/// <summary>
/// Creates an instance of this class
/// </summary>
/// <param name="parameters">An enumeration of projection parameters</param>
protected MapProjection(IEnumerable <ProjectionParameter> parameters)
{
_Parameters = new ProjectionParameterSet(parameters);
_semiMajor = _Parameters.GetParameterValue("semi_major");
_semiMinor = _Parameters.GetParameterValue("semi_minor");
//_es = 1.0 - (_semiMinor * _semiMinor) / (_semiMajor * _semiMajor);
_es = EccentricySquared(_semiMajor, _semiMinor);
_e = Math.Sqrt(_es);
scale_factor = _Parameters.GetOptionalParameterValue("scale_factor", 1);
central_meridian = Degrees2Radians(_Parameters.GetParameterValue("central_meridian", "longitude_of_center"));
lat_origin = Degrees2Radians(_Parameters.GetParameterValue("latitude_of_origin", "latitude_of_center"));
_metersPerUnit = _Parameters.GetParameterValue("unit");
false_easting = _Parameters.GetOptionalParameterValue("false_easting", 0) * _metersPerUnit;
false_northing = _Parameters.GetOptionalParameterValue("false_northing", 0) * _metersPerUnit;
// TODO: Should really convert to the correct linear units??
// Compute constants for the mlfn
double t;
en0 = C00 - _es * (C02 + _es *
(C04 + _es * (C06 + _es * C08)));
en1 = _es * (C22 - _es *
(C04 + _es * (C06 + _es * C08)));
en2 = (t = _es * _es) *
(C44 - _es * (C46 + _es * C48));
en3 = (t *= _es) * (C66 - _es * C68);
en4 = t * _es * C88;
}
/// <summary>
/// Checks this projection parameter set with <paramref name="other"/>-
/// </summary>
/// <param name="other">The other projection parameter set.</param>
/// <returns><value>true</value> if both sets are equal.</returns>
public bool Equals(ProjectionParameterSet other)
{
if (other == null)
{
return(false);
}
if (other.Count != Count)
{
return(false);
}
foreach (var kvp in this)
{
if (!other.ContainsKey(kvp.Key))
{
return(false);
}
double otherValue = other.GetParameterValue(kvp.Key);
if (otherValue != kvp.Value)
{
return(false);
}
}
return(true);
}
private static IEnumerable <ProjectionParameter> VerifyParameters(IEnumerable <ProjectionParameter> parameters)
{
var p = new ProjectionParameterSet(parameters);
double semi_major = p.GetParameterValue("semi_major");
p.SetParameterValue("semi_minor", semi_major);
p.SetParameterValue("scale_factor", 1);
return(p.ToProjectionParameter());
}