/// <summary>
/// This method assigns the holes for a Polygon (formed from a list of
/// MinimalEdgeRings) to its shell.
/// Determining the holes for a MinimalEdgeRing polygon serves two purposes:
/// it is faster than using a point-in-polygon check later on.
/// it ensures correctness, since if the PIP test was used the point
/// chosen might lie on the shell, which might return an incorrect result from the
/// PIP test.
/// </summary>
/// <param name="shell"></param>
/// <param name="minEdgeRings"></param>
private void PlacePolygonHoles(EdgeRing shell, IList minEdgeRings)
{
for (IEnumerator it = minEdgeRings.GetEnumerator(); it.MoveNext();)
{
MinimalEdgeRing er = (MinimalEdgeRing)it.Current;
if (er.IsHole)
{
er.Shell = shell;
}
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public virtual IList BuildMinimalRings()
{
IList minEdgeRings = new ArrayList();
DirectedEdge de = startDe;
do
{
if (de.MinEdgeRing == null)
{
EdgeRing minEr = new MinimalEdgeRing(de, geometryFactory);
minEdgeRings.Add(minEr);
}
de = de.Next;
}while (de != startDe);
return(minEdgeRings);
}