sdl_setgamma(3) [redhat man page]

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)

xgamma(1)						      General Commands Manual							 xgamma(1)

NAME

       xgamma - Alter a monitor's gamma correction through the X server

SYNOPSIS

       xgamma [-display display] [-screen screen] [-quiet] [-gamma f.f | [[-rgamma f.f] [-ggamma f.f] [-bgamma f.f]]]

DESCRIPTION

       xgamma allows X users to query and alter the gamma correction of a monitor via the X video mode extension (XFree86-VidModeExtension).

       If no value for the gamma correction is given via the -gamma or -rgamma/-ggamma/-bgamma options, xgamma prints the current gamma correction
       of the display.

OPTIONS

       -display display
	       This argument allows you to specify the server to connect to; see X(7).

       -screen screen
	       When multiple displays are configured as a single logical display, this option allows you to select the screen you wish to change.

       -quiet  Silence the normal output of xgamma

       -help   Print out the `Usage:' command syntax summary.

       -gamma f.f
	       The gamma correction can either be defined as a single value, or separately for the red, green and blue components.  This  argument
	       specifies the gamma correction as a single value.

       -rgamma f.f
	       This argument specifies the red component of the gamma correction.

       -ggamma f.f
	       This argument specifies the green component of the gamma correction.

       -bgamma f.f
	       This argument specifies the blue component of the gamma correction.

ENVIRONMENT

       DISPLAY To get default host and display number.

BUGS

       This  client  changes the internal values of the gamma correction for the Xserver. Whether or not these values are respected depends on the
       video drivers.

       The gamma values are passed to the Xserver with 3 decimal places of accuracy.

SEE ALSO

       xvidtune(1)

AUTHORS

       Kaleb S. Keithley, X Consortium.
       David Dawes, David Bateman

X Version 11							   xgamma 1.0.2 							 xgamma(1)