public virtual void FastCollapsePass(double fMinEdgeLength)
{
if (mesh.TriangleCount == 0) // badness if we don't catch this...
{
return;
}
MinEdgeLength = fMinEdgeLength;
double min_sqr = MinEdgeLength * MinEdgeLength;
// we don't collapse on the boundary
HaveBoundary = false;
begin_pass();
begin_setup();
Precompute();
end_setup();
begin_ops();
begin_collapse();
int N = mesh.MaxEdgeID;
Vector3d va = Vector3d.Zero, vb = Vector3d.Zero;
for (int eid = 0; eid < N; ++eid)
{
if (!mesh.IsEdge(eid))
{
continue;
}
if (mesh.IsBoundaryEdge(eid))
{
continue;
}
mesh.GetEdgeV(eid, ref va, ref vb);
if (va.DistanceSquared(ref vb) > min_sqr)
{
continue;
}
COUNT_ITERATIONS++;
Vector3d midpoint = (va + vb) * 0.5;
int vKept;
ProcessResult result = CollapseEdge(eid, midpoint, out vKept);
if (result == ProcessResult.Ok_Collapsed)
{
// do nothing?
}
}
end_collapse();
end_ops();
Reproject();
end_pass();
}
public bool IsInternalSpan()
{
int NV = Vertices.Length;
for (int i = 0; i < NV-1; ++i ) {
int eid = Mesh.FindEdge(Vertices[i], Vertices[i + 1]);
Debug.Assert(eid != DMesh3.InvalidID);
if (Mesh.IsBoundaryEdge(eid))
return false;
}
return true;
}
public bool IsInternalLoop()
{
int NV = Vertices.Length;
for (int i = 0; i < NV; ++i)
{
int eid = Mesh.FindEdge(Vertices[i], Vertices[(i + 1) % NV]);
Debug.Assert(eid != DMesh3.InvalidID);
if (Mesh.IsBoundaryEdge(eid))
{
return(false);
}
}
return(true);
}
/// <summary>
/// construct EdgeLoop from a list of vertices of mesh
/// if loop is a boundary edge, we can correct orientation if requested
/// </summary>
public static EdgeLoop FromVertices(DMesh3 mesh, IList <int> vertices, bool bAutoOrient = true)
{
int[] Vertices = new int[vertices.Count];
for (int i = 0; i < Vertices.Length; i++)
{
Vertices[i] = vertices[i];
}
if (bAutoOrient)
{
int a = Vertices[0], b = Vertices[1];
int eid = mesh.FindEdge(a, b);
if (mesh.IsBoundaryEdge(eid))
{
Index2i ev = mesh.GetOrientedBoundaryEdgeV(eid);
if (ev.a == b && ev.b == a)
{
Array.Reverse(Vertices);
}
}
}
int[] Edges = new int[Vertices.Length];
for (int i = 0; i < Edges.Length; ++i)
{
int a = Vertices[i], b = Vertices[(i + 1) % Vertices.Length];
Edges[i] = mesh.FindEdge(a, b);
if (Edges[i] == DMesh3.InvalidID)
{
throw new Exception("EdgeLoop.FromVertices: invalid edge [" + a + "," + b + "]");
}
}
return(new EdgeLoop(mesh, Vertices, Edges, false));
}
/// <summary>
/// if before a flip we have normals (n1,n2) and after we have (m1,m2), check if
/// the dot between any of the 4 pairs changes sign after the flip, or is
/// less than the dot-product tolerance (ie angle tolerance)
/// </summary>
public static bool CheckIfEdgeFlipCreatesFlip(DMesh3 mesh, int eID, double flip_dot_tol = 0.0)
{
Util.gDevAssert(mesh.IsBoundaryEdge(eID) == false);
Index4i einfo = mesh.GetEdge(eID);
Index2i ov = mesh.GetEdgeOpposingV(eID);
int a = einfo.a, b = einfo.b, c = ov.a, d = ov.b;
int t0 = einfo.c;
Vector3d vC = mesh.GetVertex(c), vD = mesh.GetVertex(d);
Index3i tri_v = mesh.GetTriangle(t0);
int oa = a, ob = b;
IndexUtil.orient_tri_edge(ref oa, ref ob, ref tri_v);
Vector3d vOA = mesh.GetVertex(oa), vOB = mesh.GetVertex(ob);
Vector3d n0 = MathUtil.FastNormalDirection(ref vOA, ref vOB, ref vC);
Vector3d n1 = MathUtil.FastNormalDirection(ref vOB, ref vOA, ref vD);
Vector3d f0 = MathUtil.FastNormalDirection(ref vC, ref vD, ref vOB);
if (edge_flip_metric(ref n0, ref f0, flip_dot_tol) <= flip_dot_tol ||
edge_flip_metric(ref n1, ref f0, flip_dot_tol) <= flip_dot_tol)
{
return(true);
}
Vector3d f1 = MathUtil.FastNormalDirection(ref vD, ref vC, ref vOA);
if (edge_flip_metric(ref n0, ref f1, flip_dot_tol) <= flip_dot_tol ||
edge_flip_metric(ref n1, ref f1, flip_dot_tol) <= flip_dot_tol)
{
return(true);
}
return(false);
}
/// <summary>
/// if this is a border edge-loop, we can check that it is oriented correctly, and
/// if not, reverse it.
/// Returns true if we reversed orientation.
/// </summary>
public bool CorrectOrientation()
{
int a = Vertices[0], b = Vertices[1];
int eid = Mesh.FindEdge(a, b);
if (Mesh.IsBoundaryEdge(eid))
{
Index2i ev = Mesh.GetOrientedBoundaryEdgeV(eid);
if (ev.a == b && ev.b == a)
{
Reverse();
return(true);
}
}
return(false);
}
// return point that minimizes quadric error for edge [ea,eb]
Vector3d OptimalPoint(int eid, ref QuadricError q, int ea, int eb)
{
// if we would like to preserve boundary, we need to know that here
// so that we properly score these edges
if (HaveBoundary && PreserveBoundary)
{
if (mesh.IsBoundaryEdge(eid))
{
return((mesh.GetVertex(ea) + mesh.GetVertex(eb)) * 0.5);
}
else
{
if (IsBoundaryV(ea))
{
return(mesh.GetVertex(ea));
}
else if (IsBoundaryV(eb))
{
return(mesh.GetVertex(eb));
}
}
}
// [TODO] if we have constraints, we should apply them here, for same reason as bdry above...
if (MinimizeQuadricPositionError == false)
{
return(project((mesh.GetVertex(ea) + mesh.GetVertex(eb)) * 0.5));
}
else
{
Vector3d result = Vector3d.Zero;
if (q.OptimalPoint(ref result))
{
return(project(result));
}
// degenerate matrix, evaluate quadric at edge end and midpoints
// (could do line search here...)
Vector3d va = mesh.GetVertex(ea);
Vector3d vb = mesh.GetVertex(eb);
Vector3d c = project((va + vb) * 0.5);
double fa = q.Evaluate(va);
double fb = q.Evaluate(vb);
double fc = q.Evaluate(c);
double m = MathUtil.Min(fa, fb, fc);
if (m == fa)
{
return(va);
}
else if (m == fb)
{
return(vb);
}
return(c);
}
}
/// <summary>
/// we can vastly speed things up if we precompute some invariants.
/// You need to re-run this if you are changing the mesh externally
/// between remesh passes, otherwise you will get weird results.
