LineFromEncodedPolyline Class Reference

Creates a LineString from the encoded polyline format. More...

Inheritance diagram for LineFromEncodedPolyline:

Collaboration diagram for LineFromEncodedPolyline:

Public Member Functions
Geometry	construct (String input)
String	getURI ()
Value	evaluate (ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException

Static Public Member Functions
static List< Coordinate >	decodePolyline (String polyline, int precision)
	Decodes a polyline with a given precision. More...

Detailed Description

Creates a LineString from the encoded polyline format.

Member Function Documentation

construct()

Geometry construct

(

String

input

)

Reimplemented from GeometricConstructor.

                                                {
                GeometryFactory fac=new GeometryFactory();
                LineString ls=fac.createLineString(decodePolyline(input, 1).toArray(new Coordinate[0]));
                return ls;
        }

References LineFromEncodedPolyline.decodePolyline().

decodePolyline()

static List<Coordinate> decodePolyline ( String  polyline, int  precision  )

static

Decodes a polyline with a given precision.

Parameters

polyline	the polyline String to decode
precision	the precision used for decoding

Returns

the list of coordinates which have been decoded

    {
        List<Coordinate> coordinates = new ArrayList<Coordinate>();
        int index = 0, shift, result;
        int byte_;
        int lat = 0, lng = 0, latitude_change, longitude_change,
            factor = (int) Math.pow(10, precision);
 
        while (index < polyline.length()) {
            byte_ = 0;
            shift = 0;
            result = 0;
 
            do {
                byte_ = polyline.charAt(index++) - 63;
                result |= (byte_ & 0x1f) << shift;
                shift += 5;
            } while (byte_ >= 0x20);
 
            latitude_change = ((result % 2 == 1) ? ~(result >> 1) : (result >> 1));
 
            shift = result = 0;
 
            do {
                byte_ = polyline.charAt(index++) - 63;
                result |= (byte_ & 0x1f) << shift;
                shift += 5;
            } while (byte_ >= 0x20);
 
            longitude_change = ((result % 2 == 1) ? ~(result >> 1) : (result >> 1));
 
            lat += latitude_change;
            lng += longitude_change;
 
            coordinates.add(new Coordinate((double)lat / factor,(double)lng / factor));
        }
 
        return coordinates;
    }

Referenced by LineFromEncodedPolyline.construct().

evaluate()

Value evaluate ( ValueFactory  valueFactory, Value...  args  ) throws ValueExprEvaluationException

inherited

                                                                                                            {
                if (args.length != 1) {
                        throw new ValueExprEvaluationException(getURI() + " requires exactly 1 arguments, got " + args.length);
                }
                String geomString = args[0].stringValue();
                Geometry result = construct(geomString);
                return valueFactory.createLiteral(WKTDatatype.INSTANCE.unparse(result), WKTDatatype.LiteralIRI);
        }

References GeometricConstructor.construct(), WKTDatatype.INSTANCE, WKTDatatype.LiteralIRI, and WKTDatatype.unparse().

Referenced by GeomFromGeoJSONTest.testGeomFromGeoJSON(), GeomFromTextTest.testGeomFromText(), GeomFromWKBTest.testGeomFromWKB(), MakeLineTest.testMakeLine1(), MakePointTest.testMakePoint1(), MakePointTest.testMakePointXYZ(), PointFromTextTest.testPointFromText(), and PolygonFromTextTest.testPolygonFromText().

getURI()

String getURI

(

)

                               {
                return POSTGIS.st_lineFromEncodedPolyline.stringValue();
        }

References POSTGIS.st_lineFromEncodedPolyline.