Re: Combining diacriticals and Cyrillic

From: Philippe Verdy (
Date: Fri Jul 11 2003 - 07:15:14 EDT

  • Next message: Kent Karlsson: "RE: Ligatures in Turkish and Azeri, was: Accented ij ligatures"

    On Friday, July 11, 2003 12:14 PM, Jungshik Shin <> wrote:
    > 'OS' here has to be interpreted a bit broadly to include 'APIs and
    > toolkits' used in text rendering. I guess that's what you meant.
    > For instance, on Win 9x/ME, MS IE that (appears to) use Uniscribe
    > APIs directly can render complex scripts but Mozilla that uses
    > standard Win32 Text APIs (such as TextOut) does not as well (except
    > for Thai, Arabic, Hebrew, Tamil and Korean for which it has built-in
    > glyph-based solution).

    The Win32 Text APIs (such as TextOut) actually DO support UniScribe transparently on Windows XP... In most applications, this means that the UniScribe support works without requiring explicit calls to the Uniscribe API.

    So there's a difference in terms of usable APIs: on Win9x/ME, the basic Win32 Text APIs don't have UniScribe support built-in, but the UniScribe API is available separately as an additional system component (installed with Internet Explorer which uses it if available). On Windows XP, an application can use either the Basic Win32 Text API, or the UniScribe API for finer controls of glyph substitutions according to user preferences and customizable or dynamic locales.

    However on XP, UniScribe is only installed if one user selects (in the regional settings) the support for complex scripts (includes the minimum system support for Hebrew, Arabic, Thai, Vietnamese). This support can be installed even if the regional locale data and fonts for these scripts and languages are not loaded.

    I don't know why UniScribe is not always installed by default, as it is also useful for Latin, Greek and Cyrillic (the regional settings checkbox label is quite confusive as users may think they they don't need it for their language, and it should have been better named "Support for text rendering using Unicode combining sequences", or just "Support for UniScribe and OpenType fonts" with some accessible help, explaining its interest such as the use of linked fonts for missing glyphs or additional glyph substitution tables, which allows the Arial font to be internally linked to Arial Unicode MS, or Lucida Console to be linked to Courrier New, or allows the browser to create and use an internal "sans-serif" font linked to a stack of fonts customized according to per script user preferences, and stylesheets).

    This archive was generated by hypermail 2.1.5 : Fri Jul 11 2003 - 07:58:41 EDT