At 04:21 AM 2/20/2001 -0800, Charlie Jolly wrote:

>Do fonts have to tie themselves to a script engine. Will an Opentype font
>for lets say Hindi such as MS Mangal work on an Apple OS or Linux? Or is
>this font tied to Uniscribe? If this is correct then shouldn't there be a
>better solution?

Mangal is not 'tied' to the Uniscribe script processing engine, but it does 
make assumptions about how it will be handled by such an engine. As Peter 
Constable has pointed out, OpenType complex script processing presumes that 
a shaping engine at the system or application level will handle some 
aspects of processing and will call appropriate, registered features in the 
font. Obviously, this means that OpenType complex script fonts have to be 
built with this in mind, and have to include those script shaping layout 
features that the engine expects to find. The MS Typography specification 
'Creating and Supporting OpenType fonts for Indic scripts' explains this in 
detail

         http://www.microsoft.com/typography/OTSPEC/indicot/default.htm

Similar documents for Arabic and Hebrew are currently in development.

The Apple AAT and SIL Graphite approach work a little differently. I'm not 
familiar enough with Graphite to know how they handle stuff like character 
reordering, or how difficult it is to achieve such things in their Graphite 
Description Language, but I do have some experience with AAT fonts. AAT 
avoids dependence on an exterior shaping engine by building a finite state 
machine into the font itself. This is an extremely powerful approach to 
glyph processing, but it has the significant development drawback of 
requiring font developers to build state tables. I don't think it reflects 
poorly on any of my type design colleagues to say that most of them are not 
up for this, and without higher level tools I doubt if many of them will 
ever make AAT fonts.

John Hudson

Tiro Typeworks     |
Vancouver, BC      |     All empty souls tend to extreme opinion.
www.tiro.com       |                                       W.B. Yeats
[EMAIL PROTECTED]        |     

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