redhat man page for sdl_setgamma

SDL_SetGamma(3) 						 SDL API Reference						   SDL_SetGamma(3)

NAME
       SDL_SetGamma- Sets the color gamma function for the display

SYNOPSIS
       #include "SDL.h"

       int SDL_SetGamma(float redgamma, float greengamma, float bluegamma);

DESCRIPTION
       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).

       This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma  adjustment  with
       SDL_SetGammaRamp.

       Not all display hardware is able to change gamma.

RETURN VALUE
       Returns -1 on error (or if gamma adjustment is not supported).

SEE ALSO
       SDL_GetGammaRamp SDL_SetGammaRamp

SDL
							      Tue 11 Sep 2001, 23:01						   SDL_SetGamma(3)