geos::operation::IsSimpleOp Class Reference

Tests whether a Geometry is simple. More...

#include <IsSimpleOp.h>

Public Member Functions
	IsSimpleOp ()
	Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule.
	IsSimpleOp (const geom::Geometry &geom)
	Creates a simplicity checker using the default SFS Mod-2 Boundary Node Rule.
	IsSimpleOp (const geom::Geometry &geom, const algorithm::BoundaryNodeRule &boundaryNodeRule)
	Creates a simplicity checker using a given algorithm::BoundaryNodeRule.
bool	isSimple ()
const geom::Coordinate *	getNonSimpleLocation () const
bool	isSimple (const geom::LineString *geom)
bool	isSimple (const geom::MultiLineString *geom)
bool	isSimple (const geom::MultiPoint *mp)
bool	isSimpleLinearGeometry (const geom::Geometry *geom)

Detailed Description

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

See also

algorithm::BoundaryNodeRule

Constructor & Destructor Documentation

IsSimpleOp() [1/3]

geos::operation::IsSimpleOp::IsSimpleOp

(

)

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

Deprecated

use IsSimpleOp(Geometry)

IsSimpleOp() [2/3]

geos::operation::IsSimpleOp::IsSimpleOp

(

const geom::Geometry &

geom

)

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

Parameters

geom	The geometry to test. Will store a reference: keep it alive.

IsSimpleOp() [3/3]

geos::operation::IsSimpleOp::IsSimpleOp	(	const geom::Geometry &	geom,
		const algorithm::BoundaryNodeRule &	boundaryNodeRule )

Creates a simplicity checker using a given algorithm::BoundaryNodeRule.

Parameters

geom	the geometry to test
boundaryNodeRule	the rule to use.

Member Function Documentation

getNonSimpleLocation()

const geom::Coordinate * geos::operation::IsSimpleOp::getNonSimpleLocation ( ) const

inline

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. Ownership retained.

the null coordinate if the geometry is simple

isSimple() [1/4]

bool geos::operation::IsSimpleOp::isSimple

(

)

Tests whether the geometry is simple.

Returns

true if the geometry is simple

isSimple() [2/4]

bool geos::operation::IsSimpleOp::isSimple

(

const geom::LineString *

geom

)

Reports whether a geom::LineString is simple.

Parameters

geom	the lineal geometry to test

Returns

true if the geometry is simple

Deprecated

use isSimple()

isSimple() [3/4]

bool geos::operation::IsSimpleOp::isSimple

(

const geom::MultiLineString *

geom

)

Reports whether a geom::MultiLineString is simple.

Parameters

geom	the lineal geometry to test

Returns

true if the geometry is simple

Deprecated

use isSimple()

isSimple() [4/4]

bool geos::operation::IsSimpleOp::isSimple

(

const geom::MultiPoint *

mp

)

A MultiPoint is simple iff it has no repeated points

Deprecated

use isSimple()

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

• IsSimpleOp.h