Re: Windows Glyph Handling

From: Philippe Verdy (
Date: Thu Aug 25 2005 - 05:53:17 CDT

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    From: "Christopher Fynn" <>
    > Adam Twardoch wrote:
    >> Currently, there is an international character encoding standard
    >> (Unicode/ISO 10646) and there will soon be an international standard for
    >> digital glyph storage in a font format (with OpenType being
    >> standardized). However, the "glue" between these two is a proprietary
    >> Microsoft technology, with no proper submission process and unsufficient
    >> resources within the Microsoft Typography group.
    > Is OpenType really being "Standardized" (or just becoming a standard font
    > format) and what exactly does this mean?

    Note that a standard does not mean that it will not be proprietary as well
    (see MPEG4...); however, to be an international standard, its specification
    mst be available to everyone without discrimination, possibly with a
    reasonnable fee, and its implementation also available from one or more
    sources (proprietary or open-source), with open licensing terms allowing
    redistribution (under conditions, which may involve the payment of a
    reasonnable fee).

    > Will the specs for shaping each complex script (now kind of a separate
    > appendix to the OpenType specification and currently determined by
    > Microsoft) be part of this standard?

    OpenType will just be the format for fonts, and the specification of all its
    feature tables used and needed for interoperability (excluding optional
    proprietary extensions only needed for specific applications or systems).
    But it won't work without the specification of the required interface used
    by Uniscribe.

    Uniscribe is unlikely to become a standard for now, but it should be
    replaceable by other layout engines, without breaking the OpenType
    compatibility contract. The problem is that Uniscribe is not replaceable by
    a Open-Type compatible layout engine, because Uniscribe also uses a second
    interface to the rendering engine (GDI(+), DirectX, and probably others
    possibly in a multi-layered architecture...) and to user-level GUI
    components (the Windows User API) such as carret management, whose
    specifications are closed and probably not even standardized across Windows

    But OpenType can be used on MacOSX or Unix/Liux without Uniscribe. They also
    have their own interface to the graphic renderer and to applications.

    The common part however is the specification of the algorithms that layout
    engines should implement to use the embedded feature tables within OpenType
    fonts. So there's effectively the need to define compliance rules and levels
    when describing those OpenType features, so that designed fonts will work
    across systems.

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