Mercurial > sdl-ios-xcode
view docs/html/sdlsetgammaramp.html @ 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 | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetGammaRamp</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Video" HREF="video.html"><LINK REL="PREVIOUS" TITLE="SDL_GetGammaRamp" HREF="sdlgetgammaramp.html"><LINK REL="NEXT" TITLE="SDL_MapRGB" HREF="sdlmaprgb.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlgetgammaramp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlmaprgb.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETGAMMARAMP" ></A >SDL_SetGammaRamp</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1624" ></A ><H2 >Name</H2 >SDL_SetGammaRamp -- Sets the color gamma lookup tables for the display</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1627" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1628" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_SetGammaRamp</B ></CODE >(Uint16 *redtable, Uint16 *greentable, Uint16 *bluetable);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1634" ></A ><H2 >Description</H2 ><P >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.</P ><P >This function adjusts the gamma based on lookup tables, you can also have the gamma calculated based on a "gamma function" parameter with <A HREF="sdlsetgamma.html" >SDL_SetGamma</A >.</P ><P >Not all display hardware is able to change gamma.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1640" ></A ><H2 >Return Value</H2 ><P >Returns -1 on error (or if gamma adjustment is not supported).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1643" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlsetgamma.html" >SDL_SetGamma</A > <A HREF="sdlgetgammaramp.html" >SDL_GetGammaRamp</A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlgetgammaramp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlmaprgb.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GetGammaRamp</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="video.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_MapRGB</TD ></TR ></TABLE ></DIV ></BODY ></HTML >