Path: utzoo!utgpu!water!watmath!clyde!rutgers!umix!umich!dwt
From: dwt@zippy.eecs.umich.edu (David West)
Newsgroups: comp.graphics
Subject: seeking pd polygon set-operation code
Keywords: polygon clipping set operations
Message-ID: <658@zippy.eecs.umich.edu>
Date: 19 Dec 87 00:16:00 GMT
Organization: University of Michigan EECS Dept., Ann Arbor
Lines: 12

Can anyone give me pointers to any public domain code ,preferably Pascal,
for doing general polygon set-operations?  In particular, non-convex polygons 
must be handled.  
The method described by K. Weiler in SIGGRAPH 80 ("Polygon comparison using a 
graph representation") is the kind of thing I'm looking for (or any improved 
version), particularly as it handles more than two polygons, and compiles 
everything into a structure that implicitly contains the answers to any of a
large number of geometric queries about the polygons.
Anyone have a current net address for Kevin Weiler?
Please reply directly, as I don't usually read this newsgroup.  Thanks,

-David West   dhw%iti@umix.cc.umich.edu   dwt@zippy.eecs.umich.edu