public void TestOnext()
{
var triangles = CreateExampleMesh();
Otri t = default;
// Start with the bottom right triangle.
t.tri = triangles[2];
// Start with edge 1 -> 2.
t.orient = 0;
// Make sure we're on the correct edge.
Assert.AreEqual(1, t.Org().ID);
Assert.AreEqual(2, t.Dest().ID);
t.Onext();
Assert.AreEqual(1, t.Org().ID);
Assert.AreEqual(4, t.Dest().ID);
Assert.AreEqual(1, t.tri.ID);
t.Onext();
Assert.AreEqual(1, t.Org().ID);
Assert.AreEqual(3, t.Dest().ID);
Assert.AreEqual(0, t.tri.ID);
// Out of mesh.
t.Onext();
Assert.AreEqual(-1, t.tri.ID);
}
private void BuildCache(Vertex vertex, bool vertices)
{
cache.Clear();
Otri init = vertex.tri;
Otri next = default(Otri);
Otri prev = default(Otri);
init.Copy(ref next);
// Move counter-clockwise around the vertex.
while (next.tri.id != TriangleNetMesh.DUMMY)
{
cache.Add(next);
next.Copy(ref prev);
next.Onext();
if (next.Equals(init))
{
break;
}
}
if (next.tri.id == TriangleNetMesh.DUMMY)
{
// We reached the boundary. To get all adjacent triangles, start
// again at init triangle and now move clockwise.
init.Copy(ref next);
if (vertices)
{
// Don't forget to add the vertex lying on the boundary.
prev.Lnext();
cache.Add(prev);
}
next.Oprev();
while (next.tri.id != TriangleNetMesh.DUMMY)
{
cache.Insert(0, next);
next.Oprev();
if (next.Equals(init))
{
break;
}
}
}
}
SplayNode FrontLocate(SplayNode splayroot, Otri bottommost, Vertex searchvertex,
ref Otri searchtri, ref bool farright)
{
bool farrightflag;
bottommost.Copy(ref searchtri);
splayroot = Splay(splayroot, searchvertex, ref searchtri);
farrightflag = false;
while (!farrightflag && RightOfHyperbola(ref searchtri, searchvertex))
{
searchtri.Onext();
farrightflag = searchtri.Equals(bottommost);
}
farright = farrightflag;
return(splayroot);
}
private void InvokePrimitive(string name)
{
if (name == "sym")
{
current.Sym();
}
else if (name == "lnext")
{
current.Lnext();
}
else if (name == "lprev")
{
current.Lprev();
}
else if (name == "onext")
{
current.Onext();
}
else if (name == "oprev")
{
current.Oprev();
}
else if (name == "dnext")
{
current.Dnext();
}
else if (name == "dprev")
{
current.Dprev();
}
else if (name == "rnext")
{
current.Rnext();
}
else if (name == "rprev")
{
current.Rprev();
}
renderControl.Update(current);
topoControlView.SetTriangle(current.Triangle);
}
/// <summary>
/// Construct Voronoi region for given vertex.
/// </summary>
/// <param name="vertex"></param>
/// <returns>The circumcenter indices which make up the cell.</returns>
private void ConstructVoronoiRegion(Vertex vertex)
{
VoronoiRegion region = new VoronoiRegion(vertex);
regions.Add(region);
List <Point> vpoints = new List <Point>();
Otri f = default(Otri);
Otri f_init = default(Otri);
Otri f_next = default(Otri);
Otri f_prev = default(Otri);
Osub sub = default(Osub);
// Call f_init a triangle incident to x
vertex.tri.Copy(ref f_init);
f_init.Copy(ref f);
f_init.Onext(ref f_next);
// Check if f_init lies on the boundary of the triangulation.
if (f_next.triangle == Mesh.dummytri)
{
f_init.Oprev(ref f_prev);
if (f_prev.triangle != Mesh.dummytri)
{
f_init.Copy(ref f_next);
// Move one triangle clockwise
f_init.OprevSelf();
f_init.Copy(ref f);
}
}
// Go counterclockwise until we reach the border or the initial triangle.
while (f_next.triangle != Mesh.dummytri)
{
// Add circumcenter of current triangle
vpoints.Add(points[f.triangle.id]);
if (f_next.Equal(f_init))
{
// Voronoi cell is complete (bounded case).
region.Add(vpoints);
return;
}
f_next.Copy(ref f);
f_next.OnextSelf();
}
// Voronoi cell is unbounded
region.Bounded = false;
Vertex torg, tdest, tapex, intersection;
int sid, n = mesh.triangles.Count;
// Find the boundary segment id.
f.Lprev(ref f_next);
f_next.SegPivot(ref sub);
sid = sub.seg.hash;
// Last valid f lies at the boundary. Add the circumcenter.
vpoints.Add(points[f.triangle.id]);
// Check if the intersection with the bounding box has already been computed.
if (rayPoints.ContainsKey(sid))
{
vpoints.Add(rayPoints[sid]);
}
else
{
torg = f.Org();
tapex = f.Apex();
BoxRayIntersection(points[f.triangle.id], torg.y - tapex.y, tapex.x - torg.x, out intersection);
// Set the correct id for the vertex
intersection.id = n + rayIndex;
points[n + rayIndex] = intersection;
rayIndex++;
vpoints.Add(intersection);
rayPoints.Add(sid, intersection);
}
// Now walk from f_init clockwise till we reach the boundary.
vpoints.Reverse();
f_init.Copy(ref f);
f.Oprev(ref f_prev);
while (f_prev.triangle != Mesh.dummytri)
{
vpoints.Add(points[f_prev.triangle.id]);
f_prev.Copy(ref f);
f_prev.OprevSelf();
}
// Find the boundary segment id.
f.SegPivot(ref sub);
sid = sub.seg.hash;
if (rayPoints.ContainsKey(sid))
{
vpoints.Add(rayPoints[sid]);
}
else
{
// Intersection has not been computed yet.
torg = f.Org();
tdest = f.Dest();
BoxRayIntersection(points[f.triangle.id], tdest.y - torg.y, torg.x - tdest.x, out intersection);
// Set the correct id for the vertex
intersection.id = n + rayIndex;
points[n + rayIndex] = intersection;
rayIndex++;
vpoints.Add(intersection);
rayPoints.Add(sid, intersection);
}
// Add the new points to the region (in counter-clockwise order)
vpoints.Reverse();
region.Add(vpoints);
}
/// <summary>
/// Construct Voronoi region for given vertex.
