Mercurial > sdl-ios-xcode
view docs/html/sdlsetgamma.html @ 939:c7c04f811994
Date: Tue, 01 Jun 2004 15:27:44 +0300
From: Martin_Storsj
Subject: Update for dynamic loading of ALSA
I sent you a patch a few months ago which enables SDL to load ALSA
dynamically. Now I've finally got time to tweak this yet some more. I've
added code from alsa.m4 (from alsa's dev package) to acinclude.m4, and
made the detection of the alsa library name a bit better. I've also
fixed up the loading versioned symbols with dlvsym, so that it falls
back to dlsym.
I wouldn't say the configure script is complete yet, but this is how far
I've come this time, and I'm no expert at those things.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 21 Aug 2004 04:20:00 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetGamma</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_SetPalette" HREF="sdlsetpalette.html"><LINK REL="NEXT" TITLE="SDL_GetGammaRamp" HREF="sdlgetgammaramp.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="sdlsetpalette.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgetgammaramp.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETGAMMA" ></A >SDL_SetGamma</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN1569" ></A ><H2 >Name</H2 >SDL_SetGamma -- Sets the color gamma function for the display</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN1572" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN1573" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_SetGamma</B ></CODE >(float redgamma, float greengamma, float bluegamma);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1579" ></A ><H2 >Description</H2 ><P >Sets the "gamma function" for the display of each color component. Gamma controls the brightness/contrast of colors displayed on the screen. A gamma value of <TT CLASS="CONSTANT" >1.0</TT > is identity (i.e., no adjustment is made).</P ><P >This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma adjustment with <A HREF="sdlsetgammaramp.html" >SDL_SetGammaRamp</A >.</P ><P >Not all display hardware is able to change gamma.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1586" ></A ><H2 >Return Value</H2 ><P >Returns -1 on error (or if gamma adjustment is not supported).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN1589" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlgetgammaramp.html" >SDL_GetGammaRamp</A > <A HREF="sdlsetgammaramp.html" >SDL_SetGammaRamp</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="sdlsetpalette.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="sdlgetgammaramp.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SetPalette</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_GetGammaRamp</TD ></TR ></TABLE ></DIV ></BODY ></HTML >