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From: ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University)
Newsgroups: comp.lang.postscript,comp.sys.mac.system
Subject: PostScript vs TrueType?
Message-ID: <1100.26af57d3@waikato.ac.nz>
Date: 26 Jul 90 08:51:31 GMT
Organization: University of Waikato, Hamilton, New Zealand
Lines: 59

The Spring 1990 issue of MacTech Quarterly had an interesting comparison
of the relative virtues of the font handling schemes in PostScript versus
Apple's TrueType system. The funny thing was, the author of the article,
Bill Woodruff, is a self-confessed PostScript fan[atic?]--to the extent
that the editor promised a future article promoting the opposing
viewpoint--but it didn't read that way to me at all.

I should admit up front that I'm not familiar with Adobe's hinting
scheme--I *still* haven't got hold of a copy of the Type 1 Font
Format book--but I do have a copy of the TrueType documentation.

Anyway, one of the points of the article was that the hints in Adobe
PostScript fonts merely identify important features of each character
outline, and leave it to the interpreter (and imaging engine) to perform
the appropriate transformations to preserve legibility at low
resolutions. This is described as a "high level" approach, as
opposed to the "assembly language" scheme of TrueType, which embeds
explicit tweaking instructions in the outline description.

The article goes on to say that Adobe has been steadily improving
its hinting software since 1984. To take advantage of the improvements,
you don't need to upgrade all your existing fonts--just your PostScript
implementation. This is contrasted with TrueType, where you'd need
new versions of your fonts, since these need to have the hinting algorithms
built-in.

Does anybody else spot what's wrong with this? It seems to me that
most current implementations of PostScript takes the form of ROMs
inside a printer or typesetter. Upgrading such a beast is far from
a straightforward, low-cost job, judging from past experience. By contrast,
for people with lots of fonts, most of those will be on disk rather
than in a ROM, so upgrading them will be, at worst, a matter of
returning the old original disks together with the upgrade charge.
In these days of non-copy-protected software, you can continue
working with copies of the originals until the new versions arrive.
Some vendors don't even want the old disks back--the fact that
they've got a record of you as a registered user is enough for them.

Of course, for those proud owners of NeXT machines with Display
PostScript interpreters included in the system software, things
may work rather differently...

What do other people think of the relative advantages of PostScript
versus TrueType? There were a few other points mentioned in the
article, but they didn't strike me as being as crucial as the
above one. For example, the rarity of font designers, and the
headaches they have to go through to support yet another font
format. I thought Apple designed TrueType to make it as easy
as possible for everybody else in the world to convert their
fonts to this format.

Comments, anyone?

Lawrence D'Oliveiro                       fone: +64-71-562-889
Computer Services Dept                     fax: +64-71-384-066
University of Waikato            electric mail: ldo@waikato.ac.nz
Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+12:00
To someone with a hammer and a screwdriver, every problem looks
like a nail with threads.