/// But you will probably still come out ahead, computation-time-wise
/// </summary>
public virtual void Precompute()
{
// if we know mesh is closed, we can skip is-boundary checks, which makes
// the flip-valence tests much faster!
MeshIsClosed = true;
foreach (int eid in mesh.EdgeIndices())
{
if (mesh.IsBoundaryEdge(eid))
{
MeshIsClosed = false;
break;
}
}
}
public static IEnumerable <int> BoundaryEdges(DMesh3 mesh)
{
int N = mesh.MaxEdgeID;
for (int i = 0; i < N; ++i)
{
if (mesh.IsEdge(i))
{
if (mesh.IsBoundaryEdge(i))
{
yield return(i);
}
}
}
}
/// <summary>
/// boundary vertices of mesh, but based on edges, so returns each vertex twice!
/// </summary>
public static IEnumerable <int> BoundaryEdgeVertices(DMesh3 mesh)
{
int N = mesh.MaxEdgeID;
for (int i = 0; i < N; ++i)
{
if (mesh.IsEdge(i) && mesh.IsBoundaryEdge(i))
{
Index2i ev = mesh.GetEdgeV(i);
yield return(ev.a);
yield return(ev.b);
}
}
}
// for all mesh boundary edges, disable flip/split/collapse
// for all mesh boundary vertices, pin in current position
public static void FixAllBoundaryEdges(MeshConstraints cons, DMesh3 mesh)
{
int NE = mesh.MaxEdgeID;
for (int ei = 0; ei < NE; ++ei)
{
if (mesh.IsEdge(ei) && mesh.IsBoundaryEdge(ei))
{
cons.SetOrUpdateEdgeConstraint(ei, EdgeConstraint.FullyConstrained);
Index2i ev = mesh.GetEdgeV(ei);
cons.SetOrUpdateVertexConstraint(ev.a, VertexConstraint.Pinned);
cons.SetOrUpdateVertexConstraint(ev.b, VertexConstraint.Pinned);
}
}
}
public static void DebugEdgeInfo(DMesh3 mesh, params int[] edgeIds)
{
foreach (var edgeId in edgeIds)
{
Debug.Write($"Info on edge {edgeId}... ");
if (!mesh.IsEdge(edgeId))
{
Debug.WriteLine("Not an edge.");
continue;
}
var e = mesh.GetEdge(edgeId);
Debug.WriteLine($"IsBorder: {mesh.IsBoundaryEdge(edgeId)}");
var from = mesh.GetVertex(e.a);
var to = mesh.GetVertex(e.b);
Debug.WriteLine($" from: {from.x},{from.y},{from.z} to {to.x},{to.y},{to.z}");
}
}
/// <summary>
/// Check if all edges of this loop are boundary edges.
/// If testMesh != null, will check that mesh instead of internal Mesh
/// </summary>
public bool IsBoundaryLoop(DMesh3 testMesh = null)
{
DMesh3 useMesh = (testMesh != null) ? testMesh : Mesh;
int NV = Vertices.Length;
for (int i = 0; i < NV; ++i)
{
int eid = useMesh.FindEdge(Vertices[i], Vertices[(i + 1) % NV]);
Debug.Assert(eid != DMesh3.InvalidID);
if (useMesh.IsBoundaryEdge(eid) == false)
{
return(false);
}
}
return(true);
}
// for all mesh boundary vertices, pin in current position, but allow splits
public static void FixAllBoundaryEdges_AllowSplit(MeshConstraints cons, DMesh3 mesh, int setID)
{
EdgeConstraint edgeCons = new EdgeConstraint(EdgeRefineFlags.NoFlip | EdgeRefineFlags.NoCollapse);
VertexConstraint vertCons = new VertexConstraint(true, setID);
int NE = mesh.MaxEdgeID;
for (int ei = 0; ei < NE; ++ei)
{
if (mesh.IsEdge(ei) && mesh.IsBoundaryEdge(ei))
{
cons.SetOrUpdateEdgeConstraint(ei, edgeCons);
Index2i ev = mesh.GetEdgeV(ei);
cons.SetOrUpdateVertexConstraint(ev.a, vertCons);
cons.SetOrUpdateVertexConstraint(ev.b, vertCons);
}
}
}
public virtual int[] AddTriangleFan_OrderedEdgeLoop(int center, int[] edge_loop, int group_id = -1)
{
int N = edge_loop.Length;
int[] new_tris = new int[N];
int i = 0;
for (i = 0; i < N; ++i)
{
if (Mesh.IsBoundaryEdge(edge_loop[i]) == false)
{
goto operation_failed;
}
Index2i ev = Mesh.GetOrientedBoundaryEdgeV(edge_loop[i]);
int a = ev.a, b = ev.b;
Index3i newT = new Index3i(center, b, a);
int new_tid = Mesh.AppendTriangle(newT, group_id);
if (new_tid == DMesh3.InvalidID)
{
goto operation_failed;
}
new_tris[i] = new_tid;
}
return(new_tris);
operation_failed:
// remove what we added so far
if (i > 0)
{
if (remove_triangles(new_tris, i - 1) == false)
{
throw new Exception("MeshConstructor.AddTriangleFan_OrderedEdgeLoop: failed to add fan, and also failed to back out changes.");
}
}
return(null);
}
public static ValidationStatus IsBoundaryLoop(DMesh3 mesh, EdgeLoop loop)
{
int N = loop.Vertices.Length;
for (int i = 0; i < N; ++i)
{
if (!mesh.vertex_is_boundary(loop.Vertices[i]))
{
return(ValidationStatus.NotBoundaryVertex);
}
}
for (int i = 0; i < N; ++i)
{
int a = loop.Vertices[i];
int b = loop.Vertices[(i + 1) % N];
int eid = mesh.FindEdge(a, b);
if (eid == DMesh3.InvalidID)
{
return(ValidationStatus.VerticesNotConnectedByEdge);
}
if (mesh.IsBoundaryEdge(eid) == false)
{
return(ValidationStatus.NotBoundaryEdge);
}
Index2i ev = mesh.GetOrientedBoundaryEdgeV(eid);
if (!(ev.a == a && ev.b == b))
{
return(ValidationStatus.IncorrectLoopOrientation);
}
}
return(ValidationStatus.Ok);
}
public virtual bool Apply()
{
HashSet <int> OnCurveVerts = new HashSet <int>(); // original vertices that were epsilon-coincident w/ curve vertices
insert_corners(OnCurveVerts);
// [RMS] not using this?
