/// <summary>
/// Computes the voronoi graph.
/// </summary>
/// <returns>
/// The voronoi graph.
/// </returns>
/// <param name='Datapoints'>
/// Datapoints.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
public static VoronoiGraph ComputeVoronoiGraph(IEnumerable Datapoints)
{
PriorityQueue <VEvent> PQ = new PriorityQueue <VEvent>(PriorityQueueType.Minimum);
Hashtable CurrentCircles = new Hashtable();
VoronoiGraph VG = new VoronoiGraph();
VNode RootNode = null;
foreach (Vector2D V in Datapoints)
{
PQ.Enqueue(new VDataEvent(V));
}
while (PQ.Count > 0)
{
VEvent VE = PQ.Dequeue() 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.Enqueue(VCE);
CurrentCircles[VD] = VCE;
}
}
if (VE is VDataEvent)
{
Vector2D DP = ((VDataEvent)VE).DataPoint;
foreach (VCircleEvent VCE in CurrentCircles.Values)
{
if (MathTools.Dist(DP.X, DP.Y, VCE.Center.X, VCE.Center.Y) < VCE.Y - VCE.Center.Y && Math.Abs(MathTools.Dist(DP.X, DP.Y, VCE.Center.X, VCE.Center.Y) - (VCE.Y - VCE.Center.Y)) > 1e-10)
{
VCE.Valid = false;
}
}
}
}
return(VG);
}
/// <summary>
/// Processes the circle event.
/// </summary>
/// <returns>
/// The circle event.
/// </returns>
/// <param name='e'>
/// E.
/// </param>
/// <param name='Root'>
/// Root.
/// </param>
/// <param name='VG'>
/// V.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
/// <param name='CircleCheckList'>
/// Circle check list.
/// </param>
public static VNode ProcessCircleEvent(VCircleEvent e, VNode Root, VoronoiGraph VG, double ys, out VDataNode[] CircleCheckList)
{
VDataNode a;
VDataNode b;
VDataNode c;
VEdgeNode eu;
VEdgeNode 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 ver 0/00ndert hat
}
eu = b.Parent as VEdgeNode;
CircleCheckList = new VDataNode[] { a, c };
//1. Create the new Vertex
Vector2D VNew = new Vector2D(e.Center.X, e.Center.Y);
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);
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>
/// <summary>
/// Processes the data event.
/// </summary>
/// <returns>
/// The data event.
/// </returns>
/// <param name='e'>
/// E.
/// </param>
/// <param name='Root'>
/// Root.
/// </param>
/// <param name='VG'>
/// V.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
/// <param name='CircleCheckList'>
/// Circle check list.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
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[] { Root as VDataNode };
return(Root);
}
//1. Find the node to be replaced
VNode C = VNode.FindDataNode(Root, ys, e.DataPoint.X);
VDataNode cData = C as VDataNode;
if (cData == null)
{
throw new Exception("Can't cast to data node");
}
//2. Create the subtree (ONE Edge, but two VEdgeNodes)
VoronoiEdge VE = new VoronoiEdge();
VE.LeftData = cData.DataPoint;
VE.RightData = e.DataPoint;
VE.VVertexA = Fortune.VVUnkown;
VE.VVertexB = Fortune.VVUnkown;
VG.Edges.Add(VE);
VNode SubRoot;
if (Math.Abs(VE.LeftData.Y - VE.RightData.Y) < 1e-10)
{
if (VE.LeftData.X < VE.RightData.X)
{
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[] { SubRoot.Left as VDataNode, SubRoot.Right as VDataNode };
}
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[] { SubRoot.Left as VDataNode, SubRoot.Right.Left as VDataNode, SubRoot.Right.Right as VDataNode };
}
//3. Apply subtree
if (C.Parent == null)
{
return(SubRoot);
}
C.Parent.Replace(C, SubRoot);
return(Root);
}
/// <summary>
/// Will return the new root (unchanged except in start-up)
/// </summary>
/// <summary>
/// Processes the data event.
