static PriorityHeap <VertexEv> setupEvQueue(IList <Vector3> poly)
{
PriorityHeap <VertexEv> queue = new PriorityHeap <VertexEv>();
for (int i = 0; i < poly.Count; ++i)
{
Vector3 pv = poly[i];
Vector3 nv = poly[(i + 1) % poly.Count];
// [v_i, v_i+1]
VertexEv ev1 = new VertexEv(pv, i, VertexEv.vType.LEFT);
VertexEv ev2 = new VertexEv(nv, i, VertexEv.vType.LEFT);
if (compareVector3(pv, nv) < 0) // pv is left of nv
{
ev2.type = VertexEv.vType.RIGHT;
}
else
{
ev1.type = VertexEv.vType.RIGHT;
}
queue.Add(ev1);
queue.Add(ev2);
}
return(queue);
}
public static void BentleyOttmann(IList <Vector3> poly)
{
PriorityHeap <VertexEv> evQ = setupEvQueue(poly);
SweepLine SL = new SweepLine(poly);
Dictionary <int, IntersectionPoint> intersectionPoints = new Dictionary <int, IntersectionPoint>();
IntersectionPoint I;
while (!evQ.Empty)
{
VertexEv ev = evQ.Pop();
if (ev.type == VertexEv.vType.LEFT)
{
int idx = SL.Add(ev.edge);
I = SL.GetIntersectionPoint(idx, idx - 1);
if (I != null) // Intersection
{
int ID = I.Id(poly.Count);
if (!intersectionPoints.ContainsKey(ID))
{
intersectionPoints[ID] = I;
//evQ.Add(new VertexEv(I.v, I.Edge1, I.Edge2, VertexEv.vType.INTERSECT));
evQ.Add(new VertexEv(I));
}
}
I = SL.GetIntersectionPoint(idx, idx + 1);
if (I != null) // intersection
{
int ID = I.Id(poly.Count);
if (!intersectionPoints.ContainsKey(ID))
{
intersectionPoints[ID] = I;
evQ.Add(new VertexEv(I.P, I.Edge1, I.Edge2, VertexEv.vType.INTERSECT));
}
}
}
else if (ev.type == VertexEv.vType.RIGHT)
{
int idx = SL.Find(ev.edge);
I = SL.GetIntersectionPoint(idx - 1, idx + 1);
if (I != null)
{
int ID = I.Id(poly.Count);
if (!intersectionPoints.ContainsKey(ID))
{
intersectionPoints[ID] = I;
evQ.Add(new VertexEv(I));
}
}
}
else // intersection point
// unfinished business ...
{
}
}
}