Re: Sequential Fathatan Final Form (Items 9 and 10)

[Mohammed Yousif <mhdyousif at gmx dot net>]

On Wednesday 16 June 2004 19:30, Mete Kural wrote:
>
> Doing the dynamic glyph substitution at the text
> client level would be a very redundant approach.
> Again, I am not that familiar with the way font are
> served in Linux, but in Windows all programs share
> Uniscribe functions to handle OpenType shaping
> behaviour.  There is no need to write this code in the 
> text client.

 Uniscribe is not magic, it's has an API that you have to use for
 all your applications to support OpenType.

> For instance I can open up the dumbest 
> text client in the world, NotePad, and still write
> Arabic text in elegant Quran'ic typography using the
> Arabic Typesetting font. Obviously NotePad knows
> nothing about complex Arabic shaping, it simply calls
> the Uniscribe functions for this shaping behaviour.
>

  That's what abdulhaq is talking about, calling Uniscribe API is
  not as obvious as it seems it still involves coding.

  Out of curiosity, what version of Windows are you using? I have been
  told that most applications doesn't support opentype tables
  For example, Office XP doesn't support any of the advanced features of
  OpenType (including layout tables)

> > Therefore, it can involve a lot of C++ code in fact.
> > This code resides (in
> > linux for instance) in Qt, Pango etc. etc. What
> > about apps that don't use
> > these librarys or where the libraries are not fully
> > compliant?
>

  Abdulhaq, I'm interested to know about that, the last time I checked
  Qt didn't support OpenType layout tables at all. Not sure about Pango
  but I tried gedit and it failed to handle OpenType tables.

> In order to support OpenType, you have to upgrade the
> text client to support OpenType, there is no other way
> around it. And yes it will take some programming to
> support OpenType. But once OpenType is supported then
> the text client can simply depend on a rendering
> engine to handle all shaping behaviour.
>

  But you still have to embed all the necessary functionality in every
  font you make.

> > On Windows you have uniscribe to do the job if the
> > programmer  accepts
> > default substitution behaviour. Is your solution
> > only for those willing to
> > pay the MS tax to view qur'aan;-)?
>
> No, of course not. OpenType is meant to be a
> cross-platform font format. 

  Supporting only Mac and Windows, they call it cross-platform and yes
  FreeType can handle a subset of it but still it has patent problems.

  To be honest, I don't want to rely on thus proprietary technology in
  something as standard as Unicode. (You are essentially handing the 
  Standard to Microsoft and Adobe here)

> This means that you can 
> take the specification and implement it on any
> platform you wish. This Indian Linux group claims that
> they have succeeded in supporting OpenType on Linux,
> maybe you might want to contact them and ask for their
> help:
> http://www.ncst.ernet.in/projects/indix/technical_details.shtml
>
> They say they did this by adding OpenType font support
> in Xserver. So once OpenType support is part of the
> Xserver then text clients can simply call the
> necessary functions in Xserver to handle the shaping
> behaviour.
>

  I have heard of that but I think FreeType has better support.

-- 
Mohammed Yousif
Egypt