Mercurial > sdl-ios-xcode
view docs/html/sdlglgetprocaddress.html @ 2866:e532417a6977
Fixed SDL 1.2 compatibility problem.
The API specifies that SDL_OpenAudio() will fill out the 'desired' audio spec
with the correct samples and size set by the driver. This value is important
since it may be used by applications that size audio buffers, etc.
However, we want to allow advanced applications to call SDL_OpenAudioDevice()
which gets passed a const 'desired' parameter, and have the correct data filled
into the 'obtained' parameter, possibly allowing or not allowing format changes.
So... 'obtained' becomes the audio format the user callback is expected to use,
and we add flags to allow the application to specify which format changes are
allowed.
Note: We really need to add a way to query the 'obtained' audio spec.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 13 Dec 2008 06:36:47 +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 >