Polygons & Nodal Points...

cabney cabney at cyberpass.net
Sun Jul 15 21:23:55 CDT 2001

On Sun, 15 Jul 2001 schoon at amgt.com wrote:

> 	I have this polygon I need to split up into in smaller elements and
> determine how many nodal points I have.... My first attempt was to brute
> force the problem and just see if my nodal points fell within the
> polygon, and start counting - but under certain conditions that fails.
> It mostly fails when the point is on an edge of the polygon... My second
> idea is to calculate how many nodal points I'm going to have by how many
> subelements are present. I'm developing the application using Perl/Tk,
> but I am new to using it. There might be a third way to determine nodal
> points by using createRectangle. I'm not looking for a direct solution -
> more along the lines of a brain storm. Any ideas greatly appreciated!!

I think the standard way to do this is take a slice of the polygon at the
point on the ordinal, and increment a count ever time you pass an edge.

You are in the polygon (if it is one :) on the odd count.

There was a time
A wind that blew so young
For this could be the biggest sky
And I could have the faintest idea


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