[XeTeX] Issue with Arabic Typography

[maxwell at umiacs.umd.edu]

> Jonathan Kew wrote:
>
>> A complete solution would involve support for the OpenType
>> justification table, although not all fonts provide this; it would
>> apply to more than just Arabic script;
>
> Yes, it would be lovely for Syriac text and poetry as well!

Does anyone (Jonathan K?) know whether this technique is used for
justification in Urdu as well?  Urdu is written in the Nasta'liq (aka
Nastaleeq) version of the Perso-Arabic script, which is quite different
from the Naskh version that most other languages written in the
Perso-Arabic script use.

We have been reasonably successful (at least by our standards) in using
the Nafees Nastaleeq font from CRULP for typesetting Urdu interlinear text
in XeTeX.  Because of the nature of interlinear text, we relegate the
Arabic script of the Urdu to a separate non-aligned line of text, above
the word-aligned left-to-right Roman transliteration and gloss lines. 
Often that means that the Urdu text in Arabic script is less than the page
width, in which case it doesn't need to be justified; but occasionally
that conceptually single line of Urdu text wraps on the printed page, in
which case I suppose these issues of justification arise.  Besides, we
might want to typeset entire paragraphs of Urdu text.

   Mike Maxwell
   CASL/ U MD