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;
}
}
}
}
return(VG);
}
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)
{
return(VC);
}
return(null);
}
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;
// /////////////////////
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;
}
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;
// /////////////////////
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);
}
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)
return VC;
return null;
}