//HashSet<int> corner_v = new HashSet<int>(CurveVertices);
// not sure we need to track all of these
HashSet <int> ZeroEdges = new HashSet <int>();
HashSet <int> ZeroVertices = new HashSet <int>();
OnCutEdges = new HashSet <int>();
HashSet <int> NewEdges = new HashSet <int>();
HashSet <int> NewCutVertices = new HashSet <int>();
sbyte[] signs = new sbyte[2 * Mesh.MaxVertexID + 2 * Curve.VertexCount];
HashSet <int> segTriangles = new HashSet <int>();
HashSet <int> segVertices = new HashSet <int>();
HashSet <int> segEdges = new HashSet <int>();
// loop over segments, insert each one in sequence
int N = (IsLoop) ? Curve.VertexCount : Curve.VertexCount - 1;
for (int si = 0; si < N; ++si)
{
int i0 = si;
int i1 = (si + 1) % Curve.VertexCount;
Segment2d seg = new Segment2d(Curve[i0], Curve[i1]);
int i0_vid = CurveVertices[i0];
int i1_vid = CurveVertices[i1];
// If these vertices are already connected by an edge, we can just continue.
int existing_edge = Mesh.FindEdge(i0_vid, i1_vid);
if (existing_edge != DMesh3.InvalidID)
{
add_cut_edge(existing_edge);
continue;
}
if (triSpatial != null)
{
segTriangles.Clear(); segVertices.Clear(); segEdges.Clear();
AxisAlignedBox2d segBounds = new AxisAlignedBox2d(seg.P0); segBounds.Contain(seg.P1);
segBounds.Expand(MathUtil.ZeroTolerancef * 10);
triSpatial.FindTrianglesInRange(segBounds, segTriangles);
IndexUtil.TrianglesToVertices(Mesh, segTriangles, segVertices);
IndexUtil.TrianglesToEdges(Mesh, segTriangles, segEdges);
}
int MaxVID = Mesh.MaxVertexID;
IEnumerable <int> vertices = Interval1i.Range(MaxVID);
if (triSpatial != null)
{
vertices = segVertices;
}
// compute edge-crossing signs
// [TODO] could walk along mesh from a to b, rather than computing for entire mesh?
if (signs.Length < MaxVID)
{
signs = new sbyte[2 * MaxVID];
}
gParallel.ForEach(vertices, (vid) => {
if (Mesh.IsVertex(vid))
{
if (vid == i0_vid || vid == i1_vid)
{
signs[vid] = 0;
}
else
{
Vector2d v2 = PointF(vid);
// tolerance defines band in which we will consider values to be zero
signs[vid] = (sbyte)seg.WhichSide(v2, SpatialEpsilon);
}
}
else
{
signs[vid] = sbyte.MaxValue;
}
});
// have to skip processing of new edges. If edge id
// is > max at start, is new. Otherwise if in NewEdges list, also new.
// (need both in case we re-use an old edge index)
int MaxEID = Mesh.MaxEdgeID;
NewEdges.Clear();
NewCutVertices.Clear();
NewCutVertices.Add(i0_vid);
NewCutVertices.Add(i1_vid);
// cut existing edges with segment
IEnumerable <int> edges = Interval1i.Range(MaxEID);
if (triSpatial != null)
{
edges = segEdges;
}
foreach (int eid in edges)
{
if (Mesh.IsEdge(eid) == false)
{
continue;
}
if (eid >= MaxEID || NewEdges.Contains(eid))
{
continue;
}
// cannot cut boundary edges?
if (Mesh.IsBoundaryEdge(eid))
{
continue;
}
Index2i ev = Mesh.GetEdgeV(eid);
int eva_sign = signs[ev.a];
int evb_sign = signs[ev.b];
// [RMS] should we be using larger epsilon here? If we don't track OnCurveVerts explicitly, we
// need to at least use same epsilon we passed to insert_corner_from_bary...do we still also
// need that to catch the edges we split in the poke?
bool eva_in_segment = false;
if (eva_sign == 0)
{
eva_in_segment = OnCurveVerts.Contains(ev.a) || Math.Abs(seg.Project(PointF(ev.a))) < (seg.Extent + SpatialEpsilon);
}
bool evb_in_segment = false;
if (evb_sign == 0)
{
evb_in_segment = OnCurveVerts.Contains(ev.b) || Math.Abs(seg.Project(PointF(ev.b))) < (seg.Extent + SpatialEpsilon);
}
// If one or both vertices are on-segment, we have special case.
// If just one vertex is on the segment, we can skip this edge.
// If both vertices are on segment, then we can just re-use this edge.
if (eva_in_segment || evb_in_segment)
{
if (eva_in_segment && evb_in_segment)
{
ZeroEdges.Add(eid);
add_cut_edge(eid);
NewCutVertices.Add(ev.a); NewCutVertices.Add(ev.b);
}
else
{
int zvid = eva_in_segment ? ev.a : ev.b;
ZeroVertices.Add(zvid);
NewCutVertices.Add(zvid);
}
continue;
}
// no crossing
if (eva_sign * evb_sign > 0)
{
continue;
}
// compute segment/segment intersection
Vector2d va = PointF(ev.a);
Vector2d vb = PointF(ev.b);
Segment2d edge_seg = new Segment2d(va, vb);
IntrSegment2Segment2 intr = new IntrSegment2Segment2(seg, edge_seg);
intr.Compute();
if (intr.Type == IntersectionType.Segment)
{
// [RMS] we should have already caught this above, so if it happens here it is probably spurious?
// we should have caught this case above, but numerics are different so it might occur again
ZeroEdges.Add(eid);
NewCutVertices.Add(ev.a); NewCutVertices.Add(ev.b);
add_cut_edge(eid);
continue;
}
else if (intr.Type != IntersectionType.Point)
{
continue; // no intersection
}
Vector2d x = intr.Point0;
double t = Math.Sqrt(x.DistanceSquared(va) / va.DistanceSquared(vb));
// this case happens if we aren't "on-segment" but after we do the test the intersection pt
// is within epsilon of one end of the edge. This is a spurious t-intersection and we
// can ignore it. Some other edge should exist that picks up this vertex as part of it.
// [TODO] what about if this edge is degenerate?
bool x_in_segment = Math.Abs(edge_seg.Project(x)) < (edge_seg.Extent - SpatialEpsilon);
if (!x_in_segment)
{
continue;
}
Index2i et = Mesh.GetEdgeT(eid);
spatial_remove_triangles(et.a, et.b);
// split edge at this segment
DMesh3.EdgeSplitInfo splitInfo;
MeshResult result = Mesh.SplitEdge(eid, out splitInfo, t);
if (result != MeshResult.Ok)
{
throw new Exception("MeshInsertUVSegment.Apply: SplitEdge failed - " + result.ToString());
//return false;
}
// move split point to intersection position
SetPointF(splitInfo.vNew, x);
NewCutVertices.Add(splitInfo.vNew);
NewEdges.Add(splitInfo.eNewBN);
NewEdges.Add(splitInfo.eNewCN);
spatial_add_triangles(et.a, et.b);
spatial_add_triangles(splitInfo.eNewT2, splitInfo.eNewT3);
// some splits - but not all - result in new 'other' edges that are on
// the polypath. We want to keep track of these edges so we can extract loop later.
Index2i ecn = Mesh.GetEdgeV(splitInfo.eNewCN);
if (NewCutVertices.Contains(ecn.a) && NewCutVertices.Contains(ecn.b))
{
add_cut_edge(splitInfo.eNewCN);
}
// since we don't handle bdry edges this should never be false, but maybe we will handle bdry later...
if (splitInfo.eNewDN != DMesh3.InvalidID)
{
NewEdges.Add(splitInfo.eNewDN);
Index2i edn = Mesh.GetEdgeV(splitInfo.eNewDN);
if (NewCutVertices.Contains(edn.a) && NewCutVertices.Contains(edn.b))
{
add_cut_edge(splitInfo.eNewDN);
}
}
}
}
// extract the cut paths
if (EnableCutSpansAndLoops)
{
find_cut_paths(OnCutEdges);
}
return(true);
} // Apply()
/// <summary>
/// Find the set of boundary EdgeLoops. Note that if we encounter topological
/// issues, we will throw MeshBoundaryLoopsException w/ more info (if possible)
/// </summary>
public bool Compute()
{
// This algorithm assumes that triangles are oriented consistently,
// so closed boundary-loop can be followed by walking edges in-order
Loops = new List <EdgeLoop>();
Spans = new List <EdgeSpan>();
// early-out if we don't actually have boundaries
if (Mesh.CachedIsClosed)
{
return(true);
}
int NE = Mesh.MaxEdgeID;
// Temporary memory used to indicate when we have "used" an edge.
var used_edge = new BitArray(NE);
used_edge.SetAll(false);
// current loop is stored here, cleared after each loop extracted
var loop_edges = new List <int>(); // [RMS] not sure we need this...
var loop_verts = new List <int>();
var bowties = new List <int>();
// Temp buffer for reading back all boundary edges of a vertex.
