org.locationtech.jts.simplify

Class DouglasPeuckerSimplifier.DPTransformer

java.lang.Object

org.locationtech.jts.geom.util.GeometryTransformer

org.locationtech.jts.simplify.DouglasPeuckerSimplifier.DPTransformer

Enclosing class:

DouglasPeuckerSimplifier

static class DouglasPeuckerSimplifier.DPTransformer
extends GeometryTransformer

Field Summary

Fields

Modifier and Type	Field and Description
private double	distanceTolerance
private boolean	isEnsureValidTopology

Fields inherited from class org.locationtech.jts.geom.util.GeometryTransformer

factory

Constructor Summary

Constructors

Constructor and Description
DPTransformer(boolean isEnsureValidTopology, double distanceTolerance)

Method Summary

Modifier and Type	Method and Description
private Geometry	createValidArea(Geometry rawAreaGeom) Creates a valid area geometry from one that possibly has bad topology (i.e.
protected CoordinateSequence	transformCoordinates(CoordinateSequence coords, Geometry parent) Transforms a CoordinateSequence.
protected Geometry	transformLinearRing(LinearRing geom, Geometry parent) Simplifies a LinearRing.
protected Geometry	transformMultiPolygon(MultiPolygon geom, Geometry parent) Simplifies a MultiPolygon, fixing it if required.
protected Geometry	transformPolygon(Polygon geom, Geometry parent) Simplifies a polygon, fixing it if required.

Methods inherited from class org.locationtech.jts.geom.util.GeometryTransformer

copy, createCoordinateSequence, getInputGeometry, transform, transformGeometryCollection, transformLineString, transformMultiLineString, transformMultiPoint, transformPoint

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

isEnsureValidTopology

private boolean isEnsureValidTopology

distanceTolerance

private double distanceTolerance

Constructor Detail

DPTransformer

public DPTransformer(boolean isEnsureValidTopology,
                     double distanceTolerance)

Method Detail

transformCoordinates

protected CoordinateSequence transformCoordinates(CoordinateSequence coords,
                                                  Geometry parent)

Description copied from class: GeometryTransformer

Transforms a CoordinateSequence. This method should always return a valid coordinate list for the desired result type. (E.g. a coordinate list for a LineString must have 0 or at least 2 points). If this is not possible, return an empty sequence - this will be pruned out.

Overrides:

transformCoordinates in class GeometryTransformer

Parameters:

coords - the coordinates to transform

parent - the parent geometry

Returns:

the transformed coordinates

transformPolygon

protected Geometry transformPolygon(Polygon geom,
                                    Geometry parent)

Simplifies a polygon, fixing it if required.

Overrides:

transformPolygon in class GeometryTransformer

transformLinearRing

protected Geometry transformLinearRing(LinearRing geom,
                                       Geometry parent)

Simplifies a LinearRing. If the simplification results in a degenerate ring, remove the component.

Overrides:

transformLinearRing in class GeometryTransformer

Parameters:

geom - the ring to simplify

parent - the parent geometry

Returns:

null if the simplification results in a degenerate ring

transformMultiPolygon

protected Geometry transformMultiPolygon(MultiPolygon geom,
                                         Geometry parent)

Simplifies a MultiPolygon, fixing it if required.

Overrides:

transformMultiPolygon in class GeometryTransformer

createValidArea

private Geometry createValidArea(Geometry rawAreaGeom)

Creates a valid area geometry from one that possibly has bad topology (i.e. self-intersections). Since buffer can handle invalid topology, but always returns valid geometry, constructing a 0-width buffer "corrects" the topology. Note this only works for area geometries, since buffer always returns areas. This also may return empty geometries, if the input has no actual area.

Parameters:

rawAreaGeom - an area geometry possibly containing self-intersections

Returns:

a valid area geometry