More or less. In 1.12, there was no difference in quality between FAST and BEST, both used a bilinear filter. For 1.14, there was a desire (mainly driven by inkscape and firefox) to have better image quality when scaling - hence the switch to a convolution filter for BEST resampling. So FAST remains the same, but BEST is slower for higher quality. The default in cairo is to use BEST.
The guiding principle is to keep data on the gpu if it ever touches the gpu, so if either your source is in hardware or the destination is, then you should be using a cairo_surface_t suitable for rendering on the same hardware. Otherwise, whether offloading the rendering onto a gpu is a benefit requires experimentation - but often fun experimentation ;-) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to cairo in Ubuntu. https://bugs.launchpad.net/bugs/1360606 Title: libcairo.so for Ubuntu 14.04 is dead-slow compared to Ubuntu 13.10 Status in “cairo” package in Ubuntu: New Bug description: I'm running the video mixer software called Snowmix that uses libcairo extensively. After updating to Ubuntu 14.04 Desktop amd64, I noticed that mixing video required 8 times more CPU compared to Ubuntu 13.10. Using oprofile I discovered the heavy CPU load was taking place in libpixman used by libcairo. However libpixman is currently the same release in Ubuntu 14.04 and 13.10. However I did notice that libcairo got upgraded from libcairo.so.2.11200.16 in Ubuntu 13.10 to libcairo.so.2.11301.0 in Uuntu 14.04. Snowmix uses libcairo2 primarily for scaling and rotating images and overlay them in memory. Replacing libcairo.so.2.11301.0 with libcairo.so.2.11200.16 in Ubuntu 14.04 lower the CPU usage by at least 8 times. So I suspect that libcairo for Ubuntu 14.04 somehow got compiled without the hardware acceleration such as MMX/SSE2/SSE3 etc. This is quite bad if this is the case. If it is not the case, something else is seriously wrong with libcairo2. 1)Description: Ubuntu 14.04.1 LTS Release: 14.04 2) libcairo2: Installed: 1.13.0~20140204-0ubuntu1 Candidate: 1.13.0~20140204-0ubuntu1 Version table: *** 1.13.0~20140204-0ubuntu1 0 500 http://dk.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages 100 /var/lib/dpkg/status 3) I expected libcairo2 (libcairo.so.2.11301.0) for Ubuntu14.04 to work as efficient as libcairo2 (libcairo.so.2.11200.16)for Ubuntu13.10. 4) Libcairo2 for Ubuntu 14.04 works 8 times slower indicating a lack of MMX/SSE2/SSE3 etc acceleration. For the source, you have the source for libcairo2 for Ubuntu14.04. I can provide you with the source code for Snowmix using libcairo2, but I don't expected you need it nor want it. Best regards Peter Maersk-Moller ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: libcairo2 1.13.0~20140204-0ubuntu1 ProcVersionSignature: Ubuntu 3.13.0-34.60-generic 3.13.11.4 Uname: Linux 3.13.0-34-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.3 Architecture: amd64 Date: Sat Aug 23 15:23:38 2014 InstallationDate: Installed on 2013-06-21 (428 days ago) InstallationMedia: Ubuntu 12.04.2 LTS "Precise Pangolin" - Release amd64 (20130213) ProcEnviron: LANGUAGE=en_US:en TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: cairo UpgradeStatus: Upgraded to trusty on 2014-08-20 (3 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cairo/+bug/1360606/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
