public List <Vector2d> FindIntersections(Polygon2d o)
{
List <Vector2d> v = new List <Vector2d>();
if (!this.GetBounds().Intersects(o.GetBounds()))
{
return(v);
}
foreach (Segment2d seg in SegmentItr())
{
foreach (Segment2d oseg in o.SegmentItr())
{
// this computes test twice for intersections, but seg.intersects doesn't
// create any new objects so it should be much faster for majority of segments (should profile!)
if (seg.Intersects(oseg))
{
IntrSegment2Segment2 intr = new IntrSegment2Segment2(seg, oseg);
if (intr.Find())
{
v.Add(intr.Point0);
if (intr.Quantity == 2)
{
v.Add(intr.Point1);
}
}
}
}
}
return(v);
}
/// <summary>
/// find set of edges in graph that intersect with edge [a,b]
/// </summary>
protected bool find_intersecting_edges(ref Vector2d a, ref Vector2d b, List <Intersection> hits, double tol = 0)
{
int num_hits = 0;
Vector2d x = Vector2d.Zero, y = Vector2d.Zero;
foreach (int eid in Graph.EdgeIndices())
{
Graph.GetEdgeV(eid, ref x, ref y);
int sidex = Segment2d.WhichSide(ref a, ref b, ref x, tol);
int sidey = Segment2d.WhichSide(ref a, ref b, ref y, tol);
if (sidex == sidey && sidex != 0)
{
continue; // both pts on same side
}
IntrSegment2Segment2 intr = new IntrSegment2Segment2(new Segment2d(x, y), new Segment2d(a, b));
if (intr.Find())
{
hits.Add(new Intersection()
{
eid = eid, sidex = sidex, sidey = sidey, intr = intr
});
num_hits++;
}
}
return(num_hits > 0);
}
public List <Vector2d> FindIntersections(Polygon2d o)
{
List <Vector2d> v = new List <Vector2d>();
if (!this.GetBounds().Intersects(o.GetBounds()))
{
return(v);
}
foreach (Segment2d seg in SegmentItr())
{
foreach (Segment2d oseg in o.SegmentItr())
{
IntrSegment2Segment2 intr = new IntrSegment2Segment2(seg, oseg);
if (intr.Find())
{
v.Add(intr.Point0);
if (intr.Quantity == 2)
{
v.Add(intr.Point1);
}
break;
}
}
}
return(v);
}
/// <summary>
/// Find any segment in set that intersects input segment.
/// Returns intersection test, and index of segment
/// </summary>
public IntrSegment2Segment2 FindAnyIntersection(Segment2d seg, out int iSegment)
{
int N = Segments.Count;
for (iSegment = 0; iSegment < N; ++iSegment)
{
var intr = new IntrSegment2Segment2(seg, Segments[iSegment]);
if (intr.Find())
{
return(intr);
}
}
return(null);
}
public bool Intersects(Polygon2d o)
{
if (!this.GetBounds().Intersects(o.GetBounds()))
{
return(false);
}
foreach (Segment2d seg in SegmentItr())
{
foreach (Segment2d oseg in o.SegmentItr())
{
IntrSegment2Segment2 intr = new IntrSegment2Segment2(seg, oseg);
if (intr.Find())
{
return(true);
}
}
}
return(false);
}
public void FindAllIntersections(Segment2d seg, List <double> segmentTs, List <int> indices = null, List <IntrSegment2Segment2> tests = null, bool bOnlySimple = true)
{
int N = Segments.Count;
for (int i = 0; i < N; ++i)
{
// want to make sure we do not miss any hits, even if it means
// we get duplicates...
var intr = new IntrSegment2Segment2(seg, Segments[i])
{
IntervalThreshold = MathUtil.ZeroTolerance
};
if (intr.Find())
{
if (bOnlySimple && intr.IsSimpleIntersection == false)
{
continue;
}
if (tests != null)
{
tests.Add(intr);
}
if (indices != null)
{
indices.Add(i);
}
if (segmentTs != null)
{
segmentTs.Add(intr.Parameter0);
if (!intr.IsSimpleIntersection)
{
segmentTs.Add(intr.Parameter1);
}
}
}
}
}
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()
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()
