You can also turn hinting off at runtime by passing a flag to freetype. matplotlib currently exposes this flag in the FT2Font extension, but we don't really expose the option to the user. It would be simple enough to make it an rcParam, though, which could then be set to "no hinting" by the test infrastructure just to rule out some of these moving parts. Of course, this doesn't rule out differences between different version numbers of freetype.
Another thing to look into might be some sort of fuzzy or perceptual diffing approach. Freddie Witheren (our GSoC student) has been looking into pdiff (http://pdiff.sf.net) for testing mathtex. I don't know what the current status of that is. In general, I think I prefer the goal of exact determinism, but if this becomes a recurring problem down the road, it may be easier to just try to "gloss over" these minor font differences. Mike John Hunter wrote: > On Sun, Aug 30, 2009 at 5:47 PM, Andrew Straw<straw...@astraw.com> wrote: > >> John Hunter wrote: >> >>> On Sun, Aug 30, 2009 at 4:17 PM, John Hunter<jdh2...@gmail.com> wrote: >>> >>>> According to RobK, you can reconfigure your ubuntu system to turn >>>> these off. He suggests: >>>> >>>> To use autohinting, use the hint in this post, or just run the >>>> following command: >>>> >>>> sudo dpkg-reconfigure fontconfig-config >>>> >>>> then choose “autohinter”, then choose “always”, then choose “no” >>>> >>> If that doesn't work, this guy has more involved instructions on how >>> to rebuild ubuntu libfreetype and disable the bytecode patch >>> >>> http://ubuntuforums.org/showthread.php?t=84359 >>> >> OK, I disabled all Ubuntu patches to libfreetype and recompiled and >> re-installed it. Unfortunately, I'm still getting the same failures. >> >> Then I additionally installed fontconfig-config and did the >> dpkg-reconfigure fontconfig-config step, setting everything to "Never". >> Same failures. >> >> These font errors make me unhappy. I think we should test some very >> simple pure libfreetype C program outputs generated on the various >> machines. I've just been playing with ftview, but that doesn't seem to >> have a command-line interface to save directly to a file. >> > > Attached is "example1.c" from the freetype tutorial. When I wrote > ft2font, I started with this tutorial and built around it, so some of > the core logic is the same. A lot has been added since then, > including a lot of stuff Michael has added to improve hinting, so we > may not see any differences at this level. The program outputs an > ascii-art file to stdout, so we could start by checking the md5 on the > output. Since *most* of your unit tests agree with the baseline, we > may struggle to find a difference. > > I compiled the example with > > gcc -I/Users/jdhunter/dev/include > -I/Users/jdhunter/dev/include/freetype2 -L/Users/jdhunter/dev/lib -o > example1 example1.c -lfreetype > > and ran it with > > ./example1 ~/mpl/lib/matplotlib/mpl-data/fonts/ttf/Vera.ttf "this is a > test" > run.out > > my md5 on the output is > > home:~/tmp> md5 run.out > MD5 (run.out) = 01868827436d858b4452ff03f80f7222 > > The example and output are attached -- we could easily replace the > example "show_image" with a binary output file that we could read into > numpy arrays to diff or display with imshow. > > I'm available to skype if you want to brainstorm this. > > JDH > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > ------------------------------------------------------------------------ > > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
