Mercurial > sdl-ios-xcode
view docs/html/sdlsetgammaramp.html @ 1798:49b4b8413734
Date: Tue, 9 May 2006 23:01:49 -0400
From: Mike Frysinger
Subject: [SDL] [patch] fall back to using MAP_PRIVATE with mmap() in fbcon dri
trying to use MAP_SHARED with mmap() on uClinux (aka non-mmu) hosts nowadays
will simply fail since the kernel disallows it ... falling back to using
MAP_PRIVATE on these hosts is acceptable ... as such, ive attached a patch
for the fbcon driver that will fall back to using MAP_PRIVATE if mmap() with
MAP_SHARED failed
going by a grep of MAP_SHARED, the only other drivers that utilize this flag
are video/wscons, video/ps2gs, and sound/dmaaudio ... i dont think these
would appear on a non-mmu host so the patch i wrote is restricted to just
SDL_fbvideo.c ...
-mike
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 10 May 2006 04:05:46 +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 >