// probably always small but in pathological cases it could be large...
int[] all_e = new int[16];
// [TODO] might make sense to precompute some things here, like num_be for each bdry vtx?
// process all edges of mesh
for (int eid = 0; eid < NE; ++eid)
{
if (!Mesh.IsEdge(eid))
{
continue;
}
if (used_edge[eid] == true)
{
continue;
}
if (Mesh.IsBoundaryEdge(eid) == false)
{
continue;
}
if (EdgeFilterF != null && EdgeFilterF(eid) == false)
{
used_edge[eid] = true;
continue;
}
// ok this is start of a boundary chain
int eStart = eid;
used_edge[eStart] = true;
loop_edges.Add(eStart);
int eCur = eid;
// follow the chain in order of oriented edges
bool bClosed = false;
bool bIsOpenSpan = false;
while (!bClosed)
{
Index2i ev = Mesh.GetOrientedBoundaryEdgeV(eCur);
int cure_a = ev.a, cure_b = ev.b;
if (bIsOpenSpan)
{
cure_a = ev.b; cure_b = ev.a;
}
else
{
loop_verts.Add(cure_a);
}
int e0 = -1, e1 = 1;
int bdry_nbrs = Mesh.VtxBoundaryEdges(cure_b, ref e0, ref e1);
// have to filter this list, if we are filtering. this is ugly.
if (EdgeFilterF != null)
{
if (bdry_nbrs > 2)
{
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[bdry_nbrs];
}
// we may repreat this below...irritating...
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
num_be = BufferUtil.CountValid(all_e, EdgeFilterF, num_be);
}
else
{
if (EdgeFilterF(e0) == false)
{
bdry_nbrs--;
}
if (EdgeFilterF(e1) == false)
{
bdry_nbrs--;
}
}
}
if (bdry_nbrs < 2)
{ // hit an 'endpoint' vertex (should only happen when Filter is on...)
if (SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: found open span at vertex " + cure_b)
{
UnclosedLoop = true
};
}
if (bIsOpenSpan)
{
bClosed = true;
continue;
}
else
{
bIsOpenSpan = true; // begin open span
eCur = loop_edges[0]; // restart at other end of loop
loop_edges.Reverse(); // do this so we can push to front
continue;
}
}
int eNext = -1;
if (bdry_nbrs > 2)
{
// found "bowtie" vertex...things just got complicated!
if (cure_b == loop_verts[0])
{
// The "end" of the current edge is the same as the start vertex.
// This means we can close the loop here. Might as well!
eNext = -2; // sentinel value used below
}
else
{
// try to find an unused outgoing edge that is oriented properly.
// This could create sub-loops, we will handle those later
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[2 * bdry_nbrs];
}
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
Debug.Assert(num_be == bdry_nbrs);
if (EdgeFilterF != null)
{
num_be = BufferUtil.FilterInPlace(all_e, EdgeFilterF, num_be);
}
// Try to pick the best "turn left" vertex.
eNext = find_left_turn_edge(eCur, cure_b, all_e, num_be, used_edge);
if (eNext == -1)
{
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: cannot find valid outgoing edge at bowtie vertex " + cure_b)
{
BowtieFailure = true
};
}
// ok, we are stuck. all we can do now is terminate this loop and keep it as a span
if (bIsOpenSpan)
{
bClosed = true;
}
else
{
bIsOpenSpan = true;
bClosed = true;
}
continue;
}
}
if (bowties.Contains(cure_b) == false)
{
bowties.Add(cure_b);
}
}
else
{
// walk forward to next available edge
Debug.Assert(e0 == eCur || e1 == eCur);
eNext = (e0 == eCur) ? e1 : e0;
}
if (eNext == -2)
{
// found a bowtie vert that is the same as start-of-loop, so we
// are just closing it off explicitly
bClosed = true;
}
else if (eNext == eStart)
{
// found edge at start of loop, so loop is done.
bClosed = true;
}
else if (used_edge[eNext] != false)
{
// disaster case - the next edge is already used, but it is not the start of our loop
// All we can do is convert to open span and terminate
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: encountered repeated edge " + eNext)
{
RepeatedEdge = true
};
}
bIsOpenSpan = true;
bClosed = true;
}
else
{
// push onto accumulated list
Debug.Assert(used_edge[eNext] == false);
loop_edges.Add(eNext);
used_edge[eNext] = true;
eCur = eNext;
}
}
if (bIsOpenSpan)
{
SawOpenSpans = true;
if (SpanBehavior == SpanBehaviors.Compute)
{
loop_edges.Reverse(); // orient properly
var span = EdgeSpan.FromEdges(Mesh, loop_edges);
Spans.Add(span);
}
}
else if (bowties.Count > 0)
{
// if we saw a bowtie vertex, we might need to break up this loop,
// so call extract_subloops
Subloops subloops = extract_subloops(loop_verts, loop_edges, bowties);
foreach (var loop in subloops.Loops)
{
Loops.Add(loop);
}
if (subloops.Spans.Count > 0)
{
FellBackToSpansOnFailure = true;
foreach (var span in subloops.Spans)
{
Spans.Add(span);
}
}
}
else
{
// clean simple loop, convert to EdgeLoop instance
var loop = new EdgeLoop(Mesh);
loop.Vertices = loop_verts.ToArray();
loop.Edges = loop_edges.ToArray();
Loops.Add(loop);
}
// reset these lists
loop_edges.Clear();
loop_verts.Clear();
bowties.Clear();
}
return(true);
}
public bool IsVertex(int vID)
{
return(Mesh.IsEdge(vID) && Mesh.IsBoundaryEdge(vID));
}
/// <summary>
/// Find the set of boundary EdgeLoops. Note that if we encounter topological
/// issues, we will throw MeshBoundaryLoopsException w/ more info (if possible)
/// </summary>
public bool Compute()
{
// This algorithm assumes that triangles are oriented consistently,
// so closed boundary-loop can be followed by walking edges in-order
Loops = new List <EdgeLoop>();
Spans = new List <EdgeSpan>();
// early-out if we don't actually have boundaries
if (Mesh.CachedIsClosed)
{
return(true);
}
int NE = Mesh.MaxEdgeID;
// Temporary memory used to indicate when we have "used" an edge.
BitArray used_edge = new BitArray(NE);
used_edge.SetAll(false);
// current loop is stored here, cleared after each loop extracted
List <int> loop_edges = new List <int>(); // [RMS] not sure we need this...
List <int> loop_verts = new List <int>();
List <int> bowties = new List <int>();
// Temp buffer for reading back all boundary edges of a vertex.
