public static VoronoiGraph ComputeVoronoiGraph(IEnumerable Datapoints)
        {
            BinaryPriorityQueue PQ             = new BinaryPriorityQueue();
            Hashtable           CurrentCircles = new Hashtable();
            VoronoiGraph        VG             = new VoronoiGraph();
            VNode RootNode = null;

            foreach (Vector V in Datapoints)
            {
                PQ.Push(new VDataEvent(V));
            }
            while (PQ.Count > 0)
            {
                VEvent      VE = PQ.Pop() as VEvent;
                VDataNode[] CircleCheckList;
                if (VE is VDataEvent)
                {
                    RootNode = VNode.ProcessDataEvent(VE as VDataEvent, RootNode, VG, VE.Y, out CircleCheckList);
                }
                else if (VE is VCircleEvent)
                {
                    CurrentCircles.Remove(((VCircleEvent)VE).NodeN);
                    if (!((VCircleEvent)VE).Valid)
                    {
                        continue;
                    }
                    RootNode = VNode.ProcessCircleEvent(VE as VCircleEvent, RootNode, VG, VE.Y, out CircleCheckList);
                }
                else
                {
                    throw new Exception("Got event of type " + VE.GetType().ToString() + "!");
                }
                foreach (VDataNode VD in CircleCheckList)
                {
                    if (CurrentCircles.ContainsKey(VD))
                    {
                        ((VCircleEvent)CurrentCircles[VD]).Valid = false;
                        CurrentCircles.Remove(VD);
                    }
                    VCircleEvent VCE = VNode.CircleCheckDataNode(VD, VE.Y);
                    if (VCE != null)
                    {
                        PQ.Push(VCE);
                        CurrentCircles[VD] = VCE;
                    }
                }
                if (VE is VDataEvent)
                {
                    Vector DP = ((VDataEvent)VE).DataPoint;
                    foreach (VCircleEvent VCE in CurrentCircles.Values)
                    {
                        if (MathTools.Dist(DP[0], DP[1], VCE.Center[0], VCE.Center[1]) < VCE.Y - VCE.Center[1] && Math.Abs(MathTools.Dist(DP[0], DP[1], VCE.Center[0], VCE.Center[1]) - (VCE.Y - VCE.Center[1])) > 1e-10)
                        {
                            VCE.Valid = false;
                        }
                    }
                }
            }
            VNode.CleanUpTree(RootNode);
            foreach (VoronoiEdge VE in VG.Edges)
            {
                if (VE.Done)
                {
                    continue;
                }
                if (VE.VVertexB == Fortune.VVUnkown)
                {
                    VE.AddVertex(Fortune.VVInfinite);
                    if (Math.Abs(VE.LeftData[1] - VE.RightData[1]) < 1e-10 && VE.LeftData[0] < VE.RightData[0])
                    {
                        Vector T = VE.LeftData;
                        VE.LeftData  = VE.RightData;
                        VE.RightData = T;
                    }
                }
            }

            ArrayList MinuteEdges = new ArrayList();

            foreach (VoronoiEdge VE in VG.Edges)
            {
                if (!VE.IsPartlyInfinite && VE.VVertexA.Equals(VE.VVertexB))
                {
                    MinuteEdges.Add(VE);
                    // prevent rounding errors from expanding to holes
                    foreach (VoronoiEdge VE2 in VG.Edges)
                    {
                        if (VE2.VVertexA.Equals(VE.VVertexA))
                        {
                            VE2.VVertexA = VE.VVertexA;
                        }
                        if (VE2.VVertexB.Equals(VE.VVertexA))
                        {
                            VE2.VVertexB = VE.VVertexA;
                        }
                    }
                }
            }
            foreach (VoronoiEdge VE in MinuteEdges)
            {
                VG.Edges.Remove(VE);
            }

            return(VG);
        }
        private void GenerateRelations(Vector[] points, VoronoiGraph voronoi)
        {
            centers.Clear();
            corners.Clear();
            edges.Clear();

