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From: oster@dewey.soe.berkeley.edu (David Phillip Oster)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Thin lines on Laser
Message-ID: <31888@ucbvax.BERKELEY.EDU>
Date: 13 Oct 89 09:36:30 GMT
References: <847@chyde.uwasa.fi> <89284.171455CXT105@PSUVM.BITNET> <UZB_yoW00UzxQ1R4wY@andrew.cmu.edu> <4703@internal.Apple.COM>
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Reply-To: oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster)
Organization: School of Education, UC-Berkeley
Lines: 22

Some caveats to the posting of others on this subject:
1.) You don't always want 1-device pixel wide lines. On a 2000dpi
phototypesetter, 1-device pixel wide lines are not visible to the naked
eye. You shouldn't blindly use the device's best resolution, but pick the
resolution closest to what you really want.  (There is a great story about
Mandelbrot making this exact mistake: He thought he was printing a page of
fractals, but the output appeared to be blank, slightly grayish paper.
The fractals _were_ there, you just needed a disecting microscope to see
them.)

2.) The tech notes on SetLineWidth are un-clear on this point: after you
get through drawing fine lines, you should reset the postscript pen size.
The way to do this is not calling.  SetLineWidth with a handle pointing to
(1,1), as the tech note would have you believe, but by calling it with a
handle pointing to the inverse of the previous conversion. i.e., (1,4)
cancels (4,1).  This is consistent with the way postscript tends to work,
in addition to being what actually happens, according to my experiments.
SetLineWidth (1,1) is a no-op.

--David Oster, master of the ad hoc odd hack.
Arpa: oster@dewey.soe.berkeley.edu
Uucp: {uwvax,decvax}!ucbvax!oster%dewey.soe.berkeley.edu