Vertex *InsertPointInEdge(float2 point, Edge *edge)
{
_flipStack.Push(edge->ONext->Sym);
_flipStack.Push(edge->DPrev->Sym);
_flipStack.Push(edge->OPrev);
_flipStack.Push(edge->DNext);
for (var i = 0; i < _flipStack.Count; i++)
{
Assert.IsTrue(Math.Ccw(_flipStack[i]->Org->Point, _flipStack[i]->Dest->Point, point));
}
DestroyedTriangle(edge->TriangleId);
DestroyedTriangle(edge->Sym->TriangleId);
var crep = edge->QuadEdge->Crep;
var e = edge->OPrev;
C.Remove((IntPtr)edge);
RemoveEdge(edge, false);
var result = CreateVertex(point);
V.TryAdd((IntPtr)result);
V.TryAdd((IntPtr)e->Org);
var newEdge = CreateEdge(e->Org, result);
newEdge->QuadEdge->Crep = GetCrep(crep);
Splice(newEdge, e);
V.TryAdd((IntPtr)e->Dest);
V.TryAdd((IntPtr)newEdge->Sym->Org);
newEdge = Connect(e, newEdge->Sym);
e = newEdge->OPrev;
V.TryAdd((IntPtr)e->Dest);
V.TryAdd((IntPtr)newEdge->Sym->Org);
newEdge = Connect(e, newEdge->Sym);
newEdge->QuadEdge->Crep = crep;
e = newEdge->OPrev;
V.TryAdd((IntPtr)e->Dest);
V.TryAdd((IntPtr)newEdge->Sym->Org);
Connect(e, newEdge->Sym);
var te = result->Edge;
NewTriangle(te);
te = te->ONext;
NewTriangle(te);
te = te->ONext;
NewTriangle(te);
te = te->ONext;
NewTriangle(te);
FlipEdges(point);
return(result);
}
void IsCdt(Navmesh *lct, int constraint = -1, int vertex = -1)
{
var e = lct->GetEdgeEnumerator(true);
while (e.MoveNext())
{
if (e.Current->Constrained)
{
continue;
}
var o = e.Current->Org->Point;
var d = e.Current->Dest->Point;
if (Math.Contains(o, -lct->Extent, lct->Extent) && Math.Contains(d, -lct->Extent, lct->Extent))
{
var on = e.Current->ONext->Dest->Point;
var dn = e.Current->DNext->Org->Point;
if (Math.CircumcircleContains(o, d, on, dn) && Math.Ccw(dn, d, on) && Math.Ccw(on, o, dn))
{
Debug.Log($"delaunay fail, constraint: {constraint}, vertex:{vertex}, from: {o}, to: {d}");
throw new Exception();
}
}
}
}
// https://www.researchgate.net/publication/2478154_Fully_Dynamic_Constrained_Delaunay_Triangulations
void FlipEdges(float2 p)
{
while (_flipStack.Count > 0)
{
var e = _flipStack.Pop();
Assert.IsTrue(Math.Ccw(e->Org->Point, e->Dest->Point, p));
if (!e->Constrained && Math.CircumcircleContains(e->Org->Point, e->Dest->Point, p, e->DNext->Org->Point))
{
_flipStack.Push(e->OPrev);
_flipStack.Push(e->DNext);
Assert.IsTrue(Math.Ccw(e->OPrev->Org->Point, e->OPrev->Dest->Point, p));
Assert.IsTrue(Math.Ccw(e->DNext->Org->Point, e->DNext->Dest->Point, p));
Swap(e);
}
}
}
static Edge *GetLeftEdge(Vertex *a, float2 p)
{
var result = a->Edge;
var o = result->Org->Point;
InfiniteLoopDetection.Reset();
while (!Math.Ccw(o, p, result->Dest->Point))
{
InfiniteLoopDetection.Register(1000, "GetLeftEdge 0");
result = result->ONext;
}
InfiniteLoopDetection.Reset();
while (Math.Ccw(o, p, result->OPrev->Dest->Point))
{
InfiniteLoopDetection.Register(1000, "GetLeftEdge 1");
result = result->OPrev;
}
return(result);
}
Vertex *InsertPointInFace(float2 p, Edge *edge)
{
_flipStack.Push(edge->ONext->Sym);
_flipStack.Push(edge);
_flipStack.Push(edge->DPrev->Sym);
for (var i = 0; i < _flipStack.Count; i++)
{
Assert.IsTrue(Math.Ccw(_flipStack[i]->Org->Point, _flipStack[i]->Dest->Point, p));
}
DestroyedTriangle(edge->TriangleId);
var result = CreateVertex(p);
V.TryAdd((IntPtr)result);
V.TryAdd((IntPtr)edge->Org);
V.TryAdd((IntPtr)edge->Dest);
V.TryAdd((IntPtr)edge->LNext->Dest);
var newEdge = CreateEdge(edge->Org, result);
Splice(newEdge, edge);
newEdge = Connect(edge, newEdge->Sym);
Connect(newEdge->OPrev, newEdge->Sym);
var te = result->Edge;
NewTriangle(te);
te = te->ONext;
NewTriangle(te);
te = te->ONext;
NewTriangle(te);
FlipEdges(p);
return(result);
}
// http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.61.3862&rep=rep1&type=pdf
// TriangulatePseudopolygonDelaunay()
void RetriangulateFace(Edge *edge)
{
Assert.IsTrue(edge != null);
Assert.IsTrue(edge != edge->LNext->LNext);
if (edge->LNext->LNext->LNext == edge)
{
NewTriangle(edge);
return;
}
InfiniteLoopDetection.Reset();
while (!Math.Ccw(edge->Org->Point, edge->Dest->Point, edge->LNext->Dest->Point))
{
InfiniteLoopDetection.Register(1000, "RetriangulateFace 0");
edge = edge->LNext;
}
var c = edge->LNext;
var e = c;
InfiniteLoopDetection.Reset();
while (true)
{
InfiniteLoopDetection.Register(1000, "RetriangulateFace 1");
e = e->LNext;
if (e->LNext == edge)
{
break;
}
if (Math.CircumcircleContains(edge->Org->Point, edge->Dest->Point, c->Dest->Point, e->Dest->Point))
{
c = e;
}
}
Assert.IsTrue(c != edge);
var connected = false;
if (c->LNext->LNext != edge)
{
V.TryAdd((IntPtr)edge->LPrev->Dest);
V.TryAdd((IntPtr)c->LNext->Org);
var b = Connect(edge->LPrev, c->LNext);
RetriangulateFace(b);
connected = true;
}
if (c != edge->LNext)
{
V.TryAdd((IntPtr)c->Dest);
V.TryAdd((IntPtr)edge->LNext->Org);
var a = Connect(c, edge->LNext);
RetriangulateFace(a);
connected = true;
}
if (connected)
{
NewTriangle(edge);
}
}