Re: Open-Type Support (was: Greek Prosgegrammeni)

From: John Hudson (
Date: Wed Nov 22 2000 - 13:14:22 EST

At 08:05 AM 11/22/2000 -0800, Lukas Pietsch wrote:

>Mind that the case-mapping question we were discussing is just one minor
>aspect of the issue; the main task is much more general, and at the same
>time more straightforward (If we leave aside the issue of automatic case
>conversion and the fancy problems of, let's say, small-caps): the decomposed
>character sequences simply need to be mapped to the precomposed ones. It
>affects not only the iota subscripts/adscripts but also all the other
>diacritics. Without some glyph processing most combinations will never
>display readably. Since the precomposed glyphs already exist as Unicode
>codepoints, I suppose that the implementation would probably not even be
>very difficult, and not much of it would even depend on the individual font,
>would it?

Mapping decomposed character sequences to precomposed is not something that
necessarily needs to be done in a font, or even in a script shaping engine
like those in Uniscribe. This could be handled entirely at the IME level
(e.g. as a simple extension of keyboard input). Font level glyph processing
is particularly adapt at handling character-to-glyph and glyph-to-glyph
manipulations, character-to-character manipulations can be handled almost
anywhere in an input process.

>By the way, I wouldn't agree with Kenneth that it wasn't a good idea to have
>the precomposed characters in Unicode in the first place. I'm very glad they
>are there, since, as we see, the beautiful smart rendering features we are
>talking about are simply not yet available in mainstream text processing

The counter argument could be made: that if Unicode had not accepted so
many precomposed diacritic characters, especially in the Latin blocks,
smart rendering software would have become mainstream much sooner. It is
unfortunately true that, if smart rendering were necessary to process
German and French, it would have been a priority many years ago.

John Hudson

Tiro Typeworks |
Vancouver, BC | All empty souls tend to extreme opinion. | W.B. Yeats |

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