[omega] Question about the paper published in EuroTeX 2005

[Gábor BELLA]

> > That's a very interesting issue we are dealing with. technically 
> > speaking, the glyph index is not a robust way to access a glyph in a 
> > TrueType-like structure. For example, you can re-order the glyphs in a 
> > TrueType font and it still is exactly the same font (while Type 1 fonts 
> > have glyph names).
> > 
> 
> Exactly: and that is the problem, no glyph `names'!
> 
> My main point is that this should be seen as an important
> implementation issue when using this particular font technology, not
> as a reason for building `glyph access via Unicode slots numbers' into
> the model.

Chris, Yannis,

Sorry to interfere with your dialogue but allow me one question. Chris:
are you implying that a modern font technology today does not
necessarily need to be based on a Unicode-to-glyph mapping? That "glyph
access via Unicode" is just a consequence of OpenType's inability to
access glyphs by their "names"?

I believe the OpenType people's choice to use Unicode-based glyph
lookups was well considered. Correct me if I'm wrong but to me the term
"glyph name", in the Adobe sense, suggests that there is a finite set of
glyphs (typographic signs) that may be designed. If a font allows glyph
lookup only by names, the typesetting engine will need to have a "glyph
name list" built in as well as a mapping between them and the input
characters. But what if a font designer would like to include a
completely new glyph, let's say, a ligature, that has no official name
yet? How could such a glyph be used by the typesetting engine?

The OpenType model (as well as AAT etc.) widens the possibilities of the
font designer by giving control over how pure Unicode character streams
become glyph streams. The Unicode character set is finite by definition
(at least at any given point of time; let's hope they won't go much
beyond 20 bits in the near future...) whereas there should be no
limitation of the glyphs that may exist. Establishing glyph names
independently of Unicode slot numbers seems redundant to me at the best,
and a severe limitation of the font designer's possibilities at the
worst.

Or maybe I didn't get your point? What kind of glyph naming would you
suggest that could avoid these problems and provide something more than
Unicode-based access?

Regards,
Gábor