PerimeterEdge ShortcutTwoListElements(PerimeterEdge a)
{
var b = a.Next;
Debug.Assert(a.End == b.Start);
var t = new CdtTriangle(a.Start, a.End, b.End, a.Edge, b.Edge,
createEdgeDelegate);
Triangles.Insert(t);
var newEdge = t.Edges[2];
Debug.Assert(newEdge.IsAdjacent(a.Start) && newEdge.IsAdjacent(b.End));
LegalizeEdge(a.Start, t.OppositeEdge(a.Start));
t = newEdge.CcwTriangle ?? newEdge.CwTriangle;
LegalizeEdge(b.End, t.OppositeEdge(b.End));
var c = new PerimeterEdge(newEdge)
{
Start = a.Start, End = b.End
};
a.Prev.Next = c;
c.Prev = a.Prev;
c.Next = b.Next;
b.Next.Prev = c;
return(c);
}
/// <summary>
/// aNode is to the left of bNode, and they are consecutive
/// </summary>
/// <param name="aNode"></param>
/// <param name="bNode"></param>
RBNode <CdtFrontElement> ShortcutTwoFrontElements(RBNode <CdtFrontElement> aNode, RBNode <CdtFrontElement> bNode)
{
var aElem = aNode.Item;
var bElem = bNode.Item;
Debug.Assert(aElem.RightSite == bElem.LeftSite);
CdtTriangle t = new CdtTriangle(aElem.LeftSite, aElem.RightSite, bElem.RightSite, aElem.Edge, bElem.Edge,
createEdgeDelegate);
Triangles.Insert(t);
front.DeleteNodeInternal(aNode);
//now bNode might b not valid anymore
front.Remove(bElem);
var newEdge = t.Edges[2];
Debug.Assert(newEdge.IsAdjacent(aElem.LeftSite) && newEdge.IsAdjacent(bElem.RightSite));
LegalizeEdge(aElem.LeftSite, t.OppositeEdge(aElem.LeftSite));
t = newEdge.CcwTriangle ?? newEdge.CwTriangle;
LegalizeEdge(bElem.RightSite, t.OppositeEdge(bElem.RightSite));
return(front.Insert(new CdtFrontElement(aElem.LeftSite, newEdge)));
}
void InsertAndLegalizeTriangle(CdtSite pi, CdtFrontElement frontElement)
{
if (Point.GetTriangleOrientationWithNoEpsilon(pi.Point, frontElement.LeftSite.Point, frontElement.RightSite.Point) != TriangleOrientation.Collinear)
{
var tr = new CdtTriangle(pi, frontElement.Edge, createEdgeDelegate);
Triangles.Insert(tr);
LegalizeEdge(pi, tr.Edges[0]);
}
else //we need to split the triangle below the element in to two triangles and legalize the old edges
//we also delete, that is forget, the frontElement.Edge
{
var e = frontElement.Edge;
e.upperSite.Edges.Remove(e);
var t = e.CcwTriangle ?? e.CwTriangle;
var oppositeSite = t.OppositeSite(e);
RemoveTriangleButLeaveEdges(triangles, t);
t = new CdtTriangle(frontElement.LeftSite, oppositeSite, pi, createEdgeDelegate);
var t1 = new CdtTriangle(frontElement.RightSite, oppositeSite, pi, createEdgeDelegate);
triangles.Insert(t);
triangles.Insert(t1);
LegalizeEdge(pi, t.OppositeEdge(pi));
LegalizeEdge(pi, t1.OppositeEdge(pi));
}
}
CdtEdge GetPiercedEdgeInSiteTriangle(CdtTriangle t, CdtSite site, Point target) {
var e = t.OppositeEdge(site);
return PiercedEdgeQuery(e, site.Point, target, t);
}
void InsertAndLegalizeTriangle(CdtSite pi, CdtFrontElement frontElement) {
if (Point.GetTriangleOrientationWithNoEpsilon(pi.Point, frontElement.LeftSite.Point, frontElement.RightSite.Point) != TriangleOrientation.Collinear) {
var tr = new CdtTriangle(pi, frontElement.Edge, createEdgeDelegate);
Triangles.Insert(tr);
LegalizeEdge(pi, tr.Edges[0]);
} else { //we need to split the triangle below the element in to two triangles and legalize the old edges
//we also delete, that is forget, the frontElement.Edge
var e = frontElement.Edge;
e.upperSite.Edges.Remove(e);
var t=e.CcwTriangle??e.CwTriangle;
var oppositeSite = t.OppositeSite(e);
RemoveTriangleButLeaveEdges(triangles, t);
t=new CdtTriangle(frontElement.LeftSite, oppositeSite, pi, createEdgeDelegate);
var t1 = new CdtTriangle(frontElement.RightSite, oppositeSite, pi, createEdgeDelegate);
triangles.Insert(t);
triangles.Insert(t1);
LegalizeEdge(pi, t.OppositeEdge(pi));
LegalizeEdge(pi,t1.OppositeEdge(pi));
}
}
/// <summary>
/// aNode is to the left of bNode, and they are consecutive
/// </summary>
/// <param name="aNode"></param>
/// <param name="bNode"></param>
RBNode<CdtFrontElement> ShortcutTwoFrontElements(RBNode<CdtFrontElement> aNode, RBNode<CdtFrontElement> bNode) {
var aElem = aNode.Item;
var bElem = bNode.Item;
Debug.Assert(aElem.RightSite == bElem.LeftSite);
CdtTriangle t = new CdtTriangle(aElem.LeftSite, aElem.RightSite, bElem.RightSite, aElem.Edge, bElem.Edge,
createEdgeDelegate);
Triangles.Insert(t);
front.DeleteNodeInternal(aNode);
//now bNode might b not valid anymore
front.Remove(bElem);
var newEdge = t.Edges[2];
Debug.Assert(newEdge.IsAdjacent( aElem.LeftSite) && newEdge.IsAdjacent(bElem.RightSite));
LegalizeEdge(aElem.LeftSite, t.OppositeEdge(aElem.LeftSite));
t=newEdge.CcwTriangle ?? newEdge.CwTriangle;
LegalizeEdge(bElem.RightSite, t.OppositeEdge(bElem.RightSite));
return front.Insert(new CdtFrontElement(aElem.LeftSite, newEdge));
}
PerimeterEdge ShortcutTwoListElements(PerimeterEdge a) {
var b = a.Next;
Debug.Assert(a.End == b.Start);
var t = new CdtTriangle(a.Start, a.End, b.End, a.Edge, b.Edge,
createEdgeDelegate);
Triangles.Insert(t);
var newEdge = t.Edges[2];
Debug.Assert(newEdge.IsAdjacent(a.Start) && newEdge.IsAdjacent(b.End));
LegalizeEdge(a.Start, t.OppositeEdge(a.Start));
t = newEdge.CcwTriangle ?? newEdge.CwTriangle;
LegalizeEdge(b.End, t.OppositeEdge(b.End));
var c = new PerimeterEdge(newEdge) { Start = a.Start, End = b.End };
a.Prev.Next = c;
c.Prev = a.Prev;
c.Next = b.Next;
b.Next.Prev = c;
return c;
}
CdtEdge GetPiercedEdgeInSiteTriangle(CdtTriangle t, CdtSite site, Point target)
{
var e = t.OppositeEdge(site);
return(PiercedEdgeQuery(e, site.Point, target, t));
}
