private int RemoveBox()
{
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Otri otri3 = new Otri();
Otri otri4 = new Otri();
Otri otri5 = new Otri();
bool poly = !this.mesh.behavior.Poly;
otri3.triangle = Mesh.dummytri;
otri3.orient = 0;
otri3.SymSelf();
otri3.Lprev(ref otri4);
otri3.LnextSelf();
otri3.SymSelf();
otri3.Lprev(ref otri1);
otri1.SymSelf();
otri3.Lnext(ref otri2);
otri2.SymSelf();
if (otri2.triangle == Mesh.dummytri)
{
otri1.LprevSelf();
otri1.SymSelf();
}
Mesh.dummytri.neighbors[0] = otri1;
int num = -2;
while (!otri3.Equal(otri4))
{
num++;
otri3.Lprev(ref otri5);
otri5.SymSelf();
if (poly && otri5.triangle != Mesh.dummytri)
{
Vertex vertex = otri5.Org();
if (vertex.mark == 0)
{
vertex.mark = 1;
}
}
otri5.Dissolve();
otri3.Lnext(ref otri);
otri.Sym(ref otri3);
this.mesh.TriangleDealloc(otri.triangle);
if (otri3.triangle != Mesh.dummytri)
{
continue;
}
otri5.Copy(ref otri3);
}
this.mesh.TriangleDealloc(otri4.triangle);
return(num);
}
/// <summary>
/// Scout the first triangle on the path from one endpoint to another, and check
/// for completion (reaching the second endpoint), a collinear vertex, or the
/// intersection of two segments.
/// </summary>
/// <param name="searchtri"></param>
/// <param name="endpoint2"></param>
/// <param name="newmark"></param>
/// <returns>
/// Returns true if the entire segment is successfully inserted, and false
/// if the job must be finished by ConstrainedEdge().
/// </returns>
/// <remarks>
/// If the first triangle on the path has the second endpoint as its
/// destination or apex, a subsegment is inserted and the job is done.
/// If the first triangle on the path has a destination or apex that lies on
/// the segment, a subsegment is inserted connecting the first endpoint to
/// the collinear vertex, and the search is continued from the collinear
/// vertex.
/// If the first triangle on the path has a subsegment opposite its origin,
/// then there is a segment that intersects the segment being inserted.
/// Their intersection vertex is inserted, splitting the subsegment.
/// </remarks>
private bool ScoutSegment(ref Otri searchtri, Vertex endpoint2, ushort newmark)
{
Otri crosstri = default(Otri);
Osub crosssubseg = default(Osub);
Vertex leftvertex, rightvertex;
FindDirectionResult collinear;
collinear = FindDirection(ref searchtri, endpoint2);
rightvertex = searchtri.Dest();
leftvertex = searchtri.Apex();
if (((leftvertex.X == endpoint2.X) && (leftvertex.Y == endpoint2.Y)) ||
((rightvertex.X == endpoint2.X) && (rightvertex.Y == endpoint2.Y)))
{
// The segment is already an edge in the mesh.
if ((leftvertex.X == endpoint2.X) && (leftvertex.Y == endpoint2.Y))
{
searchtri.Lprev();
}
// Insert a subsegment, if there isn't already one there.
mesh.InsertSubseg(ref searchtri, newmark);
return(true);
}
if (collinear == FindDirectionResult.Leftcollinear)
{
// We've collided with a vertex between the segment's endpoints.
// Make the collinear vertex be the triangle's origin.
searchtri.Lprev();
mesh.InsertSubseg(ref searchtri, newmark);
// Insert the remainder of the segment.
return(ScoutSegment(ref searchtri, endpoint2, newmark));
}
if (collinear == FindDirectionResult.Rightcollinear)
{
// We've collided with a vertex between the segment's endpoints.
mesh.InsertSubseg(ref searchtri, newmark);
// Make the collinear vertex be the triangle's origin.
searchtri.Lnext();
// Insert the remainder of the segment.
return(ScoutSegment(ref searchtri, endpoint2, newmark));
}
searchtri.Lnext(ref crosstri);
crosstri.Pivot(ref crosssubseg);
// Check for a crossing segment.
if (crosssubseg.seg.hash == Mesh.DUMMY)
{
return(false);
}
// Insert a vertex at the intersection.
SegmentIntersection(ref crosstri, ref crosssubseg, endpoint2);
crosstri.Copy(ref searchtri);
mesh.InsertSubseg(ref searchtri, newmark);
// Insert the remainder of the segment.
return(ScoutSegment(ref searchtri, endpoint2, newmark));
}
private int RemoveGhosts(ref Otri startghost)
{
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
bool poly = !this.mesh.behavior.Poly;
startghost.Lprev(ref otri);
otri.SymSelf();
Mesh.dummytri.neighbors[0] = otri;
startghost.Copy(ref otri1);
int num = 0;
do
{
num++;
otri1.Lnext(ref otri2);
otri1.LprevSelf();
otri1.SymSelf();
if (poly && otri1.triangle != Mesh.dummytri)
{
Vertex vertex = otri1.Org();
if (vertex.mark == 0)
{
vertex.mark = 1;
}
}
otri1.Dissolve();
otri2.Sym(ref otri1);
this.mesh.TriangleDealloc(otri2.triangle);
}while (!otri1.Equal(startghost));
return(num);
}
public void TestLprev()
{
var triangles = CreateExampleMesh();
Otri t = default;
// The center triangle.
t.tri = triangles[1];
t.orient = 0;
t.Lprev();
Assert.AreEqual(3, t.Org().ID);
t.Lprev();
Assert.AreEqual(4, t.Org().ID);
t.Lprev();
Assert.AreEqual(1, t.Org().ID);
}
/// <summary>
/// Removes ghost triangles.
/// </summary>
/// <param name="startghost"></param>
/// <returns>Number of vertices on the hull.</returns>
int RemoveGhosts(ref Otri startghost)
{
Otri searchedge = default(Otri);
Otri dissolveedge = default(Otri);
Otri deadtriangle = default(Otri);
Vertex markorg;
int hullsize;
bool noPoly = !mesh.behavior.Poly;
var dummytri = mesh.dummytri;
// Find an edge on the convex hull to start point location from.
startghost.Lprev(ref searchedge);
searchedge.Sym();
dummytri.neighbors[0] = searchedge;
// Remove the bounding box and count the convex hull edges.
startghost.Copy(ref dissolveedge);
hullsize = 0;
do
{
hullsize++;
dissolveedge.Lnext(ref deadtriangle);
dissolveedge.Lprev();
dissolveedge.Sym();
// If no PSLG is involved, set the boundary markers of all the vertices
// on the convex hull. If a PSLG is used, this step is done later.
if (noPoly)
{
// Watch out for the case where all the input vertices are collinear.
if (dissolveedge.tri.id != Mesh.DUMMY)
{
markorg = dissolveedge.Org();
if (markorg.label == 0)
{
markorg.label = 1;
}
}
}
// Remove a bounding triangle from a convex hull triangle.
dissolveedge.Dissolve(dummytri);
// Find the next bounding triangle.
deadtriangle.Sym(ref dissolveedge);
// Delete the bounding triangle.
mesh.TriangleDealloc(deadtriangle.tri);
} while (!dissolveedge.Equals(startghost));
return(hullsize);
}
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>
/// Inserts a vertex at the circumcenter of a triangle. Deletes
/// the newly inserted vertex if it encroaches upon a segment.
/// </summary>
/// <param name="badtri"></param>
private void SplitTriangle(BadTriangle badtri)
{
Otri badotri = default(Otri);
Vertex borg, bdest, bapex;
Point newloc; // Location of the new vertex
double xi = 0, eta = 0;
InsertVertexResult success;
bool errorflag;
badotri = badtri.poortri;
borg = badotri.Org();
bdest = badotri.Dest();
bapex = badotri.Apex();
// Make sure that this triangle is still the same triangle it was
// when it was tested and determined to be of bad quality.
// Subsequent transformations may have made it a different triangle.
if (!Otri.IsDead(badotri.tri) && (borg == badtri.org) &&
(bdest == badtri.dest) && (bapex == badtri.apex))
{
errorflag = false;
// Create a new vertex at the triangle's circumcenter.
// Using the original (simpler) Steiner point location method
// for mesh refinement.
// TODO: NewLocation doesn't work for refinement. Why? Maybe
// reset VertexType?
if (behavior.fixedArea || behavior.VarArea)
{
newloc = predicates.FindCircumcenter(borg, bdest, bapex, ref xi, ref eta, behavior.offconstant);
}
else
{
newloc = newLocation.FindLocation(borg, bdest, bapex, ref xi, ref eta, true, badotri);
}
// Check whether the new vertex lies on a triangle vertex.
if (((newloc.x == borg.x) && (newloc.y == borg.y)) ||
((newloc.x == bdest.x) && (newloc.y == bdest.y)) ||
((newloc.x == bapex.x) && (newloc.y == bapex.y)))
{
if (Log.Verbose)
{
logger.Warning("New vertex falls on existing vertex.", "Quality.SplitTriangle()");
errorflag = true;
}
}
else
{
// The new vertex must be in the interior, and therefore is a
// free vertex with a marker of zero.
Vertex newvertex = new Vertex(newloc.x, newloc.y, 0
#if USE_ATTRIBS
, mesh.nextras
#endif
);
newvertex.type = VertexType.FreeVertex;
// Ensure that the handle 'badotri' does not represent the longest
// edge of the triangle. This ensures that the circumcenter must
// fall to the left of this edge, so point location will work.
// (If the angle org-apex-dest exceeds 90 degrees, then the
// circumcenter lies outside the org-dest edge, and eta is
// negative. Roundoff error might prevent eta from being
// negative when it should be, so I test eta against xi.)
if (eta < xi)
{
badotri.Lprev();
}
// Assign triangle for attributes interpolation.
newvertex.tri.tri = newvertex_tri;
// Insert the circumcenter, searching from the edge of the triangle,
// and maintain the Delaunay property of the triangulation.
Osub tmp = default(Osub);
success = mesh.InsertVertex(newvertex, ref badotri, ref tmp, true, true);
if (success == InsertVertexResult.Successful)
{
newvertex.hash = mesh.hash_vtx++;
newvertex.id = newvertex.hash;
#if USE_ATTRIBS
if (mesh.nextras > 0)
{
Interpolation.InterpolateAttributes(newvertex, newvertex.tri.tri, mesh.nextras);
}
#endif
#if USE_Z
Interpolation.InterpolateZ(newvertex, newvertex.tri.tri);
#endif
mesh.vertices.Add(newvertex.hash, newvertex);
if (mesh.steinerleft > 0)
{
mesh.steinerleft--;
}
}
else if (success == InsertVertexResult.Encroaching)
{
// If the newly inserted vertex encroaches upon a subsegment,
// delete the new vertex.
mesh.UndoVertex();
}
else if (success == InsertVertexResult.Violating)
{
// Failed to insert the new vertex, but some subsegment was
// marked as being encroached.
}
else
{ // success == DUPLICATEVERTEX
// Couldn't insert the new vertex because a vertex is already there.
