Re: [Dri-devel] depth artifacts from different rendering paths

[Allen A. <ak...@po...>]

On Sat, Feb 09, 2002 at 05:03:31AM +0000, Keith Whitwell wrote:
|     ... opengl doesn't require that we get exactly the same results in these
| two cases - certainly it's desirable, but the specification specifically
| allows these types of variances.

Yes.  This subject came up on opengl-gamedev recently, and it's also an
issue for the vertex programming extension that the ARB is debating.

The spec for this (appendix A) is nontrivial, but an easy generalization
is that if you enable or disable something, the spec explicitly allows
the transformed coordinates to change.  To be safe, you need to use
state values that are no-ops instead of disabling a feature.  For
example, instead of disabling texturing, use a white texture with the
GL_MODULATE texture environment.

Allen