/// <summary>
/// Computes the Euclidean distance (L2 metric) from a <see cref="Coordinate"/> to a <see cref="Geometry"/>.
/// </summary>
/// <param name="geom">The geometry</param>
/// <param name="pt">The Point</param>
/// <param name="ptDist">The <c>PointPairDistance</c></param>
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);
}
}
/// <summary>
/// Computes the Euclidean distance (L2 metric) from a <see cref="Coordinate"/> to a <see cref="LineString"/>.
/// </summary>
/// <param name="line">The <c>LineString</c></param>
/// <param name="pt">The Point</param>
/// <param name="ptDist">The <c>PointPairDistance</c></param>
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);
}
}
/// <summary>
/// Computes the Euclidean distance (L2 metric) from a <see cref="Coordinate"/> to a <see cref="LineSegment"/>.
/// </summary>
/// <param name="segment">The <c>LineSegment</c></param>
/// <param name="pt">The Point</param>
/// <param name="ptDist">The <c>PointPairDistance</c></param>
public static void ComputeDistance(LineSegment segment, Coordinate pt, PointPairDistance ptDist)
{
var closestPt = segment.ClosestPoint(pt);
ptDist.SetMinimum(closestPt, pt);
}