public List <BeachLineEdge> DoVoronoi(List <VoronoiSite> siteList)
{
List <BeachLineEdge> outEdges = new List <BeachLineEdge>();
beachLine = new BeachLine();
events = new List <VoronoiEvent>();
// Add site list to event list.
foreach (VoronoiSite site in siteList)
{
events.Add(new SiteEvent(site));
}
// Sort site list.
events.Sort();
// Test for first two events being very close in y
if (events.Count >= 2)
{
if (events[0].y - events[1].y < 0.01f)
{
// Add another site events far above them to prevent this from happening
events.Insert(0, new SiteEvent(new VoronoiSite(new Vector2(0, -10))));
}
}
// Start processing events
int iterations = 0;
while (events.Count != 0)
{
if (use_max_iterations && iterations == max_iterations)
{
break;
}
else
{
iterations++;
}
// Pop event off front of list
VoronoiEvent thisEvent = events[0];
// Set sweepline
sweepLine = thisEvent.y;
if (sweepLine >= target_sweepline)
{
sweepLine = target_sweepline;
beachLine.Update(sweepLine);
break;
}
beachLine.Update(sweepLine);
if (thisEvent.IsValid())
{
// Check event type
if (thisEvent is SiteEvent)
{
SiteEvent siteEvent = (SiteEvent)thisEvent;
// Create a new arc for this event.
BeachLineArc newArc = new BeachLineArc(siteEvent.Site.Point, sweepLine);
// Find arc at this site
BeachLineArc arcToSplit = beachLine.SearchX(siteEvent.x);
if (arcToSplit == null)
{
// We could not find an arc, meaning this is the first one.
// Lets just add it to the beachline as root.
beachLine.SetRoot(newArc);
}
else
{
// Split the arc
arcToSplit.Split(newArc);
// The split will have added newArc to the tree and also created two new edges.
// We need to check those for intersections.
List <BeachLineArc> arcsToSqueeze = new List <BeachLineArc> {
newArc.LeftArc, newArc.RightArc
};
foreach (BeachLineArc arc in arcsToSqueeze)
{
CheckForNewEdgeEvents(arc);
}
}
}
else if (thisEvent is EdgeEvent)
{
EdgeEvent edgeEvent = (EdgeEvent)thisEvent;
if (edgeEvent.SqueezedArc != null)
{
if (edgeEvent.SqueezedArc.LeftEdge != null && edgeEvent.SqueezedArc.RightEdge != null)
{
BeachLineEdge newEdge;
List <BeachLineEdge> outputEdges = edgeEvent.SqueezedArc.Squeeze(out newEdge);
// Add edges to output
foreach (BeachLineEdge edge in outputEdges)
{
outEdges.Add(edge);
}
// Squeeze function will have removed arc and edges from tree and created a new edge.
// We need to check that edge for any new intersections.
CheckForNewEdgeEvents(newEdge.LeftArc);
CheckForNewEdgeEvents(newEdge.RightArc);
}
}
// Otherwise, this must have been pre-empted but not invalidated for some reason
}
else
{
Debug.LogError("Wrong event type! Should not happen!");
}
}
events.RemoveAt(0);
}
if (iterations != max_iterations)
{
sweepLine = target_sweepline;
beachLine.Update(sweepLine);
}
if (events.Count == 0)
{
// We completed the events list.
// Add the remaining edges to the output.
BeachLineElement node = beachLine.GetRoot();
if (node != null)
{
// Mode node to start
while (node.Prev != null)
{
node = node.Prev;
}
// Add all remaining edges
while (node.Next != null)
{
if (node is BeachLineEdge)
{
outEdges.Add(node as BeachLineEdge);
}
node = node.Next;
}
}
}
return(outEdges);
}