtime support for Visual C++ 5,6
     1 .TH "SDL_SetColorKey" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
     2 .SH "NAME"
     3 SDL_SetColorKey\- Sets the color key (transparent pixel) in a blittable surface and RLE acceleration\&.
     4 .SH "SYNOPSIS"
     5 .PP
     6 \fB#include "SDL\&.h"
     7 .sp
     8 \fBint \fBSDL_SetColorKey\fP\fR(\fBSDL_Surface *surface, Uint32 flag, Uint32 key\fR);
     9 .SH "DESCRIPTION"
    10 .PP
    11  Sets the color key (transparent pixel) in a blittable surface and enables or disables RLE blit acceleration\&.
    12 .PP
    13 RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i\&.e\&., pixels that match the \fBkey\fR value)\&. The \fBkey\fR must be of the same pixel format as the \fBsurface\fR, \fI\fBSDL_MapRGB\fP\fR is often useful for obtaining an acceptable value\&.
    14 .PP
    15 If \fBflag\fR is \fBSDL_SRCCOLORKEY\fP then \fBkey\fR is the transparent pixel value in the source image of a blit\&.
    16 .PP
    17 If \fBflag\fR is OR\&'d with \fBSDL_RLEACCEL\fP then the surface will be draw using RLE acceleration when drawn with \fISDL_BlitSurface\fR\&. The surface will actually be encoded for RLE acceleration the first time \fISDL_BlitSurface\fR or \fISDL_DisplayFormat\fR is called on the surface\&.
    18 .PP
    19 If \fBflag\fR is 0, this function clears any current color key\&.
    20 .SH "RETURN VALUE"
    21 .PP
    22 This function returns \fB0\fR, or \fB-1\fR if there was an error\&.
    23 .SH "SEE ALSO"
    24 .PP
    25 \fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_DisplayFormat\fP\fR, \fI\fBSDL_MapRGB\fP\fR, \fI\fBSDL_SetAlpha\fP\fR
    26 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01