sdl_setgammaramp(3) [redhat man page]

SDL_SetGammaRamp(3)						 SDL API Reference					       SDL_SetGammaRamp(3)

NAME

       SDL_SetGammaRamp- Sets the color gamma lookup tables for the display

SYNOPSIS

       #include "SDL.h"

       int SDL_SetGammaRamp(Uint16 *redtable, Uint16 *greentable, Uint16 *bluetable);

DESCRIPTION

       Sets  the gamma lookup tables for the display for each color component. Each table is an array of 256 Uint16 values, representing a mapping
       between the input and output for that channel. The input is the index into the array, and the output is the  16-bit  gamma  value  at  that
       index, scaled to the output color precision. You may pass NULL to any of the channels to leave them unchanged.

       This  function  adjusts the gamma based on lookup tables, you can also have the gamma calculated based on a "gamma function" parameter with
       SDL_SetGamma.

       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_SetGamma SDL_GetGammaRamp

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

xgamma(1)						      General Commands Manual							 xgamma(1)

NAME

       xgamma - Alter a monitor's gamma correction for XFree86

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 XFree86 X server video mode extension (XFree86-VidMode-
       Extension).

OPTIONS

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

       -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. If no value for the gamma correction is given xgamma returns the current gamma
	       correction of the display.

       -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

XFree86 						       Version Version 4.3.0							 xgamma(1)