Re: Unicode and math symbols

["Berthold K.P. Horn" <bkph@ai.mit.edu>]

   Berthold

   Just a few questions to you to clarify matters:

   Does this dependence of OSs on the Unicode standard mean that whenever
   Unicode changes, everyone needs a new version of the OS or just new
   font-files, or what?

The support for all this right now is still rather poor, actually.

(1) For example, the Microsoft NT font installer has a fixed table
of glyph name to UNICODE mappings (complete with typos like
aroowleft, hungerumlaunt, traglf).  If your Type 1 font has
glyphs names that are not in that table those glyphs will not
be converted, and hence are not usable.

(2) The table makes no provision for alternate names.  Thus
you have to have Odblacute: Ohungarumlaut will not work.  And
it has to be Tcedilla: Tcommaaccent will not work. etc.

(3) The coverage of this table is limited, mostly WGL4 (which covers
about 662 glyphs, including all the Latin alphabets, Greek, Cyrillic)
(And in the current implementation it actually covers less).

(4) ATM for NT apparenlty has a similar table, with some differences in 
names and some differences in UNICODE codes from the MicroSoft version.

one can only hope that they at least get together and `unify' these
tables.

   > BUT: what they consider not to be in UNICODE is not accessible.
   by "not in" do you mean that if a slot is empty in what that OS thinks
   is the Unicode encoding then I cannot access a glyph in that slot in any
   font?

   So how does one use Poetica on NT?

Oh, keep in mind that there are two flavours of fonts: UGL (text) fonts
and `symbol' (or rather: non-text) fonts.  non-text fonts can be layed o
out anyway you want and you access them by numeric codes (although this
is restricted to 0 - 255 as far as I can tell (you can use 16 bit
numbers but the mapping is weird and wonderful and useless I think).
This is how all CM, AMS, extra LaTeX + SliTeX fonts are treated now.
They are *not* text fonts, because they all have their own bizarre
encoding.

   Thanks


   And, if anyone knows, does plan 9 also have font-encodings hard-wired
   like this?

   chris