if (Log.Verbose)
{
logger.Warning("New vertex falls on existing vertex.", "Quality.SplitTriangle()");
errorflag = true;
}
}
}
if (errorflag)
{
logger.Error("The new vertex is at the circumcenter of triangle: This probably "
+ "means that I am trying to refine triangles to a smaller size than can be "
+ "accommodated by the finite precision of floating point arithmetic.",
"Quality.SplitTriangle()");
throw new Exception("The new vertex is at the circumcenter of triangle.");
}
}
}
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));
}
private void MergeHulls(ref Otri farleft, ref Otri innerleft, ref Otri innerright, ref Otri farright, int axis)
{
Vertex vertex;
Vertex vertex1;
Vertex vertex2;
Vertex vertex3;
Vertex vertex4;
Vertex i;
bool flag;
bool flag1;
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();
Otri otri7 = new Otri();
Vertex vertex5 = innerleft.Dest();
Vertex vertex6 = innerleft.Apex();
Vertex vertex7 = innerright.Org();
Vertex vertex8 = innerright.Apex();
if (this.useDwyer && axis == 1)
{
vertex = farleft.Org();
vertex2 = farleft.Apex();
vertex1 = farright.Dest();
vertex3 = farright.Apex();
while (vertex2.y < vertex.y)
{
farleft.LnextSelf();
farleft.SymSelf();
vertex = vertex2;
vertex2 = farleft.Apex();
}
innerleft.Sym(ref otri6);
for (i = otri6.Apex(); i.y > vertex5.y; i = otri6.Apex())
{
otri6.Lnext(ref innerleft);
vertex6 = vertex5;
vertex5 = i;
innerleft.Sym(ref otri6);
}
while (vertex8.y < vertex7.y)
{
innerright.LnextSelf();
innerright.SymSelf();
vertex7 = vertex8;
vertex8 = innerright.Apex();
}
farright.Sym(ref otri6);
for (i = otri6.Apex(); i.y > vertex1.y; i = otri6.Apex())
{
otri6.Lnext(ref farright);
vertex3 = vertex1;
vertex1 = i;
farright.Sym(ref otri6);
}
}
do
{
flag = false;
if (Primitives.CounterClockwise(vertex5, vertex6, vertex7) > 0)
{
innerleft.LprevSelf();
innerleft.SymSelf();
vertex5 = vertex6;
vertex6 = innerleft.Apex();
flag = true;
}
if (Primitives.CounterClockwise(vertex8, vertex7, vertex5) <= 0)
{
continue;
}
innerright.LnextSelf();
innerright.SymSelf();
vertex7 = vertex8;
vertex8 = innerright.Apex();
flag = true;
}while (flag);
innerleft.Sym(ref otri);
innerright.Sym(ref otri1);
this.mesh.MakeTriangle(ref otri7);
otri7.Bond(ref innerleft);
otri7.LnextSelf();
otri7.Bond(ref innerright);
otri7.LnextSelf();
otri7.SetOrg(vertex7);
otri7.SetDest(vertex5);
vertex = farleft.Org();
if (vertex5 == vertex)
{
otri7.Lnext(ref farleft);
}
vertex1 = farright.Dest();
if (vertex7 == vertex1)
{
otri7.Lprev(ref farright);
}
Vertex vertex9 = vertex5;
Vertex vertex10 = vertex7;
Vertex vertex11 = otri.Apex();
Vertex vertex12 = otri1.Apex();
while (true)
{
bool flag2 = Primitives.CounterClockwise(vertex11, vertex9, vertex10) <= 0;
bool flag3 = Primitives.CounterClockwise(vertex12, vertex9, vertex10) <= 0;
if (flag2 & flag3)
{
break;
}
if (!flag2)
{
otri.Lprev(ref otri2);
otri2.SymSelf();
vertex4 = otri2.Apex();
if (vertex4 != null)
{
flag1 = Primitives.InCircle(vertex9, vertex10, vertex11, vertex4) > 0;
while (flag1)
{
otri2.LnextSelf();
otri2.Sym(ref otri4);
otri2.LnextSelf();
otri2.Sym(ref otri3);
otri2.Bond(ref otri4);
otri.Bond(ref otri3);
otri.LnextSelf();
otri.Sym(ref otri5);
otri2.LprevSelf();
otri2.Bond(ref otri5);
otri.SetOrg(vertex9);
otri.SetDest(null);
otri.SetApex(vertex4);
otri2.SetOrg(null);
otri2.SetDest(vertex11);
otri2.SetApex(vertex4);
vertex11 = vertex4;
otri3.Copy(ref otri2);
vertex4 = otri2.Apex();
flag1 = (vertex4 == null ? false : Primitives.InCircle(vertex9, vertex10, vertex11, vertex4) > 0);
}
}
}
if (!flag3)
{
otri1.Lnext(ref otri2);
otri2.SymSelf();
vertex4 = otri2.Apex();
if (vertex4 != null)
{
flag1 = Primitives.InCircle(vertex9, vertex10, vertex12, vertex4) > 0;
while (flag1)
{
otri2.LprevSelf();
otri2.Sym(ref otri4);
otri2.LprevSelf();
otri2.Sym(ref otri3);
otri2.Bond(ref otri4);
otri1.Bond(ref otri3);
otri1.LprevSelf();
otri1.Sym(ref otri5);
otri2.LnextSelf();
otri2.Bond(ref otri5);
otri1.SetOrg(null);
otri1.SetDest(vertex10);
otri1.SetApex(vertex4);
otri2.SetOrg(vertex12);
otri2.SetDest(null);
otri2.SetApex(vertex4);
vertex12 = vertex4;
otri3.Copy(ref otri2);
vertex4 = otri2.Apex();
flag1 = (vertex4 == null ? false : Primitives.InCircle(vertex9, vertex10, vertex12, vertex4) > 0);
}
}
}
if (flag2 || !flag3 && Primitives.InCircle(vertex11, vertex9, vertex10, vertex12) > 0)
{
otri7.Bond(ref otri1);
otri1.Lprev(ref otri7);
otri7.SetDest(vertex9);
vertex10 = vertex12;
otri7.Sym(ref otri1);
vertex12 = otri1.Apex();
}
else
{
otri7.Bond(ref otri);
otri.Lnext(ref otri7);
otri7.SetOrg(vertex10);
vertex9 = vertex11;
otri7.Sym(ref otri);
vertex11 = otri.Apex();
}
}
this.mesh.MakeTriangle(ref otri2);
otri2.SetOrg(vertex9);
otri2.SetDest(vertex10);
otri2.Bond(ref otri7);
otri2.LnextSelf();
otri2.Bond(ref otri1);
otri2.LnextSelf();
otri2.Bond(ref otri);
if (this.useDwyer && axis == 1)
{
vertex = farleft.Org();
vertex2 = farleft.Apex();
vertex1 = farright.Dest();
vertex3 = farright.Apex();
farleft.Sym(ref otri6);
for (i = otri6.Apex(); i.x < vertex.x; i = otri6.Apex())
{
otri6.Lprev(ref farleft);
vertex2 = vertex;
vertex = i;
farleft.Sym(ref otri6);
}
while (vertex3.x > vertex1.x)
{
farright.LprevSelf();
farright.SymSelf();
vertex1 = vertex3;
vertex3 = farright.Apex();
}
}
}
/// <summary>
/// Find a triangle or edge containing a given point.
/// </summary>
/// <param name="searchpoint">The point to locate.</param>
/// <param name="searchtri">The triangle to start the search at.</param>
/// <param name="stopatsubsegment"> If 'stopatsubsegment' is set, the search
/// will stop if it tries to walk through a subsegment, and will return OUTSIDE.</param>
/// <returns>Location information.</returns>
/// <remarks>
/// Begins its search from 'searchtri'. It is important that 'searchtri'
/// be a handle with the property that 'searchpoint' is strictly to the left
/// of the edge denoted by 'searchtri', or is collinear with that edge and
/// does not intersect that edge. (In particular, 'searchpoint' should not
/// be the origin or destination of that edge.)
///
/// These conditions are imposed because preciselocate() is normally used in
/// one of two situations:
///
/// (1) To try to find the location to insert a new point. Normally, we
/// know an edge that the point is strictly to the left of. In the
/// incremental Delaunay algorithm, that edge is a bounding box edge.
/// In Ruppert's Delaunay refinement algorithm for quality meshing,
/// that edge is the shortest edge of the triangle whose circumcenter
/// is being inserted.
///
/// (2) To try to find an existing point. In this case, any edge on the
/// convex hull is a good starting edge. You must screen out the
/// possibility that the vertex sought is an endpoint of the starting
/// edge before you call preciselocate().
///
/// On completion, 'searchtri' is a triangle that contains 'searchpoint'.
///
/// This implementation differs from that given by Guibas and Stolfi. It
/// walks from triangle to triangle, crossing an edge only if 'searchpoint'
/// is on the other side of the line containing that edge. After entering
/// a triangle, there are two edges by which one can leave that triangle.
/// If both edges are valid ('searchpoint' is on the other side of both
/// edges), one of the two is chosen by drawing a line perpendicular to
/// the entry edge (whose endpoints are 'forg' and 'fdest') passing through
/// 'fapex'. Depending on which side of this perpendicular 'searchpoint'
/// falls on, an exit edge is chosen.
///
/// This implementation is empirically faster than the Guibas and Stolfi
/// point location routine (which I originally used), which tends to spiral
/// in toward its target.
///
/// Returns ONVERTEX if the point lies on an existing vertex. 'searchtri'
/// is a handle whose origin is the existing vertex.
///
/// Returns ONEDGE if the point lies on a mesh edge. 'searchtri' is a
/// handle whose primary edge is the edge on which the point lies.
///
/// Returns INTRIANGLE if the point lies strictly within a triangle.
/// 'searchtri' is a handle on the triangle that contains the point.
///
/// Returns OUTSIDE if the point lies outside the mesh. 'searchtri' is a
/// handle whose primary edge the point is to the right of. This might
/// occur when the circumcenter of a triangle falls just slightly outside
/// the mesh due to floating-point roundoff error. It also occurs when
/// seeking a hole or region point that a foolish user has placed outside
/// the mesh.
///
/// WARNING: This routine is designed for convex triangulations, and will
/// not generally work after the holes and concavities have been carved.
/// However, it can still be used to find the circumcenter of a triangle, as
/// long as the search is begun from the triangle in question.</remarks>
public LocateResult PreciseLocate(Point searchpoint, ref Otri searchtri,
bool stopatsubsegment)
{
Otri backtracktri = default(Otri);
Osub checkedge = default(Osub);
Vertex forg, fdest, fapex;
double orgorient, destorient;
bool moveleft;
// Where are we?
forg = searchtri.Org();
fdest = searchtri.Dest();
fapex = searchtri.Apex();
while (true)
{
// Check whether the apex is the point we seek.
if ((fapex.x == searchpoint.X) && (fapex.y == searchpoint.Y))
{
searchtri.LprevSelf();
return(LocateResult.OnVertex);
}
// Does the point lie on the other side of the line defined by the
// triangle edge opposite the triangle's destination?
destorient = Primitives.CounterClockwise(forg, fapex, searchpoint);
// Does the point lie on the other side of the line defined by the
// triangle edge opposite the triangle's origin?
orgorient = Primitives.CounterClockwise(fapex, fdest, searchpoint);
if (destorient > 0.0)
{
if (orgorient > 0.0)
{
// Move left if the inner product of (fapex - searchpoint) and
// (fdest - forg) is positive. This is equivalent to drawing
// a line perpendicular to the line (forg, fdest) and passing
// through 'fapex', and determining which side of this line
// 'searchpoint' falls on.
moveleft = (fapex.x - searchpoint.X) * (fdest.x - forg.x) +
(fapex.y - searchpoint.Y) * (fdest.y - forg.y) > 0.0;
}
else
{
moveleft = true;
}
}
else
{
if (orgorient > 0.0)
{
moveleft = false;
}
else
{
// The point we seek must be on the boundary of or inside this
// triangle.
if (destorient == 0.0)
{
searchtri.LprevSelf();
return(LocateResult.OnEdge);
}
if (orgorient == 0.0)
{
searchtri.LnextSelf();
return(LocateResult.OnEdge);
}
return(LocateResult.InTriangle);
}
}
// Move to another triangle. Leave a trace 'backtracktri' in case
// floating-point roundoff or some such bogey causes us to walk
// off a boundary of the triangulation.
if (moveleft)
{
searchtri.Lprev(ref backtracktri);
fdest = fapex;
}
else
{
searchtri.Lnext(ref backtracktri);
forg = fapex;
}
backtracktri.Sym(ref searchtri);
if (mesh.checksegments && stopatsubsegment)
{
// Check for walking through a subsegment.
backtracktri.SegPivot(ref checkedge);
if (checkedge.seg != Mesh.dummysub)
{
// Go back to the last triangle.
backtracktri.Copy(ref searchtri);
return(LocateResult.Outside);
}
}
// Check for walking right out of the triangulation.
if (searchtri.triangle == Mesh.dummytri)
{
// Go back to the last triangle.
backtracktri.Copy(ref searchtri);
return(LocateResult.Outside);
}
fapex = searchtri.Apex();
}
}
/// <summary>
/// Remove the "infinite" bounding triangle, setting boundary markers as appropriate.
/// </summary>
/// <returns>Returns the number of edges on the convex hull of the triangulation.</returns>
/// <remarks>
/// The triangular bounding box has three boundary triangles (one for each
/// side of the bounding box), and a bunch of triangles fanning out from
/// the three bounding box vertices (one triangle for each edge of the
/// convex hull of the inner mesh). This routine removes these triangles.
/// </remarks>
int RemoveBox()
{
Otri deadtriangle = default(Otri);
Otri searchedge = default(Otri);
Otri checkedge = default(Otri);
Otri nextedge = default(Otri), finaledge = default(Otri), dissolveedge = default(Otri);
Vertex markorg;
int hullsize;
bool noPoly = !mesh.behavior.Poly;
// Find a boundary triangle.
nextedge.triangle = Mesh.dummytri;
nextedge.orient = 0;
nextedge.SymSelf();
// Mark a place to stop.
nextedge.Lprev(ref finaledge);
nextedge.LnextSelf();
nextedge.SymSelf();
// Find a triangle (on the boundary of the vertex set) that isn't
// a bounding box triangle.
nextedge.Lprev(ref searchedge);
searchedge.SymSelf();
// Check whether nextedge is another boundary triangle
// adjacent to the first one.
nextedge.Lnext(ref checkedge);
checkedge.SymSelf();
if (checkedge.triangle == Mesh.dummytri)
{
// Go on to the next triangle. There are only three boundary
// triangles, and this next triangle cannot be the third one,
// so it's safe to stop here.
searchedge.LprevSelf();
searchedge.SymSelf();
}
// Find a new boundary edge to search from, as the current search
// edge lies on a bounding box triangle and will be deleted.
Mesh.dummytri.neighbors[0] = searchedge;
hullsize = -2;
while (!nextedge.Equal(finaledge))
{
hullsize++;
nextedge.Lprev(ref dissolveedge);
dissolveedge.SymSelf();
// If not using a PSLG, the vertices should be marked now.
// (If using a PSLG, markhull() will do the job.)
if (noPoly)
{
// Be careful! One must check for the case where all the input
// vertices are collinear, and thus all the triangles are part of
// the bounding box. Otherwise, the setvertexmark() call below
// will cause a bad pointer reference.
if (dissolveedge.triangle != Mesh.dummytri)
{
markorg = dissolveedge.Org();
if (markorg.mark == 0)
{
markorg.mark = 1;
}
}
}
// Disconnect the bounding box triangle from the mesh triangle.
dissolveedge.Dissolve();
nextedge.Lnext(ref deadtriangle);
deadtriangle.Sym(ref nextedge);
// Get rid of the bounding box triangle.
mesh.TriangleDealloc(deadtriangle.triangle);
// Do we need to turn the corner?
if (nextedge.triangle == Mesh.dummytri)
{
// Turn the corner.
dissolveedge.Copy(ref nextedge);
}
}
mesh.TriangleDealloc(finaledge.triangle);
return(hullsize);
}
public LocateResult PreciseLocate(Point searchpoint, ref Otri searchtri, bool stopatsubsegment)
{
bool flag;
Otri otri = new Otri();
Osub osub = new Osub();
Vertex vertex = searchtri.Org();
Vertex vertex1 = searchtri.Dest();
for (Vertex i = searchtri.Apex(); i.x != searchpoint.X || i.y != searchpoint.Y; i = searchtri.Apex())
{
double num = Primitives.CounterClockwise(vertex, i, searchpoint);
double num1 = Primitives.CounterClockwise(i, vertex1, searchpoint);
if (num <= 0)
{
if (num1 <= 0)
{
if (num == 0)
{
searchtri.LprevSelf();
return(LocateResult.OnEdge);
}
if (num1 != 0)
{
return(LocateResult.InTriangle);
}
searchtri.LnextSelf();
return(LocateResult.OnEdge);
}
flag = false;
}
else
{
flag = (num1 <= 0 ? true : (i.x - searchpoint.X) * (vertex1.x - vertex.x) + (i.y - searchpoint.Y) * (vertex1.y - vertex.y) > 0);
}
if (!flag)
{
searchtri.Lnext(ref otri);
vertex = i;
}
else
{
searchtri.Lprev(ref otri);
vertex1 = i;
}
otri.Sym(ref searchtri);
if (this.mesh.checksegments & stopatsubsegment)
{
otri.SegPivot(ref osub);
if (osub.seg != Mesh.dummysub)
{
otri.Copy(ref searchtri);
return(LocateResult.Outside);
}
}
if (searchtri.triangle == Mesh.dummytri)
{
otri.Copy(ref searchtri);
return(LocateResult.Outside);
}
}
searchtri.LprevSelf();
return(LocateResult.OnVertex);
}
/// <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);
}
/// <summary>
/// Merge two adjacent Delaunay triangulations into a single Delaunay triangulation.
