Mercurial > sdl-ios-xcode
view docs/html/sdlglgetprocaddress.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_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 >