[NTG-context] Open Type trickery [was Re: Encoding and mapping glyphs from an expert font

Adam Lindsay atl at comp.lancs.ac.uk
Sun Apr 10 17:29:20 CEST 2005

Idris Samawi Hamid said this at Sat, 9 Apr 2005 19:27:21 -0600:

>On Sun, 10 Apr 2005 00:22:31 +0100, Adam Lindsay <atl at comp.lancs.ac.uk> 
>> But wait, where are you coming from? Are your source fonts really Minion
>> .pfbs, or are they from OpenType? With OpenType, you can use some nice
>> TeXFont stuff to select the features (OSF, SC, alternates) without having
>> to draw from two arbitrary encodings.
>I am very interested in the Open Type trickery. I have been wrestling for 
>quite some time about the problem of multiple accents over ligatures in 
>Arabic. I can do it in Aleph but the present procedure (due originally to 
>Yannis) is much too slow and cumbersome, especially when dealing with huge 
>fonts (my present virtual ovf has about 10,000 characters!). I finally 
>found a solution that OpenType might help with--multiple glyphs for one 
>character. I can implement this without OpenType, but OpenType opens the 
>possiblity for word searches in Acrobat of Arabic text, something that is 
>well-nigh impossible with the usual pfb approach.

I have to admit that last issue is one that I've stepped lightly around.

>While we will still need huge fonts, the processing of complicated accents 
>should be much faster with the approach I have in mind (smaller otp's and 

It sounds a bit tricky with the eTeX line, because of the 256-character-
per-TeX-font limit. Not necessarily impossible, but certainly
contortionate. I'm led to think about XeTeX--a fair number of people on
the list are happy with the AAT/OpenType support they get with some very
sophisticated Arabic fonts. And when you consider the educational price
of a Mac mini, you're still way below the price of some software
packages... :)

> Do you think TeXFont can be tweaked to generate ovf's and ofm's as 

From my experience, it's certainly possible. For it to be done, it needs
a confluence of time, motivation, and expertise!
 Adam T. Lindsay, Computing Dept.     atl at comp.lancs.ac.uk
 Lancaster University, InfoLab21        +44(0)1524/510.514
 Lancaster, LA1 4WA, UK             Fax:+44(0)1524/510.492

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