Polygonflow: clockwise or counter-clockwise?

[Michael Kristensen]

Thanks to Jeff and Alex for your replies

Alex, your script worked perfectly. Thanks

I needed to do the check in two cases:

1. I needed to calculate the area of multiple polygons by "stringing"  
them together in one superpolygon.
If they did'nt have the same flowdirection the calculation would be  
wrong.

2. If you need to string two polygons together and one is to act as a  
punch-out for the first, the two polygons must have opposite  
flowdirection. Otherwise the area will be wrong.

It is so easy to see the direction, but relatively difficult to  
calculate the direction.
Thanks again to both of you.

Michael