Re: Internal Error (overlap) for some fonts when running make

[Werner LEMBERG]

>> Now that Dan has made default make commands 'terser' I am noticing
>> while building our fonts that I see quite a few 'errors' that look
>> like this:
>>
>> Internal Error (overlap) in clefs.petrucci.c5_change:
>>   Winding number did not return to 0 when x=25.9951
>> Internal Error (overlap) in clefs.petrucci.c5_change:
>>   monotonic is >> both needed and unneeded
>> (22.1885,310.434)->(25.9951,304.135). x=25.9951 (prev=8.40259)
>>
>> Of course they have 'always' (probably) been there - I don't want to
>> claim anything like a regression.

It's not a regression, right.

>> But do we need to care?

We should.

> The first is pretty typical for Metafont/Metapost fonts, affecting
> cusps.  The latter looks like there might be a logic error in the
> programming for a variable called "monotonic".  Fixing those kinds
> of bugs would improve confidence in the font creation instructions,
> but the real test is whether people complain about the look of the
> resulting character.

Usually it is not noticeable.

Note that recently I saw some improvements w.r.t. monotonic stuff in
FontForge's git repository.  We thus should do two things for testing.

(1) Use a FontForge binary built from current git.

(2) Report any conversion errors to the FontForge maintainers.
    Hopefully, they now have the expertise to fix something (a few
    years ago, they didn't).


   Werner