// probably always small but in pathological cases it could be large...
int[] all_e = new int[16];
// [TODO] might make sense to precompute some things here, like num_be for each bdry vtx?
// process all edges of mesh
for (int eid = 0; eid < NE; ++eid)
{
if (!Mesh.IsEdge(eid))
{
continue;
}
if (used_edge[eid] == true)
{
continue;
}
if (Mesh.IsBoundaryEdge(eid) == false)
{
continue;
}
if (EdgeFilterF != null && EdgeFilterF(eid) == false)
{
used_edge[eid] = true;
continue;
}
// ok this is start of a boundary chain
int eStart = eid;
used_edge[eStart] = true;
loop_edges.Add(eStart);
int eCur = eid;
// follow the chain in order of oriented edges
bool bClosed = false;
bool bIsOpenSpan = false;
while (!bClosed)
{
Index2i ev = Mesh.GetOrientedBoundaryEdgeV(eCur);
int cure_a = ev.a, cure_b = ev.b;
if (bIsOpenSpan)
{
cure_a = ev.b; cure_b = ev.a;
}
else
{
loop_verts.Add(cure_a);
}
int e0 = -1, e1 = 1;
int bdry_nbrs = Mesh.VtxBoundaryEdges(cure_b, ref e0, ref e1);
// have to filter this list, if we are filtering. this is ugly.
if (EdgeFilterF != null)
{
if (bdry_nbrs > 2)
{
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[bdry_nbrs];
}
// we may repreat this below...irritating...
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
num_be = BufferUtil.CountValid(all_e, EdgeFilterF, num_be);
}
else
{
if (EdgeFilterF(e0) == false)
{
bdry_nbrs--;
}
if (EdgeFilterF(e1) == false)
{
bdry_nbrs--;
}
}
}
if (bdry_nbrs < 2) // hit an 'endpoint' vertex (should only happen when Filter is on...)
{
if (SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: found open span at vertex " + cure_b)
{
UnclosedLoop = true
}
}
;
if (bIsOpenSpan)
{
bClosed = true;
continue;
}
else
{
bIsOpenSpan = true; // begin open span
eCur = loop_edges[0]; // restart at other end of loop
loop_edges.Reverse(); // do this so we can push to front
continue;
}
}
int eNext = -1;
if (bdry_nbrs > 2)
{
// found "bowtie" vertex...things just got complicated!
if (cure_b == loop_verts[0])
{
// The "end" of the current edge is the same as the start vertex.
// This means we can close the loop here. Might as well!
eNext = -2; // sentinel value used below
}
else
{
// try to find an unused outgoing edge that is oriented properly.
// This could create sub-loops, we will handle those later
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[2 * bdry_nbrs];
}
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
Debug.Assert(num_be == bdry_nbrs);
if (EdgeFilterF != null)
{
num_be = BufferUtil.FilterInPlace(all_e, EdgeFilterF, num_be);
}
// Try to pick the best "turn left" vertex.
eNext = find_left_turn_edge(eCur, cure_b, all_e, num_be, used_edge);
if (eNext == -1)
{
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: cannot find valid outgoing edge at bowtie vertex " + cure_b)
{
BowtieFailure = true
}
}
;
// ok, we are stuck. all we can do now is terminate this loop and keep it as a span
if (bIsOpenSpan)
{
bClosed = true;
}
else
{
bIsOpenSpan = true;
bClosed = true;
}
continue;
}
}
if (bowties.Contains(cure_b) == false)
{
bowties.Add(cure_b);
}
}
else
{
// walk forward to next available edge
Debug.Assert(e0 == eCur || e1 == eCur);
eNext = (e0 == eCur) ? e1 : e0;
}
if (eNext == -2)
{
// found a bowtie vert that is the same as start-of-loop, so we
// are just closing it off explicitly
bClosed = true;
}
else if (eNext == eStart)
{
// found edge at start of loop, so loop is done.
bClosed = true;
}
else if (used_edge[eNext] != false)
{
// disaster case - the next edge is already used, but it is not the start of our loop
// All we can do is convert to open span and terminate
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: encountered repeated edge " + eNext)
{
RepeatedEdge = true
}
}
;
bIsOpenSpan = true;
bClosed = true;
}
else
{
// push onto accumulated list
Debug.Assert(used_edge[eNext] == false);
loop_edges.Add(eNext);
used_edge[eNext] = true;
eCur = eNext;
}
}
if (bIsOpenSpan)
{
SawOpenSpans = true;
if (SpanBehavior == SpanBehaviors.Compute)
{
loop_edges.Reverse(); // orient properly
EdgeSpan span = EdgeSpan.FromEdges(Mesh, loop_edges);
Spans.Add(span);
}
}
else if (bowties.Count > 0)
{
// if we saw a bowtie vertex, we might need to break up this loop,
// so call extract_subloops
Subloops subloops = extract_subloops(loop_verts, loop_edges, bowties);
foreach (var loop in subloops.Loops)
{
Loops.Add(loop);
}
if (subloops.Spans.Count > 0)
{
FellBackToSpansOnFailure = true;
foreach (var span in subloops.Spans)
{
Spans.Add(span);
}
}
}
else
{
// clean simple loop, convert to EdgeLoop instance
EdgeLoop loop = new EdgeLoop(Mesh);
loop.Vertices = loop_verts.ToArray();
loop.Edges = loop_edges.ToArray();
Loops.Add(loop);
}
// reset these lists
loop_edges.Clear();
loop_verts.Clear();
bowties.Clear();
}
return(true);
}
// [TODO] cache this in a dictionary? we will not need very many, but we will
// need each multiple times!
Vector3d get_vtx_normal(int vid)
{
Vector3d n = Vector3d.Zero;
foreach (int ti in Mesh.VtxTrianglesItr(vid))
{
n += Mesh.GetTriNormal(ti);
}
n.Normalize();
return(n);
}
// ok, bdry_edges[0...bdry_edges_count] contains the boundary edges coming out of bowtie_v.
// We want to pick the best one to continue the loop that came in to bowtie_v on incoming_e.
// If the loops are all sane, then we will get the smallest loops by "turning left" at bowtie_v.
// So, we compute the tangent plane at bowtie_v, and then the signed angle for each
// viable edge in this plane.
//
// [TODO] handle degenerate edges. what do we do then? Currently will only chose
// degenerate edge if there are no other options (I think...)
int find_left_turn_edge(int incoming_e, int bowtie_v, int[] bdry_edges, int bdry_edges_count, BitArray used_edges)
{
// compute normal and edge [a,bowtie]
Vector3d n = get_vtx_normal(bowtie_v);
int other_v = Mesh.edge_other_v(incoming_e, bowtie_v);
Vector3d ab = Mesh.GetVertex(bowtie_v) - Mesh.GetVertex(other_v);
// our winner
int best_e = -1;
double best_angle = double.MaxValue;
for (int i = 0; i < bdry_edges_count; ++i)
{
int bdry_eid = bdry_edges[i];
if (used_edges[bdry_eid] == true)
{
continue; // this edge is already used
}
Index2i bdry_ev = Mesh.GetOrientedBoundaryEdgeV(bdry_eid);
if (bdry_ev.a != bowtie_v)
{
continue; // have to be able to chain to end of current edge, orientation-wise
}
// compute projected angle
Vector3d bc = Mesh.GetVertex(bdry_ev.b) - Mesh.GetVertex(bowtie_v);
float fAngleS = MathUtil.PlaneAngleSignedD((Vector3f)ab, (Vector3f)bc, (Vector3f)n);
// turn left!
if (best_angle == double.MaxValue || fAngleS < best_angle)
{
best_angle = fAngleS;
best_e = bdry_eid;
}
}
// [RMS] w/ bowtie vertices and open spans, this does happen
//Debug.Assert(best_e != -1);
return(best_e);
}
/// <summary>
/// Find the set of boundary EdgeLoops. Note that if we encounter topological
/// issues, we will throw MeshBoundaryLoopsException w/ more info (if possible)
/// </summary>
public bool Compute()
{
// This algorithm assumes that triangles are oriented consistently,
// so closed boundary-loop can be followed by walking edges in-order
Loops = new List <EdgeLoop>();
Spans = new List <EdgeSpan>();
int NE = Mesh.MaxEdgeID;
// Temporary memory used to indicate when we have "used" an edge.
