<div dir="ltr"><div>I suspect I will need to check the X server version, actually. That seems to be what the other tests are doing. </div>My main concern is to figure out *which* version this (will) happen in. I am hoping this can be known before code release so Cairo can be updated to use it at the same time. </div><div class="gmail_extra"> <div class="gmail_quote">On Sun, Dec 20, 2015 at 5:58 AM, Oded Gabbay <<a href="mailto:oded.gabbay@gmail.com" target="_blank">oded.gabbay@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Wed, Dec 16, 2015 at 4:41 AM, Bill Spitzak <<a href="mailto:spitzak@gmail.com">spitzak@gmail.com</a>> wrote: > > > On Tue, Dec 15, 2015 at 1:29 AM, Oded Gabbay <<a href="mailto:oded.gabbay@gmail.com">oded.gabbay@gmail.com</a>> wrote: >> >> On Sat, Dec 12, 2015 at 9:10 PM, Bill Spitzak <<a href="mailto:spitzak@gmail.com">spitzak@gmail.com</a>> wrote: >> > >> > >> > On Sat, Dec 12, 2015 at 10:37 AM, Oded Gabbay <<a href="mailto:oded.gabbay@gmail.com">oded.gabbay@gmail.com</a>> >> > wrote: >> >> >> >> On Sat, Dec 12, 2015 at 8:34 PM, Bill Spitzak <<a href="mailto:spitzak@gmail.com">spitzak@gmail.com</a>> >> >> wrote: >> >> > On Fri, Dec 11, 2015 at 4:15 AM, Oded Gabbay <<a href="mailto:oded.gabbay@gmail.com">oded.gabbay@gmail.com</a>> >> >> > wrote: >> >> >> >> >> >> On Thu, Dec 10, 2015 at 11:19 PM, Bill Spitzak <<a href="mailto:spitzak@gmail.com">spitzak@gmail.com</a>> >> >> >> wrote: >> >> >> > Can you include my patches to fix the filtering? They have been >> >> >> > posted >> >> >> > for a >> >> >> > long time now. >> >> >> > >> >> >> > The last patch makes GOOD/BEST use filtering for scaling images >> >> >> > down. >> >> >> > This >> >> >> > matches the current Cairo behavior and would allow Cairo to use >> >> >> > the >> >> >> > pixman >> >> >> > backend rather than doing an image fallback for any image scaling >> >> >> > smaller >> >> >> > than .75. It also contains a bunch of minor optimizaion and filter >> >> >> > selection >> >> >> > tweaks that makes the output somewhat better than current Cairo. >> >> >> > >> >> >> Hi Bill, >> >> >> >> >> >> Unfortunately, I don't see anyone reviewed your patches, and from >> >> >> what >> >> >> I heard, those are quite significant changes. >> >> >> >> >> >> It's a shame you didn't bring this up when I did the first >> >> >> development >> >> >> release 4 months ago. Then we had enough time to check and test it. >> >> >> I'm quite hesitant of including such changes right before the final >> >> >> development version, even with a review. >> >> > >> >> > >> >> > I did send email on May 22, 2015, in response to your comments. >> >> >> >> That's strange, because I only started working on pixman during June of >> >> 2015... >> > >> > >> > You are right. That was just a general email I sent trying to get >> > somebody >> > to look at the patches. Searching in the history I found 3 of these. >> > >> >> >> >> >> >> >> >> > >> >> >> I suggest that you try to contact one of pixman's veterans (Soren, >> >> >> Siarhei, Matt, Pekka, Ben) offline and ask them nicely to at least >> >> >> skim over the patches and give a high-level opinion about the >> >> >> series. >> >> > >> >> > >> >> > These were discussed with Soren before. He disagreed with my previous >> >> > version because I changed to a single filter calculation rather than >> >> > his >> >> > pair of filters being convoluted. This version preserves the pair of >> >> > filters, with some fixes of bugs that caused artifacts in the >> >> > resulting >> >> > filters. I'm sending email directly in case they are not reading the >> >> > pixman >> >> > list. >> >> >> >> Could you send me those emails ? >> > >> > >> > I forwarded the big one from him and my response. The patches I have had >> > since then I believe address his concerns and preserve the 2-filter >> > convolution api, they are just bug fixes and some efficiency changes. >> >> >> >> >> >> >> >> >> >> >> >> >> Also, check