/// </summary>
/// <param name="region"></param>
private void ConstructCell(VoronoiRegion region)
{
var vertex = region.Generator as Vertex;
var vpoints = new List <Point>();
Otri f = default(Otri);
Otri f_init = default(Otri);
Otri f_next = default(Otri);
Otri f_prev = default(Otri);
Osub sub = default(Osub);
// Call f_init a triangle incident to x
vertex.tri.Copy(ref f_init);
f_init.Copy(ref f);
f_init.Onext(ref f_next);
// Check if f_init lies on the boundary of the triangulation.
if (f_next.tri.id == Mesh.DUMMY)
{
f_init.Oprev(ref f_prev);
if (f_prev.tri.id != Mesh.DUMMY)
{
f_init.Copy(ref f_next);
// Move one triangle clockwise
f_init.Oprev();
f_init.Copy(ref f);
}
}
// Go counterclockwise until we reach the border or the initial triangle.
while (f_next.tri.id != Mesh.DUMMY)
{
// Add circumcenter of current triangle
vpoints.Add(points[f.tri.id]);
region.AddNeighbor(f.tri.id, regions[f.Apex().id]);
if (f_next.Equals(f_init))
{
// Voronoi cell is complete (bounded case).
region.Add(vpoints);
return;
}
f_next.Copy(ref f);
f_next.Onext();
}
// Voronoi cell is unbounded
region.Bounded = false;
Vertex torg, tdest, tapex;
Point intersection;
int sid, n = mesh.triangles.Count;
// Find the boundary segment id (we use this id to number the endpoints of infinit rays).
f.Lprev(ref f_next);
f_next.Pivot(ref sub);
sid = sub.seg.hash;
// Last valid f lies at the boundary. Add the circumcenter.
vpoints.Add(points[f.tri.id]);
region.AddNeighbor(f.tri.id, regions[f.Apex().id]);
// Check if the intersection with the bounding box has already been computed.
if (!rayPoints.TryGetValue(sid, out intersection))
{
torg = f.Org();
tapex = f.Apex();
intersection = IntersectionHelper.BoxRayIntersection(bounds, points[f.tri.id], torg.y - tapex.y, tapex.x - torg.x);
// Set the correct id for the vertex
intersection.id = n + rayIndex;
points[n + rayIndex] = intersection;
rayIndex++;
rayPoints.Add(sid, intersection);
}
vpoints.Add(intersection);
// Now walk from f_init clockwise till we reach the boundary.
vpoints.Reverse();
f_init.Copy(ref f);
f.Oprev(ref f_prev);
while (f_prev.tri.id != Mesh.DUMMY)
{
vpoints.Add(points[f_prev.tri.id]);
region.AddNeighbor(f_prev.tri.id, regions[f_prev.Apex().id]);
f_prev.Copy(ref f);
f_prev.Oprev();
}
// Find the boundary segment id.
f.Pivot(ref sub);
sid = sub.seg.hash;
if (!rayPoints.TryGetValue(sid, out intersection))
{
// Intersection has not been computed yet.
torg = f.Org();
tdest = f.Dest();
intersection = IntersectionHelper.BoxRayIntersection(bounds, points[f.tri.id], tdest.y - torg.y, torg.x - tdest.x);
// Set the correct id for the vertex
intersection.id = n + rayIndex;
rayPoints.Add(sid, intersection);
points[n + rayIndex] = intersection;
rayIndex++;
}
vpoints.Add(intersection);
region.AddNeighbor(intersection.id, regions[f.Dest().id]);
// Add the new points to the region (in counter-clockwise order)
vpoints.Reverse();
region.Add(vpoints);
}
private void ConstructBoundaryCell(Vertex vertex)
{
VoronoiRegion region = new VoronoiRegion(vertex);
regions.Add(region);
Otri f = default(Otri);
Otri f_init = default(Otri);
Otri f_next = default(Otri);
Otri f_prev = default(Otri);
Osub sf = default(Osub);
Osub sfn = default(Osub);
Vertex torg, tdest, tapex, sorg, sdest;
Point cc_f, cc_f_next, p;
int n = _TriangleNetMesh.triangles.Count;
// Call P the polygon (cell) in construction
List <Point> vpoints = new List <Point>();
// Call f_init a triangle incident to x
vertex.tri.Copy(ref f_init);
if (f_init.Org() != vertex)
{
throw new Exception("ConstructBoundaryCell: inconsistent topology.");
}
// Let f be initialized to f_init
f_init.Copy(ref f);
// Call f_next the next triangle counterclockwise around x
f_init.Onext(ref f_next);
f_init.Oprev(ref f_prev);
// Is the border to the left?
if (f_prev.tri.id != TriangleNetMesh.DUMMY)
{
// Go clockwise until we reach the border (or the initial triangle)
while (f_prev.tri.id != TriangleNetMesh.DUMMY && !f_prev.Equals(f_init))
{
f_prev.Copy(ref f);
f_prev.Oprev();
}
f.Copy(ref f_init);
f.Onext(ref f_next);
}
if (f_prev.tri.id == TriangleNetMesh.DUMMY)
{
// For vertices on the domain boundaray, add the vertex. For
// internal boundaries don't add it.
