Path: utzoo!mnetor!uunet!husc6!bbn!rochester!PT.CS.CMU.EDU!andrew.cmu.edu!jv0l+
From: jv0l+@andrew.cmu.edu (Justin Chris Vallon)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Polygon question
Message-ID: <0WK9yny00UjHAgw0-f@andrew.cmu.edu>
Date: 5 Apr 88 08:49:55 GMT
Organization: Carnegie Mellon University
Lines: 13
In-Reply-To: <24153@brunix.UUCP>


>[stuff about finding the area of a polygon]

Since you know the verticies of the polygon (as far as I gather from your
post), apply a very simple algorithm:

    Area = 0
    ForEach edge (E) in polygon with endpoints P1, P2:
        Area = Area + (P1.h + P2.h)*(P1.v - P2.v)/2

Note that you'll probably have to use long-ints, or bigger to prevent
overflows.  This is about as simple as it could get.

-Justin