Returns the address of the GL function proc, or NULL if the function is not found. If the GL library is loaded at runtime, with SDL_GL_LoadLibrary, then all GL functions must be retrieved this way. Usually this is used to retrieve function pointers to OpenGL extensions.
typedef void (*GL_ActiveTextureARB_Func)(unsigned int);
GL_ActiveTextureARB_Func glActiveTextureARB_ptr = 0;
int has_multitexture=1;
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.
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/* 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;
}
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if(has_multitexture){
glActiveTextureARB_ptr(GL_TEXTURE0_ARB);
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}
else{
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}