p = new Point(vertex.x, vertex.y);
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
// Add midpoint of start triangles' edge.
torg = f.Org();
tdest = f.Dest();
p = new Point((torg.x + tdest.x) / 2, (torg.y + tdest.y) / 2);
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
// repeat ... until f = f_init
do
{
// Call Lffnext the line going through the circumcenters of f and f_next
cc_f = points[f.tri.id];
if (f_next.tri.id == TriangleNetMesh.DUMMY)
{
if (!f.tri.infected)
{
// Add last circumcenter
vpoints.Add(cc_f);
}
// Add midpoint of last triangles' edge (chances are it has already
// been added, so post process cell to remove duplicates???)
torg = f.Org();
tapex = f.Apex();
p = new Point((torg.x + tapex.x) / 2, (torg.y + tapex.y) / 2);
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
break;
}
cc_f_next = points[f_next.tri.id];
// if f is tagged non-blind then
if (!f.tri.infected)
{
// Insert the circumcenter of f into P
vpoints.Add(cc_f);
if (f_next.tri.infected)
{
// Call S_fnext the constrained edge blinding f_next
sfn.seg = subsegMap[f_next.tri.hash];
// Insert point Lf,f_next /\ Sf_next into P
if (SegmentsIntersect(sfn.Org(), sfn.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
}
else
{
// Call Sf the constrained edge blinding f
sf.seg = subsegMap[f.tri.hash];
sorg = sf.Org();
sdest = sf.Dest();
// if f_next is tagged non-blind then
if (!f_next.tri.infected)
{
tdest = f.Dest();
tapex = f.Apex();
// Both circumcenters lie on the blinded side, but we
// have to add the intersection with the segment.
// Center of f edge dest->apex
Point bisec = new Point((tdest.x + tapex.x) / 2, (tdest.y + tapex.y) / 2);
// Find intersection of seg with line through f's bisector and circumcenter
if (SegmentsIntersect(sorg, sdest, bisec, cc_f, out p, false))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
// Insert point Lf,f_next /\ Sf into P
if (SegmentsIntersect(sorg, sdest, cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
else
{
// Call Sf_next the constrained edge blinding f_next
sfn.seg = subsegMap[f_next.tri.hash];
// if Sf != Sf_next then
if (!sf.Equal(sfn))
{
// Insert Lf,fnext /\ Sf and Lf,fnext /\ Sfnext into P
if (SegmentsIntersect(sorg, sdest, cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
if (SegmentsIntersect(sfn.Org(), sfn.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
else
{
// Both circumcenters lie on the blinded side, but we
// have to add the intersection with the segment.
// Center of f_next edge org->dest
Point bisec = new Point((torg.x + tdest.x) / 2, (torg.y + tdest.y) / 2);
// Find intersection of seg with line through f_next's bisector and circumcenter
if (SegmentsIntersect(sorg, sdest, bisec, cc_f_next, out p, false))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
}
}
// f <- f_next
f_next.Copy(ref f);
// Call f_next the next triangle counterclockwise around x
f_next.Onext();
}while (!f.Equals(f_init));
// Output: Bounded Voronoi cell of x in counterclockwise order.
region.Add(vpoints);
}
private void ConstructCell(Vertex vertex)
{
VoronoiRegion region = new VoronoiRegion(vertex);
regions.Add(region);
Otri f = default(Otri);
Otri f_init = default(Otri);
Otri f_next = default(Otri);
Osub sf = default(Osub);
Osub sfn = default(Osub);
Point cc_f, cc_f_next, p;
int n = _TriangleNetMesh.triangles.Count;
// Call P the polygon (cell) in construction
List <Point> vpoints = new List <Point>();
// Call f_init a triangle incident to x
vertex.tri.Copy(ref f_init);
if (f_init.Org() != vertex)
{
throw new Exception("ConstructCell: inconsistent topology.");
}
// Let f be initialized to f_init
f_init.Copy(ref f);
// Call f_next the next triangle counterclockwise around x
f_init.Onext(ref f_next);
// repeat ... until f = f_init
do
{
// Call Lffnext the line going through the circumcenters of f and f_next
cc_f = points[f.tri.id];
cc_f_next = points[f_next.tri.id];
// if f is tagged non-blind then
if (!f.tri.infected)
{
// Insert the circumcenter of f into P
vpoints.Add(cc_f);
if (f_next.tri.infected)
{
// Call S_fnext the constrained edge blinding f_next
sfn.seg = subsegMap[f_next.tri.hash];
// Insert point Lf,f_next /\ Sf_next into P
if (SegmentsIntersect(sfn.Org(), sfn.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
}
else
{
// Call Sf the constrained edge blinding f
sf.seg = subsegMap[f.tri.hash];
// if f_next is tagged non-blind then
if (!f_next.tri.infected)
{
// Insert point Lf,f_next /\ Sf into P
if (SegmentsIntersect(sf.Org(), sf.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
else
{
// Call Sf_next the constrained edge blinding f_next
sfn.seg = subsegMap[f_next.tri.hash];
// if Sf != Sf_next then
if (!sf.Equal(sfn))
{
// Insert Lf,fnext /\ Sf and Lf,fnext /\ Sfnext into P
if (SegmentsIntersect(sf.Org(), sf.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
if (SegmentsIntersect(sfn.Org(), sfn.Dest(), cc_f, cc_f_next, out p, true))
{
p.id = n + segIndex++;
segPoints.Add(p);
vpoints.Add(p);
}
}
}
}
// f <- f_next
f_next.Copy(ref f);
// Call f_next the next triangle counterclockwise around x
f_next.Onext();
}while (!f.Equals(f_init));
// Output: Bounded Voronoi cell of x in counterclockwise order.
