/// <summary>
/// Reads and parses a WKT-formatted projection string.
/// </summary>
/// <param name="wkt">String containing WKT.</param>
/// <param name="encoding">The encoding to use.</param>
/// <returns>Object representation of the WKT.</returns>
/// <exception cref="System.ArgumentException">If a token is not recognised.</exception>
public static IInfo Parse(string wkt, Encoding encoding)
{
if (String.IsNullOrEmpty(wkt))
{
throw new ArgumentNullException("wkt");
}
if (encoding == null)
{
throw new ArgumentNullException("encoding");
}
byte[] arr = encoding.GetBytes(wkt);
using (Stream stream = new MemoryStream(arr))
using (TextReader reader = new StreamReader(stream, encoding))
{
WktStreamTokenizer tokenizer = new WktStreamTokenizer(reader);
tokenizer.NextToken();
string objectName = tokenizer.GetStringValue();
switch (objectName)
{
case "UNIT":
return(ReadUnit(tokenizer));
case "SPHEROID":
return(ReadEllipsoid(tokenizer));
case "DATUM":
return(ReadHorizontalDatum(tokenizer));
case "PRIMEM":
return(ReadPrimeMeridian(tokenizer));
case "VERT_CS":
case "GEOGCS":
case "PROJCS":
case "COMPD_CS":
case "GEOCCS":
case "FITTED_CS":
case "LOCAL_CS":
return(ReadCoordinateSystem(wkt, tokenizer));
default:
throw new ArgumentException(String.Format("'{0}' is not recognized.", objectName));
}
}
}
private static IProjection ReadProjection(WktStreamTokenizer tokenizer)
{
if (tokenizer.GetStringValue() != "PROJECTION")
{
tokenizer.ReadToken("PROJECTION");
}
tokenizer.ReadToken("[");//[
string projectionName = tokenizer.ReadDoubleQuotedWord();
string authority = string.Empty;
long authorityCode = -1L;
tokenizer.NextToken(true);
if (tokenizer.GetStringValue() == ",")
{
tokenizer.ReadAuthority(ref authority, ref authorityCode);
tokenizer.ReadToken("]");
}
tokenizer.ReadToken(",");//,
tokenizer.ReadToken("PARAMETER");
List <ProjectionParameter> paramList = new List <ProjectionParameter>();
while (tokenizer.GetStringValue() == "PARAMETER")
{
tokenizer.ReadToken("[");
string paramName = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
tokenizer.NextToken();
double paramValue = tokenizer.GetNumericValue();
tokenizer.ReadToken("]");
paramList.Add(new ProjectionParameter(paramName, paramValue));
tokenizer.NextToken();
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
}
else
{
break;
}
}
IProjection projection = new Projection(projectionName, paramList, projectionName, authority, authorityCode, String.Empty, String.Empty, string.Empty);
return(projection);
}
// Reads either 3, 6 or 7 parameter Bursa-Wolf values from TOWGS84 token
private static Wgs84ConversionInfo ReadWGS84ConversionInfo(WktStreamTokenizer tokenizer)
{
//TOWGS84[0,0,0,0,0,0,0]
tokenizer.ReadToken("[");
Wgs84ConversionInfo info = new Wgs84ConversionInfo();
tokenizer.NextToken();
info.Dx = tokenizer.GetNumericValue();
tokenizer.ReadToken(",");
tokenizer.NextToken();
info.Dy = tokenizer.GetNumericValue();
tokenizer.ReadToken(",");
tokenizer.NextToken();
info.Dz = tokenizer.GetNumericValue();
tokenizer.NextToken();
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
info.Ex = tokenizer.GetNumericValue();
tokenizer.ReadToken(",");
tokenizer.NextToken();
info.Ey = tokenizer.GetNumericValue();
tokenizer.ReadToken(",");
tokenizer.NextToken();
info.Ez = tokenizer.GetNumericValue();
tokenizer.NextToken();
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
info.Ppm = tokenizer.GetNumericValue();
}
}
if (tokenizer.GetStringValue() != "]")
{
tokenizer.ReadToken("]");
}
return(info);
}
/// <summary>
/// Returns a <see cref="AngularUnit"/> given a piece of WKT.
