Kern Feature to Kern Table?

Michael Vokits

Hello. I'm trying to generate a TT-flavored font from the OTF, but I can't seem to make kerning work, whether using TypeTool or FontForge. The generated TTF is otherwise fine from either app, kerning correctly in LaTeX, but nowhere else. I've tried expanding the kerning classes with enum everywhere, but that doesn't work either. Is there a way to automagically convert from feature to table? I guess I could sprinkle "enum" everywhere, generate an intermediary font, examine the expanded kern feature, then search and replace, and so forth, but this is the sort of tedious task that should be automated.

Dave Crossland

or FontForge

Please do file an issue and we in the FontForge community will make it happen

Michael Vokits

Good idea; filed.

Michael Vokits

Ooh, shiny new version of FontForge, even -- the one I'd been using dates from 2011.

Anyhoo, my enum/intermediary font idea more or less works, except that I can't kern with periods or commas; I think it's a matter of too many pairs. Does anybody know how many kerning pairs TTF allows?

Jens Kutilek

Does anybody know how many kerning pairs TTF allows?

Practically: 10920.

Long explanation: A kern table can store 10920 pairs per subtable, but all subtables except the first one are ignored in all known environments. Mac OS X even reports fonts with too many subtables as defective.

Michael Vokits

Cool, thanks. I "only" have 1499 pairs, so there's that hypothesis out the window.

Thomas Phinney

Note also that some apps may have other functional limits that are less than 10920. It used to be this was a widespread problem, but I think a lot of apps have been fixed over the years.