Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!uakari.primate.wisc.edu!ginosko!uunet!microsoft!kensy
From: kensy@microsoft.UUCP (Ken Sykes)
Newsgroups: comp.graphics
Subject: Re: Need an algorithm to calculate area of polygons
Keywords: Polygon, algorithm
Message-ID: <7967@microsoft.UUCP>
Date: 6 Oct 89 00:23:25 GMT
References: <484@ctycal.UUCP>
Reply-To: kensy@microsoft.UUCP (Ken Sykes)
Organization: Microsoft Corp., Redmond WA
Lines: 15

One technique that has been mentioned in the past is to "FloodFill" the
area, but instead of drawing the interior points, count them.  This will
handle all of the irregular areas as well.  The two drawbacks to this
approach is it *can* be slow and you need to find the interior of the
area to use as the seed point for FloodFill.  Of course, the areas will
have to be closed as well.

If you need a faster solution you could ScanConvert the polygons, again
counting points instead of plotting them.  This could also work for
other areas such as arcs, but the ScanConverter would have to be smart
enough to deal with non-polygonal areas.

-----------------------
Ken Sykes
SDE at large.