symbian-qemu-0.9.1-12/libsdl-trunk/docs/man3/SDL_SetGamma.3
author Faisal Memon <faisal.memon@nokia.com>
Fri, 26 Mar 2010 15:45:51 +0000
changeset 69 c9d64fb26f98
parent 1 2fb8b9db1c86
permissions -rw-r--r--
Test program updated to create a blank background surface of the appropriate type. This program needs to be improved by loading a real YUV image so that the algorithm can be confirmed.

.TH "SDL_SetGamma" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetGamma \- Sets the color gamma function for the display
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetGamma\fP\fR(\fBfloat redgamma, float greengamma, float bluegamma\fR);
.SH "DESCRIPTION"
.PP
Sets the "gamma function" for the display of each color component\&. Gamma controls the brightness/contrast of colors displayed on the screen\&. A gamma value of 1\&.0 is identity (i\&.e\&., no adjustment is made)\&.
.PP
This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma adjustment with \fISDL_SetGammaRamp\fR\&.
.PP
Not all display hardware is able to change gamma\&.
.SH "RETURN VALUE"
.PP
Returns -1 on error (or if gamma adjustment is not supported)\&.
.SH "SEE ALSO"
.PP
\fISDL_GetGammaRamp\fR \fISDL_SetGammaRamp\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01