Re: "Missing character" glyph

From: John H. Jenkins (jenkins@apple.com)
Date: Fri Aug 02 2002 - 11:33:41 EDT


On Friday, August 2, 2002, at 01:24 AM, Martin Kochanski wrote:

> 1. Since all existing fonts already display the new character
> correctly, there would be no overwhelming need for any font designer
> to alter any font at all. If they choose, despite this, to copy their
> own interpretation of 'missing character' from Glyph ID zero into the
> new slot, this will also give exactly the display that is required.
>

This is where I start to get uncomfortable. Most (not all) *TrueType*
fonts display the new character correctly. Other font technologies
which are still in use and may be used, for example, by a Web browser,
do *not* automatically use an empty box or anything visual for an
undefined character.

There has been considerable uproar in the font development community
lately about Unicode making unwarranted assumptions about how fonts
work. I think it would be improper for us to add a character to the
standard on the basis of "font technology X solves the problem". In
particular, if we want to have a Web page that includes a visual
representation for "this is what you'll see if your system can't
support this character"—there are too many variables depending on the
system and the particular application to make any guarantees. This
isn't a font issue.

Even mandating that the character should have the visual appearance of
an unsupported character on the given platform/application/font is
really meaningless. On Mac OS X, the precise appearance of such a
character can have any of several dozen appearances, depending on the
Unicode block in which it's found.

==========
John H. Jenkins
jenkins@apple.com
jhjenkins@mac.com
http://homepage.mac.com/jhjenkins/



This archive was generated by hypermail 2.1.2 : Fri Aug 02 2002 - 09:52:01 EDT