RE: Generic base characters

From: Kent Karlsson (
Date: Sun Jul 15 2007 - 15:44:57 CDT

  • Next message: Asmus Freytag: "Re: Generic base characters"

    Peter Constable wrote:
    > Uniscribe inserts a dotted circle glyph only when the author has not
    > included a valid base character for the mark.

    There is always a base character for any non-empty sequence of combining
    characters in a text. If there is no explicit one (it occurring at
    beginning text or after a control character), NBSP is the implicit base
    character. (It is probably best if rendering engines insert it during
    rendering, to get consistent behaviour, esp. w.r.t. explicit NBSP in
    the text.)

    There is no notion of "invalid"/"valid" base character for a combining
    character in Unicode.

    > Perhaps you have in mind that a font developer should control what glyph
    > is used in that situation, but I see a need, on the assumption that
    > authors should, and normally are, explicitly intentional about what is in
    > their document, and that Uniscribe's fallback rendering is just that: a
    > fallback.

    No, it is:

    > A bug, which can be looked at.

    No dotted circle is to be inserted by any rendering engine or by any font.
    The only dotted circles to be rendered are those explicitly in the text.

            /kent k

    This archive was generated by hypermail 2.1.5 : Sun Jul 15 2007 - 15:48:51 CDT