view docs/man3/SDL_SetGammaRamp.3 @ 1795:398ac0f88e4d

Fixed bug #220 The AltiVec blitters don't compile, since they require __VEC__ to be enabled in order for the compiler to understand "vector" and friends (i.e. do AltiVec) But you don't want to turn AltiVec on globally, since then the code would only run on a G4 (there are already runtime tests, before using the AltiVec variants) The solution here is to enable AltiVec locally, for the actual AltiVec code.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 09 May 2006 15:09:47 +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