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From: zap@lysator.liu.se ("Zap" Andersson)
Newsgroups: comp.graphics
Subject: Re: Point in Polygon Problem
Message-ID: <185@lysator.liu.se>
Date: 27 Aug 90 20:02:07 GMT
References: <2034@idunno.Princeton.EDU> <1990Aug23.174650.3592@odin.corp.sgi.com> <1990Aug23.181401.2258@jarvis.csri.toronto.edu> <1990Aug24.014840.18610@twinsun.com>
Sender: news@isy.liu.se (Lord of the News)
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Organization: Lysator Computer Club, Linkoping University, Sweden
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Forgive me if I am but a fool, but I have created a very simple algorithm and I have never had any problems with the Ambiguos Ray Intersections. But perhaps
my polygon storage methods help me? I simply swap all endpoints so each
line has its 'first' end upwards and its 'last' end downwards. Then I simply EXCLUDE the 'first' point from the intersection test, but INCLUDE the 'last' i.e. point is on the line if first < point <= last .... I havn't been thinking to hard if this is a loser method but it works ok in my implementations.....???

/Zap