Well you also use a third texture unit throughout the program so on a GeForce you’d have to modify that and do it using multiple passes over the geometry.
Unless there is some other way to do it?
I am currently reading over the source code to get an understanding of whats going on, I will try and see if I can get it too run on a GeForce.
Isn’t the idea of this extension that you send down a normal map (with x,y,z delta substituted for r,g,b) as one texture, and send down the diffuse light direction as the texture environment color? That way, you get “per-pixel” lighting (really per-texel, but who’s counting?
Apart from preparing the normal map texture, it seems pretty straightforward.