public static VCircleEvent CircleCheckDataNode(VDataNode n, double ys)
{
VDataNode l = LeftDataNode(n);
VDataNode r = RightDataNode(n);
if (l == null || r == null || l.DataPoint == r.DataPoint || l.DataPoint == n.DataPoint || n.DataPoint == r.DataPoint)
return null;
if (MathTools.Ccw(l.DataPoint.X, l.DataPoint.Y, n.DataPoint.X, n.DataPoint.Y, r.DataPoint.X, r.DataPoint.Y, false) <= 0)
return null;
Vector2 center = Fortune.CircumCircleCenter(l.DataPoint, n.DataPoint, r.DataPoint);
VCircleEvent vc = new VCircleEvent();
vc.NodeN = n;
vc.NodeL = l;
vc.NodeR = r;
vc.Center = center;
vc.Valid = true;
if (vc.Y >= ys)
return vc;
return null;
}
public static VNode ProcessCircleEvent(VCircleEvent e, VNode root, VoronoiGraph vg, out VDataNode[] circleCheckList)
{
VEdgeNode eo;
VDataNode b = e.NodeN;
VDataNode a = LeftDataNode(b);
VDataNode c = RightDataNode(b);
if (a == null || b.Parent == null || c == null || !a.DataPoint.Equals(e.NodeL.DataPoint) || !c.DataPoint.Equals(e.NodeR.DataPoint))
{
circleCheckList = new VDataNode[] { };
return root; // Abbruch da sich der Graph verändert hat
}
VEdgeNode eu = (VEdgeNode)b.Parent;
circleCheckList = new[] { a, c };
//1. Create the new Vertex
Vector2 vNew = new Vector2(e.Center.X, e.Center.Y);
// VNew[0] = Fortune.ParabolicCut(a.DataPoint[0],a.DataPoint[1],c.DataPoint[0],c.DataPoint[1],ys);
// VNew[1] = (ys + a.DataPoint[1])/2 - 1/(2*(ys-a.DataPoint[1]))*(VNew[0]-a.DataPoint[0])*(VNew[0]-a.DataPoint[0]);
vg.Vertices.Add(vNew);
//2. Find out if a or c are in a distand part of the tree (the other is then b's sibling) and assign the new vertex
if (eu.Left == b) // c is sibling
{
eo = EdgeToRightDataNode(a);
// replace eu by eu's Right
eu.Parent.Replace(eu, eu.Right);
}
else // a is sibling
{
eo = EdgeToRightDataNode(b);
// replace eu by eu's Left
eu.Parent.Replace(eu, eu.Left);
}
eu.Edge.AddVertex(vNew);
// ///////////////////// uncertain
// if(eo==eu)
// return root;
// /////////////////////
eo.Edge.AddVertex(vNew);
//2. Replace eo by new Edge
VoronoiEdge ve = new VoronoiEdge();
ve.LeftData = a.DataPoint;
ve.RightData = c.DataPoint;
ve.AddVertex(vNew);
vg.Edges.Add(ve);
VEdgeNode ven = new VEdgeNode(ve, false);
ven.Left = eo.Left;
ven.Right = eo.Right;
if (eo.Parent == null)
return ven;
eo.Parent.Replace(eo, ven);
return root;
}
