/// <summary>
/// Circles the check data node.
/// </summary>
/// <returns>
/// The check data node.
/// </returns>
/// <param name='n'>
/// N.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
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.X, l.DataPoint.Y, n.DataPoint.X, n.DataPoint.Y, r.DataPoint.X, r.DataPoint.Y, false) <= 0)
{
return(null);
}
Vector2D 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);
}
/// <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>
/// Circles the check data node.
/// </summary>
/// <returns>
/// The check data node.
/// </returns>
/// <param name='n'>
/// N.
/// </param>
/// <param name='ys'>
/// Ys.
/// </param>
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.X, l.DataPoint.Y, n.DataPoint.X, n.DataPoint.Y, r.DataPoint.X, r.DataPoint.Y, false ) <= 0 ) {
return null;
}
Vector2D 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;
}
/// <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>
/// 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;
}
