private void build(List <VoronoiCell> cells, int lastMaxYIndex)
{
init(cells, lastMaxYIndex);
// handle all
while (_eventList.Count > 0)
{
FortuneEvent currentEvent = _eventList.First.Value;
_eventList.RemoveFirst();
switch (currentEvent.Kind)
{
case FortuneEvent.EventKind.Point:
handlePointEvent((FortunePointEvent)currentEvent);
break;
case FortuneEvent.EventKind.Circle:
handleCircleEvent((FortuneCircleEvent)currentEvent);
break;
}
}
// calculate the coordinates of the "free" sites
_shoreLine.Finish(_rectangle, _startVerticalNodes);
// remove degenerate edges
clean(cells);
}
private void addCircleEvent(FortuneEvent ev)
{
LinkedListNode <FortuneEvent> currentEvent = _eventList.First;
while (currentEvent != null)
{
if (currentEvent.Value.Point.Y < ev.Point.Y)
{
_eventList.AddBefore(currentEvent, ev);
return;
}
currentEvent = currentEvent.Next;
}
_eventList.AddLast(ev);
}
private void handleCircleEvent(FortuneCircleEvent ev)
{
FortuneArc ln = ev.Arc.LeftNeighbor;
FortuneArc rn = ev.Arc.RightNeighbor;
// remove events range associated with this arc
if (ln.CircleEvent != null)
{
_eventList.Remove(ln.CircleEvent);
}
if (rn.CircleEvent != null)
{
_eventList.Remove(rn.CircleEvent);
}
// remove the arc of coastline
_shoreLine.RemoveArc(ev.Arc);
//fix slave nodes arc ribs
if (ev.Arc.LeftNode != null)
{
ev.Arc.LeftNode.Point = ev.CircleCenter;
ev.Arc.LeftNode.IsInfinit = false;
}
if (ev.Arc.RightNode != null)
{
ev.Arc.RightNode.Point = ev.CircleCenter;
ev.Arc.RightNode.IsInfinit = false;
}
// add a new edge
VoronoiEdge edge = new VoronoiEdge(ln.Site.Cell, rn.Site.Cell);
edge.Node1 = new VoronoiNode(ev.CircleCenter.X, ev.CircleCenter.Y);
edge.Node2 = new VoronoiNode((ln.Site.Cell.DataPoint.X + rn.Site.Cell.DataPoint.X) / 2,
(ln.Site.Cell.DataPoint.Y + rn.Site.Cell.DataPoint.Y) / 2);
//expand the bounding rectangle of the chart
_rectangle.Join(ev.CircleCenter);
// one node of the new edge is fixed, the second - no
edge.Node1.IsInfinit = false;
edge.Node2.IsInfinit = true;
// dobavleyaem edge to cells
ln.Site.Cell.AddEdge(edge);
rn.Site.Cell.AddEdge(edge);
//add a triangle in the Delaunay triangulation, if necessary
if (_buildTriangles)
{
_triangles.Add(ev.Triangle);
}
// not a fixed node is a new edge now vanished neighbors arc
ln.RightNode = edge.Node2;
rn.LeftNode = edge.Node2;
FortuneArc lnln = ln.LeftNeighbor;
FortuneArc lnrn = ln.RightNeighbor;
FortuneArc rnln = rn.LeftNeighbor;
FortuneArc rnrn = rn.RightNeighbor;
// add events to the newly formed circle arcs triples
if (lnln != null)
{
if (lnrn != null)
{
FortuneEvent eventToAdd = getCircleEvent(lnln, ln, lnrn, ev.Point.Y);
if (eventToAdd != null)
{
addCircleEvent(eventToAdd);
}
ln.CircleEvent = eventToAdd;
}
}
if (rnln != null)
{
if (rnrn != null)
{
FortuneEvent eventToAdd = getCircleEvent(rnln, rn, rnrn, ev.Point.Y);
if (eventToAdd != null)
{
addCircleEvent(eventToAdd);
}
rn.CircleEvent = eventToAdd;
}
}
}
private void handlePointEvent(FortunePointEvent ev)
{
if (_shoreLine.Root == null)
{
FortuneArc arc = new FortuneArc();
FortuneSite site = new FortuneSite();
site.Cell = ev.Cell;
arc.Site = site;
_shoreLine.Root = arc;
return;
}
FortuneArc arcAbove = _shoreLine.FindArc(ev.Point.X, ev.Point.Y);
// remove events range from the queue
if (arcAbove.CircleEvent != null)
{
_eventList.Remove(arcAbove.CircleEvent);
}
// create an arc
FortuneArc splitter = new FortuneArc();
splitter.Site = new FortuneSite();
splitter.Site.Cell = ev.Cell;
FortuneArc newArc = _shoreLine.SplitArc(arcAbove, splitter);
FortuneArc ln = newArc.LeftNeighbor;
FortuneArc lnln = null;
if (ln != null)
{
lnln = ln.LeftNeighbor;
}
FortuneArc rn = newArc.RightNeighbor;
FortuneArc rnrn = null;
if (rn != null)
{
rnrn = rn.RightNeighbor;
}
if (ln != null)
{
if (lnln != null)
{
FortuneEvent eventToAdd = getCircleEvent(lnln, ln, newArc, ev.Point.Y);
if (eventToAdd != null)
{
addCircleEvent(eventToAdd);
}
ln.CircleEvent = eventToAdd;
}
}
if (rn != null)
{
if (rnrn != null)
{
FortuneEvent eventToAdd = getCircleEvent(newArc, rn, rnrn, ev.Point.Y);
if (eventToAdd != null)
{
addCircleEvent(eventToAdd);
}
rn.CircleEvent = eventToAdd;
}
}
}
