Re: vertical direction control

From: Peter Kirk (peterkirk@qaya.org)
Date: Wed Mar 24 2004 - 13:30:12 EST

  • Next message: Michael Everson: "Re: vertical direction control"

    On 24/03/2004 05:49, Chris Jacobs wrote:

    >>It seems strangely inconsistent to me that Unicode has detailed controls
    >>for horizontal layout direction and the complex bidi algorithm, but has
    >>nothing for vertical layout. I can force Latin text to be rendered right
    >>to left or Hebrew left to right (although such overrides are hardly
    >>plain text issues), but there is no way I can select vertical layout
    >>even for languages in which that is a normal way of writing. We already
    >>have U+202A LEFT-TO-RIGHT EMBEDDING and U+202B RIGHT-TO-LEFT EMBEDDING.
    >>It would be easy to define new characters TOP-TO-BOTTOM EMBEDDING and
    >>BOTTOM-TO-TOP EMBEDDING, with similar scope until the next PDF
    >>character.
    >>
    >>
    >
    >Which scripts are written bottom to top in vertical layout?
    >
    >If I remember well then both latin and hebrew script are written top to
    >bottom.
    >
    >
    >
    >.
    >
    >
    >
    I think we are talking at cross purposes here. You are talking about the
    direction of successive lines. I was thinking of the direction of
    characters. That is what I thought the original question was about, and
    it is certainly what most of the ongoing discussion has been about.

    I don't know of any scripts in which the ordering of lines is bottom to
    top. But in scripts in which the character direction is top to bottom
    the column direction may be right to left (e.g. Chinese) or left to
    right (e.g. Mongolian).

    -- 
    Peter Kirk
    peter@qaya.org (personal)
    peterkirk@qaya.org (work)
    http://www.qaya.org/
    


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