/// </summary>
/// <param name="farleft">Bounding triangles of the left triangulation.</param>
/// <param name="innerleft">Bounding triangles of the left triangulation.</param>
/// <param name="innerright">Bounding triangles of the right triangulation.</param>
/// <param name="farright">Bounding triangles of the right triangulation.</param>
/// <param name="axis"></param>
/// <remarks>
/// This is similar to the algorithm given by Guibas and Stolfi, but uses
/// a triangle-based, rather than edge-based, data structure.
///
/// The algorithm walks up the gap between the two triangulations, knitting
/// them together. As they are merged, some of their bounding triangles
/// are converted into real triangles of the triangulation. The procedure
/// pulls each hull's bounding triangles apart, then knits them together
/// like the teeth of two gears. The Delaunay property determines, at each
/// step, whether the next "tooth" is a bounding triangle of the left hull
/// or the right. When a bounding triangle becomes real, its apex is
/// changed from NULL to a real vertex.
///
/// Only two new triangles need to be allocated. These become new bounding
/// triangles at the top and bottom of the seam. They are used to connect
/// the remaining bounding triangles (those that have not been converted
/// into real triangles) into a single fan.
///
/// On entry, 'farleft' and 'innerleft' are bounding triangles of the left
/// triangulation. The origin of 'farleft' is the leftmost vertex, and
/// the destination of 'innerleft' is the rightmost vertex of the
/// triangulation. Similarly, 'innerright' and 'farright' are bounding
/// triangles of the right triangulation. The origin of 'innerright' and
/// destination of 'farright' are the leftmost and rightmost vertices.
///
/// On completion, the origin of 'farleft' is the leftmost vertex of the
/// merged triangulation, and the destination of 'farright' is the rightmost
/// vertex.
/// </remarks>
void MergeHulls(ref Otri farleft, ref Otri innerleft, ref Otri innerright,
ref Otri farright, int axis)
{
Otri leftcand = default(Otri), rightcand = default(Otri);
Otri nextedge = default(Otri);
Otri sidecasing = default(Otri), topcasing = default(Otri), outercasing = default(Otri);
Otri checkedge = default(Otri);
Otri baseedge = default(Otri);
Vertex innerleftdest;
Vertex innerrightorg;
Vertex innerleftapex, innerrightapex;
Vertex farleftpt, farrightpt;
Vertex farleftapex, farrightapex;
Vertex lowerleft, lowerright;
Vertex upperleft, upperright;
Vertex nextapex;
Vertex checkvertex;
bool changemade;
bool badedge;
bool leftfinished, rightfinished;
innerleftdest = innerleft.Dest();
innerleftapex = innerleft.Apex();
innerrightorg = innerright.Org();
innerrightapex = innerright.Apex();
// Special treatment for horizontal cuts.
if (useDwyer && (axis == 1))
{
farleftpt = farleft.Org();
farleftapex = farleft.Apex();
farrightpt = farright.Dest();
farrightapex = farright.Apex();
// The pointers to the extremal vertices are shifted to point to the
// topmost and bottommost vertex of each hull, rather than the
// leftmost and rightmost vertices.
while (farleftapex.y < farleftpt.y)
{
farleft.LnextSelf();
farleft.SymSelf();
farleftpt = farleftapex;
farleftapex = farleft.Apex();
}
innerleft.Sym(ref checkedge);
checkvertex = checkedge.Apex();
while (checkvertex.y > innerleftdest.y)
{
checkedge.Lnext(ref innerleft);
innerleftapex = innerleftdest;
innerleftdest = checkvertex;
innerleft.Sym(ref checkedge);
checkvertex = checkedge.Apex();
}
while (innerrightapex.y < innerrightorg.y)
{
innerright.LnextSelf();
innerright.SymSelf();
innerrightorg = innerrightapex;
innerrightapex = innerright.Apex();
}
farright.Sym(ref checkedge);
checkvertex = checkedge.Apex();
while (checkvertex.y > farrightpt.y)
{
checkedge.Lnext(ref farright);
farrightapex = farrightpt;
farrightpt = checkvertex;
farright.Sym(ref checkedge);
checkvertex = checkedge.Apex();
}
}
// Find a line tangent to and below both hulls.
do
{
changemade = false;
// Make innerleftdest the "bottommost" vertex of the left hull.
if (Primitives.CounterClockwise(innerleftdest, innerleftapex, innerrightorg) > 0.0)
{
innerleft.LprevSelf();
innerleft.SymSelf();
innerleftdest = innerleftapex;
innerleftapex = innerleft.Apex();
changemade = true;
}
// Make innerrightorg the "bottommost" vertex of the right hull.
if (Primitives.CounterClockwise(innerrightapex, innerrightorg, innerleftdest) > 0.0)
{
innerright.LnextSelf();
innerright.SymSelf();
innerrightorg = innerrightapex;
innerrightapex = innerright.Apex();
changemade = true;
}
} while (changemade);
// Find the two candidates to be the next "gear tooth."
innerleft.Sym(ref leftcand);
innerright.Sym(ref rightcand);
// Create the bottom new bounding triangle.
mesh.MakeTriangle(ref baseedge);
// Connect it to the bounding boxes of the left and right triangulations.
baseedge.Bond(ref innerleft);
baseedge.LnextSelf();
baseedge.Bond(ref innerright);
baseedge.LnextSelf();
baseedge.SetOrg(innerrightorg);
baseedge.SetDest(innerleftdest);
// Apex is intentionally left NULL.
// Fix the extreme triangles if necessary.
farleftpt = farleft.Org();
if (innerleftdest == farleftpt)
{
baseedge.Lnext(ref farleft);
}
farrightpt = farright.Dest();
if (innerrightorg == farrightpt)
{
baseedge.Lprev(ref farright);
}
// The vertices of the current knitting edge.
lowerleft = innerleftdest;
lowerright = innerrightorg;
// The candidate vertices for knitting.
upperleft = leftcand.Apex();
upperright = rightcand.Apex();
// Walk up the gap between the two triangulations, knitting them together.
while (true)
{
// Have we reached the top? (This isn't quite the right question,
// because even though the left triangulation might seem finished now,
// moving up on the right triangulation might reveal a new vertex of
// the left triangulation. And vice-versa.)
leftfinished = Primitives.CounterClockwise(upperleft, lowerleft, lowerright) <= 0.0;
rightfinished = Primitives.CounterClockwise(upperright, lowerleft, lowerright) <= 0.0;
if (leftfinished && rightfinished)
{
// Create the top new bounding triangle.
mesh.MakeTriangle(ref nextedge);
nextedge.SetOrg(lowerleft);
nextedge.SetDest(lowerright);
// Apex is intentionally left NULL.
// Connect it to the bounding boxes of the two triangulations.
nextedge.Bond(ref baseedge);
nextedge.LnextSelf();
nextedge.Bond(ref rightcand);
nextedge.LnextSelf();
nextedge.Bond(ref leftcand);
// Special treatment for horizontal cuts.
if (useDwyer && (axis == 1))
{
farleftpt = farleft.Org();
farleftapex = farleft.Apex();
farrightpt = farright.Dest();
farrightapex = farright.Apex();
farleft.Sym(ref checkedge);
checkvertex = checkedge.Apex();
// The pointers to the extremal vertices are restored to the
// leftmost and rightmost vertices (rather than topmost and
// bottommost).
while (checkvertex.x < farleftpt.x)
{
checkedge.Lprev(ref farleft);
farleftapex = farleftpt;
farleftpt = checkvertex;
farleft.Sym(ref checkedge);
checkvertex = checkedge.Apex();
}
while (farrightapex.x > farrightpt.x)
{
farright.LprevSelf();
farright.SymSelf();
farrightpt = farrightapex;
farrightapex = farright.Apex();
}
}
return;
}
// Consider eliminating edges from the left triangulation.
if (!leftfinished)
{
// What vertex would be exposed if an edge were deleted?
leftcand.Lprev(ref nextedge);
nextedge.SymSelf();
nextapex = nextedge.Apex();
// If nextapex is NULL, then no vertex would be exposed; the
// triangulation would have been eaten right through.
if (nextapex != null)
{
// Check whether the edge is Delaunay.
badedge = Primitives.InCircle(lowerleft, lowerright, upperleft, nextapex) > 0.0;
while (badedge)
{
// Eliminate the edge with an edge flip. As a result, the
// left triangulation will have one more boundary triangle.
nextedge.LnextSelf();
nextedge.Sym(ref topcasing);
nextedge.LnextSelf();
nextedge.Sym(ref sidecasing);
nextedge.Bond(ref topcasing);
leftcand.Bond(ref sidecasing);
leftcand.LnextSelf();
leftcand.Sym(ref outercasing);
nextedge.LprevSelf();
nextedge.Bond(ref outercasing);
// Correct the vertices to reflect the edge flip.
leftcand.SetOrg(lowerleft);
leftcand.SetDest(null);
leftcand.SetApex(nextapex);
nextedge.SetOrg(null);
nextedge.SetDest(upperleft);
nextedge.SetApex(nextapex);
// Consider the newly exposed vertex.
upperleft = nextapex;
// What vertex would be exposed if another edge were deleted?
sidecasing.Copy(ref nextedge);
nextapex = nextedge.Apex();
if (nextapex != null)
{
// Check whether the edge is Delaunay.
badedge = Primitives.InCircle(lowerleft, lowerright, upperleft, nextapex) > 0.0;
}
else
{
// Avoid eating right through the triangulation.
badedge = false;
}
}
}
}
// Consider eliminating edges from the right triangulation.
if (!rightfinished)
{
// What vertex would be exposed if an edge were deleted?
rightcand.Lnext(ref nextedge);
nextedge.SymSelf();
nextapex = nextedge.Apex();
// If nextapex is NULL, then no vertex would be exposed; the
// triangulation would have been eaten right through.
if (nextapex != null)
{
// Check whether the edge is Delaunay.
badedge = Primitives.InCircle(lowerleft, lowerright, upperright, nextapex) > 0.0;
while (badedge)
{
// Eliminate the edge with an edge flip. As a result, the
// right triangulation will have one more boundary triangle.
nextedge.LprevSelf();
nextedge.Sym(ref topcasing);
nextedge.LprevSelf();
nextedge.Sym(ref sidecasing);
nextedge.Bond(ref topcasing);
rightcand.Bond(ref sidecasing);
rightcand.LprevSelf();
rightcand.Sym(ref outercasing);
nextedge.LnextSelf();
nextedge.Bond(ref outercasing);
// Correct the vertices to reflect the edge flip.
rightcand.SetOrg(null);
rightcand.SetDest(lowerright);
rightcand.SetApex(nextapex);
nextedge.SetOrg(upperright);
nextedge.SetDest(null);
nextedge.SetApex(nextapex);
// Consider the newly exposed vertex.
upperright = nextapex;
// What vertex would be exposed if another edge were deleted?
sidecasing.Copy(ref nextedge);
nextapex = nextedge.Apex();
if (nextapex != null)
{
// Check whether the edge is Delaunay.
badedge = Primitives.InCircle(lowerleft, lowerright, upperright, nextapex) > 0.0;
}
else
{
// Avoid eating right through the triangulation.
badedge = false;
}
}
}
}
if (leftfinished || (!rightfinished &&
(Primitives.InCircle(upperleft, lowerleft, lowerright, upperright) > 0.0)))
{
// Knit the triangulations, adding an edge from 'lowerleft'
// to 'upperright'.
baseedge.Bond(ref rightcand);
rightcand.Lprev(ref baseedge);
baseedge.SetDest(lowerleft);
lowerright = upperright;
baseedge.Sym(ref rightcand);
upperright = rightcand.Apex();
}
else
{
// Knit the triangulations, adding an edge from 'upperleft'
// to 'lowerright'.
