public static VCircleEvent CircleCheckDataNode(VDataNode n, double ys)
{
VDataNode l = VNode.LeftDataNode(n);
VDataNode r = VNode.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[0],l.DataPoint[1],n.DataPoint[0],n.DataPoint[1],r.DataPoint[0],r.DataPoint[1],false)<=0)
return null;
Vector 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 || Math.Abs(VC.Y - ys) < 1e-10)
return VC;
return null;
}
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;
}
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;
}