private void init(List <VoronoiCell> cells, int lastMaxYIndex)
{
_rectangle = new BoundingRectangle();
_eventList = new LinkedList <FortuneEvent>();
_startVerticalNodes = new List <VoronoiNode>();
// Where several points have the minimum ordinate requires a separate pre-treatment
int skipEventCount = 0;
if (lastMaxYIndex > 0)
{
VoronoiNode previousNode = null;
FortuneArc currentArc = null;
skipEventCount = lastMaxYIndex + 1;
for (int i = 0; i <= lastMaxYIndex; i++)
{
// add an arc of coastline
FortuneArc arc = new FortuneArc();
FortuneSite site = new FortuneSite();
site.Cell = cells[i];
arc.Site = site;
if (currentArc != null)
{
currentArc.Right = arc;
}
currentArc = arc;
if (_shoreLine.Root == null)
{
_shoreLine.Root = arc;
}
if (previousNode != null)
{
arc.LeftNode = previousNode;
}
// add the vertical edges of the Voronoi diagram
if (i < lastMaxYIndex)
{
VoronoiEdge edge = new VoronoiEdge(cells[i], cells[i + 1]);
double middleX = (cells[i].DataPoint.X + cells[i + 1].DataPoint.X) / 2;
double middleY = cells[i].DataPoint.Y;
edge.Node1 = new VoronoiNode(middleX, middleY);
edge.Node1.IsInfinit = true;
_startVerticalNodes.Add(edge.Node1);
edge.Node2 = new VoronoiNode(middleX, middleY);
edge.Node2.IsInfinit = true;
previousNode = edge.Node2;
arc.RightNode = edge.Node2;
cells[i].AddEdge(edge);
cells[i + 1].AddEdge(edge);
}
}
}
// fill all point events
int j = 0;
foreach (VoronoiCell cell in cells)
{
if (skipEventCount > j++)
{
continue;
}
FortunePointEvent ev = new FortunePointEvent();
ev.Point = cell.DataPoint;
ev.Cell = cell;
_eventList.AddLast(ev);
}
}
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;
}
}
}