/// <summary>
/// Computes the distance to another facet sequence
/// </summary>
/// <param name="facetSeq">The other facet sequence</param>
/// <returns>The distance between this and <paramref name="facetSeq"/>.</returns>
public double Distance(FacetSequence facetSeq)
{
bool isPoint = IsPoint;
bool isPointOther = facetSeq.IsPoint;
if (isPoint && isPointOther)
{
_pts.GetCoordinate(_start, _pt);
facetSeq._pts.GetCoordinate(facetSeq._start, _seqPt);
return(_pt.Distance(_seqPt));
}
if (isPoint)
{
_pts.GetCoordinate(_start, _pt);
return(ComputePointLineDistance(_pt, facetSeq));
}
if (isPointOther)
{
facetSeq._pts.GetCoordinate(facetSeq._start, _seqPt);
return(ComputePointLineDistance(_seqPt, this));
}
return(ComputeLineLineDistance(facetSeq));
}
//// temporary Coordinates to materialize points from the CoordinateSequence
//private readonly Coordinate _p0 = new Coordinate();
//private readonly Coordinate _p1 = new Coordinate();
//private readonly Coordinate _q0 = new Coordinate();
//private readonly Coordinate _q1 = new Coordinate();
private double ComputeLineLineDistance(FacetSequence facetSeq)
{
// both linear - compute minimum segment-segment distance
var minDistance = Double.MaxValue;
var p0 = new Coordinate();
var p1 = new Coordinate();
var q0 = new Coordinate();
var q1 = new Coordinate();
for (int i = _start; i < _end - 1; i++)
{
for (int j = facetSeq._start; j < facetSeq._end - 1; j++)
{
_pts.GetCoordinate(i, p0);
_pts.GetCoordinate(i + 1, p1);
facetSeq._pts.GetCoordinate(j, q0);
facetSeq._pts.GetCoordinate(j + 1, q1);
double dist = DistanceComputer.SegmentToSegment(p0, p1, q0, q1);
if (dist == 0.0)
{
return(0.0);
}
if (dist < minDistance)
{
minDistance = dist;
}
}
}
return(minDistance);
}
private static void AddFacetSequences(ICoordinateSequence pts, List <FacetSequence> sections)
{
int i = 0;
int size = pts.Count;
while (i <= size - 1)
{
int end = i + FacetSequenceSize + 1;
// if only one point remains after this section, include it in this
// section
if (end >= size - 1)
{
end = size;
}
var sect = new FacetSequence(pts, i, end);
sections.Add(sect);
i = i + FacetSequenceSize;
}
}
private static double ComputePointLineDistance(Coordinate pt, FacetSequence facetSeq)
{
var minDistance = Double.MaxValue;
var q0 = new Coordinate();
var q1 = new Coordinate();
for (var i = facetSeq._start; i < facetSeq._end - 1; i++)
{
facetSeq._pts.GetCoordinate(i, q0);
facetSeq._pts.GetCoordinate(i + 1, q1);
var dist = DistanceComputer.PointToSegment(pt, q0, q1);
if (dist == 0.0)
{
return(0.0);
}
if (dist < minDistance)
{
minDistance = dist;
}
}
return(minDistance);
}