[XeTeX] Position of kasra when used together with tashdid in Arabic

[Khaled Hosny]

On Thu, Jul 08, 2010 at 06:14:06AM -0700, Meho R. wrote:
> Hi,
> 
> This issue is bothering me for some time now: when kasra and tashdid are used
> together, kasra gets positioned just below tashdid instead of below the actual
> letter. This is a well-known issue and some workarounds have been made (e.g.,
> reversing the order of writing, first kasra, then tashdid). However, I still
> haven't find a proper way to solve this with XeLaTeX. I tried with some custom
> LaTeX commands (\raisebox and similar), but the problem is, if you enter a
> command in the middle of a word, the link between letters is broken (e.g.
> instead of سُيِّرَت one gets سُىِّ رَتْ). Does anyone know if there's a way to move
> kasra below the letter instead of below tashdid only?

You make it sound like a bug! This is standard typesetting practice
since 1912 when Ahmad Zaki Pasha opted for it over the, then more
common, kasra bellow base character, citing better readability, which
was then followed by the royal press and other printing shops in Egypt
(the actual introduction of kasra below shadda dates much older than
this).

That being said, the position of kasra relative to shadda is up to the
font designer. For example I prefer the more traditional behaviour in my
fonts, while fonts like Scheherazade make sure that both <shadda><kasra>
and <kasra><shadda> render kasra bellow shadda, so reordering will not
work here.

Regards,
 Khaled

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer