On Wed, Jan 11, 2017 at 4:14 PM, Nicolai Hähnle <nhaeh...@gmail.com> wrote: > On 11.01.2017 13:17, Marek Olšák wrote: >> >> On Tue, Jan 10, 2017 at 6:48 PM, Jason Ekstrand <ja...@jlekstrand.net> >> wrote: >>> >>> I'll be honest, I'm not a fan... Given that D3D10 has one defined >>> behavior, >>> D3D9 has another, and GL doesn't specify, I don't really think we should >>> be >>> making a global change to all drivers to do the D3D9 behavior just to fix >>> one app. Sure, other apps probably have the same bug, but are we going >>> to >>> have apps that expect the D3D10 behavior that we've now explicitly made >>> not >>> work? >>> >>> If we're going to hack around an app bug, I would really rather see it >>> behind a driconf option rather than a global change to driver behavior. >>> Even better, it'd be cool if we could see the app get fixed. (Yes, I know >>> that's not likely). >> >> >> I think we are not in a position to refuse this workaround, or put >> more precisely, to have a different behavior from everybody else. By >> "we", I mean i965, radeonsi, svga. All closed drivers use abs. Many >> Mesa drivers also use abs internally (r300, r600, nv30, nv50/nvc0). >> This is not really a workaround for a specific application, even >> though it's strongly motivated by that. It's a fix to align the few >> remaining drivers with all others. >> >> We talked with the publisher about this a very long time ago. While I >> don't remember the details (Nicolai?), I think they refused to fix it >> because radeonsi appeared to be the only driver not doing abs. > > > If I remember correctly, it wasn't so much a refusal as a lack of > follow-through. They even had an option in their framework to add the > abs(...) when translating shaders, but somehow didn't turn it on > unconditionally for some reason...
VP even says so here: https://github.com/virtual-programming/specops-linux/issues/20 They recommend against patching mesa to do abs, though. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
