Xref: utzoo comp.fonts:400 comp.lang.postscript:1121
Path: utzoo!utgpu!attcan!uunet!tektronix!reed!barry
From: barry@reed.UUCP (Barry Smith)
Newsgroups: comp.fonts,comp.lang.postscript
Subject: Re: METAFONT & PostScript
Summary: Metafont vs PostScript is no contest
Message-ID: <10936@reed.UUCP>
Date: 7 Nov 88 03:10:46 GMT
References: <902@cps3xx.UUCP> <10417@s.ms.uky.edu> <422@trigraph.UUCP> <3455@pt.cs.cmu.edu> <423@trigraph.UUCP>
Reply-To: barry@reed.UUCP (Barry Smith)
Organization: Blue Sky Research, Portland OR
Lines: 46

In article <423@trigraph.UUCP> you write:
>I envisage a good PostScript font (one that has gone to the expensive
>end of the time-quality tradeoff) working as follows.  At reasonable
>font sizes, the font is represented as an outline with non-linear
>scaling of various dimensions.  At extremely small font sizes (w.r.t.
>device resolution), the font becomes a pre-computed bitmap to ensure
>that not one pixel is painted that shouldn't be.
>
>I will readily admit that I have not designed such a font, nor would
>I look forward to doing so, except by writing a METAFONT-PostScript
>translator, but it is well within PostScript's abilities to execute
>such a font.
>
>I also believe that the quality possible with such a font would be
>very difficult to imitate in METAFONT, though this may just be a
>PostScript programmer's bias.  Can one easily make `this pixel stays
>on, but that one should be turned off' decisions in METAFONT?


John, pardon me for being so short, but you really don't know what you're
talking about here.  Why don't you take a look at the Metafont book?
Keep in mind the experience and credentials of the author, too.

"In extremis", of course, you're correct:  it's possible, although not
practical, to run Metafont IN PostScript.

In more practical terms, one might pose the question thusly: "At 300 dpi,
does PostScript rasterize outlines (of, say, Times Roman) as well as
Metafont rasterizes, say, Computer Modern 10 point?"  And the answer,
quite simply, is that it's no contest.

It's actually quite an interesting comparison, and an education to the
untrained eye; what previously appeared to be clear, crisp Times Roman
characters suddenly become muddy and coarse.

(Here I'm speaking solely of rendering, not esthetics; personally, I
can think of several fonts I might prefer to Computer Modern for my uses.)

Another respondent referred to the poor quality of 78 dpi fonts rendered
by Metafont.  I agree wholeheartedly (as, I believe, does Knuth); it may be 
perfectly correct to say that automatic rendering of low-resolution fonts 
from outlines is beyond the state of the art.


Barry Smith
Blue Sky Research