Re: RTL PUA?

On 08/22/2011 09:31 PM, Doug Ewell wrote:
> Philippe Verdy<verdy underscore p at wanadoo dot fr> wrote:
>
>> As well, the small properties files can be embedded, in a very compact
>> form, in the PUA font.
>
> As soon as you embed all the information in the font, you require
> different solutions for systems that use different font technologies.

Why? In the end all the systems base upon the character properties
specified by the standard. For the PUA characters in question, what is
needed for a table of properties to override the default ones. The
systems would then handle those new properties in the same way that they
would handle the regular ones. Granted, if the renderers hardcode the
properties (as most OT ones do) then some parsing is required to import
all the override data provided by the extra font table into a struct or
such -- after which (I presume) it would be possible (to a large
extent?) to treat it the same as an encoded script. [Actually, this
seems quite difficult to implement in OT, where the philosophy is to
explicitly hardcode the properties, but Graphite and AAT should be fine
I guess.]

> I generally assume there is more to character handling than display.

True -- so if someone wanted a PUA script to be handled properly in
sorting etc one would have to prepare collation tables which would
obviously go *outside* the font.

-- 
Shriramana Sharma