[HarfBuzz] A couple of clarifications regarding HarfBuzz

[Khaled Hosny]

On Wed, Oct 20, 2010 at 05:07:34PM +0200, Tom Hacohen wrote:
> 2. What does language (in hb_buffer) does? Isn't script enough?

Each OpenType lookup is associated with script(s) and language(s) where
it should be active.

> 7. That's maybe not completely HarfBuzz related, but how do I get the
> pen positions inside a ligature? (for drawing cursor, handling
> selection, etc etc) or should I just treat the ligature as one group
> once it has shaped into one?

There is the ligature caret in GDEF table (I don't know how HB presents
such data), but most fonts don't have such carets set so you may want to
divide the ligature into equal parts by the number of its components
(may be HB already does such thing?), see:
http://weblogs.mozillazine.org/roc/archives/2006/10/partial_ligatur.html

Regards,
 Khaled

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer