/**
* This function only removes the Halfedge from the left-right list.
* We cannot dispose it yet because we are still using it.
* @param halfEdge
*
*/
public void Remove (Halfedge halfEdge)
{
halfEdge.edgeListLeftNeighbor.edgeListRightNeighbor = halfEdge.edgeListRightNeighbor;
halfEdge.edgeListRightNeighbor.edgeListLeftNeighbor = halfEdge.edgeListLeftNeighbor;
halfEdge.edge = Edge.DELETED;
halfEdge.edgeListLeftNeighbor = halfEdge.edgeListRightNeighbor = null;
}
/**
* Insert newHalfedge to the right of lb
* @param lb
* @param newHalfedge
*
*/
public void Insert (Halfedge lb, Halfedge newHalfedge)
{
newHalfedge.edgeListLeftNeighbor = lb;
newHalfedge.edgeListRightNeighbor = lb.edgeListRightNeighbor;
lb.edgeListRightNeighbor.edgeListLeftNeighbor = newHalfedge;
lb.edgeListRightNeighbor = newHalfedge;
}
private Halfedge Init (Edge edge, Nullable<Side> lr)
{
this.edge = edge;
leftRight = lr;
nextInPriorityQueue = null;
vertex = null;
return this;
}
private int Bucket (Halfedge halfEdge)
{
int theBucket = (int)((halfEdge.ystar - _ymin) / _deltay * _hashsize);
if (theBucket < 0)
theBucket = 0;
if (theBucket >= _hashsize)
theBucket = _hashsize - 1;
return theBucket;
}
public void ReallyDispose()
{
edgeListLeftNeighbor = null;
edgeListRightNeighbor = null;
nextInPriorityQueue = null;
edge = null;
leftRight = null;
vertex = null;
_pool.Add(this);
}
public void Insert (Halfedge halfEdge)
{
Halfedge previous, next;
int insertionBucket = Bucket (halfEdge);
if (insertionBucket < _minBucket) {
_minBucket = insertionBucket;
}
previous = _hash [insertionBucket];
while ((next = previous.nextInPriorityQueue) != null
&& (halfEdge.ystar > next.ystar || (halfEdge.ystar == next.ystar && halfEdge.vertex.x > next.vertex.x))) {
previous = next;
}
halfEdge.nextInPriorityQueue = previous.nextInPriorityQueue;
previous.nextInPriorityQueue = halfEdge;
++_count;
}
public void Remove (Halfedge halfEdge)
{
Halfedge previous;
int removalBucket = Bucket (halfEdge);
if (halfEdge.vertex != null) {
previous = _hash [removalBucket];
while (previous.nextInPriorityQueue != halfEdge) {
previous = previous.nextInPriorityQueue;
}
previous.nextInPriorityQueue = halfEdge.nextInPriorityQueue;
_count--;
halfEdge.vertex = null;
halfEdge.nextInPriorityQueue = null;
halfEdge.Dispose ();
}
}
/**
* This is the only way to make a Vertex
*
* @param halfedge0
* @param halfedge1
* @return
*
*/
public static Vertex Intersect(Halfedge halfedge0, Halfedge halfedge1)
{
Edge edge0, edge1, edge;
Halfedge halfedge;
float determinant, intersectionX, intersectionY;
bool rightOfSite;
edge0 = halfedge0.edge;
edge1 = halfedge1.edge;
if (edge0 == null || edge1 == null)
{
return null;
}
if (edge0.RightSite == edge1.RightSite)
{
return null;
}
determinant = edge0.a * edge1.b - edge0.b * edge1.a;
if (-1.0e-10 < determinant && determinant < 1.0e-10)
{
// the edges are parallel
return null;
}
intersectionX = (edge0.c * edge1.b - edge1.c * edge0.b) / determinant;
intersectionY = (edge1.c * edge0.a - edge0.c * edge1.a) / determinant;
if (Voronoi.CompareByYThenX(edge0.RightSite, edge1.RightSite) < 0)
{
halfedge = halfedge0; edge = edge0;
}
else
{
halfedge = halfedge1; edge = edge1;
}
rightOfSite = intersectionX >= edge.RightSite.X;
if ((rightOfSite && halfedge.leftRight == LR.LEFT)
|| (!rightOfSite && halfedge.leftRight == LR.RIGHT))
{
return null;
}
return Vertex.Create(intersectionX, intersectionY);
}
public EdgeList (float xmin, float deltax, int sqrt_nsites)
{
_xmin = xmin;
_deltax = deltax;
_hashsize = 2 * sqrt_nsites;
_hash = new Halfedge[_hashsize];
// two dummy Halfedges:
_leftEnd = Halfedge.CreateDummy ();
_rightEnd = Halfedge.CreateDummy ();
_leftEnd.edgeListLeftNeighbor = null;
_leftEnd.edgeListRightNeighbor = _rightEnd;
_rightEnd.edgeListLeftNeighbor = _leftEnd;
_rightEnd.edgeListRightNeighbor = null;
_hash [0] = _leftEnd;
_hash [_hashsize - 1] = _rightEnd;
}
public void Dispose ()
{
Halfedge halfEdge = _leftEnd;
Halfedge prevHe;
while (halfEdge != _rightEnd) {
prevHe = halfEdge;
halfEdge = halfEdge.edgeListRightNeighbor;
prevHe.Dispose ();
}
_leftEnd = null;
_rightEnd.Dispose ();
_rightEnd = null;
int i;
for (i = 0; i < _hashsize; ++i) {
_hash [i] = null;
}
_hash = null;
}
public EdgeList(float xmin, float deltax, int sqrt_nsites)
{
_xmin = xmin;
_deltax = deltax;
_hashsize = 2 * sqrt_nsites;
int i;
_hash = new List<Halfedge>(_hashsize);
while (_hash.Count < _hashsize)
{
_hash.Add(null);
}
// two dummy Halfedges:
_leftEnd = Halfedge.CreateDummy();
_rightEnd = Halfedge.CreateDummy();
_leftEnd.edgeListLeftNeighbor = null;
_leftEnd.edgeListRightNeighbor = _rightEnd;
_rightEnd.edgeListLeftNeighbor = _leftEnd;
_rightEnd.edgeListRightNeighbor = null;
_hash[0] = _leftEnd;
_hash[_hashsize - 1] = _rightEnd;
}
private Site FortunesAlgorithm_rightRegion (Halfedge he)
{
Edge edge = he.edge;
if (edge == null) {
return fortunesAlgorithm_bottomMostSite;
}
return edge.Site (SideHelper.Other ((Side)he.leftRight));
}
Site RightRegion(Halfedge he, Site bottomMostSite)
{
Edge edge = he.edge;
if (edge == null)
{
return bottomMostSite;
}
return edge.GetSite(LR.Other(he.leftRight));
}
private Site FortunesAlgorithm_leftRegion(Halfedge he)
{
Edge edge = he.edge;
if (edge == null) {
return fortunesAlgorithm_bottomMostSite;
}
return edge.Site ((LR.Side)he.leftRight);
}
