/// <summary> /// Returns a IUnit 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 Unit ReadUnit(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 Unit() { Id = authorityCode + "", Name = unitName, Abbreviation = unitName, ConversionFactor = unitsPerUnit }); }
/// <summary> /// 读取 HorizontalDatum /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static HorizontalDatum ReadHorizontalDatum(WktStreamTokenizer tokenizer) { //DATUM["OSGB 1936",SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6277"]] BursaTransParams wgsInfo = null; string authority = String.Empty; long authorityCode = -1; tokenizer.ReadToken("["); string name = tokenizer.ReadDoubleQuotedWord(); tokenizer.ReadToken(","); tokenizer.ReadToken("SPHEROID"); Ellipsoid ellipsoid = ReadEllipsoid(tokenizer); tokenizer.NextToken(); while (tokenizer.GetStringValue() == ",") { tokenizer.NextToken(); if (tokenizer.GetStringValue() == "TOWGS84") { wgsInfo = ReadWGS84ConversionInfo(tokenizer); tokenizer.NextToken(); } else if (tokenizer.GetStringValue() == "AUTHORITY") { tokenizer.ReadAuthority(ref authority, ref authorityCode); tokenizer.ReadToken("]"); } } // make an assumption about the datum type. HorizontalDatum horizontalDatum = new HorizontalDatum( ellipsoid, wgsInfo, DatumType.HD_Geocentric, name, authorityCode + ""); return(horizontalDatum); }
/// <summary> /// /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static PrimeMeridian 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. PrimeMeridian primeMeridian = new PrimeMeridian(longitude, AngularUnit.Degree, name, authorityCode + ""); return(primeMeridian); }
/// <summary> /// /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static GeographicCs 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"); HorizontalDatum horizontalDatum = ReadHorizontalDatum(tokenizer); tokenizer.ReadToken(","); tokenizer.ReadToken("PRIMEM"); PrimeMeridian primeMeridian = ReadPrimeMeridian(tokenizer); tokenizer.ReadToken(","); tokenizer.ReadToken("UNIT"); AngularUnit angularUnit = ReadAngularUnit(tokenizer); string authority = String.Empty; long authorityCode = -1; tokenizer.NextToken(); List <IAxis> info = new List <IAxis>(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 Axis("Lon", Direction.East)); info.Add(new Axis("Lat", Direction.North)); } GeographicCs geographicCS = new GeographicCs(angularUnit, horizontalDatum, primeMeridian, info, name, authorityCode + ""); return(geographicCS); }
/// <summary> /// /// </summary> /// <param name="tokenizer"></param> /// <returns></returns> private static ProjectedCs 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"); GeographicCs geographicCS = ReadGeographicCoordinateSystem(tokenizer); tokenizer.ReadToken(","); Projection projection = ReadProjection(tokenizer); Unit unit = ReadLinearUnit(tokenizer); string authority = String.Empty; long authorityCode = -1; tokenizer.NextToken(); List <IAxis> axes = new List <IAxis>(2); if (tokenizer.GetStringValue() == ",") { tokenizer.NextToken(); while (tokenizer.GetStringValue() == "AXIS") { axes.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 (axes.Count == 0) { axes.Add(new Axis("X", Direction.East)); axes.Add(new Axis("Y", Direction.North)); } ProjectedCs projectedCS = new ProjectedCs(geographicCS.HorizontalDatum, geographicCS, unit as LinearUnit, projection, axes, name, authorityCode + ""); return(projectedCS); }