geos::operation::overlay::snap::GeometrySnapper Class Reference

Snaps the vertices and segments of a geom::Geometry to another Geometry's vertices. More...

#include <GeometrySnapper.h>

Public Types
typedef std::unique_ptr< geom::Geometry >	GeomPtr

Public Member Functions
	GeometrySnapper (const geom::Geometry &g)
std::unique_ptr< geom::Geometry >	snapTo (const geom::Geometry &g, double snapTolerance)
	Snaps the vertices in the component geom::LineStrings of the source geometry to the vertices of the given snap geometry with a given snap tolerance. More...
std::unique_ptr< geom::Geometry >	snapToSelf (double snapTolerance, bool cleanResult)
	Snaps the vertices in the component geom::LineStrings of the source geometry to the vertices of itself with a given snap tolerance and optionally cleaning the result. More...

Static Public Member Functions
static void	snap (const geom::Geometry &g0, const geom::Geometry &g1, double snapTolerance, geom::GeomPtrPair &ret)
static GeomPtr	snapToSelf (const geom::Geometry &g0, double snapTolerance, bool cleanResult)
static double	computeOverlaySnapTolerance (const geom::Geometry &g)
	Estimates the snap tolerance for a Geometry, taking into account its precision model. More...
static double	computeSizeBasedSnapTolerance (const geom::Geometry &g)
static double	computeOverlaySnapTolerance (const geom::Geometry &g1, const geom::Geometry &g2)
	Computes the snap tolerance based on input geometries;.

Detailed Description

Snaps the vertices and segments of a geom::Geometry to another Geometry's vertices.

A snap distance tolerance is used to control where snapping is performed. Snapping one geometry to another can improve robustness for overlay operations by eliminating nearly-coincident edges (which cause problems during noding and intersection calculation). Too much snapping can result in invalid topology being created, so the number and location of snapped vertices is decided using heuristics to determine when it is safe to snap. This can result in some potential snaps being omitted, however.

Constructor & Destructor Documentation

GeometrySnapper()

geos::operation::overlay::snap::GeometrySnapper::GeometrySnapper ( const geom::Geometry &  g )

inline

Creates a new snapper acting on the given geometry

Parameters

g	the geometry to snap

Member Function Documentation

computeOverlaySnapTolerance()

static double geos::operation::overlay::snap::GeometrySnapper::computeOverlaySnapTolerance ( const geom::Geometry &  g )

static

Estimates the snap tolerance for a Geometry, taking into account its precision model.

Parameters

g	a Geometry

Returns

the estimated snap tolerance

snap()

static void geos::operation::overlay::snap::GeometrySnapper::snap ( const geom::Geometry &  g0, const geom::Geometry &  g1, double  snapTolerance, geom::GeomPtrPair &  ret  )

static

Snaps two geometries together with a given tolerance.

Parameters

g0	a geometry to snap
g1	a geometry to snap
snapTolerance	the tolerance to use
ret	the snapped geometries as a pair of smart pointers (output parameter)

snapTo()

std::unique_ptr< geom::Geometry > geos::operation::overlay::snap::GeometrySnapper::snapTo	(	const geom::Geometry &	g,
		double	snapTolerance
	)

Snaps the vertices in the component geom::LineStrings of the source geometry to the vertices of the given snap geometry with a given snap tolerance.

Parameters

g	a geometry to snap the source to
snapTolerance

Returns

a new snapped Geometry

snapToSelf()

std::unique_ptr< geom::Geometry > geos::operation::overlay::snap::GeometrySnapper::snapToSelf	(	double	snapTolerance,
		bool	cleanResult
	)

Snaps the vertices in the component geom::LineStrings of the source geometry to the vertices of itself with a given snap tolerance and optionally cleaning the result.

Parameters

snapTolerance
cleanResult	clean the result

Returns

a new snapped Geometry

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

• GeometrySnapper.h