-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 09/08/2011 12:18 PM, Roland Scheidegger wrote: > Am 08.09.2011 21:03, schrieb Roland Scheidegger: >> Am 08.09.2011 19:53, schrieb Ian Romanick: >>> On 09/06/2011 03:21 PM, Roland Scheidegger wrote: >>>> Am 06.09.2011 22:13, schrieb Ian Romanick: >>>>> From: Ian Romanick <ian.d.roman...@intel.com> >>>>> >>>>> Core Mesa already does the dispatch offset remapping for >>>>> every function that could possibly ever be supported. >>>>> There's no need to continue using that cruft in the >>>>> driver. >>>>> >>>>> Since the call to _mesa_enable_imaging_extensions (via >>>>> driInitExtensions) is removed, EXT_blend_logic_op is >>>>> explicitly added to the list. EXT_blend_color is also >>>>> added, but it depends on the drmSupportsBlendColor flag. >>> >>>> Hmm, I don't think EXT_blend_logic_op was advertized before. >>>> The reason for this is that EXT_blend_logic_op together with >>> >>> EXT_blend_logic_op *was* previously enabled. r200CreateContext >>> called driInitExtensions( ctx, card_extensions, GL_TRUE );. >>> The GL_TRUE parameter tells driInitExtensions to call >>> _mesa_enable_imaging_extensions. >>> _mesa_enable_imaging_extensions in turn enables: >>> >>> GL_EXT_blend_color GL_EXT_blend_logic_op GL_EXT_blend_minmax >>> GL_EXT_blend_subtract >> That's right. _mesa_enable_imaging_extensions however did not >> always enable EXT_blend_logic_op. I was curious (as I was sure it >> was correct at one point for r200) when this got broken for r200 >> and that's the answer: 6775c1e8ccc2c543d97eb273a342140a62d99aee - >> that is OLD (interestingly the commit mentions some discussion >> apparently however I did not realize it in fact made r200 >> advertize EXT_blend_logic_op which I knew would be incorrect). >> >>> >>> I didn't see anything in r200_state.c to handle blend equation >>> being set to GL_LOGIC_OP. >> Yes - there was code initially handling this (trivial as long as >> it's the same on all RGBA channels) but I removed that a decade >> or so ago when adding support for EXT_blend_equation_separate >> (and removing support for EXT_blend_logic_op at the same time). >> >>> >>> Of course, we have *zero* piglit tests for this extension. >>> >>>> 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. >> >> I don't think it works at least for r300. FWIW there's a mesa >> helper function (_mesa_rgba_logicop_enabled) which also only >> makes sense if the logicop blend equation is set for either both >> of none of RGB/A. >> >> I certainly wouldn't mourn the loss of EXT_blend_logic_op. > > > Hmm actually a quick search of ARB_color_imaging reveals that > EXT_blend_logic_op isn't even part of it (not that it matters much > as we don't support the imaging subset any longer anyway) so I > don't know why it got enabled there. In any case since that imaging > subset enable is gone, it's not really a problem anymore and > drivers can just enable it if they really want - r200 certainly > does not.
Okay. I'll disable it in r200 and r300. With that change, do I have your Reviewed-by? -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk5pGscACgkQX1gOwKyEAw93RwCgiu/i79FyervNFtqdKxJC4NR5 N44An0e1KrPouqyjA/ZnecKGkxMw+8AE =ds06 -----END PGP SIGNATURE----- _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
