[HarfBuzz] Thai shaping and dotted circle

[Theppitak Karoonboonyanan]

On Tue, Oct 1, 2013 at 5:49 AM, Richard Wordingham
<richard.wordingham at ntlworld.com> wrote:

> I am wondering whether this particular combination is being entered
> deliberately.  I got over a million raw Google hits on "อีีก"; "อีก"
> means 'additional, extra', so it could be an expressive writing of the
> word rather than an unnoticed typing error.

For most cases, it's the latter, because some systems render both just
the same, including the current Harfbuzz, although the extra vowel may
cause a little more thickness, but that's hardly noticable.

The old Pango distinguished these with dotted circle, so the error was
easily spotted, but that raised issues on minority languages.

Relying on 'mkmk' is a little bit costly, as it would need two sets of glyphs
under different GDEF's for each combining vowel. And currently, most
fonts are not prepared for this. However, it looks more feasible to cover
minority languages.


Regards,
-- 
Theppitak Karoonboonyanan
http://linux.thai.net/~thep/