BitArray used_edge = new BitArray(NE);
used_edge.SetAll(false);
// current loop is stored here, cleared after each loop extracted
List <int> loop_edges = new List <int>(); // [RMS] not sure we need this...
List <int> loop_verts = new List <int>();
List <int> bowties = new List <int>();
// Temp buffer for reading back all boundary edges of a vertex.
// probably always small but in pathological cases it could be large...
int[] all_e = new int[16];
// [TODO] might make sense to precompute some things here, like num_be for each bdry vtx?
// process all edges of mesh
for (int eid = 0; eid < NE; ++eid)
{
if (!Mesh.IsEdge(eid))
{
continue;
}
if (used_edge[eid] == true)
{
continue;
}
if (Mesh.IsBoundaryEdge(eid) == false)
{
continue;
}
if (EdgeFilterF != null && EdgeFilterF(eid) == false)
{
used_edge[eid] = true;
continue;
}
// ok this is start of a boundary chain
int eStart = eid;
used_edge[eStart] = true;
loop_edges.Add(eStart);
int eCur = eid;
// follow the chain in order of oriented edges
bool bClosed = false;
bool bIsOpenSpan = false;
while (!bClosed)
{
Index2i ev = Mesh.GetOrientedBoundaryEdgeV(eCur);
int cure_a = ev.a, cure_b = ev.b;
if (bIsOpenSpan)
{
cure_a = ev.b; cure_b = ev.a;
}
else
{
loop_verts.Add(cure_a);
}
int e0 = -1, e1 = 1;
int bdry_nbrs = Mesh.VtxBoundaryEdges(cure_b, ref e0, ref e1);
// have to filter this list, if we are filtering. this is ugly.
if (EdgeFilterF != null)
{
if (bdry_nbrs > 2)
{
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[bdry_nbrs];
}
// we may repreat this below...irritating...
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
num_be = BufferUtil.CountValid(all_e, EdgeFilterF, num_be);
}
else
{
if (EdgeFilterF(e0) == false)
{
bdry_nbrs--;
}
if (EdgeFilterF(e1) == false)
{
bdry_nbrs--;
}
}
}
if (bdry_nbrs < 2) // hit an 'endpoint' vertex (should only happen when Filter is on...)
{
if (SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: found open span at vertex " + cure_b)
{
UnclosedLoop = true
}
}
;
if (bIsOpenSpan)
{
bClosed = true;
continue;
}
else
{
bIsOpenSpan = true; // begin open span
eCur = loop_edges[0]; // restart at other end of loop
loop_edges.Reverse(); // do this so we can push to front
continue;
}
}
int eNext = -1;
if (bdry_nbrs > 2)
{
// found "bowtie" vertex...things just got complicated!
if (cure_b == loop_verts[0])
{
// The "end" of the current edge is the same as the start vertex.
// This means we can close the loop here. Might as well!
eNext = -2; // sentinel value used below
}
else
{
// try to find an unused outgoing edge that is oriented properly.
// This could create sub-loops, we will handle those later
if (bdry_nbrs >= all_e.Length)
{
all_e = new int[2 * bdry_nbrs];
}
int num_be = Mesh.VtxAllBoundaryEdges(cure_b, all_e);
Debug.Assert(num_be == bdry_nbrs);
if (EdgeFilterF != null)
{
num_be = BufferUtil.FilterInPlace(all_e, EdgeFilterF, num_be);
}
// Try to pick the best "turn left" vertex.
eNext = find_left_turn_edge(eCur, cure_b, all_e, num_be, used_edge);
if (eNext == -1)
{
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: cannot find valid outgoing edge at bowtie vertex " + cure_b)
{
BowtieFailure = true
}
}
;
// ok, we are stuck. all we can do now is terminate this loop and keep it as a span
if (bIsOpenSpan)
{
bClosed = true;
}
else
{
bIsOpenSpan = true;
bClosed = true;
}
continue;
}
}
if (bowties.Contains(cure_b) == false)
{
bowties.Add(cure_b);
}
}
else
{
// walk forward to next available edge
Debug.Assert(e0 == eCur || e1 == eCur);
eNext = (e0 == eCur) ? e1 : e0;
}
if (eNext == -2)
{
// found a bowtie vert that is the same as start-of-loop, so we
// are just closing it off explicitly
bClosed = true;
}
else if (eNext == eStart)
{
// found edge at start of loop, so loop is done.
bClosed = true;
}
else if (used_edge[eNext] != false)
{
// disaster case - the next edge is already used, but it is not the start of our loop
// All we can do is convert to open span and terminate
if (FailureBehavior == FailureBehaviors.ThrowException || SpanBehavior == SpanBehaviors.ThrowException)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: encountered repeated edge " + eNext)
{
RepeatedEdge = true
}
}
;
bIsOpenSpan = true;
bClosed = true;
}
else
{
// push onto accumulated list
Debug.Assert(used_edge[eNext] == false);
loop_edges.Add(eNext);
used_edge[eNext] = true;
eCur = eNext;
}
}
if (bIsOpenSpan)
{
SawOpenSpans = true;
if (SpanBehavior == SpanBehaviors.Compute)
{
loop_edges.Reverse(); // orient properly
EdgeSpan span = EdgeSpan.FromEdges(Mesh, loop_edges);
Spans.Add(span);
}
}
else if (bowties.Count > 0)
{
// if we saw a bowtie vertex, we might need to break up this loop,
// so call extract_subloops
List <EdgeLoop> subloops = extract_subloops(loop_verts, loop_edges, bowties);
for (int i = 0; i < subloops.Count; ++i)
{
Loops.Add(subloops[i]);
}
}
else
{
// clean simple loop, convert to EdgeLoop instance
EdgeLoop loop = new EdgeLoop(Mesh);
loop.Vertices = loop_verts.ToArray();
loop.Edges = loop_edges.ToArray();
Loops.Add(loop);
}
// reset these lists
loop_edges.Clear();
loop_verts.Clear();
bowties.Clear();
}
return(true);
}
// [TODO] cache this in a dictionary? we will not need very many, but we will
// need each multiple times!
Vector3d get_vtx_normal(int vid)
{
Vector3d n = Vector3d.Zero;
foreach (int ti in Mesh.VtxTrianglesItr(vid))
{
n += Mesh.GetTriNormal(ti);
}
n.Normalize();
return(n);
}
// ok, bdry_edges[0...bdry_edges_count] contains the boundary edges coming out of bowtie_v.
