public static void ComputeDistance(Geometry geom, Coordinate pt, PointPairDistance ptDist)
{
if (geom is LineString)
{
ComputeDistance((LineString)geom, pt, ptDist);
}
else if (geom is Polygon)
{
ComputeDistance((Polygon)geom, pt, ptDist);
}
else if (geom is GeometryCollection)
{
var gc = (GeometryCollection)geom;
for (int i = 0; i < gc.NumGeometries; i++)
{
var g = gc.GetGeometryN(i);
ComputeDistance(g, pt, ptDist);
}
}
else
{
// assume geom is Point
ptDist.SetMinimum(geom.Coordinate, pt);
}
}
public static void ComputeDistance(Polygon poly, Coordinate pt, PointPairDistance ptDist)
{
ComputeDistance(poly.ExteriorRing, pt, ptDist);
for (int i = 0; i < poly.NumInteriorRings; i++)
{
ComputeDistance(poly.GetInteriorRingN(i), pt, ptDist);
}
}
public static void ComputeDistance(LineString line, Coordinate pt, PointPairDistance ptDist)
{
var coords = line.Coordinates;
var tempSegment = new LineSegment();
for (int i = 0; i < coords.Length - 1; i++)
{
tempSegment.SetCoordinates(coords[i], coords[i + 1]);
// this is somewhat inefficient - could do better
var closestPt = tempSegment.ClosestPoint(pt);
ptDist.SetMinimum(closestPt, pt);
}
}
public void SetMinimum(PointPairDistance ptDist)
{
SetMinimum(ptDist._pt[0], ptDist._pt[1]);
}
public static void ComputeDistance(LineSegment segment, Coordinate pt, PointPairDistance ptDist)
{
var closestPt = segment.ClosestPoint(pt);
ptDist.SetMinimum(closestPt, pt);
}