Mercurial > sdl-ios-xcode
view docs/html/sdlsetgammaramp.html @ 885:9f6ad2286011
Date: Wed, 28 Apr 2004 16:52:41 -0400
From: "Damien A"
Subject: testdyngl fix
The test program you included in the latest version of SDL crashes on startup in Window (XP). The reason for this is that OpenGL functions on Windows use the __stdcall calling convention, not the C convention. Placing APIENTRY infront of the * operator solves this problem.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 30 Apr 2004 18:33:30 +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 >