Il giorno mer, 28/01/2009 alle 12.34 +0100, Henri Verbeet ha scritto: > 2009/1/28 Paul TBBle Hampson <paul.hamp...@pobox.com>: > > The only position I have on this is that this code exists and if the > > vertex shader code exists, I am unaware of it. The last comment I > > thought I read regarding vertex shaders was that they had produced a > > marked speed decrease (in my thread late last year about this issue) but > > on reflection, I may have conflated two things here. > > > Stefan implemented shader based fixed function vertex processing a > while ago. It does have performance issues, but I think it should be > possible to fix those. > > > You're suggesting in effect a specialised vertex shader that can just > > perform this matrix blending, rather than a full shader-based FFP, > > right? > > > It's not quite that easy, since we need to handle stuff like lighting > and texcoord generation as well. However, we do need shader based > fixed function vertex processing for things like specular alpha fog, > certain combinations of material tracking and drawing pre-transformed > vertices. My argument is essentially that if we're going to have > shader based fixed function vertex processing anyway, that's where we > should implement vertex blending, not as another drawStridedSlow() > fallback.
Why not both? I mean, you could implement a hardware based vertex blending routine using a vertex shader and keep the software vertex blending routine in case vertex programs are not supported by underlying hardware. Actually this is what the patch does: fall back to software vertex blending when hardware vertex blending is not supported. > > > If I understand, the software-only wined3d backend is dead and gone, so > Slightly OT, but we might need to implement software shaders at some > point, although that has a rather low priority right now. Would be > interesting to see if we could use Mesa swrast for that. Implementing shaders in software would be terribly slow. Doing vertex blending in software instead doesn't have a relevant impact on the performance side. Honestly I think that we have been waiting too much for a fix to this bug. There are many games in the AppDB that could go "gold" with this patch. http://appdb.winehq.org/viewbugs.php?bug_id=6955