            var centerMap = new Dictionary <Vector, Center>();
            var cornerMap = new Dictionary <Vector, Corner>();
            var edgeMap   = new Dictionary <VoronoiEdge, Edge>();

            foreach (var point in points)
            {
                centerMap.Add(point, new Center(new Vec2((float)point[0], (float)point[1]), centerIds++));
            }
            foreach (var point in voronoi.Vertizes)
            {
                cornerMap.Add(point, new Corner(new Vec2((float)point[0], (float)point[1]), cornerIds++));
            }

            foreach (var edge in voronoi.Edges)
            {
                if (edge.IsPartlyInfinite || edge.VVertexA == Fortune.VVUnkown || edge.VVertexB == Fortune.VVUnkown)
                {
                    continue;
                }

                var newEdge = new Edge(edgeIds++);
                edgeMap.Add(edge, newEdge);

                newEdge.d0 = centerMap[edge.LeftData];
                newEdge.d0.borders.Add(newEdge);

                newEdge.d1 = centerMap[edge.RightData];
                newEdge.d1.borders.Add(newEdge);

                newEdge.d0.neighbors.Add(newEdge.d1);
                newEdge.d1.neighbors.Add(newEdge.d0);

                newEdge.v0 = cornerMap[edge.VVertexA];
                newEdge.v0.protrudes.Add(newEdge);
                newEdge.v0.touches.Add(newEdge.d0);
                newEdge.v0.touches.Add(newEdge.d1);

                newEdge.v1 = cornerMap[edge.VVertexB];
                newEdge.v1.protrudes.Add(newEdge);
                newEdge.v1.touches.Add(newEdge.d0);
                newEdge.v1.touches.Add(newEdge.d1);

                newEdge.v0.adjacent.Add(newEdge.v1);
                newEdge.v1.adjacent.Add(newEdge.v0);

                newEdge.d0.corners.Add(newEdge.v0);
                newEdge.d0.corners.Add(newEdge.v1);

                newEdge.d1.corners.Add(newEdge.v0);
                newEdge.d1.corners.Add(newEdge.v1);
            }

            centers.AddRange(centerMap.Values);
            edges.AddRange(edgeMap.Values);
            corners.AddRange(cornerMap.Values);
        }
        public static VNode ProcessCircleEvent(VCircleEvent e, VNode Root, VoronoiGraph VG, double ys, out VDataNode[] CircleCheckList)
        {
            VDataNode a, b, c;
            VEdgeNode eu, eo;

            b = e.NodeN;
            a = VNode.LeftDataNode(b);
            c = VNode.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
            }
            eu = (VEdgeNode)b.Parent;
            CircleCheckList = new VDataNode[] { a, c };
            //1. Create the new Vertex
            Vector VNew = new Vector(e.Center[0], e.Center[1]);

//			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.Vertizes.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 = VNode.EdgeToRightDataNode(a);

                // replace eu by eu's Right
                eu.Parent.Replace(eu, eu.Right);
            }
            else             // a is sibling
            {
                eo = VNode.EdgeToRightDataNode(b);

                // replace eu by eu's Left
                eu.Parent.Replace(eu, eu.Left);
            }
            eu.Edge.AddVertex(VNew);
//			///////////////////// uncertain
//			if(eo==eu)
//				return Root;
//			/////////////////////

            //complete & cleanup eo
            eo.Edge.AddVertex(VNew);
            //while(eo.Edge.VVertexB == Fortune.VVUnkown)
            //{
            //    eo.Flipped = !eo.Flipped;
            //    eo.Edge.AddVertex(Fortune.VVInfinite);
            //}
            //if(eo.Flipped)
            //{
            //    Vector T = eo.Edge.LeftData;
            //    eo.Edge.LeftData = eo.Edge.RightData;
            //    eo.Edge.RightData = T;
            //}


            //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);
        }