[SDL] SDL and OpenGL extensions

[Maciej Babinski]

On Thu, Nov 07, 2002 at 12:57:45AM +0100, Alexander Bierbrauer wrote:
> Hi people,
> 
> I'm having some trouble with OpenGL extensions via SDL. I've looked at 
> many opengl examples using SDL and they don't have any code to 
> "activate" the extensions. So, does SDL initialize all the function 
> pointers itself ?
> 
> If yes, how do I use them ??
> 

You need to initialize the function pointers yourself using an SDL
helper routine:

PFNGLACTIVETEXTUREARBPROC glActiveTextureARB   = NULL;
PFNGLMULTITEXCOORD2FARBPROC glMultiTexCoord2fARB = NULL;
PFNGLMULTITEXCOORD2IARBPROC glMultiTexCoord2iARB = NULL;
unsigned char *exts;
exts = glGetString(GL_EXTEINSIONS);
if (strstr((char *) exts, "GL_ARB_multitexture")) {
	glActiveTextureARB = (PFNGLACTIVETEXTUREARBPROC)
	               SDL_GL_GetProcAddress ("glActiveTextureARB");
	glMultiTexCoord2fARB = (PFNGLMULTITEXCOORD2FARBPROC)
	               SDL_GL_GetProcAddress ("glMultiTexCoord2fARB");
	glMultiTexCoord2iARB = (PFNGLMULTITEXCOORD2IARBPROC)
	               SDL_GL_GetProcAddress ("glMultiTexCoord2iARB");
}