com.revolsys.jts.operation.polygonize

Class Polygonizer

java.lang.Object

com.revolsys.jts.operation.polygonize.Polygonizer

public class Polygonizer
extends Object

Polygonizes a set of Geometrys which contain linework that represents the edges of a planar graph. All types of Geometry are accepted as input; the constituent linework is extracted as the edges to be polygonized. The processed edges must be correctly noded; that is, they must only meet at their endpoints. The Polygonizer will run on incorrectly noded input but will not form polygons from non-noded edges, and will report them as errors.

The Polygonizer reports the follow kinds of errors:

• Dangles - edges which have one or both ends which are not incident on another edge endpoint
• Cut Edges - edges which are connected at both ends but which do not form part of polygon
• Invalid Ring Lines - edges which form rings which are invalid (e.g. the component lines contain a self-intersection)

Version:

1.7

Field Summary

Fields

Modifier and Type	Field and Description
protected List	cutEdges
protected Collection	dangles
protected com.revolsys.jts.operation.polygonize.PolygonizeGraph	graph
protected List	holeList
protected List	invalidRingLines
protected List	polyList
protected List	shellList

Constructor Summary

Constructors

Constructor and Description
Polygonizer() Create a polygonizer with the same GeometryFactory as the input Geometrys

Method Summary

Methods

Modifier and Type	Method and Description
void	add(Collection geomList) Adds a collection of geometries to the edges to be polygonized.
void	add(Geometry geometry) Add a Geometry to the edges to be polygonized.
Collection	getCutEdges() Gets the list of cut edges found during polygonization.
Collection	getDangles() Gets the list of dangling lines found during polygonization.
Collection	getInvalidRingLines() Gets the list of lines forming invalid rings found during polygonization.
Collection	getPolygons() Gets the list of polygons formed by the polygonization.
void	setCheckRingsValid(boolean isCheckingRingsValid) Allows disabling the valid ring checking, to optimize situations where invalid rings are not expected.

Methods inherited from class java.lang.Object

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

Field Detail

graph

protected com.revolsys.jts.operation.polygonize.PolygonizeGraph graph

dangles

protected Collection dangles

cutEdges

protected List cutEdges

invalidRingLines

protected List invalidRingLines

holeList

protected List holeList

shellList

protected List shellList

polyList

protected List polyList

Constructor Detail

Polygonizer

public Polygonizer()

Create a polygonizer with the same GeometryFactory as the input Geometrys

Method Detail

add

public void add(Collection geomList)

Adds a collection of geometries to the edges to be polygonized. May be called multiple times. Any dimension of Geometry may be added; the constituent linework will be extracted and used.

Parameters:

geomList - a list of Geometrys with linework to be polygonized

add

public void add(Geometry geometry)

Add a Geometry to the edges to be polygonized. May be called multiple times. Any dimension of Geometry may be added; the constituent linework will be extracted and used

Parameters:

geometry - a Geometry with linework to be polygonized

getCutEdges

public Collection getCutEdges()

Gets the list of cut edges found during polygonization.

Returns:

a collection of the input LineStrings which are cut edges

getDangles

public Collection getDangles()

Gets the list of dangling lines found during polygonization.

Returns:

a collection of the input LineStrings which are dangles

getInvalidRingLines

public Collection getInvalidRingLines()

Gets the list of lines forming invalid rings found during polygonization.

Returns:

a collection of the input LineStrings which form invalid rings

getPolygons

public Collection getPolygons()

Gets the list of polygons formed by the polygonization.

Returns:

a collection of Polygons

setCheckRingsValid

public void setCheckRingsValid(boolean isCheckingRingsValid)

Allows disabling the valid ring checking, to optimize situations where invalid rings are not expected.

The default is true

Parameters:

isCheckingRingsValid - true if generated rings should be checked for validity