/// </summary>
/// <returns>
/// The data event.
/// </returns>
/// <param name='e'>
/// E.
/// </param>
/// <param name='Root'>
/// Root.
/// </param>
/// <param name='VG'>
/// V.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
/// <param name='CircleCheckList'>
/// Circle check list.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
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[] {Root as VDataNode};
return Root;
}
//1. Find the node to be replaced
VNode C = VNode.FindDataNode( Root, ys, e.DataPoint.X );
VDataNode cData = C as VDataNode;
if( cData == null ) {
throw new Exception( "Can't cast to data node" );
}
//2. Create the subtree (ONE Edge, but two VEdgeNodes)
VoronoiEdge VE = new VoronoiEdge();
VE.LeftData = cData.DataPoint;
VE.RightData = e.DataPoint;
VE.VVertexA = Fortune.VVUnkown;
VE.VVertexB = Fortune.VVUnkown;
VG.Edges.Add( VE );
VNode SubRoot;
if( Math.Abs( VE.LeftData.Y - VE.RightData.Y ) < 1e-10 ) {
if( VE.LeftData.X < VE.RightData.X ) {
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[] {SubRoot.Left as VDataNode, SubRoot.Right as VDataNode};
} 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[] {SubRoot.Left as VDataNode, SubRoot.Right.Left as VDataNode, SubRoot.Right.Right as VDataNode};
}
//3. Apply subtree
if( C.Parent == null ) {
return SubRoot;
}
C.Parent.Replace( C, SubRoot );
return Root;
}
/// <summary>
/// Processes the circle event.
/// </summary>
/// <returns>
/// The circle event.
/// </returns>
/// <param name='e'>
/// E.
/// </param>
/// <param name='Root'>
/// Root.
/// </param>
/// <param name='VG'>
/// V.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
/// <param name='CircleCheckList'>
/// Circle check list.
/// </param>
public static VNode ProcessCircleEvent( VCircleEvent e, VNode Root, VoronoiGraph VG, double ys, out VDataNode[] CircleCheckList )
{
VDataNode a;
VDataNode b;
VDataNode c;
VEdgeNode eu;
VEdgeNode 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 ver 0/00ndert hat
}
eu = b.Parent as VEdgeNode;
CircleCheckList = new VDataNode[] {a,c};
//1. Create the new Vertex
Vector2D VNew = new Vector2D( e.Center.X, e.Center.Y );
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 );
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>
/// Computes the voronoi graph.
/// </summary>
/// <returns>
/// The voronoi graph.
/// </returns>
/// <param name='Datapoints'>
/// Datapoints.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
public static VoronoiGraph ComputeVoronoiGraph(IEnumerable Datapoints)
{
PriorityQueue<VEvent> PQ = new PriorityQueue<VEvent>(PriorityQueueType.Minimum);
Hashtable CurrentCircles = new Hashtable();
VoronoiGraph VG = new VoronoiGraph();
VNode RootNode = null;
foreach(Vector2D V in Datapoints)
{
PQ.Enqueue(new VDataEvent(V));
}
while(PQ.Count>0)
{
VEvent VE = PQ.Dequeue() 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.Enqueue(VCE);
CurrentCircles[VD]=VCE;
}
}
if(VE is VDataEvent)
{
Vector2D DP = ((VDataEvent)VE).DataPoint;
foreach(VCircleEvent VCE in CurrentCircles.Values)
{
if(MathTools.Dist(DP.X,DP.Y,VCE.Center.X,VCE.Center.Y)<VCE.Y-VCE.Center.Y && Math.Abs(MathTools.Dist(DP.X,DP.Y,VCE.Center.X,VCE.Center.Y)-(VCE.Y-VCE.Center.Y))>1e-10) {
VCE.Valid = false;
}
}
}
}
return VG;
}