Am 08.09.2011 19:59, schrieb Eric Anholt: > On Thu, 08 Sep 2011 10:53:45 -0700, Ian Romanick <i...@freedesktop.org> wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> On 09/06/2011 03:21 PM, Roland Scheidegger wrote: >>> EXT_blend_equation_separate allows some unholy combinations which the >>> r200 (possibly other hw too) can't handle correctly. Namely this >>> combination makes it possible to have logic ops on rgb or alpha channels >>> and color blending on the other channels. >>> I know that at least sometime in the past this driver did not advertize >>> EXT_blend_logic_op, since OpenGL 1.1 style logic ops do not have that >>> problem and EXT_blend_logic_op wasn't really all that important. I guess >>> though it's not exactly a severe problem since surely apps old enough to >>> use EXT_blend_logic_op wouldn't try to use EXT_blend_equation_separate >>> (though in theory some app could be clever and really want to do that...). >> >> That's a good point. I suspect that no hardware actually handles this >> case correctly. I seem to recall that this is the reason NVIDIA doesn't >> support GL_EXT_blend_logic_op in their drivers. I know the non-Quadro >> cards don't support it, anyway. >> >> Does this work on later chips in the Radeon family? >> >> I don't think anyone will miss GL_EXT_blend_logic_op if we just remove >> it altogether. > > Sadly, for the purpose of doing X on top of GL, we actually do want > logic ops.
Yes but do we need GL_EXT_blend_logic_op and not the GL 1.1 style logic ops? Roland _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
