I just converted the code in the game I’m working on to use NVidia’s VAR extension. The thing is, in scenes with a lot of detail, it seems like I was actually getting better performance using plain vertex arrays. But, if I turn to face a wall or corner in a room (so that there are relatively few polygons), the frame is better with VARs.
After experimenting, I noticed that if I disable the texture arrays (it’s multi-textured), the performance more than doubles in some places! The polys are still being textured (although with seemingly random texture coordinates now that the tex array is disabled), so I dont’ think it’s directly related to the card’s texture or fill-rate capabilities. (It’s a GForce2, btw)
So, why would enabling texture arrays slow it down so much? Right now, I’m using an array that has the position, color, and texture coordingates all in one. Every thing is defined as a float, so it should be 4-byte aligned.
Thanks,
Marc