/// </summary>
/// <param name="tokenizer">WktStreamTokenizer that has the WKT.</param>
/// <returns>An object that implements the IUnit interface.</returns>
private static IAngularUnit ReadAngularUnit(WktStreamTokenizer tokenizer)
{
tokenizer.ReadToken("[");
string unitName = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
tokenizer.NextToken();
double unitsPerUnit = tokenizer.GetNumericValue();
string authority = String.Empty;
long authorityCode = -1;
tokenizer.NextToken();
if (tokenizer.GetStringValue() == ",")
{
tokenizer.ReadAuthority(ref authority, ref authorityCode);
tokenizer.ReadToken("]");
}
return(new AngularUnit(unitsPerUnit, unitName, authority, authorityCode, String.Empty, String.Empty, String.Empty));
}
/// <summary>
/// Reads math transform from using current token from the specified tokenizer
/// </summary>
/// <param name="tokenizer"></param>
/// <returns></returns>
internal static IMathTransform ReadMathTransform(WktStreamTokenizer tokenizer)
{
if (tokenizer.GetStringValue() != "PARAM_MT")
{
tokenizer.ReadToken("PARAM_MT");
}
tokenizer.ReadToken("[");
string transformName = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
switch (transformName.ToUpperInvariant())
{
case "AFFINE":
return(ReadAffineTransform(tokenizer));
default:
throw new NotSupportedException("Transform not supported '" + transformName + "'");
}
}
private static IPrimeMeridian ReadPrimeMeridian(WktStreamTokenizer tokenizer)
{
//PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]
tokenizer.ReadToken("[");
string name = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
tokenizer.NextToken();
double longitude = tokenizer.GetNumericValue();
tokenizer.NextToken();
string authority = String.Empty;
long authorityCode = -1;
if (tokenizer.GetStringValue() == ",")
{
tokenizer.ReadAuthority(ref authority, ref authorityCode);
tokenizer.ReadToken("]");
}
// make an assumption about the Angular units - degrees.
IPrimeMeridian primeMeridian = new PrimeMeridian(longitude, AngularUnit.Degrees, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);
return(primeMeridian);
}
private static IGeographicCoordinateSystem ReadGeographicCoordinateSystem(WktStreamTokenizer tokenizer)
{
/*
* GEOGCS["OSGB 1936",
* DATUM["OSGB 1936",SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6277"]]
* PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]
* AXIS["Geodetic latitude","NORTH"]
* AXIS["Geodetic longitude","EAST"]
* AUTHORITY["EPSG","4277"]
* ]
*/
tokenizer.ReadToken("[");
string name = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
tokenizer.ReadToken("DATUM");
IHorizontalDatum horizontalDatum = ReadHorizontalDatum(tokenizer);
tokenizer.ReadToken(",");
tokenizer.ReadToken("PRIMEM");
IPrimeMeridian primeMeridian = ReadPrimeMeridian(tokenizer);
tokenizer.ReadToken(",");
tokenizer.ReadToken("UNIT");
IAngularUnit angularUnit = ReadAngularUnit(tokenizer);
string authority = String.Empty;
long authorityCode = -1;
tokenizer.NextToken();
List <AxisInfo> info = new List <AxisInfo>(2);
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
while (tokenizer.GetStringValue() == "AXIS")
{
info.Add(ReadAxis(tokenizer));
tokenizer.NextToken();
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
}
}
if (tokenizer.GetStringValue() == ",")
{
tokenizer.NextToken();
}
if (tokenizer.GetStringValue() == "AUTHORITY")
{
tokenizer.ReadAuthority(ref authority, ref authorityCode);
tokenizer.ReadToken("]");
}
}
//This is default axis values if not specified.
if (info.Count == 0)
{
info.Add(new AxisInfo("Lon", AxisOrientationEnum.East));
info.Add(new AxisInfo("Lat", AxisOrientationEnum.North));
}
IGeographicCoordinateSystem geographicCS = new GeographicCoordinateSystem(angularUnit, horizontalDatum,
primeMeridian, info, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);
return(geographicCS);
}
private static IProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStreamTokenizer tokenizer)
{
/*PROJCS[
* "OSGB 1936 / British National Grid",
* GEOGCS[
* "OSGB 1936",
* DATUM[...]
* PRIMEM[...]
* AXIS["Geodetic latitude","NORTH"]
* AXIS["Geodetic longitude","EAST"]
* AUTHORITY["EPSG","4277"]
* ],
* PROJECTION["Transverse Mercator"],
* PARAMETER["latitude_of_natural_origin",49],
* PARAMETER["longitude_of_natural_origin",-2],
* PARAMETER["scale_factor_at_natural_origin",0.999601272],
* PARAMETER["false_easting",400000],
* PARAMETER["false_northing",-100000],
* AXIS["Easting","EAST"],
* AXIS["Northing","NORTH"],
* AUTHORITY["EPSG","27700"]
* ]
*/
tokenizer.ReadToken("[");
string name = tokenizer.ReadDoubleQuotedWord();
tokenizer.ReadToken(",");
tokenizer.ReadToken("GEOGCS");
IGeographicCoordinateSystem geographicCS = ReadGeographicCoordinateSystem(tokenizer);
tokenizer.ReadToken(",");
IProjection projection = null;
IUnit unit = null;
List <AxisInfo> axes = new List <AxisInfo>(2);
string authority = String.Empty;
long authorityCode = -1;
TokenType ct = tokenizer.NextToken();
while (ct != TokenType.Eol && ct != TokenType.Eof)
{
switch (tokenizer.GetStringValue())
{
case ",":
case "]":
break;
case "PROJECTION":
projection = ReadProjection(tokenizer);
ct = tokenizer.GetTokenType();
continue;
//break;
case "UNIT":
unit = ReadLinearUnit(tokenizer);
break;
case "AXIS":
axes.Add(ReadAxis(tokenizer));
tokenizer.NextToken();
break;
case "AUTHORITY":
tokenizer.ReadAuthority(ref authority, ref authorityCode);
//tokenizer.ReadToken("]");
break;
}
ct = tokenizer.NextToken();
}
//This is default axis values if not specified.
