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>SDL_GL_GetProcAddress</TITLE
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><H1
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>SDL_GL_GetProcAddress</H1
><DIV
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><A
NAME="AEN2678"
></A
><H2
>Name</H2
>SDL_GL_GetProcAddress&nbsp;--&nbsp;Get the address of a GL function</DIV
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>Synopsis</H2
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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
CLASS="emphasis"
><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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>See Also</H2
><P
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><TT
CLASS="FUNCTION"
>SDL_GL_LoadLibrary</TT
></A
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author	Sam Lantinga <slouken@libsdl.org>
date	Fri, 30 Apr 2004 18:33:30 +0000
parents	355632dca928
children