baseedge.Bond(ref leftcand);
leftcand.Lnext(ref baseedge);
baseedge.SetOrg(lowerright);
lowerleft = upperleft;
baseedge.Sym(ref leftcand);
upperleft = leftcand.Apex();
}
}
}
public void TestTriangle(ref Otri testtri)
{
Vertex vertex;
Vertex vertex1;
double num;
double num1;
double num2;
Otri otri = new Otri();
Otri otri1 = new Otri();
Osub osub = new Osub();
Vertex vertex2 = testtri.Org();
Vertex vertex3 = testtri.Dest();
Vertex vertex4 = testtri.Apex();
double num3 = vertex2.x - vertex3.x;
double num4 = vertex2.y - vertex3.y;
double num5 = vertex3.x - vertex4.x;
double num6 = vertex3.y - vertex4.y;
double num7 = vertex4.x - vertex2.x;
double num8 = vertex4.y - vertex2.y;
double num9 = num3 * num3;
double num10 = num4 * num4;
double num11 = num5 * num5;
double num12 = num6 * num6;
double num13 = num8 * num8;
double num14 = num9 + num10;
double num15 = num11 + num12;
double num16 = num7 * num7 + num13;
if (num14 < num15 && num14 < num16)
{
num = num14;
num1 = num5 * num7 + num6 * num8;
num1 = num1 * num1 / (num15 * num16);
vertex = vertex2;
vertex1 = vertex3;
testtri.Copy(ref otri);
}
else if (num15 >= num16)
{
num = num16;
num1 = num3 * num5 + num4 * num6;
num1 = num1 * num1 / (num14 * num15);
vertex = vertex4;
vertex1 = vertex2;
testtri.Lprev(ref otri);
}
else
{
num = num15;
num1 = num3 * num7 + num4 * num8;
num1 = num1 * num1 / (num14 * num16);
vertex = vertex3;
vertex1 = vertex4;
testtri.Lnext(ref otri);
}
if (this.behavior.VarArea || this.behavior.fixedArea || this.behavior.Usertest)
{
double num17 = 0.5 * (num3 * num6 - num4 * num5);
if (this.behavior.fixedArea && num17 > this.behavior.MaxArea)
{
this.queue.Enqueue(ref testtri, num, vertex4, vertex2, vertex3);
return;
}
if (this.behavior.VarArea && num17 > testtri.triangle.area && testtri.triangle.area > 0)
{
this.queue.Enqueue(ref testtri, num, vertex4, vertex2, vertex3);
return;
}
if (this.behavior.Usertest && this.userTest != null && this.userTest(vertex2, vertex3, vertex4, num17))
{
this.queue.Enqueue(ref testtri, num, vertex4, vertex2, vertex3);
return;
}
}
if (num14 <= num15 || num14 <= num16)
{
num2 = (num15 <= num16 ? (num14 + num15 - num16) / (2 * Math.Sqrt(num14 * num15)) : (num14 + num16 - num15) / (2 * Math.Sqrt(num14 * num16)));
}
else
{
num2 = (num15 + num16 - num14) / (2 * Math.Sqrt(num15 * num16));
}
if (num1 > this.behavior.goodAngle || num2 < this.behavior.maxGoodAngle && this.behavior.MaxAngle != 0)
{
if (vertex.type == VertexType.SegmentVertex && vertex1.type == VertexType.SegmentVertex)
{
otri.SegPivot(ref osub);
if (osub.seg == Mesh.dummysub)
{
otri.Copy(ref otri1);
do
{
otri.OprevSelf();
otri.SegPivot(ref osub);
}while (osub.seg == Mesh.dummysub);
Vertex vertex5 = osub.SegOrg();
Vertex vertex6 = osub.SegDest();
do
{
otri1.DnextSelf();
otri1.SegPivot(ref osub);
}while (osub.seg == Mesh.dummysub);
Vertex vertex7 = osub.SegOrg();
Vertex vertex8 = osub.SegDest();
Vertex vertex9 = null;
if (vertex6.x == vertex7.x && vertex6.y == vertex7.y)
{
vertex9 = vertex6;
}
else if (vertex5.x == vertex8.x && vertex5.y == vertex8.y)
{
vertex9 = vertex5;
}
if (vertex9 != null)
{
double num18 = (vertex.x - vertex9.x) * (vertex.x - vertex9.x) + (vertex.y - vertex9.y) * (vertex.y - vertex9.y);
double num19 = (vertex1.x - vertex9.x) * (vertex1.x - vertex9.x) + (vertex1.y - vertex9.y) * (vertex1.y - vertex9.y);
if (num18 < 1.001 * num19 && num18 > 0.999 * num19)
{
return;
}
}
}
}
this.queue.Enqueue(ref testtri, num, vertex4, vertex2, vertex3);
}
}
/// <summary>
/// Split all the encroached subsegments.
/// </summary>
/// <param name="triflaws">A flag that specifies whether one should take
/// note of new bad triangles that result from inserting vertices to repair
/// encroached subsegments.</param>
/// <remarks>
/// Each encroached subsegment is repaired by splitting it - inserting a
/// vertex at or near its midpoint. Newly inserted vertices may encroach
/// upon other subsegments; these are also repaired.
/// </remarks>
private void SplitEncSegs(bool triflaws)
{
Otri enctri = default(Otri);
Otri testtri = default(Otri);
Osub testsh = default(Osub);
Osub currentenc = default(Osub);
BadSubseg seg;
Vertex eorg, edest, eapex;
Vertex newvertex;
InsertVertexResult success;
float segmentlength, nearestpoweroftwo;
float split;
float multiplier, divisor;
bool acuteorg, acuteorg2, acutedest, acutedest2;
// Note that steinerleft == -1 if an unlimited number
// of Steiner points is allowed.
while (badsubsegs.Count > 0)
{
if (mesh.steinerleft == 0)
{
break;
}
seg = badsubsegs.Dequeue();
currentenc = seg.encsubseg;
eorg = currentenc.Org();
edest = currentenc.Dest();
// Make sure that this segment is still the same segment it was
// when it was determined to be encroached. If the segment was
// enqueued multiple times (because several newly inserted
// vertices encroached it), it may have already been split.
if (!Osub.IsDead(currentenc.seg) && (eorg == seg.subsegorg) && (edest == seg.subsegdest))
{
// To decide where to split a segment, we need to know if the
// segment shares an endpoint with an adjacent segment.
// The concern is that, if we simply split every encroached
// segment in its center, two adjacent segments with a small
// angle between them might lead to an infinite loop; each
// vertex added to split one segment will encroach upon the
// other segment, which must then be split with a vertex that
// will encroach upon the first segment, and so on forever.
// To avoid this, imagine a set of concentric circles, whose
// radii are powers of two, about each segment endpoint.
// These concentric circles determine where the segment is
// split. (If both endpoints are shared with adjacent
// segments, split the segment in the middle, and apply the
// concentric circles for later splittings.)
// Is the origin shared with another segment?
currentenc.TriPivot(ref enctri);
enctri.Lnext(ref testtri);
testtri.SegPivot(ref testsh);
acuteorg = testsh.seg != Mesh.dummysub;
// Is the destination shared with another segment?
testtri.LnextSelf();
testtri.SegPivot(ref testsh);
acutedest = testsh.seg != Mesh.dummysub;
// If we're using Chew's algorithm (rather than Ruppert's)
// to define encroachment, delete free vertices from the
// subsegment's diametral circle.
if (!behavior.ConformingDelaunay && !acuteorg && !acutedest)
{
eapex = enctri.Apex();
while ((eapex.type == VertexType.FreeVertex) &&
((eorg.x - eapex.x) * (edest.x - eapex.x) +
(eorg.y - eapex.y) * (edest.y - eapex.y) < 0.0))
{
mesh.DeleteVertex(ref testtri);
currentenc.TriPivot(ref enctri);
eapex = enctri.Apex();
enctri.Lprev(ref testtri);
}
}
// Now, check the other side of the segment, if there's a triangle there.
enctri.Sym(ref testtri);
if (testtri.triangle != Mesh.dummytri)
{
// Is the destination shared with another segment?
testtri.LnextSelf();
testtri.SegPivot(ref testsh);
acutedest2 = testsh.seg != Mesh.dummysub;
acutedest = acutedest || acutedest2;
// Is the origin shared with another segment?
testtri.LnextSelf();
testtri.SegPivot(ref testsh);
acuteorg2 = testsh.seg != Mesh.dummysub;
acuteorg = acuteorg || acuteorg2;
// Delete free vertices from the subsegment's diametral circle.
if (!behavior.ConformingDelaunay && !acuteorg2 && !acutedest2)
{
eapex = testtri.Org();
while ((eapex.type == VertexType.FreeVertex) &&
((eorg.x - eapex.x) * (edest.x - eapex.x) +
(eorg.y - eapex.y) * (edest.y - eapex.y) < 0.0))
{
mesh.DeleteVertex(ref testtri);
enctri.Sym(ref testtri);
eapex = testtri.Apex();
testtri.LprevSelf();
}
}
}
// Use the concentric circles if exactly one endpoint is shared
// with another adjacent segment.
if (acuteorg || acutedest)
{
segmentlength = UnityEngine.Mathf.Sqrt((edest.x - eorg.x) * (edest.x - eorg.x) +
(edest.y - eorg.y) * (edest.y - eorg.y));
// Find the power of two that most evenly splits the segment.
// The worst case is a 2:1 ratio between subsegment lengths.
nearestpoweroftwo = 1.0f;
while (segmentlength > 3.0f * nearestpoweroftwo)
{
nearestpoweroftwo *= 2.0f;
}
while (segmentlength < 1.5f * nearestpoweroftwo)
{
nearestpoweroftwo *= 0.5f;
}
// Where do we split the segment?
split = nearestpoweroftwo / segmentlength;
if (acutedest)
{
split = 1.0f - split;
}
}
else
{
// If we're not worried about adjacent segments, split
// this segment in the middle.
split = 0.5f;
}
// Create the new vertex (interpolate coordinates).
newvertex = new Vertex(
eorg.x + split * (edest.x - eorg.x),
eorg.y + split * (edest.y - eorg.y),
currentenc.Mark(),
mesh.nextras);
newvertex.type = VertexType.SegmentVertex;
newvertex.hash = mesh.hash_vtx++;
newvertex.id = newvertex.hash;
mesh.vertices.Add(newvertex.hash, newvertex);
// Interpolate attributes.
for (int i = 0; i < mesh.nextras; i++)
{
newvertex.attributes[i] = eorg.attributes[i]
+ split * (edest.attributes[i] - eorg.attributes[i]);
}
if (!Behavior.NoExact)
{
// Roundoff in the above calculation may yield a 'newvertex'
// that is not precisely collinear with 'eorg' and 'edest'.
// Improve collinearity by one step of iterative refinement.
multiplier = Primitives.CounterClockwise(eorg, edest, newvertex);
divisor = ((eorg.x - edest.x) * (eorg.x - edest.x) +
(eorg.y - edest.y) * (eorg.y - edest.y));
if ((multiplier != 0.0) && (divisor != 0.0))
{
multiplier = multiplier / divisor;
// Watch out for NANs.
if (!float.IsNaN(multiplier))
{
newvertex.x += multiplier * (edest.y - eorg.y);
newvertex.y += multiplier * (eorg.x - edest.x);
}
}
}
// Check whether the new vertex lies on an endpoint.
if (((newvertex.x == eorg.x) && (newvertex.y == eorg.y)) ||
((newvertex.x == edest.x) && (newvertex.y == edest.y)))
{
logger.Error("Ran out of precision: I attempted to split a"
+ " segment to a smaller size than can be accommodated by"
+ " the finite precision of floating point arithmetic.",
"Quality.SplitEncSegs()");
throw new Exception("Ran out of precision");
}
// Insert the splitting vertex. This should always succeed.
success = mesh.InsertVertex(newvertex, ref enctri, ref currentenc, true, triflaws);
if ((success != InsertVertexResult.Successful) && (success != InsertVertexResult.Encroaching))
{
logger.Error("Failure to split a segment.", "Quality.SplitEncSegs()");
throw new Exception("Failure to split a segment.");
}
if (mesh.steinerleft > 0)
{
mesh.steinerleft--;
}
// Check the two new subsegments to see if they're encroached.
CheckSeg4Encroach(ref currentenc);
currentenc.NextSelf();
CheckSeg4Encroach(ref currentenc);
}
// Set subsegment's origin to NULL. This makes it possible to detect dead
// badsubsegs when traversing the list of all badsubsegs.
seg.subsegorg = null;
}
}
private void SplitEncSegs(bool triflaws)
{
Vertex vertex;
double num;
Otri otri = new Otri();
Otri otri1 = new Otri();
Osub osub = new Osub();
Osub osub1 = new Osub();
while (this.badsubsegs.Count > 0 && this.mesh.steinerleft != 0)
{
BadSubseg badSubseg = this.badsubsegs.Dequeue();
osub1 = badSubseg.encsubseg;
Vertex vertex1 = osub1.Org();
Vertex vertex2 = osub1.Dest();
if (!Osub.IsDead(osub1.seg) && vertex1 == badSubseg.subsegorg && vertex2 == badSubseg.subsegdest)
{
osub1.TriPivot(ref otri);
otri.Lnext(ref otri1);
otri1.SegPivot(ref osub);
bool flag = osub.seg != Mesh.dummysub;
otri1.LnextSelf();
otri1.SegPivot(ref osub);
bool flag1 = osub.seg != Mesh.dummysub;
if (!this.behavior.ConformingDelaunay && !flag && !flag1)
{
vertex = otri.Apex();
while (vertex.type == VertexType.FreeVertex && (vertex1.x - vertex.x) * (vertex2.x - vertex.x) + (vertex1.y - vertex.y) * (vertex2.y - vertex.y) < 0)
{
this.mesh.DeleteVertex(ref otri1);
osub1.TriPivot(ref otri);
vertex = otri.Apex();
otri.Lprev(ref otri1);
}
}
otri.Sym(ref otri1);
if (otri1.triangle != Mesh.dummytri)
{
otri1.LnextSelf();
otri1.SegPivot(ref osub);
bool flag2 = osub.seg != Mesh.dummysub;
flag1 = flag1 | flag2;
otri1.LnextSelf();
otri1.SegPivot(ref osub);
bool flag3 = osub.seg != Mesh.dummysub;
flag = flag | flag3;
if (!this.behavior.ConformingDelaunay && !flag3 && !flag2)
{
vertex = otri1.Org();
while (vertex.type == VertexType.FreeVertex && (vertex1.x - vertex.x) * (vertex2.x - vertex.x) + (vertex1.y - vertex.y) * (vertex2.y - vertex.y) < 0)
{
this.mesh.DeleteVertex(ref otri1);
otri.Sym(ref otri1);
vertex = otri1.Apex();
otri1.LprevSelf();
}
}
}
if (!(flag | flag1))
{
num = 0.5;
}
else
{
double num1 = Math.Sqrt((vertex2.x - vertex1.x) * (vertex2.x - vertex1.x) + (vertex2.y - vertex1.y) * (vertex2.y - vertex1.y));
double num2 = 1;
while (num1 > 3 * num2)
{
num2 = num2 * 2;
}
while (num1 < 1.5 * num2)
{
num2 = num2 * 0.5;
}
num = num2 / num1;
if (flag1)
{
num = 1 - num;
}
}
Vertex vertex3 = new Vertex(vertex1.x + num * (vertex2.x - vertex1.x), vertex1.y + num * (vertex2.y - vertex1.y), osub1.Mark(), this.mesh.nextras)
{
type = VertexType.SegmentVertex
};
Mesh mesh = this.mesh;
int hashVtx = mesh.hash_vtx;
mesh.hash_vtx = hashVtx + 1;
vertex3.hash = hashVtx;
vertex3.id = vertex3.hash;
this.mesh.vertices.Add(vertex3.hash, vertex3);
for (int i = 0; i < this.mesh.nextras; i++)
{
vertex3.attributes[i] = vertex1.attributes[i] + num * (vertex2.attributes[i] - vertex1.attributes[i]);
}
if (!Behavior.NoExact)
{
double num3 = Primitives.CounterClockwise(vertex1, vertex2, vertex3);
double num4 = (vertex1.x - vertex2.x) * (vertex1.x - vertex2.x) + (vertex1.y - vertex2.y) * (vertex1.y - vertex2.y);
if (num3 != 0 && num4 != 0)
{
num3 = num3 / num4;
if (!double.IsNaN(num3))
{
Vertex vertex4 = vertex3;
vertex4.x = vertex4.x + num3 * (vertex2.y - vertex1.y);
Vertex vertex5 = vertex3;
vertex5.y = vertex5.y + num3 * (vertex1.x - vertex2.x);
}
}
}
if (vertex3.x == vertex1.x && vertex3.y == vertex1.y || vertex3.x == vertex2.x && vertex3.y == vertex2.y)
{
this.logger.Error("Ran out of precision: I attempted to split a segment to a smaller size than can be accommodated by the finite precision of floating point arithmetic.", "Quality.SplitEncSegs()");
throw new Exception("Ran out of precision");
}
InsertVertexResult insertVertexResult = this.mesh.InsertVertex(vertex3, ref otri, ref osub1, true, triflaws);
if (insertVertexResult != InsertVertexResult.Successful && insertVertexResult != InsertVertexResult.Encroaching)
{
this.logger.Error("Failure to split a segment.", "Quality.SplitEncSegs()");
throw new Exception("Failure to split a segment.");
}
if (this.mesh.steinerleft > 0)
{
Mesh mesh1 = this.mesh;
mesh1.steinerleft = mesh1.steinerleft - 1;
}
this.CheckSeg4Encroach(ref osub1);
osub1.NextSelf();
this.CheckSeg4Encroach(ref osub1);
}
badSubseg.subsegorg = null;
}
}
/// <summary>
/// Finds the adjacencies between triangles by forming a stack of triangles for
/// each vertex. Each triangle is on three different stacks simultaneously.
