[texhax] Justification through glyph variants

[Philip TAYLOR]

Joel C. Salomon wrote:

> In some older Hebrew books, and in Hebrew calligraphy, a technique used
> to align text to the outer margin is stretching letters.  Certain
> letters are particularly stretchable; in fact, Unicode has several "wide
> letters" encoded in the Alphabetic Presentation Forms area.
>
> For reference, compare:
>
>     א = ﬡ, ד = ﬢ, ה = ﬣ, כ = ﬤ, ל = ﬥ, ם = ﬦ, ר = ﬧ, ת = ﬨ.
>
> At any rate, is there any way to make (any version of) TeX use these to
> help justify lines?

I personally know of no way of instructing TeX to consider these when
optimising the layout of a paragraph, but Hàn Thế Thành's microtypographic
extensions to PdfTeX offer an alternative.  It seems to me that, in
an ideal world, what one would actually want is a combination of the two
such that given (for example) "ת" and "ﬨ" as the lower- and upper-
bound respectively, a variant of Thành's work might usefully interpolate
between the two.  What this might add to the complexity of TeX's already
complex paragraphing algorithm [2], I do not like to think !

Philip Taylor
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[1] http://www.tug.org/TUGboat/tb21-4/tb69thanh.pdf
[2] http://onlinelibrary.wiley.com/doi/10.1002/spe.4380111102/abstract;jsessionid=20FB682D495BBFC15B1C9A9A826ED42F.d03t01?systemMessage=Wiley+Online+Library+will+be+disrupted+3+Dec+from+10-12+GMT+for+monthly+maintenance