Re: [ft-devel] ttfautohint vs FontForge

[Werner LEMBERG]

>> Why don't enhance existing autohinter in FontForge?  Currently it
>> is more advanced and it is reasonable to add more features/fixes to
>> FontForge instead of writing new one from scratch.
>
> They are not comparable.  As far as i know ttfautohint takes a
> completely different approach that fontforges autohinter.

Actually, the first thing I've done for this project was looking at
FontForge's autohinting code.  While it has been derived from
FreeType's autohinter, the deviations are extreme, and its tight
integration into FontForge made it impossible to me to fully
understand the code without diving into FontForge itself.  For
example, there is code for handling diagonal lines, something which
FreeType's autohinter doesn't do at all.

Ttfautohint directly translates FreeType's autohinting results into
TrueType instructions in a very non-standard way; essentially, it
ignores almost all native capabilities which the TrueType language
itself provides for hinting.  This is very different to what
FontForge's autohinter is doing.


    Werner