On Mon, Mar 4, 2013 at 11:47 PM, Marek Olšák <mar...@gmail.com> wrote: > On Mon, Mar 4, 2013 at 4:54 AM, Dave Airlie <airl...@gmail.com> wrote: >> I've been playing with softpipe msaa on and off, but I hit a problem >> with the clears and am just wondering if the state tracker should be >> doing something like this. >> >> Or maybe only if any bound buffer has nr_samples > 1, or fallback to >> the non-quad draw method. >> >> I can't see how else the driver could distinguish a multisample clear. >> >> The other problem I have and not figuring out is if rendering to a >> buffer with multisample off, then turning it on is meant to be >> meaningful, if you have to clear >> the buffer in between, then with this fixed it should be cool. >> >> Dave. >> >> From e1ee59d87ba42d8a58be640ee1fd2b952414f45e Mon Sep 17 00:00:00 2001 >> From: Dave Airlie <airl...@redhat.com> >> Date: Mon, 4 Mar 2013 13:39:17 +1000 >> Subject: [PATCH] st/mesa: enable multisample in clear quad code >> >> Not sure if this is correct at all > > For clears, blits, and the like, multisampling doesn't have to be > enabled, which means pixel values are stored in all samples regardless > of sample positions. > > Multisampling can be problematic if the rendered quad doesn't cover > whole pixels (floating-point precision may play a role, not sure), so > it's better not to enable it. >
Yeah I thought about it a bit more and I think you are right, I was being premature in my optimisation, in that if I had a multisample buffer with say 4 samples and I was rendering non-multisampled into it I was only using one sample and storing how many I'd used. However I should just replicate samples at this point and look towards optimising it later if possible. Dave. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
