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;
}
/// <summary>
/// Visualization of Delaunay Triangulation
/// </summary>
/// <param name="weight">Weight of result image.</param>
/// <param name="height">Height of result image.</param>
/// <param name="Datapoints">Result bitmap.</param>
/// <returns></returns>
public static Bitmap GetDelaunayTriangulation(int weight, int height, IEnumerable Datapoints)
{
Bitmap bmp = new Bitmap(weight, height);
VoronoiGraph graph = Fortune.ComputeVoronoiGraph(Datapoints);
Graphics g = Graphics.FromImage(bmp);
foreach (object o in Datapoints)
{
Vector v = (Vector)o;
g.DrawEllipse(Pens.Red, (int)v[0] - 1, (int)v[1] - 1, 2, 2);
foreach (object obj in graph.Edges)
{
VoronoiEdge edge = (VoronoiEdge)obj;
if ((edge.LeftData[0] == v[0]) & (edge.LeftData[1] == v[1]))
{
g.DrawLine(Pens.Black, (int)edge.LeftData[0], (int)edge.LeftData[1], (int)edge.RightData[0], (int)edge.RightData[1]);
}
}
}
return(bmp);
}
public VoronoiTemparature(List<TemperatureLocation> temp)
{
temperature = temp;
List<Vector> vectors = new List<Vector>();
foreach (TemperatureLocation t in temperature)
{
vectors.Add(new Vector(t.X, t.Y));
}
maxTemperature = GetMaxTemperature();
minTemperature = GetMinTemperature();
graph = Fortune.ComputeVoronoiGraph(vectors);
}
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);
}
/// <summary>
/// Will return the new root (unchanged except in start-up)
/// </summary>
public static VNode ProcessDataEvent(VDataEvent e, VNode Root, VoronoiGraph VG, double ys, out VDataNode[] CircleCheckList)
{
if(Root==null)
{
Root = new VDataNode(e.DataPoint);
CircleCheckList = new VDataNode[] {(VDataNode)Root};
return Root;
}
//1. Find the node to be replaced
VNode C = VNode.FindDataNode(Root, ys, e.DataPoint[0]);
//2. Create the subtree (ONE Edge, but two VEdgeNodes)
VoronoiEdge VE = new VoronoiEdge();
VE.LeftData = ((VDataNode)C).DataPoint;
VE.RightData = e.DataPoint;
VE.VVertexA = Fortune.VVUnkown;
VE.VVertexB = Fortune.VVUnkown;
VG.Edges.Add(VE);
VNode SubRoot;
if(Math.Abs(VE.LeftData[1]-VE.RightData[1])<1e-10)
{
if(VE.LeftData[0]<VE.RightData[0])
{
SubRoot = new VEdgeNode(VE,false);
SubRoot.Left = new VDataNode(VE.LeftData);
SubRoot.Right = new VDataNode(VE.RightData);
}
else
{
SubRoot = new VEdgeNode(VE,true);
SubRoot.Left = new VDataNode(VE.RightData);
SubRoot.Right = new VDataNode(VE.LeftData);
}
CircleCheckList = new VDataNode[] {(VDataNode)SubRoot.Left,(VDataNode)SubRoot.Right};
}
else
{
SubRoot = new VEdgeNode(VE,false);
SubRoot.Left = new VDataNode(VE.LeftData);
SubRoot.Right = new VEdgeNode(VE,true);
SubRoot.Right.Left = new VDataNode(VE.RightData);
SubRoot.Right.Right = new VDataNode(VE.LeftData);
CircleCheckList = new VDataNode[] {(VDataNode)SubRoot.Left,(VDataNode)SubRoot.Right.Left,(VDataNode)SubRoot.Right.Right};
}
//3. Apply subtree
if(C.Parent == null)
return SubRoot;
C.Parent.Replace(C,SubRoot);
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;
}
