Re: Font Technology Standards

From: Frank Yung-Fong Tang (ytang0648@aol.com)
Date: Wed Mar 03 2004 - 10:24:03 EST

  • Next message: Antoine Leca: "Re: Font Technology Standards"
    BDF is also widly used, although the quality and features is not that powerful these day.

    Also, there are other "standard" about the font:
    1. Glyph set "standard"- how to make sure one font contains all the glyph for a particular group of users- for example- WGL4 is a glyph set standard from MS for pan european users.
    2. Glyph naming standard- how to name a particular glyph. I remember Adobe have a "standard" glyph naming scheme for at least Cyrillic Glyph. This is needed to put the common glyph name into a PostScript font /TTF font.

    And I am sure the following DOES NOT exist although I hope there we can have one day- Glyph Encoding Standard. Map a glyph to a fixed glyph ID. (The Arabic presentation block A and B sort of like this one)  For example, it will be much easier for people to understand the Indic font if there a INFOS glyph mapping standard for all their indic fonts.


    Bob_Hallissy@sil.org wrote on 3/3/2004, 3:52 AM:


    Not sure exactly what you are looking for because "Font Technology" covers a broad spectrum, but a *simplified* picture might be something like the following:

    First, we should distinguish bitmap font technologies from scalable font technologies ... I assume you are more interested in the latter.

    For scalable fonts, there are a number of fundamentally different ways to describe the curves: Postscript outlines are based on bezier curves, TrueType outlines on quadratic curves, and I can't remember what Metafont is.

    The next level is how you package the individual glyphs into a font:
            Postscript type1 fonts -- bundle up Postscript outlines
            TrueType fonts -- bundle up TrueType outlines
            OpenType fonts -- bundle up either TrueType or Postscript outlines (and bitmaps)
    and there are others.

    Next level is how you encode into the font the smarts for complex rendering. At least three technologies utilize extensions of the TrueType font:
            OpenType from Microsoft & Adobe
            GX and AAT from Apple
            SIL Graphite from SIL

    (Note that the TrueType file structure is inherently extensible, and OpenType, GX/AAT and Graphite fonts are TrueType fonts with extra tables. Because of this people often interchange and blur the terms "TrueType" and "OpenType".)

    As is common in this world, at each level the various options each have pros and cons.

    Bob

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