Mercurial > sdl-ios-xcode
view docs/html/sdlsetcolorkey.html @ 3957:b1d5b56aa549 SDL-1.2
Date: Mon, 4 Jun 2007 06:17:59 +0000 (UTC)
From: George Gensure <werkt0@gmail.com>
Subject: [SDL] error removal patch for SDL_x11dyn.c
I found that calling SDL_GetError when an error hasn't necessarily occurred is
still reporting problems from loadso regarding dynamic functions in X11. I've
added the following to my local copy to avoid revealing the 'many library
lookup' approach adopted by x11dyn.c:
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Wed, 13 Jun 2007 07:54:10 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetColorKey</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_SaveBMP" HREF="sdlsavebmp.html"><LINK REL="NEXT" TITLE="SDL_SetAlpha" HREF="sdlsetalpha.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="sdlsavebmp.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlsetalpha.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETCOLORKEY" ></A >SDL_SetColorKey</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2045" ></A ><H2 >Name</H2 >SDL_SetColorKey -- Sets the color key (transparent pixel) in a blittable surface and RLE acceleration.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2048" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2049" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_SetColorKey</B ></CODE >(SDL_Surface *surface, Uint32 flag, Uint32 key);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2055" ></A ><H2 >Description</H2 ><P > Sets the color key (transparent pixel) in a blittable surface and enables or disables RLE blit acceleration.</P ><P >RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i.e., pixels that match the <TT CLASS="PARAMETER" ><I >key</I ></TT > value). The <TT CLASS="PARAMETER" ><I >key</I ></TT > must be of the same pixel format as the <TT CLASS="PARAMETER" ><I >surface</I ></TT >, <A HREF="sdlmaprgb.html" ><TT CLASS="FUNCTION" >SDL_MapRGB</TT ></A > is often useful for obtaining an acceptable value.</P ><P >If <TT CLASS="PARAMETER" ><I >flag</I ></TT > is <TT CLASS="LITERAL" >SDL_SRCCOLORKEY</TT > then <TT CLASS="PARAMETER" ><I >key</I ></TT > is the transparent pixel value in the source image of a blit.</P ><P >If <TT CLASS="PARAMETER" ><I >flag</I ></TT > is OR'd with <TT CLASS="LITERAL" >SDL_RLEACCEL</TT > then the surface will be draw using RLE acceleration when drawn with <A HREF="sdlblitsurface.html" >SDL_BlitSurface</A >. The surface will actually be encoded for RLE acceleration the first time <A HREF="sdlblitsurface.html" >SDL_BlitSurface</A > or <A HREF="sdldisplayformat.html" >SDL_DisplayFormat</A > is called on the surface.</P ><P >If <TT CLASS="PARAMETER" ><I >flag</I ></TT > is 0, this function clears any current color key.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2076" ></A ><H2 >Return Value</H2 ><P >This function returns <SPAN CLASS="RETURNVALUE" >0</SPAN >, or <SPAN CLASS="RETURNVALUE" >-1</SPAN > if there was an error.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2081" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlblitsurface.html" ><TT CLASS="FUNCTION" >SDL_BlitSurface</TT ></A >, <A HREF="sdldisplayformat.html" ><TT CLASS="FUNCTION" >SDL_DisplayFormat</TT ></A >, <A HREF="sdlmaprgb.html" ><TT CLASS="FUNCTION" >SDL_MapRGB</TT ></A >, <A HREF="sdlsetalpha.html" ><TT CLASS="FUNCTION" >SDL_SetAlpha</TT ></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="sdlsavebmp.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="sdlsetalpha.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_SaveBMP</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_SetAlpha</TD ></TR ></TABLE ></DIV ></BODY ></HTML >