GEOS  3.8.0dev
Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
geos::geom::util::GeometryTransformer Class Reference

A framework for processes which transform an input Geometry into an output Geometry, possibly changing its structure and type(s). More...

#include <GeometryTransformer.h>

Public Member Functions

std::unique_ptr< Geometrytransform (const Geometry *nInputGeom)
void setSkipTransformedInvalidInteriorRings (bool b)

Protected Member Functions

CoordinateSequence::Ptr createCoordinateSequence (std::unique_ptr< std::vector< Coordinate > > coords)
virtual CoordinateSequence::Ptr transformCoordinates (const CoordinateSequence *coords, const Geometry *parent)
virtual Geometry::Ptr transformPoint (const Point *geom, const Geometry *parent)
virtual Geometry::Ptr transformMultiPoint (const MultiPoint *geom, const Geometry *parent)
virtual Geometry::Ptr transformLinearRing (const LinearRing *geom, const Geometry *parent)
virtual Geometry::Ptr transformLineString (const LineString *geom, const Geometry *parent)
virtual Geometry::Ptr transformMultiLineString (const MultiLineString *geom, const Geometry *parent)
virtual Geometry::Ptr transformPolygon (const Polygon *geom, const Geometry *parent)
virtual Geometry::Ptr transformMultiPolygon (const MultiPolygon *geom, const Geometry *parent)
virtual Geometry::Ptr transformGeometryCollection (const GeometryCollection *geom, const Geometry *parent)

Protected Attributes

const GeometryFactoryfactory

Detailed Description

A framework for processes which transform an input Geometry into an output Geometry, possibly changing its structure and type(s).

This class is a framework for implementing subclasses which perform transformations on various different Geometry subclasses. It provides an easy way of applying specific transformations to given geometry types, while allowing unhandled types to be simply copied. Also, the framework ensures that if subcomponents change type the parent geometries types change appropriately to maintain valid structure. Subclasses will override whichever transformX methods they need to to handle particular Geometry types.

A typically usage would be a transformation that may transform Polygons into Polygons, LineStrings or Points. This class would likely need to override the transformMultiPolygon method to ensure that if input Polygons change type the result is a GeometryCollection, not a MultiPolygon

The default behaviour of this class is to simply recursively transform each Geometry component into an identical object by copying.

Note that all transformX methods may return null, to avoid creating empty geometry objects. This will be handled correctly by the transformer. The transform method itself will always return a geometry object.

See also

Possible extensions: getParent() method to return immediate parent e.g. of LinearRings in Polygons

Member Function Documentation

CoordinateSequence::Ptr geos::geom::util::GeometryTransformer::createCoordinateSequence ( std::unique_ptr< std::vector< Coordinate > >  coords)

Convenience method which provides standard way of creating a CoordinateSequence

coordsthe coordinate array to copy
a coordinate sequence for the array


The documentation for this class was generated from the following file: