view docs/html/sdlglgetprocaddress.html @ 858:5db50aa5bf08

Date: Wed, 25 Feb 2004 06:41:17 -0500 From: "Ryan C. Gordon" Subject: Re: MacOS X bugs... This isn't an ideal patch (trying to open a joystick that has previously been unplugged will report success, but it'll just never give any input, etc), but it handles the worst case of deadlock in the event subsystem.
author Sam Lantinga <slouken@libsdl.org>
date Thu, 26 Feb 2004 13:45:22 +0000
parents 355632dca928
children
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>SDL_GL_GetProcAddress</TITLE
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><H1
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>SDL_GL_GetProcAddress</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN2678"
></A
><H2
>Name</H2
>SDL_GL_GetProcAddress&nbsp;--&nbsp;Get the address of a GL function</DIV
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CLASS="REFSYNOPSISDIV"
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>Synopsis</H2
><DIV
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><P
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><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
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><DIV
CLASS="REFSECT1"
><A
NAME="AEN2688"
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><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
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><I
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>all</I
></SPAN
> GL functions must be retrieved this way. Usually this is used to retrieve function pointers to OpenGL extensions.</P
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><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
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>SDL_GL_LoadLibrary</TT
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