/// <summary>
/// Initializes a new instance of the <see cref = "ProjectionInfo" /> class.
/// </summary>
public ProjectionInfo()
{
GeographicInfo = new GeographicInfo();
Unit = new LinearUnit();
_scaleFactor = 1; // if not specified, default to 1
AuxiliarySphereType = AuxiliarySphereType.NotSpecified;
NoDefs = true;
}
public Proj4CrsGeographic(GeographicInfo geographicInfo)
: base(geographicInfo.Name ?? geographicInfo.Datum.Name ?? "Unknown", new AuthorityTag("PROJ4", String.Empty))
{
Contract.Requires(geographicInfo != null);
Contract.Requires(geographicInfo.Meridian != null);
Contract.Requires(geographicInfo.Datum != null);
Contract.Requires(geographicInfo.Datum.Spheroid != null);
Core = geographicInfo;
Datum = Proj4DatumWrapper.CreateWrapper(geographicInfo);
}
/// <summary>
/// This will try to read the string, but if the validation fails, then it will return false,
/// rather than throwing an exception.
/// </summary>
/// <param name="esriString">
/// The string to test and define this projection if possible.
/// </param>
/// <returns>
/// Boolean, true if at least the GEOGCS tag was found.
/// </returns>
public bool TryParseEsriString(string esriString)
{
if (esriString == null)
{
return(false);
}
if (!esriString.Contains("GEOGCS"))
{
return(false);
}
if (esriString.Contains("PROJCS") == false)
{
GeographicInfo.ParseEsriString(esriString);
IsLatLon = true;
Transform = new LongLat();
Transform.Init(this);
return(true);
}
int iStart = esriString.IndexOf(@""",");
Name = esriString.Substring(8, iStart - 8);
int iEnd = esriString.IndexOf("PARAMETER");
string gcs;
if (iEnd != -1)
{
gcs = esriString.Substring(iStart + 1, iEnd - (iStart + 2));
}
else
{
// an odd Esri projection string that doesn't have PARAMETER
gcs = esriString.Substring(iStart + 1);
}
GeographicInfo.ParseEsriString(gcs);
FalseEasting = GetParameter(new string[] { "False_Easting", "Easting_At_False_Origin" }, ref FalseEastingAlias, esriString);
FalseNorthing = GetParameter(new string[] { "False_Northing", "Northing_At_False_Origin" }, ref FalseNorthingAlias, esriString);
CentralMeridian = GetParameter("Central_Meridian", esriString);
// Esri seems to indicate that these should be treated the same, but they aren't here... http://support.esri.com/en/knowledgebase/techarticles/detail/39992
// CentralMeridian = GetParameter(new string[] { "Longitude_Of_Center", "Central_Meridian", "Longitude_Of_Origin" }, ref LongitudeOfCenterAlias, esriString);
LongitudeOfCenter = GetParameter("Longitude_Of_Center", esriString);
StandardParallel1 = GetParameter("Standard_Parallel_1", esriString);
StandardParallel2 = GetParameter("Standard_Parallel_2", esriString);
_scaleFactor = GetParameter("Scale_Factor", esriString);
alpha = GetParameter("Azimuth", esriString);
_longitudeOf1st = GetParameter("Longitude_Of_1st", esriString);
_longitudeOf2nd = GetParameter("Longitude_Of_2nd", esriString);
LatitudeOfOrigin = GetParameter(new string[] { "Latitude_Of_Origin", "Latitude_Of_Center", "Central_Parallel" }, ref LatitudeOfOriginAlias, esriString);
iStart = esriString.LastIndexOf("UNIT");
string unit = esriString.Substring(iStart, esriString.Length - iStart);
Unit.ParseEsriString(unit);
if (esriString.Contains("PROJECTION"))
{
iStart = esriString.IndexOf("PROJECTION") + 12;
iEnd = esriString.IndexOf("]", iStart) - 1;
string projection = esriString.Substring(iStart, iEnd - iStart);
Transform = TransformManager.DefaultTransformManager.GetProjection(projection);
Transform.Init(this);
}
double?auxType = GetParameter("Auxiliary_Sphere_Type", esriString);
if (auxType != null)
{
// While the Esri implementation sort of tip-toes around the datum transform,
// we simply ensure that the spheroid becomes properly spherical based on the
// parameters we have here. (The sphereoid will be read as WGS84).
AuxiliarySphereType = (AuxiliarySphereType)auxType;
if (AuxiliarySphereType == AuxiliarySphereType.SemimajorAxis)
{
// added by Jiri to properly re-initialize the 'web mercator auxiliary sphere' transform
Transform = KnownCoordinateSystems.Projected.World.WebMercator.Transform;
}
else if (AuxiliarySphereType == AuxiliarySphereType.SemiminorAxis)
{
double r = GeographicInfo.Datum.Spheroid.PolarRadius;
GeographicInfo.Datum.Spheroid = new Spheroid(r);
}
else if (AuxiliarySphereType == AuxiliarySphereType.Authalic ||
AuxiliarySphereType == AuxiliarySphereType.AuthalicWithConvertedLatitudes)
{
double a = GeographicInfo.Datum.Spheroid.EquatorialRadius;
double b = GeographicInfo.Datum.Spheroid.PolarRadius;
double r =
Math.Sqrt(
(a * a
+
a * b * b
/ (Math.Sqrt(a * a - b * b) * Math.Log((a + Math.Sqrt(a * a - b * b)) / b, Math.E)))
/ 2);
GeographicInfo.Datum.Spheroid = new Spheroid(r);
}
}
if (FalseEasting != null)
{
FalseEasting = FalseEasting * Unit.Meters;
}
if (FalseNorthing != null)
{
FalseNorthing = FalseNorthing * Unit.Meters;
}
return(true);
}
public static Proj4DatumWrapper CreateWrapper(GeographicInfo geographicInfo)
{
if (geographicInfo == null) throw new ArgumentNullException("geographicInfo");
if (geographicInfo.Meridian == null) throw new ArgumentException("Must have a meridian.", "geographicInfo");
Contract.Requires(geographicInfo.Datum != null);
Contract.Requires(geographicInfo.Datum.Spheroid != null);
Contract.Ensures(Contract.Result<Proj4DatumWrapper>() != null);
return new Proj4DatumWrapper(
geographicInfo.Datum,
new Proj4MeridianWrapper(geographicInfo.Meridian));
}
public static GeographicInfo CreateGeographic(ICrsGeodetic crsGeodetic)
{
if (crsGeodetic == null) throw new ArgumentNullException("crsGeodetic");
Contract.Requires(crsGeodetic.Datum.PrimeMeridian != null);
Contract.Ensures(Contract.Result<GeographicInfo>() != null);
var result = new GeographicInfo {
Name = crsGeodetic.Name
};
result.Datum = Proj4DatumWrapper.Create(crsGeodetic.Datum);
Contract.Assume(crsGeodetic.Datum.PrimeMeridian != null);
result.Meridian = Proj4MeridianWrapper.Create(crsGeodetic.Datum.PrimeMeridian);
// TODO: set the unit
return result;
}