Re: Tamil glyphs

From: Antoine Leca (
Date: Mon Sep 11 2000 - 10:11:52 EDT wrote:
> Michael (michka) Kaplan wrote:
> > Unfortunately, this will not work, as vowel reordering must
> > happen, and will not if ZWNJ or ZWNBSP is included. [...]
> But ZWJ and ZWNJ should be the way to go for this kind of things, especially
> since they have been recently promoted to also represent ZWL and ZWNL
> (zero-width [non] ligator).
> It is very unfortunate that ZWNJ prevents Indic vowel reordering in this
> case.
> In ordinary cases, a ZW[N]J inside a consonant cluster does not prevent
> matra reordering. E.g., in Devanagari:
> U+0915, U+094D, U+200C, U+0915, U+093F (ka, virama, ZWNJ, ka, i
> matra)
> is regularly reordered around the cluster:
> 093F, 0915, 094D, 200D, 0915 (i matra, ka, virama, ZWNJ, ka)
> and rendered with this sequence of glyphs:
> i_matra, ka_nominal, virama, ka_nominal

I am not sure this is the only way to interpret the use of ZWNJ here.
Another way would be to consider the sequence ka+halant to be a separate
syllable, and then ka+i to be a second syllable. Then, the correct
rendering would be
          ka_nominal, virama, i_matra, ka_nominal

BTW, Microsoft's Uniscribe chooses the latter way.
Similarly (and this is perhaps linked), CDAC's engine chooses the same
"solution" for the ISCII-91 explicit halant (coded with two consecutive

> It would be nice if the possibility of reordering matras around a ZW[N]J
> could be generalized, e.g. if:
> U+0915, U+200C, U+093F (ka, ZWNJ, i matra)
> would regularly reorders as:
> 093F, 0915, 200C (i matra, ka, ZWNJ)
> producing the following sequence of glyphs
> i_matra, ka
> The ZWNJ would simply be there to prevent a hypothetical single-glyph
> sequence:
> ka_i_matra_ligature

What is the point?

Since (in the general case of a non-fixed typeface where glyphs are not
always of the same width) the i_matra have to adapt itself to the glyph
of the consonant, the usual form is merely

          i_for_ki_matra, ka

Do you want to prevent this adaptation as well? If yes, what rendering should
it looks like (depending of the font, the "default" i_matra varies greatly).


This archive was generated by hypermail 2.1.2 : Tue Jul 10 2001 - 17:21:13 EDT