[HarfBuzz] Interaction between default and non default features

[Khaled Hosny]

On Fri, Aug 10, 2012 at 11:39:39AM -0400, Behdad Esfahbod wrote:
> On 08/10/2012 10:48 AM, Khaled Hosny wrote:
> > So I’m asking if the current behaviour is “final” and no intentions to
> > change it, and if anyone knows how other implementations deal with this
> > (the Uniscribe backed seems to ignore the stylistic set completely, so I
> > don’t know how to test this).
> 
> Yeah, the Uniscribe backend doesn't have features wired up.  You just gave me
> perfect reason to hack that in today.
> 
> Your best bet is 'locl' I'm afraid.  If Uniscribe compatibility is not an
> issue, I'm open to providing HarfBuzz-specific behavior.  For example, to let
> Arabic fonts opt in to have all features applied together.

This is is really meant to be a stylistic set, it shouldn't even be
enabled globally but only for words where a backward yeh looks better
(since unlike Urdu it is just an alternate form of yeh in Arabic). But
if this indeed Uniscribe behaviour, there is little benefit in
deviating from it since I’ll have to do it the hard way anyway.

Regards,
 Khaled