Re: How is a composition being done?

[Kenichi Handa <handa@m17n.org>]

In article <m3tymyhgfc.fsf@carbon.jhcloos.org>, James Cloos <cloos@jhcloos.com> writes:

> f-ligs are the lugatures which start with a miniscule f.  The most
> common ones are fi, fl, ff, ffi, ffl; some fonts have fj; some even
> have ligatures like fb, fk or ft which are only found at syllable
> boundries.

Ah, I see.

>>> I'd like to see emacs use f-ligs when in variable pitch mode.

>>> My guess is that a function which applies the GSUB liga feature would be
>>> the right solution, since monowidth fonts usualy avoid that.

KH> Yes, I think so.  But, for that, we must at first implement
KH> a function to apply specific OpenType features.

> Yes, that would be ideal.

> Perhaps the faces could specify which features should be applied, just
> like they currently specify styles.  The default set could be those
> which are generally applied by opentype-aware programs for the given
> scripts.

> I would also be useful to have a way to add features for a given span
> of text.  Perahps overlays could be used (abused?) for that?

If we make face to specify such features, we can naturally
use text property and/or overlay because both of them can
have `face' property.

---
Kenichi Handa
handa@m17n.org