/// </summary>
private static List <Otri>[] SetNeighbors(Mesh mesh, ITriangle[] triangles)
{
Otri tri = default(Otri);
Otri triangleleft = default(Otri);
Otri checktri = default(Otri);
Otri checkleft = default(Otri);
Otri nexttri;
TVertex tdest, tapex;
TVertex checkdest, checkapex;
int[] corner = new int[3];
int aroundvertex;
int i;
// Allocate a temporary array that maps each vertex to some adjacent triangle.
var vertexarray = new List <Otri> [mesh.vertices.Count];
// Each vertex is initially unrepresented.
for (i = 0; i < mesh.vertices.Count; i++)
{
Otri tmp = default(Otri);
tmp.tri = mesh.dummytri;
vertexarray[i] = new List <Otri>(3);
vertexarray[i].Add(tmp);
}
i = 0;
// Read the triangles from the .ele file, and link
// together those that share an edge.
foreach (var item in mesh.triangles)
{
tri.tri = item;
// Copy the triangle's three corners.
for (int j = 0; j < 3; j++)
{
corner[j] = triangles[i].GetVertexID(j);
if ((corner[j] < 0) || (corner[j] >= mesh.invertices))
{
Log.Instance.Error("Triangle has an invalid vertex index.", "MeshReader.Reconstruct()");
throw new Exception("Triangle has an invalid vertex index.");
}
}
// Read the triangle's attributes.
tri.tri.label = triangles[i].Label;
// TODO: VarArea
if (mesh.behavior.VarArea)
{
tri.tri.area = triangles[i].Area;
}
// Set the triangle's vertices.
tri.orient = 0;
tri.SetOrg(mesh.vertices[corner[0]]);
tri.SetDest(mesh.vertices[corner[1]]);
tri.SetApex(mesh.vertices[corner[2]]);
// Try linking the triangle to others that share these vertices.
for (tri.orient = 0; tri.orient < 3; tri.orient++)
{
// Take the number for the origin of triangleloop.
aroundvertex = corner[tri.orient];
int index = vertexarray[aroundvertex].Count - 1;
// Look for other triangles having this vertex.
nexttri = vertexarray[aroundvertex][index];
// Push the current triangle onto the stack.
vertexarray[aroundvertex].Add(tri);
checktri = nexttri;
if (checktri.tri.id != Mesh.DUMMY)
{
tdest = tri.Dest();
tapex = tri.Apex();
// Look for other triangles that share an edge.
do
{
checkdest = checktri.Dest();
checkapex = checktri.Apex();
if (tapex == checkdest)
{
// The two triangles share an edge; bond them together.
tri.Lprev(ref triangleleft);
triangleleft.Bond(ref checktri);
}
if (tdest == checkapex)
{
// The two triangles share an edge; bond them together.
checktri.Lprev(ref checkleft);
tri.Bond(ref checkleft);
}
// Find the next triangle in the stack.
index--;
nexttri = vertexarray[aroundvertex][index];
checktri = nexttri;
}while (checktri.tri.id != Mesh.DUMMY);
}
}
i++;
}
return(vertexarray);
}
/// <summary>
/// Inserts a vertex at the circumcenter of a triangle. Deletes
/// the newly inserted vertex if it encroaches upon a segment.
/// </summary>
/// <param name="badtri"></param>
private void SplitTriangle(BadTriangle badtri)
{
Otri badotri = default(Otri);
Vertex borg, bdest, bapex;
Point newloc; // Location of the new vertex
double xi = 0, eta = 0;
InsertVertexResult success;
bool errorflag;
badotri = badtri.poortri;
borg = badotri.Org();
bdest = badotri.Dest();
bapex = badotri.Apex();
// Make sure that this triangle is still the same triangle it was
// when it was tested and determined to be of bad quality.
// Subsequent transformations may have made it a different triangle.
if (!Otri.IsDead(badotri.tri) && (borg == badtri.org) &&
(bdest == badtri.dest) && (bapex == badtri.apex))
{
errorflag = false;
// Create a new vertex at the triangle's circumcenter.
// Using the original (simpler) Steiner point location method
// for mesh refinement.
// TODO: NewLocation doesn't work for refinement. Why? Maybe
// reset VertexType?
newloc = RobustPredicates.FindCircumcenter(borg, bdest, bapex, ref xi, ref eta, behavior.offconstant);
// Check whether the new vertex lies on a triangle vertex.
if (((newloc.X == borg.X) && (newloc.Y == borg.Y)) ||
((newloc.X == bdest.X) && (newloc.Y == bdest.Y)) ||
((newloc.X == bapex.X) && (newloc.Y == bapex.Y)))
{
//errorflag = true;
}
else
{
// The new vertex must be in the interior, and therefore is a
// free vertex with a marker of zero.
Vertex newvertex = new Vertex(newloc.X, newloc.Y, 0);
newvertex.type = VertexType.FreeVertex;
// Ensure that the handle 'badotri' does not represent the longest
// edge of the triangle. This ensures that the circumcenter must
// fall to the left of this edge, so point location will work.
// (If the angle org-apex-dest exceeds 90 degrees, then the
// circumcenter lies outside the org-dest edge, and eta is
// negative. Roundoff error might prevent eta from being
// negative when it should be, so I test eta against xi.)
if (eta < xi)
{
badotri.Lprev();
}
// Insert the circumcenter, searching from the edge of the triangle,
// and maintain the Delaunay property of the triangulation.
Osub tmp = default(Osub);
success = mesh.InsertVertex(newvertex, ref badotri, ref tmp, true, true);
if (success == InsertVertexResult.Successful)
{
newvertex.Id = mesh.hash_vtx++;
mesh.vertices.Add(newvertex.Id, newvertex);
if (mesh.steinerleft > 0)
{
mesh.steinerleft--;
}
}
else if (success == InsertVertexResult.Encroaching)
{
// If the newly inserted vertex encroaches upon a subsegment,
// delete the new vertex.
mesh.UndoVertex();
}
else if (success == InsertVertexResult.Violating)
{
// Failed to insert the new vertex, but some subsegment was
// marked as being encroached.
}
else
{
//errorflag = true;
}
}
if (errorflag)
{
throw new Exception("The new vertex is at the circumcenter of triangle.");
}
}
}
public IMesh Triangulate(IList <Vertex> points, Configuration config)
{
this.predicates = config.Predicates();
this.mesh = new Mesh(config);
this.mesh.TransferNodes(points);
// Nonexistent x value used as a flag to mark circle events in sweepline
// Delaunay algorithm.
xminextreme = 10 * mesh.bounds.Left - 9 * mesh.bounds.Right;
SweepEvent[] eventheap;
SweepEvent nextevent;
SweepEvent newevent;
SplayNode splayroot;
Otri bottommost = default(Otri);
Otri searchtri = default(Otri);
Otri fliptri;
Otri lefttri = default(Otri);
Otri righttri = default(Otri);
Otri farlefttri = default(Otri);
Otri farrighttri = default(Otri);
Otri inserttri = default(Otri);
Vertex firstvertex, secondvertex;
Vertex nextvertex, lastvertex;
Vertex connectvertex;
Vertex leftvertex, midvertex, rightvertex;
double lefttest, righttest;
int heapsize;
bool check4events, farrightflag = false;
splaynodes = new List <SplayNode>();
splayroot = null;
heapsize = points.Count;
CreateHeap(out eventheap, heapsize);//, out events, out freeevents);
mesh.MakeTriangle(ref lefttri);
mesh.MakeTriangle(ref righttri);
lefttri.Bond(ref righttri);
lefttri.Lnext();
righttri.Lprev();
lefttri.Bond(ref righttri);
lefttri.Lnext();
righttri.Lprev();
lefttri.Bond(ref righttri);
firstvertex = eventheap[0].vertexEvent;
HeapDelete(eventheap, heapsize, 0);
heapsize--;
do
{
if (heapsize == 0)
{
Log.Instance.Error("Input vertices are all identical.", "SweepLine.Triangulate()");
throw new Exception("Input vertices are all identical.");
}
secondvertex = eventheap[0].vertexEvent;
HeapDelete(eventheap, heapsize, 0);
heapsize--;
if ((firstvertex.x == secondvertex.x) &&
(firstvertex.y == secondvertex.y))
{
if (Log.Verbose)
{
Log.Instance.Warning("A duplicate vertex appeared and was ignored (ID " + secondvertex.id + ").",
"SweepLine.Triangulate().1");
}
secondvertex.type = VertexType.UndeadVertex;
mesh.undeads++;
}
} while ((firstvertex.x == secondvertex.x) &&
(firstvertex.y == secondvertex.y));
lefttri.SetOrg(firstvertex);
lefttri.SetDest(secondvertex);
righttri.SetOrg(secondvertex);
righttri.SetDest(firstvertex);
lefttri.Lprev(ref bottommost);
lastvertex = secondvertex;
while (heapsize > 0)
{
nextevent = eventheap[0];
HeapDelete(eventheap, heapsize, 0);
heapsize--;
check4events = true;
if (nextevent.xkey < mesh.bounds.Left)
{
fliptri = nextevent.otriEvent;
fliptri.Oprev(ref farlefttri);
Check4DeadEvent(ref farlefttri, eventheap, ref heapsize);
fliptri.Onext(ref farrighttri);
Check4DeadEvent(ref farrighttri, eventheap, ref heapsize);
if (farlefttri.Equals(bottommost))
{
fliptri.Lprev(ref bottommost);
}
mesh.Flip(ref fliptri);
fliptri.SetApex(null);
fliptri.Lprev(ref lefttri);
fliptri.Lnext(ref righttri);
lefttri.Sym(ref farlefttri);
if (randomnation(SAMPLERATE) == 0)
{
fliptri.Sym();
leftvertex = fliptri.Dest();
midvertex = fliptri.Apex();
rightvertex = fliptri.Org();
splayroot = CircleTopInsert(splayroot, lefttri, leftvertex, midvertex, rightvertex, nextevent.ykey);
}
}
else
{
nextvertex = nextevent.vertexEvent;
if ((nextvertex.x == lastvertex.x) &&
(nextvertex.y == lastvertex.y))
{
if (Log.Verbose)
{
Log.Instance.Warning("A duplicate vertex appeared and was ignored (ID " + nextvertex.id + ").",
"SweepLine.Triangulate().2");
}
nextvertex.type = VertexType.UndeadVertex;
mesh.undeads++;
check4events = false;
}
else
{
lastvertex = nextvertex;
splayroot = FrontLocate(splayroot, bottommost, nextvertex, ref searchtri, ref farrightflag);
//bottommost.Copy(ref searchtri);
//farrightflag = false;
//while (!farrightflag && RightOfHyperbola(ref searchtri, nextvertex))
//{
// searchtri.OnextSelf();
// farrightflag = searchtri.Equal(bottommost);
//}
Check4DeadEvent(ref searchtri, eventheap, ref heapsize);
searchtri.Copy(ref farrighttri);
searchtri.Sym(ref farlefttri);
mesh.MakeTriangle(ref lefttri);
mesh.MakeTriangle(ref righttri);
connectvertex = farrighttri.Dest();
lefttri.SetOrg(connectvertex);
lefttri.SetDest(nextvertex);
righttri.SetOrg(nextvertex);
righttri.SetDest(connectvertex);
lefttri.Bond(ref righttri);
lefttri.Lnext();
righttri.Lprev();
lefttri.Bond(ref righttri);
lefttri.Lnext();
righttri.Lprev();
lefttri.Bond(ref farlefttri);
righttri.Bond(ref farrighttri);
if (!farrightflag && farrighttri.Equals(bottommost))
{
lefttri.Copy(ref bottommost);
}
if (randomnation(SAMPLERATE) == 0)
{
splayroot = SplayInsert(splayroot, lefttri, nextvertex);
}
else if (randomnation(SAMPLERATE) == 0)
{
righttri.Lnext(ref inserttri);
splayroot = SplayInsert(splayroot, inserttri, nextvertex);
}
}
}
if (check4events)
{
leftvertex = farlefttri.Apex();
midvertex = lefttri.Dest();
rightvertex = lefttri.Apex();
lefttest = predicates.CounterClockwise(leftvertex, midvertex, rightvertex);
if (lefttest > 0.0)
{
newevent = new SweepEvent();
newevent.xkey = xminextreme;
