Mercurial > sdl-ios-xcode
view docs/html/sdlglgetprocaddress.html @ 3958:85b6fb6a5e3c SDL-1.2
Actually, this is a better fix...clear the error state once if everything we
need loaded; it's more efficient, and works even if the last unnecessary
xrandr symbol failed to load. Otherwise, leave the original loadso error, so
the end user can find out what symbol failed.
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Wed, 13 Jun 2007 08:00:10 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_GL_GetProcAddress</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_LoadLibrary" HREF="sdlglloadlibrary.html"><LINK REL="NEXT" TITLE="SDL_GL_GetAttribute" HREF="sdlglgetattribute.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="sdlglloadlibrary.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlglgetattribute.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLGLGETPROCADDRESS" ></A >SDL_GL_GetProcAddress</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN2678" ></A ><H2 >Name</H2 >SDL_GL_GetProcAddress -- Get the address of a GL function</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN2681" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN2682" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >void *<B CLASS="FSFUNC" >SDL_GL_GetProcAddress</B ></CODE >(const char* proc);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2688" ></A ><H2 >Description</H2 ><P >Returns the address of the GL function <TT CLASS="PARAMETER" ><I >proc</I ></TT >, or <SPAN CLASS="RETURNVALUE" >NULL</SPAN > if the function is not found. If the GL library is loaded at runtime, with <A HREF="sdlglloadlibrary.html" ><TT CLASS="FUNCTION" >SDL_GL_LoadLibrary</TT ></A >, then <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >all</I ></SPAN > GL functions must be retrieved this way. Usually this is used to retrieve function pointers to OpenGL extensions.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2696" ></A ><H2 >Example</H2 ><PRE CLASS="PROGRAMLISTING" >typedef void (*GL_ActiveTextureARB_Func)(unsigned int); GL_ActiveTextureARB_Func glActiveTextureARB_ptr = 0; int has_multitexture=1; . . . /* Get function pointer */ glActiveTextureARB_ptr=(GL_ActiveTextureARB_Func) SDL_GL_GetProcAddress("glActiveTextureARB"); /* Check for a valid function ptr */ if(!glActiveTextureARB_ptr){ fprintf(stderr, "Multitexture Extensions not present.\n"); has_multitexture=0; } . . . . if(has_multitexture){ glActiveTextureARB_ptr(GL_TEXTURE0_ARB); . . } else{ . . }</PRE ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN2699" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlglloadlibrary.html" ><TT CLASS="FUNCTION" >SDL_GL_LoadLibrary</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="sdlglloadlibrary.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="sdlglgetattribute.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_GL_LoadLibrary</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_GetAttribute</TD ></TR ></TABLE ></DIV ></BODY ></HTML >