On Mon, 20 Dec 1999, John Jenkins wrote:
> 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
>
>
Monday, December 20, 1999
To me this seems analogus to the situation with Indic scripts (among
others): An early, voted down version of ISO/IEC 10646 included a good
many Devanagari conjuncts/ligatures. Subsequent versions have not, giving
only the codes for characers and allowing rendering software to do what
available fonts permit and users' needs require (assuming they overlap).
Regards,
Jim Agenbroad ( jage@LOC.gov )
The above are purely personal opinions, not necessarily the official
views of any government or any agency of any.
Phone: 202 707-9612; Fax: 202 707-0955; US mail: I.T.S. Dev.Gp.4, Library
of Congress, 101 Independence Ave. SE, Washington, D.C. 20540-9334 U.S.A.
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