Re: ZWJ and Latin Ligatures

From: Michael Everson (
Date: Tue Jul 02 2002 - 11:49:05 EDT

At 09:41 -0600 2002-07-02, John H. Jenkins wrote:

>Alas, but that's technically impossible. Both OT and AAT (I'm not
>sure about Graphite) require that single characters map to single
>glyphs, which are then processed.

Hm? How do you handle the decomposed sequence A + COMBINING ACUTE?
Surely that is a sequence of characters mapping to a single glyph.

Just goes to show that I don't make proper Unicode fonts yet because
the tools just aren't up to snuff.

>(In OT, of course, you are also supposed to do some preprocessing in
>character space, but that doesn't solve this problem.) It would be
>nice to have a cmap format which maps multiple characters to single
>glyphs initially.

I always thought there was. Now I'm really confused as to how I would
make a complex Indic syllable.

>The way we deal with this is to have the ligatures with the ZWJ
>inserted as part of a ligature table which is on by default and
>which isn't revealed to the UI so that the user can't turn them off.

I am not sure I understand, but then I haven't been able to make use
of the AAT ligature tables yet. ;-)

Michael Everson *** Everson Typography ***

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