newevent.ykey = CircleTop(leftvertex, midvertex, rightvertex, lefttest);
newevent.otriEvent = lefttri;
HeapInsert(eventheap, heapsize, newevent);
heapsize++;
lefttri.SetOrg(new SweepEventVertex(newevent));
}
leftvertex = righttri.Apex();
midvertex = righttri.Org();
rightvertex = farrighttri.Apex();
righttest = predicates.CounterClockwise(leftvertex, midvertex, rightvertex);
if (righttest > 0.0)
{
newevent = new SweepEvent();
newevent.xkey = xminextreme;
newevent.ykey = CircleTop(leftvertex, midvertex, rightvertex, righttest);
newevent.otriEvent = farrighttri;
HeapInsert(eventheap, heapsize, newevent);
heapsize++;
farrighttri.SetOrg(new SweepEventVertex(newevent));
}
}
}
splaynodes.Clear();
bottommost.Lprev();
this.mesh.hullsize = RemoveGhosts(ref bottommost);
return(this.mesh);
}
public static int Reconstruct(Mesh mesh, InputGeometry input, ITriangle[] triangles)
{
Otri item;
int num;
int num1 = 0;
Otri region = new Otri();
Otri otri = new Otri();
Otri l = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Osub osub = new Osub();
int[] p0 = new int[3];
int[] p1 = new int[2];
int i = 0;
int num2 = (triangles == null ? 0 : (int)triangles.Length);
int count = input.segments.Count;
mesh.inelements = num2;
mesh.regions.AddRange(input.regions);
for (i = 0; i < mesh.inelements; i++)
{
mesh.MakeTriangle(ref region);
}
if (mesh.behavior.Poly)
{
mesh.insegments = count;
for (i = 0; i < mesh.insegments; i++)
{
mesh.MakeSegment(ref osub);
}
}
List <Otri>[] otris = new List <Otri> [mesh.vertices.Count];
for (i = 0; i < mesh.vertices.Count; i++)
{
Otri otri3 = new Otri()
{
triangle = Mesh.dummytri
};
otris[i] = new List <Otri>(3);
otris[i].Add(otri3);
}
i = 0;
foreach (Triangle value in mesh.triangles.Values)
{
region.triangle = value;
p0[0] = triangles[i].P0;
p0[1] = triangles[i].P1;
p0[2] = triangles[i].P2;
for (int j = 0; j < 3; j++)
{
if (p0[j] < 0 || p0[j] >= mesh.invertices)
{
SimpleLog.Instance.Error("Triangle has an invalid vertex index.", "MeshReader.Reconstruct()");
throw new Exception("Triangle has an invalid vertex index.");
}
}
region.triangle.region = triangles[i].Region;
if (mesh.behavior.VarArea)
{
region.triangle.area = triangles[i].Area;
}
region.orient = 0;
region.SetOrg(mesh.vertices[p0[0]]);
region.SetDest(mesh.vertices[p0[1]]);
region.SetApex(mesh.vertices[p0[2]]);
region.orient = 0;
while (region.orient < 3)
{
num = p0[region.orient];
int count1 = otris[num].Count - 1;
item = otris[num][count1];
otris[num].Add(region);
l = item;
if (l.triangle != Mesh.dummytri)
{
Vertex vertex = region.Dest();
Vertex vertex1 = region.Apex();
do
{
Vertex vertex2 = l.Dest();
Vertex vertex3 = l.Apex();
if (vertex1 == vertex2)
{
region.Lprev(ref otri);
otri.Bond(ref l);
}
if (vertex == vertex3)
{
l.Lprev(ref otri1);
region.Bond(ref otri1);
}
count1--;
item = otris[num][count1];
l = item;
}while (l.triangle != Mesh.dummytri);
}
region.orient = region.orient + 1;
}
i++;
}
num1 = 0;
if (mesh.behavior.Poly)
{
int boundary = 0;
i = 0;
foreach (Segment segment in mesh.subsegs.Values)
{
osub.seg = segment;
p1[0] = input.segments[i].P0;
p1[1] = input.segments[i].P1;
boundary = input.segments[i].Boundary;
for (int k = 0; k < 2; k++)
{
if (p1[k] < 0 || p1[k] >= mesh.invertices)
{
SimpleLog.Instance.Error("Segment has an invalid vertex index.", "MeshReader.Reconstruct()");
throw new Exception("Segment has an invalid vertex index.");
}
}
osub.orient = 0;
Vertex item1 = mesh.vertices[p1[0]];
Vertex item2 = mesh.vertices[p1[1]];
osub.SetOrg(item1);
osub.SetDest(item2);
osub.SetSegOrg(item1);
osub.SetSegDest(item2);
osub.seg.boundary = boundary;
osub.orient = 0;
while (osub.orient < 2)
{
num = p1[1 - osub.orient];
int count2 = otris[num].Count - 1;
Otri item3 = otris[num][count2];
item = otris[num][count2];
l = item;
Vertex vertex4 = osub.Org();
bool flag = true;
while (flag && l.triangle != Mesh.dummytri)
{
if (vertex4 == l.Dest())
{
otris[num].Remove(item3);
l.SegBond(ref osub);
l.Sym(ref otri2);
if (otri2.triangle == Mesh.dummytri)
{
mesh.InsertSubseg(ref l, 1);
num1++;
}
flag = false;
}
count2--;
item3 = otris[num][count2];
item = otris[num][count2];
l = item;
}
osub.orient = osub.orient + 1;
}
i++;
}
}
for (i = 0; i < mesh.vertices.Count; i++)
{
int count3 = otris[i].Count - 1;
item = otris[i][count3];
for (l = item; l.triangle != Mesh.dummytri; l = item)
{
count3--;
item = otris[i][count3];
l.SegDissolve();
l.Sym(ref otri2);
if (otri2.triangle == Mesh.dummytri)
{
mesh.InsertSubseg(ref l, 1);
num1++;
}
}
}
return(num1);
}
/// <summary>
/// Test a triangle for quality and size.
/// </summary>
/// <param name="testtri">Triangle to check.</param>
/// <remarks>
/// Tests a triangle to see if it satisfies the minimum angle condition and
/// the maximum area condition. Triangles that aren't up to spec are added
/// to the bad triangle queue.
/// </remarks>
public void TestTriangle(ref Otri testtri)
{
Otri tri1 = default(Otri), tri2 = default(Otri);
Osub testsub = default(Osub);
Vertex torg, tdest, tapex;
Vertex base1, base2;
Vertex org1, dest1, org2, dest2;
Vertex joinvertex;
float dxod, dyod, dxda, dyda, dxao, dyao;
float dxod2, dyod2, dxda2, dyda2, dxao2, dyao2;
float apexlen, orglen, destlen, minedge;
float angle;
float area;
float dist1, dist2;
float maxangle;
torg = testtri.Org();
tdest = testtri.Dest();
tapex = testtri.Apex();
dxod = torg.x - tdest.x;
dyod = torg.y - tdest.y;
dxda = tdest.x - tapex.x;
dyda = tdest.y - tapex.y;
dxao = tapex.x - torg.x;
dyao = tapex.y - torg.y;
dxod2 = dxod * dxod;
dyod2 = dyod * dyod;
dxda2 = dxda * dxda;
dyda2 = dyda * dyda;
dxao2 = dxao * dxao;
dyao2 = dyao * dyao;
// Find the lengths of the triangle's three edges.
apexlen = dxod2 + dyod2;
orglen = dxda2 + dyda2;
destlen = dxao2 + dyao2;
if ((apexlen < orglen) && (apexlen < destlen))
{
// The edge opposite the apex is shortest.
minedge = apexlen;
// Find the square of the cosine of the angle at the apex.
angle = dxda * dxao + dyda * dyao;
angle = angle * angle / (orglen * destlen);
base1 = torg;
base2 = tdest;
testtri.Copy(ref tri1);
}
else if (orglen < destlen)
{
// The edge opposite the origin is shortest.
minedge = orglen;
// Find the square of the cosine of the angle at the origin.
angle = dxod * dxao + dyod * dyao;
angle = angle * angle / (apexlen * destlen);
base1 = tdest;
base2 = tapex;
testtri.Lnext(ref tri1);
}
else
{
// The edge opposite the destination is shortest.
minedge = destlen;
// Find the square of the cosine of the angle at the destination.
angle = dxod * dxda + dyod * dyda;
angle = angle * angle / (apexlen * orglen);
base1 = tapex;
base2 = torg;
testtri.Lprev(ref tri1);
}
if (behavior.VarArea || behavior.fixedArea || behavior.Usertest)
{
// Check whether the area is larger than permitted.
area = 0.5f * (dxod * dyda - dyod * dxda);
if (behavior.fixedArea && (area > behavior.MaxArea))
{
// Add this triangle to the list of bad triangles.
queue.Enqueue(ref testtri, minedge, tapex, torg, tdest);
return;
}
// Nonpositive area constraints are treated as unconstrained.
if ((behavior.VarArea) && (area > testtri.triangle.area) && (testtri.triangle.area > 0.0))
{
// Add this triangle to the list of bad triangles.
queue.Enqueue(ref testtri, minedge, tapex, torg, tdest);
return;
}
}
// find the maximum edge and accordingly the pqr orientation
if ((apexlen > orglen) && (apexlen > destlen))
{
// The edge opposite the apex is longest.
// maxedge = apexlen;
// Find the cosine of the angle at the apex.
maxangle = (orglen + destlen - apexlen) / (2 * UnityEngine.Mathf.Sqrt(orglen * destlen));
}
else if (orglen > destlen)
{
// The edge opposite the origin is longest.
// maxedge = orglen;
// Find the cosine of the angle at the origin.
maxangle = (apexlen + destlen - orglen) / (2 * UnityEngine.Mathf.Sqrt(apexlen * destlen));
}
else
{
// The edge opposite the destination is longest.
// maxedge = destlen;
// Find the cosine of the angle at the destination.
maxangle = (apexlen + orglen - destlen) / (2 * UnityEngine.Mathf.Sqrt(apexlen * orglen));
}
// Check whether the angle is smaller than permitted.
if ((angle > behavior.goodAngle) || (maxangle < behavior.maxGoodAngle && behavior.MaxAngle != 0.0))
{
// Use the rules of Miller, Pav, and Walkington to decide that certain
// triangles should not be split, even if they have bad angles.
// A skinny triangle is not split if its shortest edge subtends a
// small input angle, and both endpoints of the edge lie on a
// concentric circular shell. For convenience, I make a small
// adjustment to that rule: I check if the endpoints of the edge
// both lie in segment interiors, equidistant from the apex where
// the two segments meet.
// First, check if both points lie in segment interiors.
if ((base1.type == VertexType.SegmentVertex) &&
(base2.type == VertexType.SegmentVertex))
{
// Check if both points lie in a common segment. If they do, the
// skinny triangle is enqueued to be split as usual.
tri1.SegPivot(ref testsub);
if (testsub.seg == Mesh.dummysub)
{
// No common segment. Find a subsegment that contains 'torg'.
tri1.Copy(ref tri2);
do
{
tri1.OprevSelf();
tri1.SegPivot(ref testsub);
} while (testsub.seg == Mesh.dummysub);
// Find the endpoints of the containing segment.
org1 = testsub.SegOrg();
dest1 = testsub.SegDest();
// Find a subsegment that contains 'tdest'.
do
{
tri2.DnextSelf();
tri2.SegPivot(ref testsub);
} while (testsub.seg == Mesh.dummysub);
// Find the endpoints of the containing segment.
org2 = testsub.SegOrg();
dest2 = testsub.SegDest();
// Check if the two containing segments have an endpoint in common.
joinvertex = null;
if ((dest1.x == org2.x) && (dest1.y == org2.y))
{
joinvertex = dest1;
}
else if ((org1.x == dest2.x) && (org1.y == dest2.y))
{
joinvertex = org1;
}
if (joinvertex != null)
{
// Compute the distance from the common endpoint (of the two
// segments) to each of the endpoints of the shortest edge.
dist1 = ((base1.x - joinvertex.x) * (base1.x - joinvertex.x) +
(base1.y - joinvertex.y) * (base1.y - joinvertex.y));
dist2 = ((base2.x - joinvertex.x) * (base2.x - joinvertex.x) +
(base2.y - joinvertex.y) * (base2.y - joinvertex.y));
// If the two distances are equal, don't split the triangle.
if ((dist1 < 1.001 * dist2) && (dist1 > 0.999 * dist2))
{
// Return now to avoid enqueueing the bad triangle.
return;
}
}
}
}
// Add this triangle to the list of bad triangles.
