Re: Latin ligatures and Unicode

From: John Jenkins (jenkins@apple.com)
Date: Mon Dec 20 1999 - 12:36:28 EST


on 12/20/99 4:24 AM, Michael Everson at everson@egt.ie wrote:

> Ar 02:04 -0800 1999-12-20, scríobh Christopher John Fynn:
>
>> IMO the best way of handling ligatures for "Fraktur" typefaces
>> is by creating OpenType (or Apple's AAT) fonts with the proper
>> table information. If the combinations of characters you list
>> *must* be displayed by ligatures when text is set in your
>> Fraktur font you can specify this in the OpenType substitution
>> tables or you can make the substitution optional.
>
> But on-or-off substitution, or even two or three level substitution, is not
> sufficient to describe completely the use of ligatures in printed texts. A
> font may have a repertoire of 12 ligatures, but a document may use only
> two, or three, or four, or seven of them. Or all twelve. THIS is
> font-specific, and can't be predicted. The only thing that could work well
> is to have the font's glyph tables contain all the glyphs as X-ZWL-Y
> triplets, to be displayed whenever that sequence appeared in the text.
>

Er, but Michael, that's my point -- the font-specific data doesn't belong in
plain text. It belongs in the same level of formatting as the font
specification itself.

>> The substitution (whether ligatures are formed or not) may
>> be specified on a language by language basis or you can
>> make it the default (non-language specific) behaviour for
>> your font.
>
> This is not precise enough.
>

It isn't precise enough for *plain text*, true. But I would argue that
ligature formation doesn't belong in plain text.

>> (Of course all this will only work in OT or AAT savvy applications.)
>
> Name one?
>

Adobe InDesign.

=====
John H. Jenkins
jenkins@apple.com
tseng@blueneptune.com
http://www.blueneptune.com/~tseng



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