On Tue, 22 Apr 2014 03:38:36 +0200 [email protected] (Søren Sandmann) wrote:
> Pekka Paalanen <[email protected]> writes: > > > Hi, > > > > this thread started from > > http://lists.freedesktop.org/archives/pixman/2013-February/002619.html > > and continued in > > http://lists.freedesktop.org/archives/pixman/2013-March/002677.html > > > > I'd like to hear what the thoughts of it are now, more questions > > below. > > > > > > On Wed, 13 Feb 2013 08:37:06 +0100 > > sandmann at cs.au.dk (Søren Sandmann) wrote: > > > >> I pushed the first patch to master. For this one, did you try > >> comparing Chris' patch to your on ARMv6? Also, did we ever find > >> out whether it was a bug in Firefox. I'm still somewhat skeptical > >> that it's intended for a PAD image to be accessed so far out of > >> bounds. > > > > What is the "Chris' patch", has it been merged? > > > > Do you still think there is a bug in Firefox, and the (trimmed) > > Cairo traces are therefore invalid for PAD type repeats? > > The "Chris' patch" is this: > > http://lists.freedesktop.org/archives/pixman/2013-January/002572.html > > I still believe what I wrote here: > > http://lists.freedesktop.org/archives/pixman/2013-January/002600.html > > that an operation where > > - the repeat mode is PAD > - the transformation is identity > - the source image is smaller than the destination (but it is > not a 1 x n image) > > suggests that something suboptimal is going on at a higher level than > pixman because the visual results will be an image surrounded by weird > horizontal and vertical stripes, which is not normally desirable. And > if I remember correctly, the firefox-chalkboard source image is > actually some kind of noise mask that really looks like it should be > used with repeat=NORMAL, not repeat=PAD. I agree with your general rationale. > Still, if this operation is being generated by Firefox (and I'd like > to make sure that this is not just an artefact of cairo-trace or > something like that), pixman should make it fast, so I am not opposed > to the general idea of optimizing it. So a good patch would be able > to make it upstream. Very good. I don't think we will be running Firefox on RPi too soon, as we are concentrating on Epiphany (Web) at the moment. > Sorry if this is an unsatisfactory answer. Not at all, it was quite enlightening. As far as I understand, the only case where we could show a significant improvement was that Cairo trace from Firefox, where it is questionable if it is a valid real-world scenario at all, at least in the way replaying the trace uses Pixman. I think we will leave this matter be, until we find another case where the PAD or similar optimizations would be useful. Thanks, pq _______________________________________________ Pixman mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/pixman
