Re: ct, fj and blackletter ligatures

From: John Hudson (tiro@tiro.com)
Date: Sat Nov 02 2002 - 13:33:10 EST

  • Next message: John Hudson: "Re: ct, fj and blackletter ligatures"

    At 10:55 11/2/2002, Thomas Lotze wrote:

    >How does this compare to unmapped glyphs in Type1 fonts, which can be
    >made accessible by re-encoding the font? Are they hidden at a deeper
    >level, or is it essentially the same thing? Do they get glyph names so a
    >program that can parse the font file can identify and use them even
    >though they are not mapped?

    Unencoded glyphs in OpenType fonts (which use the TrueType sfnt table
    structure but may contain either TrueType or PostScript outlines) have no
    entries in the cmap table. It is possible to hack a font and add cmap table
    entries for such glyphs, so there is a parallel to re-encoding a Type 1 font.

    Yes, variant glyphs will have glyph names (unless, e.g. a format 3 'post'
    table is used, in which case no glyphs have names), and these can be
    parsed. For example, Adobe InDesign parses the names of some standard
    ligatures (ff fi fl ffi ffl) regardless of font format, so is able to do
    ligature substitutions for these without relying on glyph substitution
    lookups in the font. For information about glyph naming and its
    relationship to Unicode, see
    http://partners.adobe.com/asn/developer/typeforum/unicodegn.html

    John Hudson

    Tiro Typeworks www.tiro.com
    Vancouver, BC tiro@tiro.com

    It is necessary that by all means and cunning,
    the cursed owners of books should be persuaded
    to make them available to us, either by argument
    or by force. - Michael Apostolis, 1467



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