Intel hardware doesn't natively support textureGrad with shadow comparisons. This patch series implements a GLSL IR level lowering pass to compute the LOD level that would be selected based on the given gradient values, based on the equations on page 205 of the OpenGL 3.0 specification. It then simply uses textureLod().
The old method had many problems: - The shadow comparison was done post-filtering. - It required state-dependent recompiles whenever the comparison function changed. - It didn't even work: many cases hit assertion failures. - I never implemented it for the VS. The new method is not perfect; it only passes 36/45 of oglconform's shadow-grad tests. That said, it seems to work a lot better than the previous method, and the remaining cases are so obscure that I'd like to just push it as is and fix up the remaining cases sometime in the future (i.e. bug reports welcome). One of the main advantages is that this reduces state-dependent recompiles, and thus increases performance certain applications. (Said applications aren't actually using TXD - we were just being overzealous in our program key handling.) _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
