private static string GetNextEmptyOrOpener(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
string nextWord = tokenizer.GetStringValue();
if (nextWord == "EMPTY" || nextWord == "(")
{
return(nextWord);
}
throw new Exception("Expected 'EMPTY' or '(' but encountered '" + nextWord + "'");
}
private static Polygon ReadPolygonText(WktStreamTokenizer tokenizer)
{
//var pol = new Polygon(new List<LineString>
//{
// new LineString(new List<GeographicPosition>()
// {
// new GeographicPosition(0,0),
// new GeographicPosition(1,1),
// new GeographicPosition(0,0)
// })
//});
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(null);
}
var aneis = new List <LineString>();
do
{
var ring = GetCoordinates(tokenizer);
var max = ring.Count;
var vertices = new List <GeographicPosition>();
for (var i = 0; i < max; i++)
{
var lng = ring[i];
var lat = ring[i + 1];
var coord = new GeographicPosition(lat, lng);
i++;
vertices.Add(coord);
}
aneis.Add(new LineString(vertices));
nextToken = GetNextCloserOrComma(tokenizer);
} while (nextToken == ",");
var pol = new Polygon(
new List <LineString>(aneis)
);
return(pol);
}
private static Point ReadPointText(WktStreamTokenizer tokenizer)
{
var p = new Point(new GeographicPosition(0, 0));
var nextToken = GetNextEmptyOrOpener(tokenizer);
if (nextToken == "EMPTY")
{
return(p);
}
var longitude = GetNextNumber(tokenizer);
var latitude = GetNextNumber(tokenizer);
p = new Point(new GeographicPosition(latitude, longitude));
GetNextCloser(tokenizer);
return(p);
}
private static GeoJSONObject ReadGeometryTaggedText(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
var type = tokenizer.GetStringValue().ToUpper();
GeoJSONObject geometry = null;
switch (type)
{
case "POINT":
geometry = ReadPointText(tokenizer);
break;
case "LINESTRING":
geometry = ReadLineStringText(tokenizer);
break;
/*case "MULTIPOINT":
* geometry = ReadMultiPointText(tokenizer);
* break;*/
/*case "MULTILINESTRING":
* geometry = ReadMultiLineStringText(tokenizer);
* break;*/
case "POLYGON":
geometry = ReadPolygonText(tokenizer);
break;
case "MULTIPOLYGON":
geometry = ReadMultiPolygonText(tokenizer);
//geometry = ReadMultiPolygonText(tokenizer);
break;
/*case "GEOMETRYCOLLECTION":
* geometry = ReadGeometryCollectionText(tokenizer);
* break;*/
default:
throw new Exception(String.Format(new CultureInfo("en-US", false).NumberFormat, "Geometrytype '{0}' is not supported.",
type));
}
return(geometry);
}
/*private static CellGeom ReadMultiPointText(WktStreamTokenizer tokenizer)
* {
* CellGeom mp = new CellGeom();
* mp.coordinates = new List<List<Coordinate>>();
*
* List<Coordinate> ring = new List<Coordinate>();
*
* string nextToken = GetNextEmptyOrOpener(tokenizer);
* if (nextToken == "EMPTY")
* return mp;
*
* Coordinate coord = new Coordinate();
* coord.lng = Convert.ToString(GetNextNumber(tokenizer));
* coord.lat = Convert.ToString(GetNextNumber(tokenizer));
* ring.Add(coord);
* mp.coordinates.Add(ring);
*
* nextToken = GetNextCloserOrComma(tokenizer);
* while (nextToken == ",")
* {
* List<Coordinate> newRing = new List<Coordinate>();
* Coordinate newCoord = new Coordinate();
* newCoord.lng = Convert.ToString(GetNextNumber(tokenizer));
* newCoord.lat = Convert.ToString(GetNextNumber(tokenizer));
* newRing.Add(newCoord);
* mp.coordinates.Add(newRing);
*
* nextToken = GetNextCloserOrComma(tokenizer);
* }
* return mp;
* }*/
/*private static CellGeom ReadMultiLineStringText(WktStreamTokenizer tokenizer)
* {
* CellGeom lines = new CellGeom();
* string nextToken = GetNextEmptyOrOpener(tokenizer);
* if (nextToken == "EMPTY")
* return lines;
*
* lines.LineStrings.Add(ReadLineStringText(tokenizer));
* nextToken = GetNextCloserOrComma(tokenizer);
* while (nextToken == ",")
* {
* lines.LineStrings.Add(ReadLineStringText(tokenizer));
* nextToken = GetNextCloserOrComma(tokenizer);
* }
* return lines;
* }*/
private static GeoJSONObject ReadLineStringText(WktStreamTokenizer tokenizer)
{
var ring = GetCoordinates(tokenizer);
var max = ring.Count;
var vertices = new List <GeographicPosition>();
for (var i = 0; i < max; i++)
{
var lng = ring[i];
var lat = ring[i + 1];
var coord = new GeographicPosition(lat, lng);
i++;
vertices.Add(coord);
}
var line = new LineString(vertices);
return(line);
}
private static double GetNextNumber(WktStreamTokenizer tokenizer)
{
tokenizer.NextToken();
return(tokenizer.GetNumericValue());
}
public static GeoJSONObject Parse(TextReader reader)
{
var tokenizer = new WktStreamTokenizer(reader);
return(ReadGeometryTaggedText(tokenizer));
}
