On Tue, Aug 8, 2017 at 11:34 AM, Roland Scheidegger <srol...@vmware.com> wrote: > Am 08.08.2017 um 17:21 schrieb Ilia Mirkin: >> On Tue, Aug 8, 2017 at 11:16 AM, Adam Jackson <a...@redhat.com> wrote: >>> On Wed, 2017-06-28 at 16:50 +0300, Plamena Manolova wrote: >>>> ARB_texture_filter_anisotropic is the ARB variation of >>>> EXT_texture_fitter_anisotropic and it operates in the >>>> same way, so there's no reason not to advertise it. >>> >>> Nak. The ARB version bups the minmax anisotropy to 16x, see issue 2 in >>> the spec. This patch would wrongly enable the ARB version for intel < >>> gen4 and nouveau < nv40. >> >> Yeah, this needs a new ext enable bit which is flipped on in >> st_extensions.c and the relevant i965 file, conditional on the driver >> being able to handle >= 16x aniso. (There should be a PIPE_CAP for it >> on the gallium end of it. If you don't want to hook it up for st/mesa >> that's fine too, I or someone else can handle that one-liner.) >> >> Well-noticed, ajax. >> >> -ilia >> > > Does it really matter, though? > The spec does not require any specific implementation. About the > strongest wording I can find is that "However, when the texture's value > of TEXTURE_MAX_ANISOTROPY is greater than 1.0, the GL implementation > should use a texture filtering scheme that accounts for a degree of > anisotropy up to..." > > So it's only "should". > Therefore implementations not really being able to handle 16xAF would > probably still be conformant with a lesser AF degree - they can just > pretend it's 16xAF with a crappy scheme :-). > > FWIW d3d10 also requires 16xAF, but is quite fine with any filtering as > long as the filtering is no worse than simple trilinear (which is > exactly what llvmpipe does if you give it a sampler with AF filtering...).
In practice though, MAX_TEXTURE_MAX_ANISOTROPY will continue to be reported as 4 or whatever it was, against the spec, without additional changes. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