region.Add(vpoints);
}
public int Triangulate(Mesh mesh)
{
SweepLine.SweepEvent[] sweepEventArray;
SweepLine.SweepEvent sweepEvent;
Vertex vertex;
Vertex vertex1;
Vertex vertex2;
Vertex vertex3;
this.mesh = mesh;
this.xminextreme = 10 * mesh.bounds.Xmin - 9 * mesh.bounds.Xmax;
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Otri otri3 = new Otri();
Otri otri4 = new Otri();
Otri otri5 = new Otri();
Otri otri6 = new Otri();
bool i = false;
this.splaynodes = new List <SweepLine.SplayNode>();
SweepLine.SplayNode splayNode = null;
this.CreateHeap(out sweepEventArray);
int num = mesh.invertices;
mesh.MakeTriangle(ref otri2);
mesh.MakeTriangle(ref otri3);
otri2.Bond(ref otri3);
otri2.LnextSelf();
otri3.LprevSelf();
otri2.Bond(ref otri3);
otri2.LnextSelf();
otri3.LprevSelf();
otri2.Bond(ref otri3);
Vertex vertex4 = sweepEventArray[0].vertexEvent;
this.HeapDelete(sweepEventArray, num, 0);
num--;
do
{
if (num == 0)
{
SimpleLog.Instance.Error("Input vertices are all identical.", "SweepLine.SweepLineDelaunay()");
throw new Exception("Input vertices are all identical.");
}
vertex = sweepEventArray[0].vertexEvent;
this.HeapDelete(sweepEventArray, num, 0);
num--;
if (vertex4.x != vertex.x || vertex4.y != vertex.y)
{
continue;
}
if (Behavior.Verbose)
{
SimpleLog.Instance.Warning("A duplicate vertex appeared and was ignored.", "SweepLine.SweepLineDelaunay().1");
}
vertex.type = VertexType.UndeadVertex;
Mesh mesh1 = mesh;
mesh1.undeads = mesh1.undeads + 1;
}while (vertex4.x == vertex.x && vertex4.y == vertex.y);
otri2.SetOrg(vertex4);
otri2.SetDest(vertex);
otri3.SetOrg(vertex);
otri3.SetDest(vertex4);
otri2.Lprev(ref otri);
Vertex vertex5 = vertex;
while (num > 0)
{
SweepLine.SweepEvent sweepEvent1 = sweepEventArray[0];
this.HeapDelete(sweepEventArray, num, 0);
num--;
bool flag = true;
if (sweepEvent1.xkey >= mesh.bounds.Xmin)
{
Vertex vertex6 = sweepEvent1.vertexEvent;
if (vertex6.x != vertex5.x || vertex6.y != vertex5.y)
{
vertex5 = vertex6;
splayNode = this.FrontLocate(splayNode, otri, vertex6, ref otri1, ref i);
otri.Copy(ref otri1);
for (i = false; !i && this.RightOfHyperbola(ref otri1, vertex6); i = otri1.Equal(otri))
{
otri1.OnextSelf();
}
this.Check4DeadEvent(ref otri1, sweepEventArray, ref num);
otri1.Copy(ref otri5);
otri1.Sym(ref otri4);
mesh.MakeTriangle(ref otri2);
mesh.MakeTriangle(ref otri3);
Vertex vertex7 = otri5.Dest();
otri2.SetOrg(vertex7);
otri2.SetDest(vertex6);
otri3.SetOrg(vertex6);
otri3.SetDest(vertex7);
otri2.Bond(ref otri3);
otri2.LnextSelf();
otri3.LprevSelf();
otri2.Bond(ref otri3);
otri2.LnextSelf();
otri3.LprevSelf();
otri2.Bond(ref otri4);
otri3.Bond(ref otri5);
if (!i && otri5.Equal(otri))
{
otri2.Copy(ref otri);
}
if (this.randomnation(SweepLine.SAMPLERATE) == 0)
{
splayNode = this.SplayInsert(splayNode, otri2, vertex6);
}
else if (this.randomnation(SweepLine.SAMPLERATE) == 0)
{
otri3.Lnext(ref otri6);
splayNode = this.SplayInsert(splayNode, otri6, vertex6);
}
}
else
{
if (Behavior.Verbose)
{
SimpleLog.Instance.Warning("A duplicate vertex appeared and was ignored.", "SweepLine.SweepLineDelaunay().2");
}
vertex6.type = VertexType.UndeadVertex;
Mesh mesh2 = mesh;
mesh2.undeads = mesh2.undeads + 1;
flag = false;
}
}
else
{
Otri otri7 = sweepEvent1.otriEvent;
otri7.Oprev(ref otri4);
this.Check4DeadEvent(ref otri4, sweepEventArray, ref num);
otri7.Onext(ref otri5);
this.Check4DeadEvent(ref otri5, sweepEventArray, ref num);
if (otri4.Equal(otri))
{
otri7.Lprev(ref otri);
}
mesh.Flip(ref otri7);
otri7.SetApex(null);
otri7.Lprev(ref otri2);
otri7.Lnext(ref otri3);
otri2.Sym(ref otri4);
if (this.randomnation(SweepLine.SAMPLERATE) == 0)
{
otri7.SymSelf();
vertex1 = otri7.Dest();
vertex2 = otri7.Apex();
vertex3 = otri7.Org();
splayNode = this.CircleTopInsert(splayNode, otri2, vertex1, vertex2, vertex3, sweepEvent1.ykey);
}
}
if (!flag)
{
continue;
}
vertex1 = otri4.Apex();
vertex2 = otri2.Dest();
vertex3 = otri2.Apex();
double num1 = Primitives.CounterClockwise(vertex1, vertex2, vertex3);
if (num1 > 0)
{
sweepEvent = new SweepLine.SweepEvent()
{
xkey = this.xminextreme,
ykey = this.CircleTop(vertex1, vertex2, vertex3, num1),
otriEvent = otri2
};
this.HeapInsert(sweepEventArray, num, sweepEvent);
num++;
otri2.SetOrg(new SweepLine.SweepEventVertex(sweepEvent));
}
vertex1 = otri3.Apex();
vertex2 = otri3.Org();
vertex3 = otri5.Apex();
double num2 = Primitives.CounterClockwise(vertex1, vertex2, vertex3);
if (num2 <= 0)
{
continue;
}
sweepEvent = new SweepLine.SweepEvent()
{
xkey = this.xminextreme,
ykey = this.CircleTop(vertex1, vertex2, vertex3, num2),
otriEvent = otri5
};
this.HeapInsert(sweepEventArray, num, sweepEvent);
num++;
otri5.SetOrg(new SweepLine.SweepEventVertex(sweepEvent));
}
this.splaynodes.Clear();
otri.LprevSelf();
return(this.RemoveGhosts(ref otri));
}
/// <summary>
/// Spread the virus from all infected triangles to any neighbors not
/// protected by subsegments. Delete all infected triangles.