if (axes.Count == 0)
{
//修改为国内常见
axes.Add(new AxisInfo("X", AxisOrientationEnum.North));
axes.Add(new AxisInfo("Y", AxisOrientationEnum.East));
//axes.Add(new AxisInfo("X", AxisOrientationEnum.East));
//axes.Add(new AxisInfo("Y", AxisOrientationEnum.North));
}
IProjectedCoordinateSystem projectedCS = new ProjectedCoordinateSystem(geographicCS.HorizontalDatum, geographicCS, unit as LinearUnit, projection, axes, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);
return(projectedCS);
}
private static ICoordinateSystem ReadCoordinateSystem(string coordinateSystem, WktStreamTokenizer tokenizer)
{
switch (tokenizer.GetStringValue())
{
case "GEOGCS":
return(ReadGeographicCoordinateSystem(tokenizer));
case "PROJCS":
return(ReadProjectedCoordinateSystem(tokenizer));
case "FITTED_CS":
return(ReadFittedCoordinateSystem(tokenizer));
case "COMPD_CS":
case "VERT_CS":
case "GEOCCS":
case "LOCAL_CS":
throw new NotSupportedException(String.Format("{0} coordinate system is not supported.", coordinateSystem));
default:
throw new InvalidOperationException(String.Format("{0} coordinate system is not recognized.", coordinateSystem));
}
}
private static IMathTransform ReadAffineTransform(WktStreamTokenizer tokenizer)
{
/*
* PARAM_MT[
* "Affine",
* PARAMETER["num_row",3],
* PARAMETER["num_col",3],
* PARAMETER["elt_0_0", 0.883485346527455],
* PARAMETER["elt_0_1", -0.468458794848877],
* PARAMETER["elt_0_2", 3455869.17937689],
* PARAMETER["elt_1_0", 0.468458794848877],
* PARAMETER["elt_1_1", 0.883485346527455],
* PARAMETER["elt_1_2", 5478710.88035753],
* PARAMETER["elt_2_2", 1]
* ]
*/
//tokenizer stands on the first PARAMETER
if (tokenizer.GetStringValue() != "PARAMETER")
{
tokenizer.ReadToken("PARAMETER");
}
IParameterInfo paramInfo = ReadParameters(tokenizer);
//manage required parameters - row, col
var rowParam = paramInfo.GetParameterByName("num_row");
var colParam = paramInfo.GetParameterByName("num_col");
if (rowParam == null)
{
throw new ArgumentNullException("Affine transform does not contain 'num_row' parameter");
}
if (colParam == null)
{
throw new ArgumentNullException("Affine transform does not contain 'num_col' parameter");
}
int rowVal = (int)rowParam.Value;
int colVal = (int)colParam.Value;
if (rowVal <= 0)
{
throw new ArgumentException("Affine transform contains invalid value of 'num_row' parameter");
}
if (colVal <= 0)
{
throw new ArgumentException("Affine transform contains invalid value of 'num_col' parameter");
}
//creates working matrix;
double[,] matrix = new double[rowVal, colVal];
//simply process matrix values - no elt_ROW_COL parsing
foreach (var param in paramInfo.Parameters)
{
if (param == null || param.Name == null)
{
continue;
}
switch (param.Name)
{
case "num_row":
case "num_col":
break;
case "elt_0_0":
matrix[0, 0] = param.Value;
break;
case "elt_0_1":
matrix[0, 1] = param.Value;
break;
case "elt_0_2":
matrix[0, 2] = param.Value;
break;
case "elt_0_3":
matrix[0, 3] = param.Value;
break;
case "elt_1_0":
matrix[1, 0] = param.Value;
break;
case "elt_1_1":
matrix[1, 1] = param.Value;
break;
case "elt_1_2":
matrix[1, 2] = param.Value;
break;
case "elt_1_3":
matrix[1, 3] = param.Value;
break;
case "elt_2_0":
matrix[2, 0] = param.Value;
break;
case "elt_2_1":
matrix[2, 1] = param.Value;
break;
case "elt_2_2":
matrix[2, 2] = param.Value;
break;
case "elt_2_3":
matrix[2, 3] = param.Value;
break;
case "elt_3_0":
matrix[3, 0] = param.Value;
break;
case "elt_3_1":
matrix[3, 1] = param.Value;
break;
case "elt_3_2":
matrix[3, 2] = param.Value;
break;
case "elt_3_3":
matrix[3, 3] = param.Value;
break;
default:
//unknown parameter
break;
}
}
//read rest of WKT
if (tokenizer.GetStringValue() != "]")
{
tokenizer.ReadToken("]");
}
//use "matrix" constructor to create transformation matrix
IMathTransform affineTransform = new AffineTransform(matrix);
return(affineTransform);
}
