[ft-devel] glyf (i.e. contour) analysis reports on libre fonts.

[Hin-Tak Leung]

Hi,

People who went to LGM 2016 London in April this year and heard my talk would 
hear that, IMHO, the most unique and valuable part of the Font Validator is its 
analysis on individual glyphs. That is broadly divided into the glyf table test 
on the glyph contours, and the rasterization test on the truetype hinting 
instructions. The latter wasn't open-sourced by Microsoft, but was 
re-implemented, much faster with broader scope and wider supported platforms, 
and superceding the old version in 2.0 a few weeks ago.

So I have turned my attention to the glyf test, and threw all my (many buggy) 
fonts to try to break it. When the glyf test itself breaks and cannot handle 
the situation, it is called "A1112 exception", and I filed them under 
https://github.com/Microsoft/Font-Validator/issues in the last few days.

Out of that activity, I collected the reports of the ~3000 fonts on Fedora 
(about ~2000 under /usr/share/fonts, and another ~1000 texlive). About half of 
them, (~1300 /~2000 for general libre fonts, and ~200 / ~1000 for texlive) have 
some level of glyph errors or warnings.

At the rate of 2/3, almost all libre font authors should have a look at their 
own reports and fix their fonts.

fedora-glyf-EW-reports-file-index-2016-08-11.txt is the file index and 
"fedora-glyf-EW-reports-2016-08-11.tgz" is the collection of reports under
http://htl10.users.sourceforge.net/tmp/FontVal-test-results-2016July/

The file index entries look like this, sorted by the "FileNameAndPath" field 
(i.e. this is the first entry, with "aa..."):

tmp6b009ab7.tmp.report.xml:<FontFile FileName="Comfortaa-Bold.ttf" 
FileNameAndPath="/usr/share/fonts/aajohan-comfortaa/Comfortaa-Bold.ttf">

and author of "/usr/share/fonts/aajohan-comfortaa/Comfortaa-Bold.ttf" should 
extract "tmp6b009ab7.tmp.report.xml" from the tar ball, etc.

Disclaimer: I am just the messager - I just ran the glyf test on all the fonts 
I have, and played no part in writing it. People disagreeing or have questions 
with the reports' content should file upstream under  
https://github.com/Microsoft/Font-Validator/issues .

People who want to make the glyf test even better can look at and help fixing 
the A1112 exception's - I honestly do not mind somebody else doing it! :-). 
People who want me to make it better, please feel free to make a donation ( 
https://sourceforge.net/p/hp-pxl-jetready/donate/ ).

Hin-Tak

P.S. It has been exactly a year ago today (baring time-zone arguments...), that 
I received and first saw the code bundle from Microsoft to get fixed up, to be 
publicly released a few months later. Hurray.