/// </summary>
/// <remarks>
/// This is the procedure that actually creates holes and concavities.
///
/// This procedure operates in two phases. The first phase identifies all
/// the triangles that will die, and marks them as infected. They are
/// marked to ensure that each triangle is added to the virus pool only
/// once, so the procedure will terminate.
///
/// The second phase actually eliminates the infected triangles. It also
/// eliminates orphaned vertices.
/// </remarks>
void Plague()
{
Otri testtri = default(Otri);
Otri neighbor = default(Otri);
Osub neighborsubseg = default(Osub);
Vertex testvertex;
Vertex norg, ndest;
bool killorg;
// Loop through all the infected triangles, spreading the virus to
// their neighbors, then to their neighbors' neighbors.
for (int i = 0; i < viri.Count; i++)
{
// WARNING: Don't use foreach, mesh.viri list may get modified.
testtri.triangle = viri[i];
// A triangle is marked as infected by messing with one of its pointers
// to subsegments, setting it to an illegal value. Hence, we have to
// temporarily uninfect this triangle so that we can examine its
// adjacent subsegments.
// TODO: Not true in the C# version (so we could skip this).
testtri.Uninfect();
// Check each of the triangle's three neighbors.
for (testtri.orient = 0; testtri.orient < 3; testtri.orient++)
{
// Find the neighbor.
testtri.Sym(ref neighbor);
// Check for a subsegment between the triangle and its neighbor.
testtri.SegPivot(ref neighborsubseg);
// Check if the neighbor is nonexistent or already infected.
if ((neighbor.triangle == Mesh.dummytri) || neighbor.IsInfected())
{
if (neighborsubseg.seg != Mesh.dummysub)
{
// There is a subsegment separating the triangle from its
// neighbor, but both triangles are dying, so the subsegment
// dies too.
mesh.SubsegDealloc(neighborsubseg.seg);
if (neighbor.triangle != Mesh.dummytri)
{
// Make sure the subsegment doesn't get deallocated again
// later when the infected neighbor is visited.
neighbor.Uninfect();
neighbor.SegDissolve();
neighbor.Infect();
}
}
}
else
{ // The neighbor exists and is not infected.
if (neighborsubseg.seg == Mesh.dummysub)
{
// There is no subsegment protecting the neighbor, so
// the neighbor becomes infected.
neighbor.Infect();
// Ensure that the neighbor's neighbors will be infected.
viri.Add(neighbor.triangle);
}
else
{
// The neighbor is protected by a subsegment.
// Remove this triangle from the subsegment.
neighborsubseg.TriDissolve();
// The subsegment becomes a boundary. Set markers accordingly.
if (neighborsubseg.seg.boundary == 0)
{
neighborsubseg.seg.boundary = 1;
}
norg = neighbor.Org();
ndest = neighbor.Dest();
if (norg.mark == 0)
{
norg.mark = 1;
}
if (ndest.mark == 0)
{
ndest.mark = 1;
}
}
}
}
// Remark the triangle as infected, so it doesn't get added to the
// virus pool again.
testtri.Infect();
}
foreach (var virus in viri)
{
testtri.triangle = virus;
// Check each of the three corners of the triangle for elimination.
// This is done by walking around each vertex, checking if it is
// still connected to at least one live triangle.
for (testtri.orient = 0; testtri.orient < 3; testtri.orient++)
{
testvertex = testtri.Org();
// Check if the vertex has already been tested.
if (testvertex != null)
{
killorg = true;
// Mark the corner of the triangle as having been tested.
testtri.SetOrg(null);
// Walk counterclockwise about the vertex.
testtri.Onext(ref neighbor);
// Stop upon reaching a boundary or the starting triangle.
while ((neighbor.triangle != Mesh.dummytri) &&
(!neighbor.Equal(testtri)))
{
if (neighbor.IsInfected())
{
// Mark the corner of this triangle as having been tested.
neighbor.SetOrg(null);
}
else
{
// A live triangle. The vertex survives.
killorg = false;
}
// Walk counterclockwise about the vertex.
neighbor.OnextSelf();
}
// If we reached a boundary, we must walk clockwise as well.
if (neighbor.triangle == Mesh.dummytri)
{
// Walk clockwise about the vertex.
testtri.Oprev(ref neighbor);
// Stop upon reaching a boundary.
while (neighbor.triangle != Mesh.dummytri)
{
if (neighbor.IsInfected())
{
// Mark the corner of this triangle as having been tested.
neighbor.SetOrg(null);
}
else
{
// A live triangle. The vertex survives.
killorg = false;
}
// Walk clockwise about the vertex.
neighbor.OprevSelf();
}
}
if (killorg)
{
// Deleting vertex
testvertex.type = VertexType.UndeadVertex;
mesh.undeads++;
}
}
}
// Record changes in the number of boundary edges, and disconnect
// dead triangles from their neighbors.
