/// <summary>
/// Merges the constraint data in the vertex <tt>other</tt> into this vertex.
/// This method is called when an inserted vertex is
/// very close to an existing vertex in the triangulation.
/// </summary>
/// <param name="other">the constraint vertex to merge</param>
protected internal void Merge(ConstraintVertex other)
{
if (other.isOnConstraint)
{
isOnConstraint = true;
constraint = other.constraint;
}
}
private void CreateVertices(IGeometry geom)
{
Coordinate[] coords = geom.Coordinates;
for (int i = 0; i < coords.Length; i++)
{
Vertex v = new ConstraintVertex(coords[i]);
_constraintVertexMap.Add(coords[i], v);
}
}
private ConstraintVertex CreateVertex(Coordinate p)
{
ConstraintVertex v = null;
if (_vertexFactory != null)
{
v = _vertexFactory.CreateVertex(p, null);
}
else
{
v = new ConstraintVertex(p);
}
return(v);
}
/// <summary>
/// Creates a vertex on a constraint segment
/// </summary>
/// <param name="p">the location of the vertex to create</param>
/// <param name="seg">the constraint segment it lies on</param>
/// <returns>the new constraint vertex</returns>
private ConstraintVertex CreateVertex(Coordinate p, Segment seg)
{
ConstraintVertex v;
if (_vertexFactory != null)
{
v = _vertexFactory.CreateVertex(p, seg);
}
else
{
v = new ConstraintVertex(p);
}
v.IsOnConstraint = true;
return(v);
}
private ConstraintVertex InsertSite(ConstraintVertex v)
{
KdNode <Vertex> kdnode = _kdt.Insert(v.Coordinate, v);
if (!kdnode.IsRepeated)
{
_incDel.InsertSite(v);
}
else
{
ConstraintVertex snappedV = (ConstraintVertex)kdnode.Data;
snappedV.Merge(v);
return(snappedV);
// testing
// if ( v.isOnConstraint() && ! currV.isOnConstraint()) {
// System.out.println(v);
// }
}
return(v);
}
/*
* private List findMissingConstraints() { List missingSegs = new ArrayList();
* for (int i = 0; i < segments.size(); i++) { Segment s = (Segment)
* segments.get(i); QuadEdge q = subdiv.locate(s.getStart(), s.getEnd()); if
* (q == null) missingSegs.add(s); } return missingSegs; }
*/
private int EnforceGabriel(ICollection <Segment> segsToInsert)
{
List <Segment> newSegments = new List <Segment>();
int splits = 0;
List <Segment> segsToRemove = new List <Segment>();
/*
* On each iteration must always scan all constraint (sub)segments, since
* some constraints may be rebroken by Delaunay triangle flipping caused by
* insertion of another constraint. However, this process must converge
* eventually, with no splits remaining to find.
*/
foreach (Segment seg in segsToInsert)
{
// System.out.println(seg);
Coordinate encroachPt = FindNonGabrielPoint(seg);
// no encroachment found - segment must already be in subdivision
if (encroachPt == null)
{
continue;
}
// compute split point
_splitPt = _splitFinder.FindSplitPoint(seg, encroachPt);
ConstraintVertex splitVertex = CreateVertex(_splitPt, seg);
/*
* Check whether the inserted point still equals the split pt. This will
* not be the case if the split pt was too close to an existing site. If
* the point was snapped, the triangulation will not respect the inserted
* constraint - this is a failure. This can be caused by:
* <ul>
* <li>An initial site that lies very close to a constraint segment The
* cure for this is to remove any initial sites which are close to
* constraint segments in a preprocessing phase.
* <li>A narrow constraint angle which causing repeated splitting until
* the split segments are too small. The cure for this is to either choose
* better split points or "guard" narrow angles by cracking the segments
* equidistant from the corner.
* </ul>
*/
ConstraintVertex insertedVertex = InsertSite(splitVertex);
//Debugging FObermaier
//Console.WriteLine("inserted vertex: " + insertedVertex.ToString());
if (!insertedVertex.Coordinate.Equals2D(_splitPt))
{
Debug.WriteLine("Split pt snapped to: " + insertedVertex);
// throw new ConstraintEnforcementException("Split point snapped to
// existing point
// (tolerance too large or constraint interior narrow angle?)",
// splitPt);
}
// split segment and record the new halves
Segment s1 = new Segment(seg.StartX, seg.StartY, seg.StartZ,
splitVertex.X, splitVertex.Y, splitVertex.Z,
seg.Data);
Segment s2 = new Segment(splitVertex.X, splitVertex.Y, splitVertex.Z,
seg.EndX, seg.EndY, seg.EndZ,
seg.Data);
//Debugging FObermaier
//Console.WriteLine("Segment " + seg.ToString() + " splitted to \n\t" + s1.ToString() + "\n\t"+ s2.ToString());
newSegments.Add(s1);
newSegments.Add(s2);
segsToRemove.Add(seg);
splits = splits + 1;
}
foreach (Segment seg in segsToRemove)
{
segsToInsert.Remove(seg);
}
foreach (Segment seg in newSegments)
{
segsToInsert.Add(seg);
}
return(splits);
}