Mercurial > sdl-ios-xcode
view docs/html/sdlglsetattribute.html @ 1897:c2a27da60b18
Solved the performance problems by introducing the concept of a single-buffered
display, which is a fast path used for the whole-surface SDL 1.2 API.
Solved the flicker problems by implementing a backbuffer in the GDI renderer.
Unfortunately, now using the GDI renderer with a backbuffer and HBITMAPs is
significantly slower than SDL's surface code. *sigh*
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 12 Jul 2006 06:39:26 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_GL_SetAttribute</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_GL_GetAttribute" HREF="sdlglgetattribute.html"><LINK REL="NEXT" TITLE="SDL_GL_SwapBuffers" HREF="sdlglswapbuffers.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="sdlglgetattribute.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlglswapbuffers.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLGLSETATTRIBUTE" ></A >SDL_GL_SetAttribute</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2742" ></A ><H2 >Name</H2 >SDL_GL_SetAttribute -- Set a special SDL/OpenGL attribute</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2745" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2746" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_GL_SetAttribute</B ></CODE >(SDL_GLattr attr, int value);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2752" ></A ><H2 >Description</H2 ><P >Sets the OpenGL <A HREF="sdlglattr.html" >attribute</A > <TT CLASS="PARAMETER" ><I >attr</I ></TT > to <TT CLASS="PARAMETER" ><I >value</I ></TT >. The attributes you set don't take effect until after a call to <A HREF="sdlsetvideomode.html" ><TT CLASS="FUNCTION" >SDL_SetVideoMode</TT ></A >. You should use <A HREF="sdlglgetattribute.html" ><TT CLASS="FUNCTION" >SDL_GL_GetAttribute</TT ></A > to check the values after a <TT CLASS="FUNCTION" >SDL_SetVideoMode</TT > call.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2763" ></A ><H2 >Return Value</H2 ><P >Returns <SPAN CLASS="RETURNVALUE" >0</SPAN > on success, or <SPAN CLASS="RETURNVALUE" >-1</SPAN > on error.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2768" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 ); SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 ); SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); if ( (screen=SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL )) == NULL ) { fprintf(stderr, "Couldn't set GL mode: %s\n", SDL_GetError()); SDL_Quit(); return; }</PRE ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >The <TT CLASS="LITERAL" >SDL_DOUBLEBUF</TT > flag is not required to enable double buffering when setting an OpenGL video mode. Double buffering is enabled or disabled using the SDL_GL_DOUBLEBUFFER attribute.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2774" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlglgetattribute.html" ><TT CLASS="FUNCTION" >SDL_GL_GetAttribute</TT ></A >, <A HREF="sdlglattr.html" >GL Attributes</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="sdlglgetattribute.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="sdlglswapbuffers.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GL_GetAttribute</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_GL_SwapBuffers</TD ></TR ></TABLE ></DIV ></BODY ></HTML >