Distinguishing COENG TA from COENG DA in Khmer script

[Richard Wordingham]

On Wed, 24 Jun 2020 08:29:38 +0900
Martin J. Dürst <duerst at it.aoyama.ac.jp> wrote:

> > ... In these usages, COENG TA and COENG DA are distinct, or
> > at least, TA and DA have distinct subscripts that are clearly
> > associated with them.
> > 
> > Is it legitimate for a font to deliberately render the corresponding
> > named sequences differently while claiming to respect characters'
> > character identities?  

> > I am therefore asking
> > here for advice on the legitimacy of such a request.  
> 
> I'm guessing that your request was either "How can I coerce a font 
> covering modern Khmer to show different glyphs for COENG TA and COENG 
> DA?" or "How can I create a font that will allow to show different 
> glyphs for COENG TA and COENG DA?"

The request would be made to the font by a combination of language and a
setting of OpenType features.

> The reply to the former question is probably "you can't because the
> font doesn't contain the necessary glyph". For the later question, I
> think it should be possible, unless there's some OpenType stuff for
> Khmer that gets in the way.

The OpenType question was closer to how do we make it easy to advise
people how to use co-operative fonts, if they exist.

> > Conceivably we need
> > a new character to make the distinction.  
> 
> Do you mean you want to make the distinction in modern Khmer fonts? 
> Would that be e.g. for words of Old Khmer that are cited in modern 
> Khmer, or something similar?

Something similar.  The application domain was Wiktionary.  I suspect
most people would be happier to see the words in a Modern Khmer style,
but not necessarily a modern Modern Khmer style.  The Angkorian styles
are quite different to the modern styles - unreadably so without practice.

My Unicode question is also relevant for fonts displaying Unicode text
in an Angkorian style.  It seems that they do exist, but complying with
TUS was probably low down on the authors' list of priorities.

Richard.