com.vividsolutions.jts.operation

Class IsSimpleOp

java.lang.Object

com.vividsolutions.jts.operation.IsSimpleOp

public class IsSimpleOp
extends java.lang.Object

Tests whether a Geometry is simple. In general, the SFS specification of simplicity follows the rule:

• A Geometry is simple if and only if the only self-intersections are at boundary points.

This definition relies on the definition of boundary points. The SFS uses the Mod-2 rule to determine which points are on the boundary of lineal geometries, but this class supports using other BoundaryNodeRules as well.

Simplicity is defined for each Geometry subclass as follows:

• Valid polygonal geometries are simple by definition, so isSimple trivially returns true. (Hint: in order to check if a polygonal geometry has self-intersections, use Geometry.isValid()).
• Linear geometries are simple iff they do not self-intersect at points other than boundary points. (Using the Mod-2 rule, this means that closed linestrings cannot be touched at their endpoints, since these are interior points, not boundary points).
• Zero-dimensional geometries (points) are simple iff they have no repeated points.
• Empty Geometrys are always simple

Version:

1.7

See Also:

BoundaryNodeRule

Constructor Summary

Constructors

Constructor and Description
IsSimpleOp() Deprecated. use IsSimpleOp(Geometry)
IsSimpleOp(Geometry geom) Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule
IsSimpleOp(Geometry geom, BoundaryNodeRule boundaryNodeRule) Creates a simplicity checker using a given BoundaryNodeRule

Method Summary

Methods

Modifier and Type	Method and Description
Coordinate	getNonSimpleLocation() Gets a coordinate for the location where the geometry fails to be simple.
boolean	isSimple() Tests whether the geometry is simple.
boolean	isSimple(LineString geom) Deprecated. use isSimple()
boolean	isSimple(MultiLineString geom) Deprecated. use isSimple()
boolean	isSimple(MultiPoint mp) Deprecated. use isSimple()

Methods inherited from class java.lang.Object

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

Constructor Detail

IsSimpleOp

public IsSimpleOp()

Deprecated. use IsSimpleOp(Geometry)

Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule

IsSimpleOp

public IsSimpleOp(Geometry geom)

Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule

Parameters:

geom - the geometry to test

IsSimpleOp

public IsSimpleOp(Geometry geom,
          BoundaryNodeRule boundaryNodeRule)

Creates a simplicity checker using a given BoundaryNodeRule

Parameters:

geom - the geometry to test

boundaryNodeRule - the rule to use.

Method Detail

isSimple

public boolean isSimple()

Tests whether the geometry is simple.

Returns:

true if the geometry is simple

getNonSimpleLocation

public Coordinate getNonSimpleLocation()

Gets a coordinate for the location where the geometry fails to be simple. (i.e. where it has a non-boundary self-intersection). isSimple() must be called before this method is called.

Returns:

a coordinate for the location of the non-boundary self-intersection

isSimple

public boolean isSimple(LineString geom)

Deprecated. use isSimple()

Reports whether a LineString is simple.

Parameters:

geom - the lineal geometry to test

Returns:

true if the geometry is simple

isSimple

public boolean isSimple(MultiLineString geom)

Deprecated. use isSimple()

Reports whether a MultiLineString geometry is simple.

Parameters:

geom - the lineal geometry to test

Returns:

true if the geometry is simple

isSimple

public boolean isSimple(MultiPoint mp)

Deprecated. use isSimple()

A MultiPoint is simple iff it has no repeated points