[geos-devel] Holes in holes
strk at keybit.net
Fri Nov 27 12:31:42 EST 2009
On Fri, Nov 27, 2009 at 02:47:17AM +0100, Frederik Ramm wrote:
> I have another remotely related question, that concerns the direction of
> a polygon ring (CW or CCW). When I create a polygon with the
> createPolygon factory method and pass it a number of rings, do I have to
> take care that they spin in the right direction, or will GEOS make sure
> that a correct polygon is created?
The createPolygon method takes an explicit shell and a list of holes.
You don't need to care about direction.
GEOS won't check validity automatic.
Use Geometry::isValid() if you want to check that.
Any ring direction is OGC valid.
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