for (testtri.orient = 0; testtri.orient < 3; testtri.orient++)
{
testtri.Sym(ref neighbor);
if (neighbor.triangle == Mesh.dummytri)
{
// There is no neighboring triangle on this edge, so this edge
// is a boundary edge. This triangle is being deleted, so this
// boundary edge is deleted.
mesh.hullsize--;
}
else
{
// Disconnect the triangle from its neighbor.
neighbor.Dissolve();
// There is a neighboring triangle on this edge, so this edge
// becomes a boundary edge when this triangle is deleted.
mesh.hullsize++;
}
}
// Return the dead triangle to the pool of triangles.
mesh.TriangleDealloc(testtri.triangle);
}
// Empty the virus pool.
viri.Clear();
}
private void ConstructVoronoiRegion(Vertex vertex)
{
Vertex vertex1;
Vertex vertex2;
VoronoiRegion voronoiRegion = new VoronoiRegion(vertex);
this.regions.Add(voronoiRegion);
List <Point> points = new List <Point>();
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Otri otri3 = new Otri();
Osub osub = new Osub();
vertex.tri.Copy(ref otri1);
otri1.Copy(ref otri);
otri1.Onext(ref otri2);
if (otri2.triangle == Mesh.dummytri)
{
otri1.Oprev(ref otri3);
if (otri3.triangle != Mesh.dummytri)
{
otri1.Copy(ref otri2);
otri1.OprevSelf();
otri1.Copy(ref otri);
}
}
while (otri2.triangle != Mesh.dummytri)
{
points.Add(this.points[otri.triangle.id]);
if (otri2.Equal(otri1))
{
voronoiRegion.Add(points);
return;
}
otri2.Copy(ref otri);
otri2.OnextSelf();
}
voronoiRegion.Bounded = false;
int count = this.mesh.triangles.Count;
otri.Lprev(ref otri2);
otri2.SegPivot(ref osub);
int num = osub.seg.hash;
points.Add(this.points[otri.triangle.id]);
if (!this.rayPoints.ContainsKey(num))
{
vertex1 = otri.Org();
Vertex vertex3 = otri.Apex();
this.BoxRayIntersection(this.points[otri.triangle.id], vertex1.y - vertex3.y, vertex3.x - vertex1.x, out vertex2);
vertex2.id = count + this.rayIndex;
this.points[count + this.rayIndex] = vertex2;
this.rayIndex = this.rayIndex + 1;
points.Add(vertex2);
this.rayPoints.Add(num, vertex2);
}
else
{
points.Add(this.rayPoints[num]);
}
points.Reverse();
otri1.Copy(ref otri);
otri.Oprev(ref otri3);
while (otri3.triangle != Mesh.dummytri)
{
points.Add(this.points[otri3.triangle.id]);
otri3.Copy(ref otri);
otri3.OprevSelf();
}
otri.SegPivot(ref osub);
num = osub.seg.hash;
if (!this.rayPoints.ContainsKey(num))
{
vertex1 = otri.Org();
Vertex vertex4 = otri.Dest();
this.BoxRayIntersection(this.points[otri.triangle.id], vertex4.y - vertex1.y, vertex1.x - vertex4.x, out vertex2);
vertex2.id = count + this.rayIndex;
this.points[count + this.rayIndex] = vertex2;
this.rayIndex = this.rayIndex + 1;
points.Add(vertex2);
this.rayPoints.Add(num, vertex2);
}
else
{
points.Add(this.rayPoints[num]);
}
points.Reverse();
voronoiRegion.Add(points);
}
/// <summary>
/// Find the intersection of an existing segment and a segment that is being
/// inserted. Insert a vertex at the intersection, splitting an existing subsegment.
/// </summary>
/// <param name="splittri"></param>
/// <param name="splitsubseg"></param>
/// <param name="endpoint2"></param>
/// <remarks>
/// The segment being inserted connects the apex of splittri to endpoint2.
/// splitsubseg is the subsegment being split, and MUST adjoin splittri.
/// Hence, endpoints of the subsegment being split are the origin and
/// destination of splittri.
/// On completion, splittri is a handle having the newly inserted
/// intersection point as its origin, and endpoint1 as its destination.
/// </remarks>
private void SegmentIntersection(ref Otri splittri, ref Osub splitsubseg, Vertex endpoint2)
{
Osub opposubseg = default(Osub);
Vertex endpoint1;
Vertex torg, tdest;
Vertex leftvertex, rightvertex;
Vertex newvertex;
InsertVertexResult success;
var dummysub = mesh.dummysub;
double ex, ey;
double tx, ty;
double etx, ety;
double split, denom;
// Find the other three segment endpoints.
endpoint1 = splittri.Apex();
torg = splittri.Org();
tdest = splittri.Dest();
// Segment intersection formulae; see the Antonio reference.
tx = tdest.X - torg.X;
ty = tdest.Y - torg.Y;
ex = endpoint2.X - endpoint1.X;
ey = endpoint2.Y - endpoint1.Y;
etx = torg.X - endpoint2.X;
ety = torg.Y - endpoint2.Y;
denom = ty * ex - tx * ey;
if (denom == 0.0)
{
throw new Exception("Attempt to find intersection of parallel segments.");
}
split = (ey * etx - ex * ety) / denom;
// Create the new vertex.
newvertex = new Vertex(
torg.X + split * (tdest.X - torg.X),
torg.Y + split * (tdest.Y - torg.Y),
splitsubseg.seg.boundary);
newvertex.Id = mesh.hash_vtx++;
mesh.vertices.Add(newvertex.Id, newvertex);
// Insert the intersection vertex. This should always succeed.
success = mesh.InsertVertex(newvertex, ref splittri, ref splitsubseg, false, false);
if (success != InsertVertexResult.Successful)
{
throw new Exception("Failure to split a segment.");
}
// Record a triangle whose origin is the new vertex.
newvertex.tri = splittri;
if (mesh.steinerleft > 0)
{
mesh.steinerleft--;
}
// Divide the segment into two, and correct the segment endpoints.
splitsubseg.Sym();
splitsubseg.Pivot(ref opposubseg);
splitsubseg.Dissolve(dummysub);
opposubseg.Dissolve(dummysub);
do
{
splitsubseg.SetSegOrg(newvertex);
splitsubseg.Next();
} while (splitsubseg.seg.hash != Mesh.DUMMY);
do
{
opposubseg.SetSegOrg(newvertex);
opposubseg.Next();
} while (opposubseg.seg.hash != Mesh.DUMMY);
// Inserting the vertex may have caused edge flips. We wish to rediscover
// the edge connecting endpoint1 to the new intersection vertex.
