When I use FontForge for a font, I can see in a field
"Descriptor" in TTF Properties comment from the font file,
such as "Generated using IcoMoon". I would like to get that
comment using FreeType (I want to know whether the font was
generated by such tools). I think that "Descriptor"
information is close to font family name and font name. Is it
possible to get that information?
First of all, do
grep 'Generated using IcoMoon' <your TTF>
If you get a result, the information should be retrievable. IIRC,
fontforge uses a small SFNT table (`PfEd' IIRC) to hold such
information. Note, however, that output of this information can be
suppressed while fontforge is generating a font.
Other tools add some information to the font's `name' table, and maybe
fontforge does the same. In other words, there is more than a single
place where fontforge might add such information – if such information
isn't suppressed.
The `PfEd' table can be extracted with `FT_Load_Sfnt_Table'; however,
you have to do the parsing by yourself. Data from the `name' table is
available via `FT_Get_Sfnt_Name'.