queue.Enqueue(ref testtri, minedge, tapex, torg, tdest);
}
}
private void DivconqRecurse(int left, int right, int axis, ref Otri farleft, ref Otri farright)
{
Otri otri = new Otri();
Otri otri1 = new Otri();
Otri otri2 = new Otri();
Otri otri3 = new Otri();
Otri otri4 = new Otri();
Otri otri5 = new Otri();
int num = right - left + 1;
if (num == 2)
{
this.mesh.MakeTriangle(ref farleft);
farleft.SetOrg(this.sortarray[left]);
farleft.SetDest(this.sortarray[left + 1]);
this.mesh.MakeTriangle(ref farright);
farright.SetOrg(this.sortarray[left + 1]);
farright.SetDest(this.sortarray[left]);
farleft.Bond(ref farright);
farleft.LprevSelf();
farright.LnextSelf();
farleft.Bond(ref farright);
farleft.LprevSelf();
farright.LnextSelf();
farleft.Bond(ref farright);
farright.Lprev(ref farleft);
return;
}
if (num != 3)
{
int num1 = num >> 1;
this.DivconqRecurse(left, left + num1 - 1, 1 - axis, ref farleft, ref otri4);
this.DivconqRecurse(left + num1, right, 1 - axis, ref otri5, ref farright);
this.MergeHulls(ref farleft, ref otri4, ref otri5, ref farright, axis);
return;
}
this.mesh.MakeTriangle(ref otri);
this.mesh.MakeTriangle(ref otri1);
this.mesh.MakeTriangle(ref otri2);
this.mesh.MakeTriangle(ref otri3);
double num2 = Primitives.CounterClockwise(this.sortarray[left], this.sortarray[left + 1], this.sortarray[left + 2]);
if (num2 == 0)
{
otri.SetOrg(this.sortarray[left]);
otri.SetDest(this.sortarray[left + 1]);
otri1.SetOrg(this.sortarray[left + 1]);
otri1.SetDest(this.sortarray[left]);
otri2.SetOrg(this.sortarray[left + 2]);
otri2.SetDest(this.sortarray[left + 1]);
otri3.SetOrg(this.sortarray[left + 1]);
otri3.SetDest(this.sortarray[left + 2]);
otri.Bond(ref otri1);
otri2.Bond(ref otri3);
otri.LnextSelf();
otri1.LprevSelf();
otri2.LnextSelf();
otri3.LprevSelf();
otri.Bond(ref otri3);
otri1.Bond(ref otri2);
otri.LnextSelf();
otri1.LprevSelf();
otri2.LnextSelf();
otri3.LprevSelf();
otri.Bond(ref otri1);
otri2.Bond(ref otri3);
otri1.Copy(ref farleft);
otri2.Copy(ref farright);
return;
}
otri.SetOrg(this.sortarray[left]);
otri1.SetDest(this.sortarray[left]);
otri3.SetOrg(this.sortarray[left]);
if (num2 <= 0)
{
otri.SetDest(this.sortarray[left + 2]);
otri1.SetOrg(this.sortarray[left + 2]);
otri2.SetDest(this.sortarray[left + 2]);
otri.SetApex(this.sortarray[left + 1]);
otri2.SetOrg(this.sortarray[left + 1]);
otri3.SetDest(this.sortarray[left + 1]);
}
else
{
otri.SetDest(this.sortarray[left + 1]);
otri1.SetOrg(this.sortarray[left + 1]);
otri2.SetDest(this.sortarray[left + 1]);
otri.SetApex(this.sortarray[left + 2]);
otri2.SetOrg(this.sortarray[left + 2]);
otri3.SetDest(this.sortarray[left + 2]);
}
otri.Bond(ref otri1);
otri.LnextSelf();
otri.Bond(ref otri2);
otri.LnextSelf();
otri.Bond(ref otri3);
otri1.LprevSelf();
otri2.LnextSelf();
otri1.Bond(ref otri2);
otri1.LprevSelf();
otri3.LprevSelf();
otri1.Bond(ref otri3);
otri2.LnextSelf();
otri3.LprevSelf();
otri2.Bond(ref otri3);
otri1.Copy(ref farleft);
if (num2 > 0)
{
otri2.Copy(ref farright);
return;
}
farleft.Lnext(ref farright);
}
/// <summary>
/// Reconstruct a triangulation from its raw data representation.
/// </summary>
/// <param name="mesh"></param>
/// <param name="input"></param>
/// <returns></returns>
/// <remarks>
/// Reads an .ele file and reconstructs the original mesh. If the -p switch
/// is used, this procedure will also read a .poly file and reconstruct the
/// subsegments of the original mesh. If the -a switch is used, this
/// procedure will also read an .area file and set a maximum area constraint
/// on each triangle.
///
/// Vertices that are not corners of triangles, such as nodes on edges of
/// subparametric elements, are discarded.
///
/// This routine finds the adjacencies between triangles (and subsegments)
/// by forming one stack of triangles for each vertex. Each triangle is on
/// three different stacks simultaneously. Each triangle's subsegment
/// pointers are used to link the items in each stack. This memory-saving
/// feature makes the code harder to read. The most important thing to keep
/// in mind is that each triangle is removed from a stack precisely when
/// the corresponding pointer is adjusted to refer to a subsegment rather
/// than the next triangle of the stack.
/// </remarks>
public static int Reconstruct(Mesh mesh, InputGeometry input, ITriangle[] triangles)
{
int hullsize = 0;
Otri tri = default(Otri);
Otri triangleleft = default(Otri);
Otri checktri = default(Otri);
Otri checkleft = default(Otri);
Otri checkneighbor = default(Otri);
Osub subseg = default(Osub);
List <Otri>[] vertexarray; // Triangle
Otri prevlink; // Triangle
Otri nexttri; // Triangle
Vertex tdest, tapex;
Vertex checkdest, checkapex;
Vertex shorg;
Vertex segmentorg, segmentdest;
int[] corner = new int[3];
int[] end = new int[2];
//bool segmentmarkers = false;
int boundmarker;
int aroundvertex;
bool notfound;
int i = 0;
int elements = triangles == null ? 0 : triangles.Length;
int numberofsegments = input.segments.Count;
mesh.inelements = elements;
mesh.regions.AddRange(input.regions);
// Create the triangles.
for (i = 0; i < mesh.inelements; i++)
{
mesh.MakeTriangle(ref tri);
// Mark the triangle as living.
//tri.triangle.neighbors[0].triangle = tri.triangle;
}
if (mesh.behavior.Poly)
{
mesh.insegments = numberofsegments;
// Create the subsegments.
for (i = 0; i < mesh.insegments; i++)
{
mesh.MakeSegment(ref subseg);
// Mark the subsegment as living.
//subseg.ss.subsegs[0].ss = subseg.ss;
}
}
// Allocate a temporary array that maps each vertex to some adjacent
// triangle. I took care to allocate all the permanent memory for
// triangles and subsegments first.
vertexarray = new List <Otri> [mesh.vertices.Count];
// Each vertex is initially unrepresented.
for (i = 0; i < mesh.vertices.Count; i++)
{
Otri tmp = default(Otri);
tmp.triangle = Mesh.dummytri;
vertexarray[i] = new List <Otri>(3);
vertexarray[i].Add(tmp);
}
i = 0;
// Read the triangles from the .ele file, and link
// together those that share an edge.
foreach (var item in mesh.triangles.Values)
{
tri.triangle = item;
corner[0] = triangles[i].P0;
corner[1] = triangles[i].P1;
corner[2] = triangles[i].P2;
// Copy the triangle's three corners.
for (int j = 0; j < 3; j++)
{
if ((corner[j] < 0) || (corner[j] >= mesh.invertices))
{
SimpleLog.Instance.Error("Triangle has an invalid vertex index.", "MeshReader.Reconstruct()");
throw new Exception("Triangle has an invalid vertex index.");
}
}
// Read the triangle's attributes.
tri.triangle.region = triangles[i].Region;
// TODO: VarArea
if (mesh.behavior.VarArea)
{
tri.triangle.area = triangles[i].Area;
}
// Set the triangle's vertices.
tri.orient = 0;
tri.SetOrg(mesh.vertices[corner[0]]);
tri.SetDest(mesh.vertices[corner[1]]);
tri.SetApex(mesh.vertices[corner[2]]);
// Try linking the triangle to others that share these vertices.
for (tri.orient = 0; tri.orient < 3; tri.orient++)
{
// Take the number for the origin of triangleloop.
aroundvertex = corner[tri.orient];
int index = vertexarray[aroundvertex].Count - 1;
// Look for other triangles having this vertex.
nexttri = vertexarray[aroundvertex][index];
// Link the current triangle to the next one in the stack.
//tri.triangle.neighbors[tri.orient] = nexttri;
// Push the current triangle onto the stack.
vertexarray[aroundvertex].Add(tri);
checktri = nexttri;
if (checktri.triangle != Mesh.dummytri)
{
tdest = tri.Dest();
tapex = tri.Apex();
// Look for other triangles that share an edge.
do
{
checkdest = checktri.Dest();
checkapex = checktri.Apex();
if (tapex == checkdest)
{
// The two triangles share an edge; bond them together.
tri.Lprev(ref triangleleft);
triangleleft.Bond(ref checktri);
}
if (tdest == checkapex)
{
// The two triangles share an edge; bond them together.
checktri.Lprev(ref checkleft);
tri.Bond(ref checkleft);
}
// Find the next triangle in the stack.
index--;
nexttri = vertexarray[aroundvertex][index];
checktri = nexttri;
} while (checktri.triangle != Mesh.dummytri);
}
}
i++;
}
// Prepare to count the boundary edges.
hullsize = 0;
if (mesh.behavior.Poly)
{
// Read the segments from the .poly file, and link them
// to their neighboring triangles.
boundmarker = 0;
i = 0;
foreach (var item in mesh.subsegs.Values)
{
subseg.seg = item;
end[0] = input.segments[i].P0;
end[1] = input.segments[i].P1;
boundmarker = input.segments[i].Boundary;
for (int j = 0; j < 2; j++)
{
if ((end[j] < 0) || (end[j] >= mesh.invertices))
{
SimpleLog.Instance.Error("Segment has an invalid vertex index.", "MeshReader.Reconstruct()");
throw new Exception("Segment has an invalid vertex index.");
}
}
// set the subsegment's vertices.
subseg.orient = 0;
segmentorg = mesh.vertices[end[0]];
segmentdest = mesh.vertices[end[1]];
subseg.SetOrg(segmentorg);
subseg.SetDest(segmentdest);
subseg.SetSegOrg(segmentorg);
subseg.SetSegDest(segmentdest);
subseg.seg.boundary = boundmarker;
// Try linking the subsegment to triangles that share these vertices.
for (subseg.orient = 0; subseg.orient < 2; subseg.orient++)
{
// Take the number for the destination of subsegloop.
aroundvertex = end[1 - subseg.orient];
int index = vertexarray[aroundvertex].Count - 1;
// Look for triangles having this vertex.
prevlink = vertexarray[aroundvertex][index];
nexttri = vertexarray[aroundvertex][index];
checktri = nexttri;
shorg = subseg.Org();
notfound = true;
// Look for triangles having this edge. Note that I'm only
// comparing each triangle's destination with the subsegment;
// each triangle's apex is handled through a different vertex.
// Because each triangle appears on three vertices' lists, each
// occurrence of a triangle on a list can (and does) represent
// an edge. In this way, most edges are represented twice, and
// every triangle-subsegment bond is represented once.
while (notfound && (checktri.triangle != Mesh.dummytri))
{
checkdest = checktri.Dest();
if (shorg == checkdest)
{
// We have a match. Remove this triangle from the list.
//prevlink = vertexarray[aroundvertex][index];
vertexarray[aroundvertex].Remove(prevlink);
// Bond the subsegment to the triangle.
checktri.SegBond(ref subseg);
// Check if this is a boundary edge.
checktri.Sym(ref checkneighbor);
if (checkneighbor.triangle == Mesh.dummytri)
{
// The next line doesn't insert a subsegment (because there's
// already one there), but it sets the boundary markers of
// the existing subsegment and its vertices.
mesh.InsertSubseg(ref checktri, 1);
hullsize++;
}
notfound = false;
}
index--;
// Find the next triangle in the stack.
prevlink = vertexarray[aroundvertex][index];
nexttri = vertexarray[aroundvertex][index];
checktri = nexttri;
}
}
i++;
}
}
// Mark the remaining edges as not being attached to any subsegment.
// Also, count the (yet uncounted) boundary edges.
for (i = 0; i < mesh.vertices.Count; i++)
{
// Search the stack of triangles adjacent to a vertex.
int index = vertexarray[i].Count - 1;
nexttri = vertexarray[i][index];
checktri = nexttri;
while (checktri.triangle != Mesh.dummytri)
{
// Find the next triangle in the stack before this
// information gets overwritten.
index--;
nexttri = vertexarray[i][index];
// No adjacent subsegment. (This overwrites the stack info.)
checktri.SegDissolve();
checktri.Sym(ref checkneighbor);
if (checkneighbor.triangle == Mesh.dummytri)
{
mesh.InsertSubseg(ref checktri, 1);
hullsize++;
}
checktri = nexttri;
}
}
return(hullsize);
}
/// <summary>
/// Enforce the Delaunay condition at an edge, fanning out recursively from
/// an existing vertex. Pay special attention to stacking inverted triangles.
/// </summary>
/// <param name="fixuptri"></param>
/// <param name="leftside">
/// Indicates whether or not fixuptri is to the left of
/// the segment being inserted. (Imagine that the segment is pointing up from
/// endpoint1 to endpoint2.)
/// </param>
/// <remarks>
/// This is a support routine for inserting segments into a constrained
/// Delaunay triangulation.
/// The origin of fixuptri is treated as if it has just been inserted, and
/// the local Delaunay condition needs to be enforced. It is only enforced
/// in one sector, however, that being the angular range defined by
/// fixuptri.
/// This routine also needs to make decisions regarding the "stacking" of
/// triangles. (Read the description of ConstrainedEdge() below before
/// reading on here, so you understand the algorithm.) If the position of
/// the new vertex (the origin of fixuptri) indicates that the vertex before
/// it on the polygon is a reflex vertex, then "stack" the triangle by
/// doing nothing. (fixuptri is an inverted triangle, which is how stacked
/// triangles are identified.)
/// Otherwise, check whether the vertex before that was a reflex vertex.
/// If so, perform an edge flip, thereby eliminating an inverted triangle
/// (popping it off the stack). The edge flip may result in the creation
/// of a new inverted triangle, depending on whether or not the new vertex
/// is visible to the vertex three edges behind on the polygon.
/// If neither of the two vertices behind the new vertex are reflex
/// vertices, fixuptri and fartri, the triangle opposite it, are not
/// inverted; hence, ensure that the edge between them is locally Delaunay.
