Re: Arabic cursive in Unicode


Peter T. Daniels wrote:
Danny wrote:
Andreas Prilop wrote:
On 21 Nov 2006, Danny wrote:

I'm trying to draw up a table of Arabic cursive characters for a text
editor: I want to take the raw data and translate into a sequence of
cursive variants.

What do you mean by "cursive characters", "cursive variants"?

I mean that I need to take the 'actual' characters (in the 06 range)
and convert to the presentation forms (in the F range). This is in
order to make my own Arabic rendering engine (bypassing the OS)

What do you mean by "presentation forms"? All the "isolated" shapes of
letters can occur within or at the end of words -- the "four" shapes of
Arabic letters exist only because some letters can connect with letters
on both sides, and some can connect only with letters before them (to
their right).

I mean exactly what I think you think I mean :) I mean the four (or
two, or one) variants of a letter (or ligature) that are displayed
according to its position within a word. I'm pretty sure the term is
the one used by Unicode - I was reminded to use it by Andreas' post.


Note that, back in Apple's Worldscript I, which was how you typed
Hebrew and Arabic back in System 7, the standard Arabic font (which
fitted into 256 characters minus control characters) accommodated
Arabic, Persian, and Urdu (certainly the three most used Arabic-written
languages) -- but a few of the vowel points were omitted, such as the
dagger alif and the wasla. It did the contextual forms automatically
and even handled the most common ligatures.

Then someone came up with the predecessor of Open Type, which was
called GX, which could do a very good job of imitating a handwritten
text (so many ligatures included), but the Arabics that come with
Windows these days have regressed.

Yes, this is the problem. I don't quite understand why the makers of
Arial (is it Monotype?) and other big-name fonts didn't just go the
whole way and include the whole damn' Unicode set, rather than just the
ones they thought people were least likely to miss. Goodness only knows
what I'll encounter when I start to tackle Chinese...

Danny

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