Re: Arabic letters separated by markup

From: John Hudson (
Date: Sat Jun 11 2005 - 14:05:14 CDT

  • Next message: John Hudson: "Re: Arabic letters separated by markup"

    Kent Karlsson wrote:

    >>>(always) be blocked over markup tags.
    >>But if one letter is at 20pt and another is at 12pt, how can
    >>the form a ligature?

    > I wrote: BLOCKED.

    I think I misinterpreted that term: I took it to refer to a 'block' of text that included
    text on either side of the markup tags. My mistake.

    >>as you change the font, you
    >>are dealing with completely separate runs of glyphs that will
    >>be independently shaped.

    > Are you saying that you cannot process ZWJ?

    ZWJ is a character, and it plays a role in glyph processing either directly or indirectly.
    ZWJ is part of the text, while something like html markup is not part of the text.

    > That way the shaping behaviour, both for cursive joining and for
    > ligature
    > formation, is the same independently of whether it is just a colour
    > change,
    > a size "change" (regardless of if the the new size is the same as
    > before), or
    > style "change" (regardless of if the the new style is the same as
    > before), etc.

    I'm not sure that I follow all of this. As I wrote before, I can see some possibilities
    for handling basic Arabic shaping, i.e. substitution of positional forms, regardless of
    intervening markup, and colour is a relatively trivial and separate issue since it is in
    no way font-specific. But I don't see at all how something like this


    Can be correctly rendered, with an obligatory ligature, without either ignoring the markup
    or applying it to both letters.

    John Hudson

    Tiro Typeworks
    Vancouver, BC
    Currently reading:
    Truth and tolerance, by Benedict XVI, Cardinal Ratzinger as was
    War (revised edition), by Gwynne Dyer

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