// We want to pick the best one to continue the loop that came in to bowtie_v on incoming_e.
// If the loops are all sane, then we will get the smallest loops by "turning left" at bowtie_v.
// So, we compute the tangent plane at bowtie_v, and then the signed angle for each
// viable edge in this plane.
//
// [TODO] handle degenerate edges. what do we do then? Currently will only chose
// degenerate edge if there are no other options (I think...)
int find_left_turn_edge(int incoming_e, int bowtie_v, int[] bdry_edges, int bdry_edges_count, BitArray used_edges)
{
// compute normal and edge [a,bowtie]
Vector3d n = get_vtx_normal(bowtie_v);
int other_v = Mesh.edge_other_v(incoming_e, bowtie_v);
Vector3d ab = Mesh.GetVertex(bowtie_v) - Mesh.GetVertex(other_v);
// our winner
int best_e = -1;
double best_angle = double.MaxValue;
for (int i = 0; i < bdry_edges_count; ++i)
{
int bdry_eid = bdry_edges[i];
if (used_edges[bdry_eid] == true)
{
continue; // this edge is already used
}
Index2i bdry_ev = Mesh.GetOrientedBoundaryEdgeV(bdry_eid);
if (bdry_ev.a != bowtie_v)
{
continue; // have to be able to chain to end of current edge, orientation-wise
}
// compute projected angle
Vector3d bc = Mesh.GetVertex(bdry_ev.b) - Mesh.GetVertex(bowtie_v);
float fAngleS = MathUtil.PlaneAngleSignedD((Vector3f)ab, (Vector3f)bc, (Vector3f)n);
// turn left!
if (best_angle == double.MaxValue || fAngleS < best_angle)
{
best_angle = fAngleS;
best_e = bdry_eid;
}
}
// [RMS] w/ bowtie vertices and open spans, this does happen
//Debug.Assert(best_e != -1);
return(best_e);
}
// This is called when loopV contains one or more "bowtie" vertices.
// These vertices *might* be duplicated in loopV (but not necessarily)
// If they are, we have to break loopV into subloops that don't contain duplicates.
//
// The list bowties contains all the possible duplicates
// (all v in bowties occur in loopV at least once)
//
// Currently loopE is not used, and the returned EdgeLoop objects do not have their Edges
// arrays initialized. Perhaps to improve in future.
List <EdgeLoop> extract_subloops(List <int> loopV, List <int> loopE, List <int> bowties)
{
List <EdgeLoop> subs = new List <EdgeLoop>();
// figure out which bowties we saw are actually duplicated in loopV
List <int> dupes = new List <int>();
foreach (int bv in bowties)
{
if (count_in_list(loopV, bv) > 1)
{
dupes.Add(bv);
}
}
// we might not actually have any duplicates, if we got luck. Early out in that case
if (dupes.Count == 0)
{
subs.Add(new EdgeLoop(Mesh)
{
Vertices = loopV.ToArray(), Edges = loopE.ToArray(), BowtieVertices = bowties.ToArray()
});
return(subs);
}
// This loop extracts subloops until we have dealt with all the
// duplicate vertices in loopV
while (dupes.Count > 0)
{
// Find shortest "simple" loop, ie a loop from a bowtie to itself that
// does not contain any other bowties. This is an independent loop.
// We're doing a lot of extra work here if we only have one element in dupes...
int bi = 0, bv = 0;
int start_i = -1, end_i = -1;
int bv_shortest = -1; int shortest = int.MaxValue;
for ( ; bi < dupes.Count; ++bi)
{
bv = dupes[bi];
if (is_simple_bowtie_loop(loopV, dupes, bv, out start_i, out end_i))
{
int len = count_span(loopV, start_i, end_i);
if (len < shortest)
{
bv_shortest = bv;
shortest = len;
}
}
}
if (bv_shortest == -1)
{
throw new MeshBoundaryLoopsException("MeshBoundaryLoops.Compute: Cannot find a valid simple loop");
}
if (bv != bv_shortest)
{
bv = bv_shortest;
// running again just to get start_i and end_i...
is_simple_bowtie_loop(loopV, dupes, bv, out start_i, out end_i);
}
Debug.Assert(loopV[start_i] == bv && loopV[end_i] == bv);
EdgeLoop loop = new EdgeLoop(Mesh);
loop.Vertices = extract_span(loopV, start_i, end_i, true);
loop.Edges = EdgeLoop.VertexLoopToEdgeLoop(Mesh, loop.Vertices);
loop.BowtieVertices = bowties.ToArray();
subs.Add(loop);
// If there are no more duplicates of this bowtie, we can treat
// it like a regular vertex now
if (count_in_list(loopV, bv) < 2)
{
dupes.Remove(bv);
}
}
// Should have one loop left that contains duplicates.
// Extract this as a separate loop
int nLeft = 0;
for (int i = 0; i < loopV.Count; ++i)
{
if (loopV[i] != -1)
{
nLeft++;
}
}
if (nLeft > 0)
{
EdgeLoop loop = new EdgeLoop(Mesh);
loop.Vertices = new int[nLeft];
int vi = 0;
for (int i = 0; i < loopV.Count; ++i)
{
if (loopV[i] != -1)
{
loop.Vertices[vi++] = loopV[i];
}
}
loop.Edges = EdgeLoop.VertexLoopToEdgeLoop(Mesh, loop.Vertices);
loop.BowtieVertices = bowties.ToArray();
subs.Add(loop);
}
return(subs);
}
/*
* In all the functions below, the list loopV is assumed to possibly
* contain "removed" vertices indicated by -1. These are ignored.
*/
// Check if the loop from bowtieV to bowtieV inside loopV contains any other bowtie verts.
// Also returns start and end indices in loopV of "clean" loop
// Note that start may be < end, if the "clean" loop wraps around the end
bool is_simple_bowtie_loop(List <int> loopV, List <int> bowties, int bowtieV, out int start_i, out int end_i)
{
// find two indices of bowtie vert
start_i = find_index(loopV, 0, bowtieV);
end_i = find_index(loopV, start_i + 1, bowtieV);
if (is_simple_path(loopV, bowties, bowtieV, start_i, end_i))
{
return(true);
}
else if (is_simple_path(loopV, bowties, bowtieV, end_i, start_i))
{
int tmp = start_i; start_i = end_i; end_i = tmp;
return(true);
}
else
{
return(false); // not a simple bowtie loop!
}
}
// check if forward path from loopV[i1] to loopV[i2] contains any bowtie verts other than bowtieV
bool is_simple_path(List <int> loopV, List <int> bowties, int bowtieV, int i1, int i2)
{
int N = loopV.Count;
for (int i = i1; i != i2; i = (i + 1) % N)
{
int vi = loopV[i];
if (vi == -1)
{
continue; // skip removed vertices
}
if (vi != bowtieV && bowties.Contains(vi))
{
return(false);
}
}
return(true);
}
// Read out the span from loop[i0] to loop [i1-1] into an array.