if you need to rebase the patches against current pixman >> >> >> and if so, maybe send the series again. It might stir up a >> >> >> discussion. >> >> > >> >> > >> >> > The patches applied to the newest version without any conflicts and >> >> > my >> >> > test >> >> > programs still work. I have resent them to the pixman mailing list. >> >> >> >> >> >> >> Great! >> >> >> >> >> >> >> >> I'm willing to review them in terms of correctness and code style, >> >> >> but >> >> >> I'm not veteran enough in pixman to give an opinion on the >> >> >> underlying >> >> >> changes (which is the most important issue). >> >> > >> >> > >> >> > Anything would be great. >> >> > >> >> > I believe these work well and have been using them for a while. This >> >> > would >> >> > allow the removal of redundant code in Cairo, and would allow 2-pass >> >> > filtering to be done at some point in the future, which would really >> >> > improve >> >> > pixman performance. >> >> > >> >> ok, I'll try to take a look next week or so. >> >> >> >> Oded >> > >> > >> >> Hi Bill, >> >> I read most of the emails you sent me and I cleared time tomorrow to >> review your patches. >> >> Having said that, IMHO, I believe it would be too risky to merge them >> into the final development release. This is due to a combination of >> two things: >> >> A. This release, although it is a "development release" is used by >> current distributions (fedora 22,23, ubuntu, debian). That's because >> there was a big gap in the release schedule earlier this year. >> >> B. The changes here affect users of pixman and cairo, by changing the >> way pixman behaves. So even if your patches are perfect, and the >> result is a better pixman, we need to give time to users (and to >> cairo) to adapt to it. This can only be done in master branch, not in >> stable branches. >> >> So, what I intend to do is to: >> >> A. Review your patches and if necessary, ask you to fix issues. >> >> B. Assuming no objection will be made by other pixman developers >> during the next couple of weeks, I will merge the patch series into >> master *after* I branch out the 0.34 release. >> >> That way, the patch series will be included in the future development >> releases that will be packaged inside "testing" distributions, such as >> fedora rawhide and debian unstable, and thus we will have time to >> receive feedback from users about the changes. >> >> I hope this is accepted by you and by everyone else. If not, please tell >> me. >> >> Thanks, >> >> Oded > > > I am fine with this all being for the next release and will be happy to > answer any questions. > > I would like to know what a compile-time test for whether libpixman is this > next release or not, and a run-time test to see if X (using both xlib and > xcb) is using this next release of pixman. This will allow code to be added > to Cairo to automatically send the filtering to pixman when possible, and > hopefully get that added at the same time this is supported in the pixman > release. > > > </div></div>For compile time, you can check PIXMAN_VERSION_MAJOR/MINOR/MICRO in pixman-version.h For run-time, check pixman_version() in pixman.c: /** * pixman_version: * * Returns the version of the pixman library encoded in a single * integer as per %PIXMAN_VERSION_ENCODE. The encoding ensures that * later versions compare greater than earlier versions. * * A run-time comparison to check that pixman's version is greater than * or equal to version X.Y.Z could be performed as follows: * * <informalexample><programlisting> * if (pixman_version() >= PIXMAN_VERSION_ENCODE(X,Y,Z)) {...} * </programlisting></informalexample> * * See also pixman_version_string() as well as the compile-time * equivalents %PIXMAN_VERSION and %PIXMAN_VERSION_STRING. * * Return value: the encoded version. **/ I don't know, however, if X server exports this function through its API. You will need to check with them. Oded </blockquote></div> </div>