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view docs/html/sdlsetgammaramp.html @ 1550:31c2b8e4885e
Fixed bug #166
From the autoconf obsolete macros documentation:
Macro: AC_CANONICAL_SYSTEM
Determine the system type and set output variables to the names of the canonical system types. See section Getting the Canonical System Type, for details about the variables this macro sets.
The user is encouraged to use either AC_CANONICAL_BUILD, or AC_CANONICAL_HOST, or AC_CANONICAL_TARGET, depending on the needs. Using AC_CANONICAL_TARGET is enough to run the two other macros.
From the documentation for the canonical environments:
case $target in
i386-*-mach* | i386-*-gnu*)
obj_format=aout emulation=mach bfd_gas=yes ;;
i960-*-bout) obj_format=bout ;;
esac
Note that the above example uses $target because it's taken from a tool which can be built on some architecture ($build), run on another ($host), but yet handle data for a third architecture ($target). Such tools are usually part of a compiler suite, they generate code for a specific $target.
However $target should be meaningless for most packages. If you want to base a decision on the system where your program will be run, make sure you use the $host variable.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 19 Mar 2006 05:27:22 +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 >