Re: openType

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

At 10:06 AM 10/12/2000 +0200, Thierry Bouche wrote

>did anybody experiment with some support for OT fonts in TeX?
>
>Is it possible to call directly a glyph (alternate version, e.g.) by a
>slot number as we usually do, or has the environment to set flags and
>the font acts as a program? This would not be natural to tex!

(1) In one way, OpenType is a "no-op" since most OpenType fonts will
be simply Type 1 (or TrueType) fonts in an OpenType wrapper.  From 
the standard API very little changes.  

(2) In another way, OpenType does for low-end applications what TeX
already does, such as ligaturing.  This in fact gets in the way when TeX
is involved because TeX needs to have total control and needs to know
how much space everything takes. It is not going to work if the font
then decides to replace some characters with other characters after TeX
has done the typesetting.  In this sense OT is potentially a great boon 
for poor typesetting programs and a potential pain for TeX.

(3) You don't need OT to use fonts with Unicode.  You can already 
do this both with TrueType and Type 1 fonts (on operating
systems that support Unicode properly).  Some TeX systems already
take advantage of this to some extent, and some Type 1 fonts are 
already set up to make this useful :-)  (for example, such fonts use
the correct glyphnames for the 1000 or so characters that have
standard PS glyph names).

It helps to remember that OT was designed in large part to kill GX
(Much like TrueType was not invented for any good technical reasons
but just to break the stranglehold Adobe had with Type 1 fonts).

Also note that many powerful features originally planned were dropped 
when it came  down to actually implementing the thing. Only if you insist 
on unpacking  and massaging the innards of the font does a load of new 
work need to be done.

Regards, Berthold.

--
Berthold K.P. Horn  mailto:bkph@ai.mit.edu  http://www.ai.mit.edu/people/bkph (MT)