private bool ComputationallyEqual(IDatumGeodetic a, IDatumGeodetic b)
{
if (a == b)
{
return(true);
}
if (a == null || b == null)
{
return(false);
}
if (!ComputationallyEqual(a.Spheroid, b.Spheroid))
{
return(false);
}
if (!ComputationallyEqual(a.PrimeMeridian, b.PrimeMeridian))
{
return(false);
}
if (a.IsTransformableToWgs84)
{
return(b.IsTransformableToWgs84 &&
ComputationallyEqual(a.BasicWgs84Transformation, b.BasicWgs84Transformation));
}
else
{
return(b.IsTransformableToWgs84 == false);
}
}
public static Datum Create(IDatumGeodetic datum)
{
if (datum == null)
{
throw new ArgumentNullException("datum");
}
Contract.Ensures(Contract.Result <Datum>() != null);
var result = new Datum {
Name = datum.Name
};
result.Spheroid = Proj4SpheroidWrapper.Create(datum.Spheroid);
if (datum.IsTransformableToWgs84)
{
var helmert = datum.BasicWgs84Transformation;
if (helmert.ScaleDeltaPartsPerMillion == 0 && Vector3.Zero.Equals(helmert.RotationArcSeconds))
{
if (Vector3.Zero.Equals(helmert.Delta))
{
if (result.Spheroid.Name == "WE")
{
result.Proj4DatumName = "wgs84";
}
else
{
result.DatumType = DatumType.WGS84;
}
}
else
{
result.ToWGS84 = new[] {
helmert.Delta.X, helmert.Delta.Y, helmert.Delta.Z
};
result.DatumType = DatumType.Param3;
}
}
else
{
result.ToWGS84 = new[] {
helmert.Delta.X, helmert.Delta.Y, helmert.Delta.Z,
helmert.RotationArcSeconds.X, helmert.RotationArcSeconds.Y, helmert.RotationArcSeconds.Z,
helmert.ScaleDeltaPartsPerMillion
};
result.DatumType = DatumType.Param7;
}
}
else
{
result.DatumType = DatumType.Unknown;
}
return(result);
}
/// <summary>
/// Constructs a new geocentric CRS.
/// </summary>
/// <param name="name">The name of the CRS.</param>
/// <param name="datum">The datum the CRS is based on.</param>
/// <param name="linearUnit">The linear UoM to use for the CRS.</param>
/// <param name="axes">The axes which define the space.</param>
/// <param name="authority">The authority.</param>
public OgcCrsGeocentric(
string name,
IDatumGeodetic datum,
IUnit linearUnit,
IEnumerable<IAxis> axes,
IAuthorityTag authority
)
: base(name, authority)
{
if (null == datum) throw new ArgumentNullException("datum");
if (null == linearUnit) throw new ArgumentNullException("linearUnit");
Contract.Requires(name != null);
Datum = datum;
Unit = linearUnit;
Axes = Array.AsReadOnly(null == axes ? new IAxis[0] : axes.ToArray());
}
/// <summary>
/// Constructs a new geographic CRS.
/// </summary>
/// <param name="name">The name of the CRS.</param>
/// <param name="datum">The datum the CRS is based on.</param>
/// <param name="angularUnit">The angular unit of measure for the CRS.</param>
/// <param name="axes">The axes defining the space.</param>
/// <param name="authority">The authority.</param>
public OgcCrsGeographic(
string name,
IDatumGeodetic datum,
IUnit angularUnit,
IEnumerable <IAxis> axes,
IAuthorityTag authority = null
)
: base(name, authority)
{
if (null == datum)
{
throw new ArgumentNullException("datum");
}
if (null == angularUnit)
{
throw new ArgumentNullException("angularUnit");
}
Contract.Requires(name != null);
Datum = datum;
Unit = angularUnit;
Axes = Array.AsReadOnly(null == axes ? new IAxis[0] : axes.ToArray());
}
private ICrsGeographic ReadGeographicCsFromParams()
{
Contract.Ensures(Contract.Result <ICrsGeographic>() != null);
IAuthorityTag authority = null;
var name = String.Empty;
IDatumGeodetic datum = null;
IPrimeMeridianInfo primeMeridian = null;
IUnit unit = OgcAngularUnit.DefaultDegrees;
var axes = new List <IAxis>();
foreach (var parameter in ReadParams())
{
if (parameter is string)
{
name = (string)parameter;
}
else if (parameter is IAuthorityTag)
{
authority = (IAuthorityTag)parameter;
}
else if (parameter is IDatumGeodetic)
{
datum = (IDatumGeodetic)parameter;
}
else if (parameter is IPrimeMeridianInfo)
{
primeMeridian = (IPrimeMeridianInfo)parameter;
}
else if (parameter is IUnit)
{
unit = (IUnit)parameter;
}
else if (parameter is IAxis)
{
axes.Add((IAxis)parameter);
}
}
if (null != authority)
{
var crs = Options.GetCrs(authority) as ICrsGeographic;
if (null != crs)
{
return(crs);
}
}
if (null != datum && datum.PrimeMeridian == null && null != primeMeridian)
{
// in this case the datum must have NOT been created from an authority source so we should remake it with a prime meridian
datum = new OgcDatumHorizontal(
datum.Name,
datum.Spheroid,
primeMeridian,
datum.BasicWgs84Transformation,
datum.Authority
);
}
if (datum == null)
{
if (Options.ThrowOnError)
{
throw new WktParseExceptioncs("Geographic CRS", "No datum.");
}
datum = OgcDatumHorizontal.DefaultWgs84;
}
return(new OgcCrsGeographic(
name,
datum,
unit,
axes,
authority
));
}
public static Datum Create(IDatumGeodetic datum)
{
if(datum == null) throw new ArgumentNullException("datum");
Contract.Ensures(Contract.Result<Datum>() != null);
var result = new Datum {
Name = datum.Name
};
result.Spheroid = Proj4SpheroidWrapper.Create(datum.Spheroid);
if (datum.IsTransformableToWgs84) {
var helmert = datum.BasicWgs84Transformation;
if (helmert.ScaleDeltaPartsPerMillion == 0 && Vector3.Zero.Equals(helmert.RotationArcSeconds)) {
if (Vector3.Zero.Equals(helmert.Delta)) {
if (result.Spheroid.Name == "WE")
result.Proj4DatumName = "wgs84";
else
result.DatumType = DatumType.WGS84;
}
else{
result.ToWGS84 = new[] {
helmert.Delta.X, helmert.Delta.Y, helmert.Delta.Z
};
result.DatumType = DatumType.Param3;
}
}
else {
result.ToWGS84 = new[] {
helmert.Delta.X, helmert.Delta.Y, helmert.Delta.Z,
helmert.RotationArcSeconds.X, helmert.RotationArcSeconds.Y, helmert.RotationArcSeconds.Z,
helmert.ScaleDeltaPartsPerMillion
};
result.DatumType = DatumType.Param7;
}
}
else {
result.DatumType = DatumType.Unknown;
}
return result;
}