FindDirection(ref splittri, endpoint1);
rightvertex = splittri.Dest();
leftvertex = splittri.Apex();
if ((leftvertex.X == endpoint1.X) && (leftvertex.Y == endpoint1.Y))
{
splittri.Onext();
}
else if ((rightvertex.X != endpoint1.X) || (rightvertex.Y != endpoint1.Y))
{
throw new Exception("Topological inconsistency after splitting a segment.");
}
// 'splittri' should have destination endpoint1.
}
/// <summary>
/// Find the first triangle on the path from one point to another.
/// </summary>
/// <param name="searchtri"></param>
/// <param name="searchpoint"></param>
/// <returns>
/// The return value notes whether the destination or apex of the found
/// triangle is collinear with the two points in question.
/// </returns>
/// <remarks>
/// Finds the triangle that intersects a line segment drawn from the
/// origin of 'searchtri' to the point 'searchpoint', and returns the result
/// in 'searchtri'. The origin of 'searchtri' does not change, even though
/// the triangle returned may differ from the one passed in. This routine
/// is used to find the direction to move in to get from one point to
/// another.
/// </remarks>
private FindDirectionResult FindDirection(ref Otri searchtri, Vertex searchpoint)
{
Otri checktri = default(Otri);
Vertex startvertex;
Vertex leftvertex, rightvertex;
double leftccw, rightccw;
bool leftflag, rightflag;
startvertex = searchtri.Org();
rightvertex = searchtri.Dest();
leftvertex = searchtri.Apex();
// Is 'searchpoint' to the left?
leftccw = RobustPredicates.CounterClockwise(searchpoint, startvertex, leftvertex);
leftflag = leftccw > 0.0;
// Is 'searchpoint' to the right?
rightccw = RobustPredicates.CounterClockwise(startvertex, searchpoint, rightvertex);
rightflag = rightccw > 0.0;
if (leftflag && rightflag)
{
// 'searchtri' faces directly away from 'searchpoint'. We could go left
// or right. Ask whether it's a triangle or a boundary on the left.
searchtri.Onext(ref checktri);
if (checktri.tri.Id == Mesh.DUMMY)
{
leftflag = false;
}
else
{
rightflag = false;
}
}
while (leftflag)
{
// Turn left until satisfied.
searchtri.Onext();
if (searchtri.tri.Id == Mesh.DUMMY)
{
throw new Exception("Unable to find a triangle on path.");
}
leftvertex = searchtri.Apex();
rightccw = leftccw;
leftccw = RobustPredicates.CounterClockwise(searchpoint, startvertex, leftvertex);
leftflag = leftccw > 0.0;
}
while (rightflag)
{
// Turn right until satisfied.
searchtri.Oprev();
if (searchtri.tri.Id == Mesh.DUMMY)
{
throw new Exception("Unable to find a triangle on path.");
}
rightvertex = searchtri.Dest();
leftccw = rightccw;
rightccw = RobustPredicates.CounterClockwise(startvertex, searchpoint, rightvertex);
rightflag = rightccw > 0.0;
}
if (leftccw == 0.0)
{
return(FindDirectionResult.Leftcollinear);
}
if (rightccw == 0.0)
{
return(FindDirectionResult.Rightcollinear);
}
return(FindDirectionResult.Within);
}
private void ConstructBoundaryBvdCell(Vertex vertex)
{
Vertex vertex1;
Point point;
VoronoiRegion voronoiRegion = new VoronoiRegion(vertex);
this.regions.Add(voronoiRegion);
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Otri otri3 = new Otri();
Osub item = new Osub();
Osub osub = new Osub();
int count = this.mesh.triangles.Count;
List <Point> points = new List <Point>();
vertex.tri.Copy(ref otri1);
if (otri1.Org() != vertex)
{
throw new Exception("ConstructBoundaryBvdCell: inconsistent topology.");
}
otri1.Copy(ref otri);
otri1.Onext(ref otri2);
otri1.Oprev(ref otri3);
if (otri3.triangle != Mesh.dummytri)
{
while (otri3.triangle != Mesh.dummytri && !otri3.Equal(otri1))
{
otri3.Copy(ref otri);
otri3.OprevSelf();
}
otri.Copy(ref otri1);
otri.Onext(ref otri2);
}
if (otri3.triangle == Mesh.dummytri)
{
point = new Point(vertex.x, vertex.y)
{
id = count + this.segIndex
};
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
Vertex vertex2 = otri.Org();
Vertex vertex3 = otri.Dest();
point = new Point((vertex2.X + vertex3.X) / 2, (vertex2.Y + vertex3.Y) / 2)
{
id = count + this.segIndex
};
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
do
{
Point point1 = this.points[otri.triangle.id];
if (otri2.triangle != Mesh.dummytri)
{
Point point2 = this.points[otri2.triangle.id];
if (otri.triangle.infected)
{
item.seg = this.subsegMap[otri.triangle.hash];
Vertex vertex4 = item.SegOrg();
Vertex vertex5 = item.SegDest();
if (otri2.triangle.infected)
{
osub.seg = this.subsegMap[otri2.triangle.hash];
if (!item.Equal(osub))
{
if (this.SegmentsIntersect(vertex4, vertex5, point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
if (this.SegmentsIntersect(osub.SegOrg(), osub.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
