Re: Question about the directionality of "Old Hungarian" (document N3531)

From: John Hudson (
Date: Mon Nov 03 2008 - 18:39:22 CST

  • Next message: Asmus Freytag: "Re: Question about the directionality of "Old Hungarian" (document N3531)"

    Kent Karlsson wrote:

    > It does NOT cover the RTL case, as I wrote. There is not
    > even a loophole (which I think is a bad approach anyway) in
    > the bidi algorithm that would cover Old Hungarian as RTL
    > overridden as LTR to even sometimes produce mirrored glyphs.

    POI: there is an OpenType working group who are spec'ing new layout
    features for LTR/RTL *glyph* mirroring, for inclusion in the v1.6 of the
    OT spec. Unicode provides for some mirroring at the character level,
    while other mirroring must happen at the glyph level, which implies font
    features; and of course the result of glyph mirroring must not reverse
    the result of character mirroring.

    I believe this approach will resolve the kind of glyph mirroring issues
    Kent describes. Indeed, Old Hungarian came up in our discussions as an
    example of a default RTL script that might require an <ltra> variant
    GSUB feature.

    John Hudson

    Tiro Typeworks
    Gulf Islands, BC
    You can't build a healthy democracy with people
    who believe in little green men from Venus.
                        -- Arthur C. Clark

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