// ================================== Circle Event
private static void CircleEvent(Vertex p, List <Point> Q, List <PointSet> T, List <Boundary> V)
{
// Step 1: Finding the two boundaries of the intersection
Boundary Cqr = p.LeftBoundary;
Boundary Crs = p.RightBoundary;
Site q = Cqr.LeftSite;
Site s = Crs.RightSite;
Boundary Cuq = null; //Boundary?
Boundary Csv = null; //Boundary?
int indexCqr = IndexOfBoundary(T, Cqr);
if (indexCqr > 1)
{
Cuq = T[indexCqr - 2] as Boundary;
}
if (indexCqr < T.Count - 4)
{
Csv = T[indexCqr + 4] as Boundary;
}
// Step 2: Creating a new boundary and covering up the boundaries and region from which it starts
Boundary Cqs = Boundary.CreateSubtype(q, s);
T.RemoveRange(indexCqr, 3);
T.Insert(indexCqr, Cqs);
CloseVertex(p, Cqr, Crs, Cqs, V);
// Step 3: Adding and removing (new) intersections in Q
if (Cuq != null)
{
Q.RemoveAll(point => Boundary.IsIntersection(Cuq, Cqr, point));
}
if (Csv != null)
{
Q.RemoveAll(point => Boundary.IsIntersection(Crs, Csv, point));
}
if (Cuq != null)
{
AddIfNotNull(Q, Cuq.Intersection(Cqs));
} // TODO check adding intersection again
if (Csv != null)
{
AddIfNotNull(Q, Cqs.Intersection(Csv));
}
}