From: Richard Wordingham (email@example.com)
Date: Thu Mar 23 2006 - 14:41:11 CST
Philippe Verdy wrote:
>From: "Richard Wordingham" <firstname.lastname@example.org>
> I don't know what you designate by the "base character", because in Indic
> scripts it happens quite often that this base character (around which
> diacritics and other letters are visually composed) is encoded in the
> middle of the cluster, or that the first encoded character will appear in
> the middle of the string of glyphs that compose a cluster.
By 'base character' I meant the first consonant of the cluster in the
> For Unicode, the base character is not that one, it's only the start of a
> combining sequence, and we all know that a combining sequence is less than
> an Indic cluster (notably when there are multiple consonnants separated by
> halant so that some of them are dead consonants, or when there are ZWNJ
> and ZWJ at end of a consonnant cluster).
Is it appropriate to call a Unicode virama acting as a control character a
halant? I thought a halant was a visible mark.
> But I still don't know any locale-sensitive conjunct that has special
> reordering or composition rules (The encoded Marathi letters in the
> Devanagari block for example don't have final dandas, so the half-form and
> repha problem does not apply to them and they apparently don't need
> complex reordering rules, but there may be cases where subjoined forms may
> occur and should be controled, complexifying the regexps that the font
> reordering algorithm uses to match the cluster patterns and then select
> their corresponding string of glyph ids.)
Hindi and Sanskrit apparently have different rules for when a conjunct is
preferred to the use of a half-form. Reportedly almost every consonant or
conjunct in Marathi has a half-form, even though the half-form may look like
the full form plus halant. (It can't be a halant, because the short i-matra
precedes the half-form. :-)
> My opinion is that a font has to match a style that first works according
> to a single locale, and that locale variations are defining a new,
> separate style, which should be supported in another font, or in a
> composite OTC font with alternate names to match those styles. In that
> case, no specific "feature" must be selectedor enabled by the application,
> it just selects the font by name according to the expected style.
Isn't this 'locale' feature what the OpenType 'language system' is for?
This archive was generated by hypermail 2.1.5 : Thu Mar 23 2006 - 14:46:26 CST