Re: News of AFII: international standard registry of glyp...

From: Werner LEMBERG (
Date: Tue Dec 22 1998 - 03:22:54 EST

          You suggested that the industry may not be ready for 32-bit
          codes. I had not thought about that. Glyph IDs in TrueType
          fonts are 16-bit, I believe, so that is an issue for
          TrueType. Also, you're very right that numbers are much
          less useful for working with glyphs than mneumonic strings.

I don't think so. There shouldn't be a relation between glyph IDs and
input code points at all in TTFs! Cmaps have been invented to
establish the needed relationship.

          You also suggested that Unicode is adequate as a glyph
          encoding for many purposes. Apparently, Adobe is thinking
          along those lines. It is a serious concern for us if they
          decide to carve up the private use area and try to
          quasi-standardize it. We may need to make heavy use of PUA
          for scripts that we work with that are not close to being
          standardized in Unicode. What I have seen of what Adobe
          wants to put into their are mostly glyph variants, which
          don't need Unicode values if one has a smart rendering

I don't see the problem. You can always populate the PUA with your
own scripts; you don't need to care of any of these assignments! If
you properly separate input encoding from glyph addressing, no
problems will occur. E.g., you can assign to code U+F012 your `foo'
glyph, and at the same time you access glyph `uniF012' mapped to
another code point.

The overlapping of the Private Use Area and the Corporate Use Subarea
is only a concern if you want to do a 1-to-1 Unicode->Glyph mapping
(e.g. for unknown glyphs or glyphs which can't be handled by your
rendering system) -- of course, it's a shame that even recent software
written by Apple, Adobe, or Microsoft still rely on the 1-to-1
Unicode->Glyph model...

          Adobe has said that they're working with Microsoft on
          OpenType (see the first quotation above). If the two of them
          got OpenType right, Adobe wouldn't need to assign PUA values
          to glyph variants. Unfortunately, Adobe and MS appear not to
          have had much success in figuring out complex script
          rendering issues in OpenType.

Exactly this is the problem. Direct Unicode->Glyph mapping is *soo*


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