Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!bbn.com!cosell
From: cosell@bbn.com (Bernie Cosell)
Newsgroups: comp.lang.postscript
Subject: Re: Multiple flattenpaths
Message-ID: <57011@bbn.BBN.COM>
Date: 5 Jun 90 21:26:55 GMT
References: <56864@bbn.BBN.COM> <2064@artcom0.artcom.north.de> <56899@bbn.BBN.COM> <2066@artcom0.artcom.north.de>
Sender: news@bbn.com
Distribution: comp,world
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pf@artcom0.artcom.north.de (Peter Funk) writes:

}THIS leads to a very interesting question :  Which internal representation
}should one use for paths when implementing a "100 % adobe compatible"
}PostScript-interpreter ?  If one uses a linear linked list, a implemantation
}of flattenpath, that will behave as bernie guessed first is trivial. 
}   Unfortunately we --and I guess "Imagen UltraScript" also ;-) -- have
}chosen another approach : We representant a path as a vector (array) of
}attributed points, where a not yet flattened bezier curve will occupy
}4 consecutive points, a straight line segment 2...  So we have to copy
}the path during the flattenpath operation.
}  I wonder, which approach adobe has implemented.  Is there someone out
}there, who is willing to test bernies code causing the limitcheck error
}on an original adobe ps-machine ?  May be that the result will be of 
}some interest to (for ?) other ps-clone developers also... ;-)

I would gladly post my 'test code', except that it wouldn't do at all:
it was a badly hacked version of the Apple LaserPrep loaded together
with TWO partially broken debugging packages.  On the other hand, I can
give you a slight data point: an Apple LaserWriter does NOT have this
problem.  My package with the multiple flattenpaths worked _just_fine_
on the LaserWriter, and only failed when I started running on the big
Imagen in the computer room.

  /Bernie\