/// </remarks>
private void DelaunayFixup(ref Otri fixuptri, bool leftside)
{
Otri neartri = default(Otri);
Otri fartri = default(Otri);
Osub faredge = default(Osub);
Vertex nearvertex, leftvertex, rightvertex, farvertex;
fixuptri.Lnext(ref neartri);
neartri.Sym(ref fartri);
// Check if the edge opposite the origin of fixuptri can be flipped.
if (fartri.tri.Id == Mesh.DUMMY)
{
return;
}
neartri.Pivot(ref faredge);
if (faredge.seg.hash != Mesh.DUMMY)
{
return;
}
// Find all the relevant vertices.
nearvertex = neartri.Apex();
leftvertex = neartri.Org();
rightvertex = neartri.Dest();
farvertex = fartri.Apex();
// Check whether the previous polygon vertex is a reflex vertex.
if (leftside)
{
if (RobustPredicates.CounterClockwise(nearvertex, leftvertex, farvertex) <= 0.0)
{
// leftvertex is a reflex vertex too. Nothing can
// be done until a convex section is found.
return;
}
}
else
{
if (RobustPredicates.CounterClockwise(farvertex, rightvertex, nearvertex) <= 0.0)
{
// rightvertex is a reflex vertex too. Nothing can
// be done until a convex section is found.
return;
}
}
if (RobustPredicates.CounterClockwise(rightvertex, leftvertex, farvertex) > 0.0)
{
// fartri is not an inverted triangle, and farvertex is not a reflex
// vertex. As there are no reflex vertices, fixuptri isn't an
// inverted triangle, either. Hence, test the edge between the
// triangles to ensure it is locally Delaunay.
if (RobustPredicates.InCircle(leftvertex, farvertex, rightvertex, nearvertex) <= 0.0)
{
return;
}
// Not locally Delaunay; go on to an edge flip.
}
// else fartri is inverted; remove it from the stack by flipping.
mesh.Flip(ref neartri);
fixuptri.Lprev(); // Restore the origin of fixuptri after the flip.
// Recursively process the two triangles that result from the flip.
DelaunayFixup(ref fixuptri, leftside);
DelaunayFixup(ref fartri, leftside);
}
/// <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>
/// Force a segment into a constrained Delaunay triangulation by deleting the
/// triangles it intersects, and triangulating the polygons that form on each
/// side of it.
/// </summary>
/// <param name="starttri"></param>
/// <param name="endpoint2"></param>
/// <param name="newmark"></param>
/// <remarks>
/// Generates a single subsegment connecting 'endpoint1' to 'endpoint2'.
/// The triangle 'starttri' has 'endpoint1' as its origin. 'newmark' is the
/// boundary marker of the segment.
/// To insert a segment, every triangle whose interior intersects the
/// segment is deleted. The union of these deleted triangles is a polygon
/// (which is not necessarily monotone, but is close enough), which is
/// divided into two polygons by the new segment. This routine's task is
/// to generate the Delaunay triangulation of these two polygons.
/// You might think of this routine's behavior as a two-step process. The
/// first step is to walk from endpoint1 to endpoint2, flipping each edge
/// encountered. This step creates a fan of edges connected to endpoint1,
/// including the desired edge to endpoint2. The second step enforces the
/// Delaunay condition on each side of the segment in an incremental manner:
/// proceeding along the polygon from endpoint1 to endpoint2 (this is done
/// independently on each side of the segment), each vertex is "enforced"
/// as if it had just been inserted, but affecting only the previous
/// vertices. The result is the same as if the vertices had been inserted
/// in the order they appear on the polygon, so the result is Delaunay.
/// In truth, ConstrainedEdge() interleaves these two steps. The procedure
/// walks from endpoint1 to endpoint2, and each time an edge is encountered
/// and flipped, the newly exposed vertex (at the far end of the flipped
/// edge) is "enforced" upon the previously flipped edges, usually affecting
/// only one side of the polygon (depending upon which side of the segment
/// the vertex falls on).
/// The algorithm is complicated by the need to handle polygons that are not
/// convex. Although the polygon is not necessarily monotone, it can be
/// triangulated in a manner similar to the stack-based algorithms for
/// monotone polygons. For each reflex vertex (local concavity) of the
/// polygon, there will be an inverted triangle formed by one of the edge
/// flips. (An inverted triangle is one with negative area - that is, its
/// vertices are arranged in clockwise order - and is best thought of as a
/// wrinkle in the fabric of the mesh.) Each inverted triangle can be
/// thought of as a reflex vertex pushed on the stack, waiting to be fixed
/// later.
/// A reflex vertex is popped from the stack when a vertex is inserted that
/// is visible to the reflex vertex. (However, if the vertex behind the
/// reflex vertex is not visible to the reflex vertex, a new inverted
/// triangle will take its place on the stack.) These details are handled
/// by the DelaunayFixup() routine above.
/// </remarks>
private void ConstrainedEdge(ref Otri starttri, Vertex endpoint2, ushort newmark)
{
Otri fixuptri = default(Otri), fixuptri2 = default(Otri);
Osub crosssubseg = default(Osub);
Vertex endpoint1;
Vertex farvertex;
double area;
bool collision;
bool done;
endpoint1 = starttri.Org();
starttri.Lnext(ref fixuptri);
mesh.Flip(ref fixuptri);
// 'collision' indicates whether we have found a vertex directly
// between endpoint1 and endpoint2.
collision = false;
done = false;
do
{
farvertex = fixuptri.Org();
// 'farvertex' is the extreme point of the polygon we are "digging"
// to get from endpoint1 to endpoint2.
if ((farvertex.X == endpoint2.X) && (farvertex.Y == endpoint2.Y))
{
fixuptri.Oprev(ref fixuptri2);
// Enforce the Delaunay condition around endpoint2.
DelaunayFixup(ref fixuptri, false);
DelaunayFixup(ref fixuptri2, true);
done = true;
}
else
{
// Check whether farvertex is to the left or right of the segment being
// inserted, to decide which edge of fixuptri to dig through next.
area = RobustPredicates.CounterClockwise(endpoint1, endpoint2, farvertex);
if (area == 0.0)
{
// We've collided with a vertex between endpoint1 and endpoint2.
collision = true;
fixuptri.Oprev(ref fixuptri2);
// Enforce the Delaunay condition around farvertex.
DelaunayFixup(ref fixuptri, false);
DelaunayFixup(ref fixuptri2, true);
done = true;
}
else
{
if (area > 0.0)
{
// farvertex is to the left of the segment.
fixuptri.Oprev(ref fixuptri2);
// Enforce the Delaunay condition around farvertex, on the
// left side of the segment only.
DelaunayFixup(ref fixuptri2, true);
// Flip the edge that crosses the segment. After the edge is
// flipped, one of its endpoints is the fan vertex, and the
// destination of fixuptri is the fan vertex.
fixuptri.Lprev();
}
else
{
// farvertex is to the right of the segment.
DelaunayFixup(ref fixuptri, false);
// Flip the edge that crosses the segment. After the edge is
// flipped, one of its endpoints is the fan vertex, and the
// destination of fixuptri is the fan vertex.
fixuptri.Oprev();
}
// Check for two intersecting segments.
fixuptri.Pivot(ref crosssubseg);
if (crosssubseg.seg.hash == Mesh.DUMMY)
{
mesh.Flip(ref fixuptri); // May create inverted triangle at left.
}
else
{
// We've collided with a segment between endpoint1 and endpoint2.
collision = true;
// Insert a vertex at the intersection.
SegmentIntersection(ref fixuptri, ref crosssubseg, endpoint2);
done = true;
}
}
}
} while (!done);
// Insert a subsegment to make the segment permanent.
mesh.InsertSubseg(ref fixuptri, newmark);
// If there was a collision with an interceding vertex, install another
// segment connecting that vertex with endpoint2.
if (collision)
{
// Insert the remainder of the segment.
if (!ScoutSegment(ref fixuptri, endpoint2, newmark))
{
ConstrainedEdge(ref fixuptri, endpoint2, newmark);
}
}
}
/// <summary>
/// Recursively form a Delaunay triangulation by the divide-and-conquer method.
/// </summary>
/// <param name="left"></param>
/// <param name="right"></param>
/// <param name="axis"></param>
/// <param name="farleft"></param>
/// <param name="farright"></param>
/// <remarks>
/// Recursively breaks down the problem into smaller pieces, which are
/// knitted together by mergehulls(). The base cases (problems of two or
/// three vertices) are handled specially here.
///
/// On completion, 'farleft' and 'farright' are bounding triangles such that
/// the origin of 'farleft' is the leftmost vertex (breaking ties by
/// choosing the highest leftmost vertex), and the destination of
/// 'farright' is the rightmost vertex (breaking ties by choosing the
/// lowest rightmost vertex).
/// </remarks>
void DivconqRecurse(int left, int right, int axis,
ref Otri farleft, ref Otri farright)
{
Otri midtri = default(Otri);
Otri tri1 = default(Otri);
Otri tri2 = default(Otri);
Otri tri3 = default(Otri);
Otri innerleft = default(Otri), innerright = default(Otri);
double area;
int vertices = right - left + 1;
int divider;
if (vertices == 2)
{
// The triangulation of two vertices is an edge. An edge is
// represented by two bounding triangles.
mesh.MakeTriangle(ref farleft);
farleft.SetOrg(sortarray[left]);
farleft.SetDest(sortarray[left + 1]);
// The apex is intentionally left NULL.
mesh.MakeTriangle(ref farright);
farright.SetOrg(sortarray[left + 1]);
farright.SetDest(sortarray[left]);
// The apex is intentionally left NULL.
farleft.Bond(ref farright);
farleft.LprevSelf();
farright.LnextSelf();
farleft.Bond(ref farright);
farleft.LprevSelf();
farright.LnextSelf();
farleft.Bond(ref farright);
// Ensure that the origin of 'farleft' is sortarray[0].
farright.Lprev(ref farleft);
return;
}
else if (vertices == 3)
{
// The triangulation of three vertices is either a triangle (with
// three bounding triangles) or two edges (with four bounding
// triangles). In either case, four triangles are created.
mesh.MakeTriangle(ref midtri);
mesh.MakeTriangle(ref tri1);
mesh.MakeTriangle(ref tri2);
mesh.MakeTriangle(ref tri3);
area = Primitives.CounterClockwise(sortarray[left], sortarray[left + 1], sortarray[left + 2]);
if (area == 0.0)
{
// Three collinear vertices; the triangulation is two edges.
midtri.SetOrg(sortarray[left]);
midtri.SetDest(sortarray[left + 1]);
tri1.SetOrg(sortarray[left + 1]);
tri1.SetDest(sortarray[left]);
tri2.SetOrg(sortarray[left + 2]);
tri2.SetDest(sortarray[left + 1]);
tri3.SetOrg(sortarray[left + 1]);
tri3.SetDest(sortarray[left + 2]);
// All apices are intentionally left NULL.
midtri.Bond(ref tri1);
tri2.Bond(ref tri3);
midtri.LnextSelf();
tri1.LprevSelf();
tri2.LnextSelf();
tri3.LprevSelf();
midtri.Bond(ref tri3);
tri1.Bond(ref tri2);
midtri.LnextSelf();
tri1.LprevSelf();
tri2.LnextSelf();
tri3.LprevSelf();
midtri.Bond(ref tri1);
tri2.Bond(ref tri3);
// Ensure that the origin of 'farleft' is sortarray[0].
tri1.Copy(ref farleft);
// Ensure that the destination of 'farright' is sortarray[2].
tri2.Copy(ref farright);
}
else
{
// The three vertices are not collinear; the triangulation is one
// triangle, namely 'midtri'.
midtri.SetOrg(sortarray[left]);
tri1.SetDest(sortarray[left]);
tri3.SetOrg(sortarray[left]);
// Apices of tri1, tri2, and tri3 are left NULL.
if (area > 0.0)
{
// The vertices are in counterclockwise order.
midtri.SetDest(sortarray[left + 1]);
tri1.SetOrg(sortarray[left + 1]);
tri2.SetDest(sortarray[left + 1]);
midtri.SetApex(sortarray[left + 2]);
tri2.SetOrg(sortarray[left + 2]);
tri3.SetDest(sortarray[left + 2]);
}
else
{
// The vertices are in clockwise order.
midtri.SetDest(sortarray[left + 2]);
tri1.SetOrg(sortarray[left + 2]);
tri2.SetDest(sortarray[left + 2]);
midtri.SetApex(sortarray[left + 1]);
tri2.SetOrg(sortarray[left + 1]);
tri3.SetDest(sortarray[left + 1]);
}
// The topology does not depend on how the vertices are ordered.
midtri.Bond(ref tri1);
midtri.LnextSelf();
midtri.Bond(ref tri2);
midtri.LnextSelf();
midtri.Bond(ref tri3);
tri1.LprevSelf();
tri2.LnextSelf();
tri1.Bond(ref tri2);
tri1.LprevSelf();
tri3.LprevSelf();
tri1.Bond(ref tri3);
tri2.LnextSelf();
tri3.LprevSelf();
tri2.Bond(ref tri3);
// Ensure that the origin of 'farleft' is sortarray[0].
tri1.Copy(ref farleft);
// Ensure that the destination of 'farright' is sortarray[2].
if (area > 0.0)
{
tri2.Copy(ref farright);
}
else
{
farleft.Lnext(ref farright);
}
}
return;
}
else
{
// Split the vertices in half.
divider = vertices >> 1;
// Recursively triangulate each half.
DivconqRecurse(left, left + divider - 1, 1 - axis, ref farleft, ref innerleft);
//DebugWriter.Session.Write(mesh, true);
DivconqRecurse(left + divider, right, 1 - axis, ref innerright, ref farright);
//DebugWriter.Session.Write(mesh, true);
// Merge the two triangulations into one.
MergeHulls(ref farleft, ref innerleft, ref innerright, ref farright, axis);
//DebugWriter.Session.Write(mesh, true);
}
}
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);
}