private void FortunesAlgorithm()
{
var dataBounds = _sites.GetSiteBounds();
var sqrtNSites = (int)Math.Sqrt(_sites.Length + 4);
var heap = new HalfEdgePriorityQueue(dataBounds.Top, dataBounds.Height, sqrtNSites);
var edgeList = new EdgeList(dataBounds.Left, dataBounds.Width, sqrtNSites);
var halfEdges = new List <HalfEdge>();
var vertices = new List <Vertex>();
var bottomMostSite = _sites.Next();
var newSite = _sites.Next();
var newIntStar = new Vector2();
for (; ;)
{
if (!heap.Empty)
{
newIntStar = heap.Min();
}
if (newSite != null && (heap.Empty || CompareByYThenX(newSite, newIntStar) < 0))
{
Console.WriteLine("smallest: new site " + newSite);
var lbnd = edgeList.EdgeListLeftNeighbor(newSite.Coord);
Console.WriteLine("lbnd: " + lbnd);
var rbnd = lbnd.EdgeListRightNeighbor;
Console.WriteLine("rbnd: " + rbnd);
var bottomSite = RightRegion(lbnd) ?? bottomMostSite;
Console.WriteLine("new site is in region of existing site: " + bottomSite);
var edge = Edge.CreateBisectingEdge(bottomSite, newSite);
Console.WriteLine("new edge: " + edge);
Edges.Add(edge);
var bisector = new HalfEdge(edge, LR.Left);
halfEdges.Add(bisector);
edgeList.Insert(lbnd, bisector);
Vertex vertex = Vertex.Intersect(lbnd, bisector);
if (vertex != null)
{
vertices.Add(vertex);
heap.Remove(lbnd);
lbnd.Vertex = vertex;
lbnd.YStar = vertex.Y + newSite.Distance(vertex);
heap.Insert(lbnd);
}
lbnd = bisector;
bisector = new HalfEdge(edge, LR.Right);
halfEdges.Add(bisector);
edgeList.Insert(lbnd, bisector);
vertex = Vertex.Intersect(bisector, rbnd);
if (vertex != null)
{
vertices.Add(vertex);
bisector.Vertex = vertex;
bisector.YStar = vertex.Y + newSite.Distance(vertex);
heap.Insert(bisector);
}
newSite = _sites.Next();
}
else if (!heap.Empty)
{
var lbnd = heap.ExtractMin();
var llbnd = lbnd.EdgeListLeftNeighbor;
var rbnd = lbnd.EdgeListRightNeighbor;
var rrbnd = rbnd.EdgeListRightNeighbor;
var bottomSite = LeftRegion(lbnd) ?? bottomMostSite;
var topSite = RightRegion(rbnd) ?? bottomMostSite;
var v = lbnd.Vertex;
v.SetIndex();
lbnd.Edge.SetVertex(lbnd.LeftRight, v);
rbnd.Edge.SetVertex(rbnd.LeftRight, v);
edgeList.Remove(lbnd);
heap.Remove(rbnd);
edgeList.Remove(rbnd);
var leftRight = LR.Left;
if (bottomSite.Y > topSite.Y)
{
var tempSite = bottomSite;
bottomSite = topSite;
topSite = tempSite;
leftRight = LR.Right;
}
var edge = Edge.CreateBisectingEdge(bottomSite, topSite);
Edges.Add(edge);
var bisector = new HalfEdge(edge, leftRight);
halfEdges.Add(bisector);
edgeList.Insert(llbnd, bisector);
edge.SetVertex(LR.Other(leftRight), v);
Vertex vertex;
if ((vertex = Vertex.Intersect(llbnd, bisector)) != null)
{
vertices.Add(vertex);
heap.Remove(llbnd);
llbnd.Vertex = vertex;
llbnd.YStar = vertex.Y + bottomSite.Distance(vertex);
heap.Insert(llbnd);
}
if ((vertex = Vertex.Intersect(bisector, rrbnd)) != null)
{
vertices.Add(vertex);
bisector.Vertex = vertex;
bisector.YStar = vertex.Y + bottomSite.Distance(vertex);
heap.Insert(bisector);
}
}
else
{
break;
}
}
halfEdges.Clear();
var nullVerts = Edges.Where(e => e.RightVertex == null || e.LeftVertex == null).ToList();
foreach (var edge in Edges)
{
edge.ClipVertices(PlotBounds);
}
vertices.Clear();
}