view docs/man3/SDL_SetGammaRamp.3 @ 614:0b4c3f5ff63d

Date: Wed, 9 Apr 2003 18:21:33 -0230 From: Stephen Anthony <stephena@roadrunner.nf.net> Subject: [SDL] First patch concerning 4.3 and refresh rates OK, here's my first draft of the patch for the above subject. A short explanation: X 4.3 introduces many more modelines than older versions. This would be fine, except it introduces many modes with the *same* resolution but different refresh rates. And SDL won't necessarily pick the one with the highest refresh rate. So this patch restores SDL to X 4.2 functionality. That is, there is only ever one refresh rate *per* resolution, and it is the highest possible. This functionality can be totally disabled by using the environment variable 'SDL_VIDEO_X11_USE_ALL_MODES' set equal to 1.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 20 Apr 2003 05:36:52 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.TH "SDL_SetGammaRamp" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetGammaRamp\- Sets the color gamma lookup tables for the display
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetGammaRamp\fP\fR(\fBUint16 *redtable, Uint16 *greentable, Uint16 *bluetable\fR);
.SH "DESCRIPTION"
.PP
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\&.
.PP
This function adjusts the gamma based on lookup tables, you can also have the gamma calculated based on a "gamma function" parameter with \fISDL_SetGamma\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_SetGamma\fR \fISDL_GetGammaRamp\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01