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From: levy@ttrdc.UUCP (Daniel R. Levy)
Newsgroups: sci.math
Subject: Re: point inside a polygon (triangl
Message-ID: <1284@ttrdc.UUCP>
Date: Fri, 31-Oct-86 01:20:04 EST
Article-I.D.: ttrdc.1284
Posted: Fri Oct 31 01:20:04 1986
Date-Received: Sat, 1-Nov-86 03:02:19 EST
References: <1482@jade.BERKELEY.EDU> <8900037@osiris> <5299@dartvax.UUCP>
Organization: AT&T, Computer Systems Division, Skokie, IL
Lines: 24

In article <5299@dartvax.UUCP>, kevins@dartvax.UUCP (Kevin M. Schofield) writes:
>In article <8900037@osiris> kaden@osiris.CSO.UIUC.EDU writes:
>>	   Count Vector on Sesame Street says: I love watching
>>	   the ray crossing the curve and creating either an
>>	   odd or even number of intersection points that I
>>	   may count! Very splendid! Very splendid! HA! HA!
>>	   HA! HA! HA! HA! HA! HA! HA! HA! HA! AH! HA! HA!
>
>Close, but not quite. You get a nasty exception to the rule when your
>ray hits a vertex of the polygon. 

So what?  Perturb the ray a little to get it off of the vertex and try again.

(One thing about this kind of solution which seems a bit clumsy to me is
that one needs to check every segment of the polygon to see if it does or
does not intersect the ray.)
-- 
 -------------------------------    Disclaimer:  The views contained herein are
|       dan levy | yvel nad      |  my own and are not at all those of my em-
|         an engihacker @        |  ployer or the administrator of any computer
| at&t computer systems division |  upon which I may hack.
|        skokie, illinois        |
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