Re: [Freefont-bugs] New glyphs are unixxxx while other glyphs are uniXXXX.

[Steve White]

Hi,

Bob, the Adobe Glyph List is deprecated.  It has not been maintained,
as it was an unfortunate idea to begin with.
We largely ignore it (except for some of the names which were good
ideas individually).

The PDF text-copying issue is known to us.  It is indeed a problem,
but no efforts on the font side will fix it.

The attempt to re-construct text from named glyph fragments was an
idea--unfortunately, an idea that could never work in general.  It
rests on severe assumptions about how glyphs might be assembled to
form other glyphs, which would be an unworkable restriction for many
font designers, and which are not followed in practice.

For one example: a ligature glyph might be formed by several different
combinations of characters.  Therefore the mapping from ligature to
text cannot generally work, as it's a one-to-many mapping.  But it
gets worse than that.

Because of this, for complex text including combining forms and
ligatures, copying text from PDF often fails, regardless of the font
used.  It's especially catastrophic with Indic text, and often can't
reconstruct anything readable.

The solution for PDF is to embed the Unicode text.

You talked about other practical considerations regarding unencoded glyphs.

First, the font's lookup tables (including the ones you mentioned) may
indeed refer to un-encoded glyphs (a main purpose of the Private Use
areas in Unicode is to provide slots for such glyphs within a font).
The purpose of these is to go in the opposite direction from the
text-copy issue--from encoded text to graphical rendering. It is to be
regarded as a reference to a glyph *internal to the font*. These
references are used by the font rendering libraries, but should not
normally be accessed from application software.  The mechanism works
so long as the glyph names are unique, and so the AGL has no bearing
on the subject.

Second, special-purpose applications can refer to unencoded glyphs in
special-purpose fonts in  multiple ways,  including glyph number and
glyph name.   By definition, there is no standard for this, so it has
nothing to do with Unicode, and by the same token has nothing to do
with the AGL.

FreeFont is explicitly and essentially a Unicode font.  We would
consider re-naming a glyph in the interest of clarity or internal
consistency, but *not* to refer to unencoded glyphs from application
software.

Cheers!