Re: [matplotlib-devel] buildbot font discrepancies

[John H. <jd...@gm...>]

On Sun, Aug 30, 2009 at 5:47 PM, Andrew Straw<str...@as...> wrote:
> John Hunter wrote:
>> On Sun, Aug 30, 2009 at 4:17 PM, John Hunter<jd...@gm...> 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