public static VoronoiGraph ComputeVoronoiGraph(IEnumerable <PointF> points, int w = 800, int h = 600, bool debug = false)
{
var sites = new SiteList(points);
if (debug)
{
sites.LogSites();
}
var graph = new VoronoiGraph(w, h)
{
Debug = debug
};
try {
var edgeList = new EdgeList(sites);
var eventQueue = new EventQueue();
sites.BottomSite = sites.ExtractMin();
graph.PlotSite(sites.BottomSite);
var newSite = sites.ExtractMin();
var newIntStar = new Site(Single.MaxValue, Single.MaxValue);
while (true)
{
if (!eventQueue.IsEmpty)
{
newIntStar = eventQueue.Min();
}
if (newSite != null && (eventQueue.IsEmpty || newSite.CompareTo(newIntStar) < 0))
{
// new site is smallest
graph.PlotSite(newSite);
var lbnd = edgeList.LeftBound(newSite);
var rbnd = lbnd.Right;
var bot = edgeList.RightRegion(lbnd);
var e = Edge.CreateBisectingEdge(bot, newSite);
graph.PlotBisector(e);
var bisector = new HalfEdge(e, Side.Left);
EdgeList.Insert(lbnd, bisector);
var p = Site.CreateIntersectingSite(lbnd, bisector);
if (p != null)
{
eventQueue.Delete(lbnd);
if (debug)
{
Console.WriteLine("Inserting {0}", p);
}
eventQueue.Insert(lbnd, p, Site.Distance(p, newSite));
}
lbnd = bisector;
bisector = new HalfEdge(e, Side.Right);
EdgeList.Insert(lbnd, bisector);
p = Site.CreateIntersectingSite(bisector, rbnd);
if (p != null)
{
if (debug)
{
Console.WriteLine("Inserting {0}", p);
}
eventQueue.Insert(bisector, p, Site.Distance(p, newSite));
}
newSite = sites.ExtractMin();
}
else if (!eventQueue.IsEmpty)
{
// intersection is smallest
var lbnd = eventQueue.ExtractMin();
var llbnd = lbnd.Left;
var rbnd = lbnd.Right;
var rrbnd = rbnd.Right;
var bot = edgeList.LeftRegion(lbnd);
var top = edgeList.RightRegion(rbnd);
graph.PlotTriple(bot, top, edgeList.RightRegion(lbnd));
var v = lbnd.Vertex;
graph.PlotVertex(v);
graph.EndPoint(lbnd.Edge, lbnd.Side, v);
graph.EndPoint(rbnd.Edge, rbnd.Side, v);
EdgeList.Delete(lbnd);
eventQueue.Delete(rbnd);
EdgeList.Delete(rbnd);
var pm = Side.Left;
if (bot.Y > top.Y)
{
var temp = bot;
bot = top;
top = temp;
pm = Side.Right;
}
var e = Edge.CreateBisectingEdge(bot, top);
graph.PlotBisector(e);
var bisector = new HalfEdge(e, pm);
EdgeList.Insert(llbnd, bisector);
graph.EndPoint(e, Side.Other(pm), v);
var p = Site.CreateIntersectingSite(llbnd, bisector);
if (p != null)
{
eventQueue.Delete(llbnd);
if (debug)
{
Console.WriteLine("Inserting {0}", p);
}
eventQueue.Insert(llbnd, p, Site.Distance(p, bot));
}
p = Site.CreateIntersectingSite(bisector, rrbnd);
if (p != null)
{
if (debug)
{
Console.WriteLine("Inserting {0}", p);
}
eventQueue.Insert(bisector, p, Site.Distance(p, bot));
}
}
else
{
break;
}
}
for (var lbnd = edgeList.LeftEnd.Right; lbnd != edgeList.RightEnd; lbnd = lbnd.Right)
{
var e = lbnd.Edge;
graph.PlotEndpoint(e);
}
} catch (Exception ex) {
Console.WriteLine("########################################");
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
}
graph.SweepLine = graph.Height;
graph.ResetNewItems();
foreach (var edge in graph.Edges)
{
edge.ClipVertices(new Rectangle(0, 0, w, h));
