Hey Michael, I need some help with Duel. I downloaded it and extracted it to my desktop. When i tried to run the application, not changing any code or anything it says this. Extension not supported: GL_NV_register_combiners. Is there some libraries or something that i need to have that i havent downloaded?

I''m gonna take a guess here:

You don''t have an NVidia graphics card, or if you do, it''s not a newer one.

GL extensions are generally added by third parties through their drivers to expose their nifty new features to OpenGL. "GL_NV_register_combiners" sounds an awful lot like an NVidia extension to me, possibly something to do with shader registers.

Could be wrong.

But a google search says I''m not, mostly. It has something to do with "computing fragment colors". Whatever that means.

ur right,
i have an ati radeon 9700, not an nvidia. is there any way around that?

ATI has created their own interface for pixel / vertex shaders. Also the ARB has agreed on a standard set of extensions for pixel/vertex shaders, but only the latest graphics cards support the extensions ( Geforce FX and Radeon 9700 and up ).

so shouldnt i be able to support it if i have a radeon 9700 with the latest catalyst drivers?

Yes, you should, but the problem is very few people have the latest video cards, so you''ll still have to implement methods using nVidia''s and ATI''s extensions, otherwise your program will drop to software mode and run painfully slow.