Path: utzoo!yunexus!geac!syntron!jtsv16!uunet!lll-winken!lll-tis!ames!elroy!cit-vax!wen-king
From: wen-king@cit-vax.Caltech.Edu (King Su)
Newsgroups: comp.graphics
Subject: Re: postscript routines for plotting
Message-ID: <8392@cit-vax.Caltech.Edu>
Date: 22 Oct 88 23:55:02 GMT
Article-I.D.: cit-vax.8392
References: <31190@bbn.COM> <4357@ubc-cs.UUCP> <7999@gryphon.CTS.COM>
Reply-To: wen-king@cit-vax.UUCP (Wen-King Su)
Organization: California Institute of Technology
Lines: 36

In article <7999@gryphon.CTS.COM> richard@gryphon.CTS.COM (Richard Sexton) writes:
>In article <4357@ubc-cs.UUCP> majka@grads.cs.ubc.ca (Marc Majka) writes:
<>In article <31190@bbn.COM> jzavgren@bbn.com (John Zavgren) writes:
>>>I beleive [sic] the way to go is PostScript. After all, all our printing is
<>>done on PostScript printers. So, we might as well eliminate as many
>>>intermediate steps as possible. [...]
<>
>>PostScript is an adequate page description language.
<
>iNo, HP's PCL is adequate. PS is excellent.
<
>>It is a poor graphical description language. 
<
>Oh ? You have a graphic that cannot be described by PS ?

Since you are very sure of your self, you won't mind sharing your
solution for my problem, would you?  I have no quarrel about the
suitablility of PostScript as a printer language, except one thing.
I am into chip plotting; I want to plot the various layers of an
integrated circuit design using different stipple patterns so that
when two or more layers overlap the union of the patterns produces
a unique stipple pattern.   Goemetries in each layer are ploted as
polygons.  Since PostScript does not allow transparent writing of
polygons (OR-ing a pattern onto a page instead of painting an opague
pattern over the page, a white dot does not erase a black dot), I
could not accomplish what I want with PostScript short of rasterizing
the whole thing and sending it to the printer as a bit array or
compute intersections of the layers and decompose all the polygons,
both of which are un-acceptibly slow.  Even the most ardent supporters
of PostScript here has to admit that this is a very serious short-coming
of the language.  Any suggestions?  I will be very grateful if you
can help me.

-- 
/*------------------------------------------------------------------------*\
| Wen-King Su  wen-king@vlsi.caltech.edu  Caltech Corp of Cosmic Engineers |
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