else if (this.SegmentsIntersect(vertex4, vertex5, new Point((vertex2.X + vertex3.X) / 2, (vertex2.Y + vertex3.Y) / 2), point2, out point, false))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
else
{
vertex3 = otri.Dest();
vertex1 = otri.Apex();
if (this.SegmentsIntersect(vertex4, vertex5, new Point((vertex3.X + vertex1.X) / 2, (vertex3.Y + vertex1.Y) / 2), point1, out point, false))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
if (this.SegmentsIntersect(vertex4, vertex5, point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
}
else
{
points.Add(point1);
if (otri2.triangle.infected)
{
osub.seg = this.subsegMap[otri2.triangle.hash];
if (this.SegmentsIntersect(osub.SegOrg(), osub.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
}
otri2.Copy(ref otri);
otri2.OnextSelf();
}
else
{
if (!otri.triangle.infected)
{
points.Add(point1);
}
vertex2 = otri.Org();
vertex1 = otri.Apex();
point = new Point((vertex2.X + vertex1.X) / 2, (vertex2.Y + vertex1.Y) / 2)
{
id = count + this.segIndex
};
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
break;
}
}while (!otri.Equal(otri1));
voronoiRegion.Add(points);
}
private void ConstructBvdCell(Vertex vertex)
{
Point point;
VoronoiRegion voronoiRegion = new VoronoiRegion(vertex);
this.regions.Add(voronoiRegion);
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Osub item = new Osub();
Osub osub = new Osub();
int count = this.mesh.triangles.Count;
List <Point> points = new List <Point>();
vertex.tri.Copy(ref otri1);
if (otri1.Org() != vertex)
{
throw new Exception("ConstructBvdCell: inconsistent topology.");
}
otri1.Copy(ref otri);
otri1.Onext(ref otri2);
do
{
Point point1 = this.points[otri.triangle.id];
Point point2 = this.points[otri2.triangle.id];
if (otri.triangle.infected)
{
item.seg = this.subsegMap[otri.triangle.hash];
if (otri2.triangle.infected)
{
osub.seg = this.subsegMap[otri2.triangle.hash];
if (!item.Equal(osub))
{
if (this.SegmentsIntersect(item.SegOrg(), item.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
if (this.SegmentsIntersect(osub.SegOrg(), osub.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
}
else if (this.SegmentsIntersect(item.SegOrg(), item.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
else
{
points.Add(point1);
if (otri2.triangle.infected)
{
osub.seg = this.subsegMap[otri2.triangle.hash];
if (this.SegmentsIntersect(osub.SegOrg(), osub.SegDest(), point1, point2, out point, true))
{
point.id = count + this.segIndex;
this.points[count + this.segIndex] = point;
this.segIndex = this.segIndex + 1;
points.Add(point);
}
}
}
otri2.Copy(ref otri);
otri2.OnextSelf();
}while (!otri.Equal(otri1));
voronoiRegion.Add(points);
}
private void Plague()
{
Otri item = new Otri();
Otri otri = new Otri();
Osub osub = new Osub();
for (int i = 0; i < this.viri.Count; i++)
{
item.triangle = this.viri[i];
item.Uninfect();
item.orient = 0;
while (item.orient < 3)
{
item.Sym(ref otri);
item.SegPivot(ref osub);
if (otri.triangle != Mesh.dummytri && !otri.IsInfected())
{
if (osub.seg != Mesh.dummysub)
{
osub.TriDissolve();
if (osub.seg.boundary == 0)
{
osub.seg.boundary = 1;
}
Vertex vertex = otri.Org();
Vertex vertex1 = otri.Dest();
if (vertex.mark == 0)
{
vertex.mark = 1;
}
if (vertex1.mark == 0)
{
vertex1.mark = 1;
}
}
else
{
otri.Infect();
this.viri.Add(otri.triangle);
}
}
else if (osub.seg != Mesh.dummysub)
{
this.mesh.SubsegDealloc(osub.seg);
if (otri.triangle != Mesh.dummytri)
{
otri.Uninfect();
otri.SegDissolve();
otri.Infect();
}
}
item.orient = item.orient + 1;
}
item.Infect();
}
foreach (Triangle virus in this.viri)
{
item.triangle = virus;
item.orient = 0;
while (item.orient < 3)
{
Vertex vertex2 = item.Org();
if (vertex2 != null)
{
bool flag = true;
item.SetOrg(null);
item.Onext(ref otri);
while (otri.triangle != Mesh.dummytri && !otri.Equal(item))
{
if (!otri.IsInfected())
{
flag = false;
}
else
{
otri.SetOrg(null);
}
otri.OnextSelf();
}
if (otri.triangle == Mesh.dummytri)
{
item.Oprev(ref otri);
while (otri.triangle != Mesh.dummytri)
{
if (!otri.IsInfected())
{
flag = false;
}
else
{
otri.SetOrg(null);
}
otri.OprevSelf();
}
}
if (flag)
{
vertex2.type = VertexType.UndeadVertex;
Mesh mesh = this.mesh;
mesh.undeads = mesh.undeads + 1;
}
}
item.orient = item.orient + 1;
}
item.orient = 0;
while (item.orient < 3)
{
item.Sym(ref otri);
if (otri.triangle != Mesh.dummytri)
{
otri.Dissolve();
Mesh mesh1 = this.mesh;
mesh1.hullsize = mesh1.hullsize + 1;
}
else
{
Mesh mesh2 = this.mesh;
mesh2.hullsize = mesh2.hullsize - 1;
}
item.orient = item.orient + 1;
}
this.mesh.TriangleDealloc(item.triangle);
}
this.viri.Clear();
}