Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!decwrl!adobe!heaven!glenn
From: glenn@heaven.woodside.ca.us (Glenn Reid)
Newsgroups: comp.lang.postscript
Subject: Re: HP PS Cart Fatal Blowup Demo
Message-ID: <369@heaven.woodside.ca.us>
Date: 17 Dec 90 03:44:12 GMT
References: <1990Dec8.145818.15028@panix.uucp> <1990Dec13.223822.28328@wsrcc.com>
Reply-To: glenn@heaven.woodside.ca.us (Glenn Reid)
Organization: RightBrain Software, Woodside, CA
Lines: 26

In article <1990Dec13.223822.28328@wsrcc.com> wolfgang@wsrcc.com (Wolfgang S. Rupprecht) writes:
>schuster@panix.uucp (Michael Schuster) writes:
>>% HP CARTRIDGE FATAL BLOWUP DEMO
>>100 200 translate 5 dup scale
>>10 {53 45 {0.12 0 360 arc stroke 0} setscreen} repeat
>>showpage quit

>(The page that gets printed is essentially blank with a single
>squarish spot with rounded corners.  Squinting at it, it looks a bit
>like a square surface mount IC with 3 leads on each of sides, drawn in
>perspective.)

When I run this on my NeXT machine and gradually increase the scale
factor I see two "PacMan" almost-circles appear.  They're not quite
circular until you blow it up fairly large (changing 5 dup scale to
something like 20 dup scale).

I've never seen any PostScript code that actually executed painting
operators inside the procedure passed to "setscreen".  Most interesting.
I can't think of why you'd want to do that, offhand, but it's sort of
amazing that it actually works (though perhaps not on the original
poster's HP cartridge :-)
-- 
 Glenn Reid				RightBrain Software
 glenn@heaven.woodside.ca.us		PostScript/NeXT developers
 ..{adobe,next}!heaven!glenn		415-851-1785