Re: Texture mapping co-ordinates

[Katie Lucas <katie@fysh.org>]

> >   2) You might have very large texture coordinates - that can cause the
> >      texture to drift around.  The Voodoo is especially sensitive to this
> >      due to poor (~14 bit) internal numerical precision.  Software OpenGL
> >      is highly insensitive to it (because it's all done in 'float's).
> 
> This isn't the problem (which was a Mesa needing upgrading thing) but
> it is something that I would have needed to know later on in the
> project.. I'll have to bear that in mind.

Actually, talking of numerical imprecision, I've got some artifacts
caused by limited precision in the depth buffer, but I can't recall
how you set up OpenGL to avoid this (In glide it's something like
"use a W buffer rather than a Z buffer) ?

I had a play with glDepthRange(), but I can't really see how fiddling
with that would help..