Re: Vertical BIDI

Date: Mon May 17 2004 - 15:28:42 CDT

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    fantasai scripsit:

    > (context: )
    > Notice that in B, the Chinese and the English are going
    > in opposite directions, even though they're both LTR scripts.

    That's because the English is rotated and the Chinese is not, and
    rotated text has no native directionality. Looking at the spines of my
    Latin-script books, the bulk of them have rl block progression and have
    the baseline on the left, but there are a few -- notably the ones in
    German -- where the baseline is on the right (and the block progression
    is presumably lr, though I don't happen to have an example where there
    are two lines on the spine in lr progression).

    The schema of your note best handles Ogham as a L2R horizontal script,
    leaving its vertical behavior to be handled by the "natural" orientation
    style in lr progression.

    Also, it's not just punctuation marks that need to get vertical glyphs
    in vertical formats, it's also things like BOPOMOFO LETTER I.

    > Another problem is mixing Arabic with Chinese and having both
    > of them read down. Because shaping happens after reordering [1],
    > you need to use BIDI to get the shapes, but not use BIDI when
    > you're actually ordering the text....

    I don't understand this. Presumably Arabic read down *has* to have the
    baseline on the right, or the shaping behavior won't work at all --
    letters are meant to link to their successors, not to their predecessors.
    I notice that one of your horizontal Chinese/Mongolian samples effectively
    abandons Mongolian shaping altogether.

    A witness cannot give evidence of his           John Cowan
    age unless he can remember being born.
      --Judge Blagden                     

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