Walter
On the MS Windows + OE system where I'm reading your message the results of
both sequences in your examples look identical - with the combining mark
centred over the right hand vertical stroke of the first glyph (which is
modified). Since I don't know Thai I cant tell whether or not this is correct.
If you are using an OpenType font there could be a problem with the lookups in
the particular font or in the order in which the lookups are applied.
There could also be a problem due the order in which the characters are stored.
This may be dependant on whether you are using a Thai "code-page" or Unicode as
your characterset (and sometimes whether or not the text has been "normalised")
Unicode always expects combining characters to be stored *after* base
characters while I understand that some 8 bit Thai encodings expect certain
vowels characters *before* the consonant which they apply to.
Of course Font lookups usually assume a particular character order. In the
case of OpenType fonts I'd expect them to be built assuming the order specified
in the Unicode & ISO 10646 standards.
If the vowel mark and tone mark characters have different "canonical combining
classes" specified in the Unicode standard they could also be getting
re-ordered in any process of "normalisation" that may be going on. Typing an
extra character may be overriding / or preventing this.
- Chris
--
CJ Fynn
----- Original Message -----
From: "Walter Betschart"