/// <summary>
/// Returns a boolean indicating whether this Geometry <paramref name="g0"/> is within <paramref name="distanceInMeter"/> meters
/// of Geometry <paramref name="g1"/>.
/// </summary>
/// <param name="g0">Geometry 1</param>
/// <param name="g1">Geometry 2</param>
/// <param name="distanceInMeter">The distance limit</param>
/// <returns>true if the geometries are within distance, false if not and NULL if unable to calculate</returns>
/// <exception cref="ArgumentNullException">g0 or g1 is null</exception>
/// <exception cref="ArgumentOutOfRangeException">The SRID of g0 and g1 don't match, are 0 or can't be resolved using <see cref="SridRegister"/></exception>
/// <exception cref="ArgumentException"></exception>
public static bool?IsWithinMeterDistance(this Geometry g0, Geometry g1, double distanceInMeter)
{
if (g0 == null)
{
throw new ArgumentNullException(nameof(g0));
}
else if (g1 == null)
{
throw new ArgumentNullException(nameof(g1));
}
int srid = g0.SRID;
if (srid == 0 || g1.SRID != g0.SRID)
{
throw new ArgumentOutOfRangeException("SRID is 0 or doesn't match");
}
DistanceOp distanceOp = new DistanceOp(g0, g1);
Coordinate[] nearestPoints = distanceOp.NearestPoints();
SridItem sridItem;
try
{
sridItem = SridRegister.GetByValue(srid);
}
catch (IndexOutOfRangeException sridExcepton)
{
throw new ArgumentOutOfRangeException("SRID not resolveable", sridExcepton);
}
// TODO: There should be possible optimizations now, with knowledg of the CRS
// Maybe we can assume that this is always false if the NTS cut-off thinks it's false
// Not 100% sure and we want correctness
using (var dt = sridItem.CRS.DistanceTransform.Clone()) // Thread safe with clone
{
double d = dt.GeoDistance(nearestPoints[0].ToPPoint(), nearestPoints[1].ToPPoint());
if (double.IsInfinity(d) || double.IsNaN(d))
{
return(null);
}
else
{
return(d <= distanceInMeter);
}
}
}
private static double?MeterDistance(this Geometry g0, Geometry g1, CoordinateTransform dt)
{
DistanceOp distanceOp = new DistanceOp(g0, g1);
Coordinate[] nearestPoints = distanceOp.NearestPoints();
double d = dt.GeoDistance(nearestPoints[0].ToPPoint(), nearestPoints[1].ToPPoint());
if (double.IsInfinity(d) || double.IsNaN(d))
{
return(null);
}
else
{
return(d);
}
}
