Re: Devanagari composing help needed

From: John Hudson (
Date: Thu Jun 07 2007 - 13:58:55 CDT

  • Next message: Jeroen Ruigrok van der Werven: "Re: Devanagari composing help needed"

    Eric Muller wrote:

    > I think that what Ambarish is telling is us is that what Unicode has
    > described as RA_sub (see rule R6 in section 9.1), aka vattu in OpenType,
    > should really considered as made of two parts, one stroke for RA and one
    > stroke for a halant.

    > In everything I have seen from Unicode and OpenType, vattu is viewed as
    > an atomic object, and is graphically depicted as two connected strokes.
    > Is it common to display a vattu as two disconnected strokes?

    No, it is not common, although arguably the floating ^ rakar (vattu) might have originally
    derived from a combination of a low-left-to-high-right 'RA_sub' stroke and
    high-left-to-low-right halant stroke. Even in manuscript, though, there would have been
    little impetus to write them separately: why lift the pen when you don't need to?

    It looks to me like what the font in Jeroen's screenshot is doing is representing the
    'RA_sub' in a way that will create merged rakar forms on-the-fly. When 'RA_sub' merges
    with a letter, it is represented by a single stroke like this. These are most commonly
    represented by precomposed glyphs, but it is possible to build them using a stroke like
    this, although I think this is a bad idea for a number of reasons. In this case, the
    problem is that 'RA-sub" does not merge with all letters, and does not merge with
    round-bottomed letters like ट. So I consider this diagonal stroke cutting through the
    bottom of ट to be an incorrect representation of rakar in this context. It looks to me
    like this font simply implements the rakar, by default, as a single stroke, which can be
    positioned to create on-th-fly merged rakar forms with most letters but which looks
    incorrect with certain letters.

    John Hudson

    Tiro Typeworks
    Gulf Islands, BC
    We say our understanding measures how things are,
    and likewise our perception, since that is how we
    find our way around, but in fact these do not measure.
    They are measured.   -- Aristotle, Metaphysics

    This archive was generated by hypermail 2.1.5 : Thu Jun 07 2007 - 14:00:41 CDT