[pdftex] ToUnicode map and virtual fonts

[Thanh Han The]

Hi Werner,

I have changed the code to follow Adobe recommendations.
Before I submit the patch to sarovar, there are a few things
on which I would like to hear your opinions first:

1. what should be put into glyphtounicode.tex?

2. the feature works only for Type1 fonts at the moment. The
first request for this feature came from ChoF to make it
work with subfont, but then I was told that it's no longer
needed as it can be done via macro. Then someone else asked
to support it for Minion. It is possible to make it work
with truetype fonts too, but I need to learn more about this
topic first.

3. although I changed the code so that \pdfglyphtounicode
can handle charcode > 0xFFFF, I have no experience at all
with such cases. Can you (or some cjk user) provide some
examples?

Thanh

On Tue, Oct 03, 2006 at 12:38:38PM +0200, The Thanh Han wrote:
> On Tue, Oct 03, 2006 at 11:06:07AM +0200, Werner LEMBERG wrote:
> >
> > > Most of the problems mentioned can be solved by following
> > > http://partners.adobe.com/public/developer/opentype/index_glyph.html,
> > > which is not very hard.
> >
> > Yes.
> >
> > > > . I dislike the automatic handling of `small', `oldstyle',
> > > >   `inferior', and `superior' suffixes which is against the AGL
> > > >   rules.  Fonts which don't follow the AGL need a bundle of calls
> > > >   to \pdfglyphtounicode anyway, so why does this exception exist?
> > >
> > > I cannot see why this is bad. I stole the idea from somewhere in the
> > > Internet (sorry I cannot exactly recall where it is; I only remember
> > > it comes from some documentation about an XSL-FO processor). This
> > > actually saves us from many calls to \pdfglyphtounicode, as such
> > > names are pretty common in opentype fonts and cannot be considered
> > > as exceptions IMO. Do you have an example when this causes problem?
> >
> > Well, the list of `official' glyph names which contains `small' in its
> > names (like `Asmall') is Adobe's glyphlist.txt.  This list is frozen.
> > Any other font which contains glyphs with a trailing `small' in its
> > name is non-standard which consequently means that you need a bunch of
> > \pdfglyphtounicode calls anyway.  However, this is my personal
> > opinion.
> >
> > Which OpenType fonts do you have in mind if you say `such names are
> > pretty common'?  Normally, glyphs like `Asmall' are called `A.small'
> > in recent fonts.
>
> you are right again, all the above mentioned suffixes are
> preceded with a dot, hence following the Adobe
> recommendations would make this unnecessary.
>
> Thanh