[XeTeX] Arabic ligatures
musaf at runbox.com
Tue Jul 6 00:49:19 CEST 2004
On 6 Jul 2004, at 00:02, Jonathan Kew wrote:
> On 5 Jul 2004, at 9:12 pm, Musa Furber wrote:
>> I started playing around with Arabic in XeLaTeX.
>> Geeza Pro works well, though it is not close enough to nuskhi (the
>> model for printed books) or thuluth (the model for Qur'an) for my
>> Al Bayan Plain is closer. Unfortunately, something odd is happening
>> with the ligatures.
>> Compare this sample using Geeza Pro:
>> with the same using Al Bayan Plain:
>> Notice that in the Geeza sample, there is an alif. It's the vertical
>> line to the left of the blank space between the two words. That alif
>> is missing in the Al Bayan sample.
>> I checked the sample in TextEdit, which takes advantage of typography
>> gobbledygook. The same thing happened here as with XeLaTeX.
>> I then checked the sample in Mellel, which does not seem to use
>> typography gobbledygook. There, Al Bayan did not lose its alif.
>> So, the problem is not XeLaTeX.
>> Can anyone suggest a solution around this?
> Well, it's clearly a bug in the AAT tables in Al Bayan. It's got a
> ligature rule to access a special glyph for "Allah", but the ligature
> glyph doesn't actually include the initial alef. I guess maybe Mellel
> is using some other way of rendering Arabic, not through ATSUI;
> perhaps it's using the Presentation Forms codepoints. (If so, I'll be
> very disappointed. But that's off-topic here.) Or perhaps it's just
> disabling optional ligatures.
In this bug, that font is not alone....
> I'll file a bug report with Apple re Al Bayan, but obviously it'll
> take some time before a fixed version appears.
...and perhaps Apple will take more note since other fonts share the
> Meanwhile, I suppose you could insert a zero-width non-joiner between
> the alef and lam, to prevent the ligature formation; but it will
> prevent getting the special ligature for "Allah". And you don't really
> want to clutter your text like that. Better to use a different font.
> Does Baghdad look any better than Geeza to you? Or how about DecoType
> Naskh, if you have it; I'm not sure which systems that shipped with.
...like Badghdad and DecoType Naskh.
Too bad, too, since the Baghdad and Naskh fonts looks better. Or should
I say "font"? I have them both and they look identical.
I would rather clutter up my TeX file than cripple my output file.
Thanks for the suggestions.
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