Re: RE: TTF and Unicode surrogates

From: Rick McGowan (
Date: Fri May 15 1998 - 20:20:01 EDT

Anyway, all the joking aside... In the Plane 1 "vision", there are a number
of complex scripts to be encoded. I think it's a bit of a problem that TT
decided to, yet again, conflate the notion of "font encoding vector" with
"character code". Yes, I know that TT fonts are supposed to be omniscient &
understand how to lay themselves out... but people still get stuck on the
notion that the CMAP is equal to the character code, and that by having such
a beast, everything is solved.

The "Unicode CMAP" is just a convenient crutch, isn't it? Fonts could
implement glyph sets for Hieroglyphics or Linear B or whatever and not have a
"Unicode CMAP". It should not matter what the encoding for surrogate codes
is -- that's irrelevant as far as the FONT is concerned.

I think the "Unicode CMAP" is convenient for some things to some people.
Rendering of Unicode text for display is a complex problem. To do it, you
need one or more ordered sets of glyphs, and a means of translating from your
stream of character codes into a corresponding stream of glyph codes. Just
having a "Unicode CMAP" doesn't get you the second piece. It will get you a
long way in the Latin script and in CJK, but it won't get you much past that
into the more complex scripts.


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