SharedPaths Class Reference

Calculates shared paths of two geometries. More...

Inheritance diagram for SharedPaths:

Collaboration diagram for SharedPaths:

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

Protected Member Functions
Geometry	relation (Geometry geom1, Geometry geom2)

Detailed Description

Calculates shared paths of two geometries.

Member Function Documentation

evaluate()

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

inherited

                                                                                                            {
                if (args.length != 2) {
                        throw new ValueExprEvaluationException(getURI() + " requires exactly 2 arguments, got " + args.length);
                }
 
                LiteralType l=LiteralRegistry.getLiteral(((Literal)args[0]).getDatatype().toString());
                LiteralType l2=LiteralRegistry.getLiteral(((Literal)args[1]).getDatatype().toString());
                if(l instanceof VectorLiteral) {
                        Geometry geom=((VectorLiteral)l).read(args[0].stringValue());
                        Geometry geom2=((VectorLiteral)l2).read(args[1].stringValue());
                        Geometry transformed=LiteralUtils.transform(geom2, geom);
                        Geometry result = relation(geom,transformed);
                        return valueFactory.createLiteral(((VectorLiteral) l).unparse(result),((Literal)args[0]).getDatatype());
                }
                throw new ValueExprEvaluationException("Arguments given are not geometry literals");
        }

References LiteralRegistry.getLiteral(), GeometricRelationModifierFunction.relation(), and LiteralUtils.transform().

Referenced by LongestLineTest.testLongestLine(), ShortestLineTest.testShortestLine(), and ShortestLine3DTest.testShortestLine3D().

getURI()

String getURI

(

)

                               {
                return POSTGIS.st_sharedPaths.stringValue();
        }

References POSTGIS.st_sharedPaths.

relation()

Geometry relation ( Geometry  geom1, Geometry  geom2  )

protected

Reimplemented from GeometricRelationModifierFunction.

                                                                    {
        List<Geometry> intersections=new LinkedList<>();
        Geometry transformed=LiteralUtils.transform(geom2, geom1);
                if((geom1.getGeometryType().equals("MultiLineString") || geom1.getGeometryType().equals("LineString"))
                                && (transformed.getGeometryType().equals("MultiLineString") || transformed.getGeometryType().equals("LineString"))) {
                        for(int i=0;i<geom1.getNumGeometries();i++) {
                                for(int j=0;j<transformed.getNumGeometries();j++) {
                                        if(geom1.intersects(transformed.getGeometryN(j))){
                                                intersections.add(geom1.getGeometryN(i).intersection(transformed.getGeometryN(j)));
                                        }
                                }
                        }
                        return LiteralUtils.createGeometryCollection(intersections, "GEOMETRYCOLLECTION", geom1.getSRID());
                }
                return null;
        }

References LiteralUtils.createGeometryCollection(), and LiteralUtils.transform().