// If bMarkInvalid, then these values are set to -1 in loop
int[] extract_span(List <int> loop, int i0, int i1, bool bMarkInvalid)
{
int num = count_span(loop, i0, i1);
int[] a = new int[num];
int ai = 0;
int N = loop.Count;
for (int i = i0; i != i1; i = (i + 1) % N)
{
if (loop[i] != -1)
{
a[ai++] = loop[i];
if (bMarkInvalid)
{
loop[i] = -1;
}
}
}
return(a);
}
// count number of valid vertices in l between loop[i0] and loop[i1-1]
int count_span(List <int> l, int i0, int i1)
{
int c = 0;
int N = l.Count;
for (int i = i0; i != i1; i = (i + 1) % N)
{
if (l[i] != -1)
{
c++;
}
}
return(c);
}
// find the index of item in loop, starting at start index
int find_index(List <int> loop, int start, int item)
{
for (int i = start; i < loop.Count; ++i)
{
if (loop[i] == item)
{
return(i);
}
}
return(-1);
}
// count number of times item appears in loop
int count_in_list(List <int> loop, int item)
{
int c = 0;
for (int i = 0; i < loop.Count; ++i)
{
if (loop[i] == item)
{
c++;
}
}
return(c);
}
}
}
public virtual bool Apply()
{
insert_corners();
// [RMS] not using this?
//HashSet<int> corner_v = new HashSet<int>(CurveVertices);
// not sure we need to track all of these
HashSet <int> ZeroEdges = new HashSet <int>();
HashSet <int> ZeroVertices = new HashSet <int>();
OnCutEdges = new HashSet <int>();
// loop over segments, insert each one in sequence
int N = (IsLoop) ? Curve.VertexCount : Curve.VertexCount - 1;
for (int si = 0; si < N; ++si)
{
int i0 = si;
int i1 = (si + 1) % Curve.VertexCount;
Segment2d seg = new Segment2d(Curve[i0], Curve[i1]);
int i0_vid = CurveVertices[i0];
int i1_vid = CurveVertices[i1];
// If these vertices are already connected by an edge, we can just continue.
int existing_edge = Mesh.FindEdge(i0_vid, i1_vid);
if (existing_edge != DMesh3.InvalidID)
{
OnCutEdges.Add(existing_edge);
continue;
}
// compute edge-crossing signs
// [TODO] could walk along mesh from a to b, rather than computing for entire mesh?
int MaxVID = Mesh.MaxVertexID;
int[] signs = new int[MaxVID];
gParallel.ForEach(Interval1i.Range(MaxVID), (vid) => {
if (Mesh.IsVertex(vid))
{
if (vid == i0_vid || vid == i1_vid)
{
signs[vid] = 0;
}
else
{
Vector2d v2 = PointF(vid);
// tolerance defines band in which we will consider values to be zero
signs[vid] = seg.WhichSide(v2, MathUtil.ZeroTolerance);
}
}
else
{
signs[vid] = int.MaxValue;
}
});
// have to skip processing of new edges. If edge id
// is > max at start, is new. Otherwise if in NewEdges list, also new.
// (need both in case we re-use an old edge index)
int MaxEID = Mesh.MaxEdgeID;
HashSet <int> NewEdges = new HashSet <int>();
HashSet <int> NewCutVertices = new HashSet <int>();
NewCutVertices.Add(i0_vid);
NewCutVertices.Add(i1_vid);
// cut existing edges with segment
for (int eid = 0; eid < MaxEID; ++eid)
{
if (Mesh.IsEdge(eid) == false)
{
continue;
}
if (eid >= MaxEID || NewEdges.Contains(eid))
{
continue;
}
// cannot cut boundary edges?
if (Mesh.IsBoundaryEdge(eid))
{
continue;
}
Index2i ev = Mesh.GetEdgeV(eid);
int eva_sign = signs[ev.a];
int evb_sign = signs[ev.b];
bool eva_in_segment = false;
if (eva_sign == 0)
{
eva_in_segment = Math.Abs(seg.Project(PointF(ev.a))) < (seg.Extent + MathUtil.ZeroTolerance);
}
bool evb_in_segment = false;
if (evb_sign == 0)
{
evb_in_segment = Math.Abs(seg.Project(PointF(ev.b))) < (seg.Extent + MathUtil.ZeroTolerance);
}
// If one or both vertices are on-segment, we have special case.
// If just one vertex is on the segment, we can skip this edge.
// If both vertices are on segment, then we can just re-use this edge.
if (eva_in_segment || evb_in_segment)
{
if (eva_in_segment && evb_in_segment)
{
ZeroEdges.Add(eid);
OnCutEdges.Add(eid);
}
else
{
ZeroVertices.Add(eva_in_segment ? ev.a : ev.b);
}
continue;
}
// no crossing
if (eva_sign * evb_sign > 0)
{
continue;
}
// compute segment/segment intersection
Vector2d va = PointF(ev.a);
Vector2d vb = PointF(ev.b);
Segment2d edge_seg = new Segment2d(va, vb);
IntrSegment2Segment2 intr = new IntrSegment2Segment2(seg, edge_seg);
intr.Compute();
if (intr.Type == IntersectionType.Segment)
{
// [RMS] we should have already caught this above, so if it happens here it is probably spurious?
// we should have caught this case above, but numerics are different so it might occur again
ZeroEdges.Add(eid);
OnCutEdges.Add(eid);
continue;
}
else if (intr.Type != IntersectionType.Point)
{
continue; // no intersection
}
Vector2d x = intr.Point0;
// this case happens if we aren't "on-segment" but after we do the test the intersection pt
// is within epsilon of one end of the edge. This is a spurious t-intersection and we
// can ignore it. Some other edge should exist that picks up this vertex as part of it.
// [TODO] what about if this edge is degenerate?
bool x_in_segment = Math.Abs(edge_seg.Project(x)) < (edge_seg.Extent - MathUtil.ZeroTolerance);
if (!x_in_segment)
{
continue;
}
// split edge at this segment
DMesh3.EdgeSplitInfo splitInfo;
MeshResult result = Mesh.SplitEdge(eid, out splitInfo);
if (result != MeshResult.Ok)
{
throw new Exception("MeshInsertUVSegment.Cut: failed in SplitEdge");
//return false;
}
// move split point to intersection position
SetPointF(splitInfo.vNew, x);
NewCutVertices.Add(splitInfo.vNew);
NewEdges.Add(splitInfo.eNewBN);
NewEdges.Add(splitInfo.eNewCN);
// some splits - but not all - result in new 'other' edges that are on
// the polypath. We want to keep track of these edges so we can extract loop later.
Index2i ecn = Mesh.GetEdgeV(splitInfo.eNewCN);
if (NewCutVertices.Contains(ecn.a) && NewCutVertices.Contains(ecn.b))
{
OnCutEdges.Add(splitInfo.eNewCN);
}
// since we don't handle bdry edges this should never be false, but maybe we will handle bdry later...
if (splitInfo.eNewDN != DMesh3.InvalidID)
{
NewEdges.Add(splitInfo.eNewDN);
Index2i edn = Mesh.GetEdgeV(splitInfo.eNewDN);
if (NewCutVertices.Contains(edn.a) && NewCutVertices.Contains(edn.b))
{
OnCutEdges.Add(splitInfo.eNewDN);
}
}
}
}
//MeshEditor editor = new MeshEditor(Mesh);
//foreach (int eid in OnCutEdges)
// editor.AppendBox(new Frame3f(Mesh.GetEdgePoint(eid, 0.5)), 0.1f);
//Util.WriteDebugMesh(Mesh, string.Format("C:\\git\\geometry3SharpDemos\\geometry3Test\\test_output\\after_inserted.obj"));
// extract the cut paths
if (EnableCutSpansAndLoops)
{
find_cut_paths(OnCutEdges);
}
return(true);
} // Apply()