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From: johnr@praxis.co.uk (John Richards)
Newsgroups: comp.graphics
Subject: Re: Algorithm or pointers to references wanted
Message-ID: <2533@newton.praxis.co.uk>
Date: 24 Jun 88 08:35:09 GMT
References: <242@granite.dec.com>
Sender: news@praxis.co.uk
Reply-To: johnr@praxis.co.uk (John Richards)
Organization: Praxis Systems plc, Bath, UK
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In article <242@granite.dec.com> pjs@granite.dec.com (Philip J. Schneider) writes:
>
>    I need an algorithm to break up a self-intersecting polygon into 
>a set of convex polygons.  A search through some of the "standard"
>references and texts has yielded several algorithms that work on 
>non-convex polygons, but fail if the polygon is self-intersecting as well.
>
Have a look at:

J.Nievergelt and F.P.Preparata, "Plane-sweep algorithms for intersecting
geometric figures", Communications of the ACM 25(10), pp.739-747 (1982)

They describe the class of plane-sweep algorithms which work by
incrementally advancing a "front" across a plane in one direction,
processing as you go.  Their algorithm processes self-intersecting polygons
and produces non-intersecting ones, though their terminology is different.

                                      John Richards