}
return(graph);
}
public VoronoiGraph StepVoronoi()
{
_graph.ResetNewItems();
if (!_edgeFixup)
{
if (!_eventQueue.IsEmpty)
{
_newIntStar = _eventQueue.Min();
}
if (_newSite != null && (_eventQueue.IsEmpty || /*Geometry.CompareByYThenX(_newSite, _newIntStar)*/ _newSite.CompareTo(_newIntStar) < 0))
{
_graph.PlotSite(_newSite);
var lbnd = _edgeList.LeftBound(_newSite);
var rbnd = lbnd.Right;
var bot = _edgeList.RightRegion(lbnd);
var e = Edge.CreateBisectingEdge(bot, _newSite);
_graph.PlotBisector(e);
var bisector = new HalfEdge(e, Side.Left);
EdgeList.Insert(lbnd, bisector);
var p = Site.CreateIntersectingSite(lbnd, bisector);
if (p != null)
{
_eventQueue.Delete(lbnd);
if (_graph.Debug)
{
Console.WriteLine("Inserting {0}", p);
}
_eventQueue.Insert(lbnd, p, Site.Distance(p, _newSite));
}
lbnd = bisector;
bisector = new HalfEdge(e, Side.Right);
EdgeList.Insert(lbnd, bisector);
p = Site.CreateIntersectingSite(bisector, rbnd);
if (p != null)
{
if (_graph.Debug)
{
Console.WriteLine("Inserting {0}", p);
}
_eventQueue.Insert(bisector, p, Site.Distance(p, _newSite));
}
_newSite = _sites.ExtractMin();
if (_newSite != null && _newSite.Y > _graph.SweepLine)
{
_graph.SweepLine = _newSite.Y;
}
else if (_newSite == null)
{
_graph.SweepLine = _graph.Height;
}
}
else if (!_eventQueue.IsEmpty) // intersection is smallest
{
var lbnd = _eventQueue.ExtractMin();
var llbnd = lbnd.Left;
var rbnd = lbnd.Right;
var rrbnd = rbnd.Right;
var bot = _edgeList.LeftRegion(lbnd);
var top = _edgeList.RightRegion(rbnd);
_graph.PlotTriple(bot, top, _edgeList.RightRegion(lbnd));
var v = lbnd.Vertex;
_graph.PlotVertex(v);
_graph.EndPoint(lbnd.Edge, lbnd.Side, v);
_graph.EndPoint(rbnd.Edge, rbnd.Side, v);
EdgeList.Delete(lbnd);
_eventQueue.Delete(rbnd);
EdgeList.Delete(rbnd);
var pm = Side.Left;
if (bot.Y > top.Y)
{
var temp = bot;
bot = top;
top = temp;
pm = Side.Right;
}
var e = Edge.CreateBisectingEdge(bot, top);
_graph.PlotBisector(e);
var bisector = new HalfEdge(e, pm);
EdgeList.Insert(llbnd, bisector);
_graph.EndPoint(e, pm == Side.Left ? Side.Right : Side.Left, v);
var p = Site.CreateIntersectingSite(llbnd, bisector);
if (p != null)
{
_eventQueue.Delete(llbnd);
if (_graph.Debug)
{
Console.WriteLine("Inserting {0}", p);
}
_eventQueue.Insert(llbnd, p, Site.Distance(p, bot));
}
p = Site.CreateIntersectingSite(bisector, rrbnd);
if (p != null)
{
if (_graph.Debug)
{
Console.WriteLine("Inserting {0}", p);
}
_eventQueue.Insert(bisector, p, Site.Distance(p, bot));
}
}
else
{
_edgeFixup = true;
}
StepNumber++;
}
else
{
var lbnd = _edgeList.LeftEnd.Right;
if (lbnd != _edgeList.RightEnd)
{
var e = lbnd.Edge;
_graph.PlotEndpoint(e);
EdgeList.Delete(lbnd);
StepNumber++;
}
else
{
foreach (var edge in _graph.Edges)
{
edge.ClipVertices(new Rectangle(0, 0, _graph.Width, _graph.Height));
}
if (_graph.Debug)
{
Console.WriteLine("Done computing graph!");
}
}
}
if (_graph.Debug)
{
Console.WriteLine("Step: " + StepNumber);
}
return(_graph);
}
private float SiteDistance()
{
return(Site.Distance(Region[Side.Left], Region[Side.Right]));
}