geos::algorithm::MinimumDiameter Class Reference

Computes the minimum diameter of a geom::Geometry. More...

#include <MinimumDiameter.h>

Public Member Functions
	MinimumDiameter (const geom::Geometry *newInputGeom)
	Compute a minimum diameter for a given Geometry. More...
	MinimumDiameter (const geom::Geometry *newInputGeom, const bool newIsConvex)
	Compute a minimum diameter for a given Geometry, with a hint if the Geometry is convex (e.g. a convex Polygon or LinearRing, or a two-point LineString, or a Point). More...
double	getLength ()
	Gets the length of the minimum diameter of the input Geometry. More...
const geom::Coordinate &	getWidthCoordinate ()
	Gets the geom::Coordinate forming one end of the minimum diameter. More...
std::unique_ptr< geom::LineString >	getSupportingSegment ()
	Gets the segment forming the base of the minimum diameter. More...
std::unique_ptr< geom::LineString >	getDiameter ()
	Gets a LineString which is a minimum diameter. More...
std::unique_ptr< geom::Geometry >	getMinimumRectangle ()
	Gets the minimum rectangular Polygon which encloses the input geometry. More...

Static Public Member Functions
static std::unique_ptr< geom::Geometry >	getMinimumRectangle (geom::Geometry *geom)
	Gets the minimum rectangle enclosing a geometry. More...
static std::unique_ptr< geom::Geometry >	getMinimumDiameter (geom::Geometry *geom)
	Gets the length of the minimum diameter enclosing a geometry. More...

Detailed Description

Computes the minimum diameter of a geom::Geometry.

The minimum diameter is defined to be the width of the smallest band that contains the geometry, where a band is a strip of the plane defined by two parallel lines. This can be thought of as the smallest hole that the geometry can be moved through, with a single rotation.

The first step in the algorithm is computing the convex hull of the Geometry. If the input Geometry is known to be convex, a hint can be supplied to avoid this computation.

This class can also be used to compute a line segment representing the minimum diameter, the supporting line segment of the minimum diameter, and a minimum rectangle enclosing the input geometry. This rectangle will have width equal to the minimum diameter, and have one side parallel to the supporting segment.

See also

ConvexHull

Constructor & Destructor Documentation

MinimumDiameter() [1/2]

geos::algorithm::MinimumDiameter::MinimumDiameter

(

const geom::Geometry *

newInputGeom

)

Compute a minimum diameter for a given Geometry.

Parameters

newInputGeom

a Geometry

MinimumDiameter() [2/2]

geos::algorithm::MinimumDiameter::MinimumDiameter	(	const geom::Geometry *	newInputGeom,
		const bool	newIsConvex
	)

Compute a minimum diameter for a given Geometry, with a hint if the Geometry is convex (e.g. a convex Polygon or LinearRing, or a two-point LineString, or a Point).

Parameters

newInputGeom	a Geometry which is convex
newIsConvex	true if the input geometry is convex

Member Function Documentation

getDiameter()

std::unique_ptr< geom::LineString > geos::algorithm::MinimumDiameter::getDiameter

(

)

Gets a LineString which is a minimum diameter.

Returns

a LineString which is a minimum diameter

getLength()

double geos::algorithm::MinimumDiameter::getLength

(

)

Gets the length of the minimum diameter of the input Geometry.

Returns

the length of the minimum diameter

getMinimumDiameter()

static std::unique_ptr< geom::Geometry > geos::algorithm::MinimumDiameter::getMinimumDiameter ( geom::Geometry *  geom )

static

Gets the length of the minimum diameter enclosing a geometry.

Parameters

geom	the geometry

Returns

the length of the minimum diameter of the geometry

getMinimumRectangle() [1/2]

std::unique_ptr< geom::Geometry > geos::algorithm::MinimumDiameter::getMinimumRectangle

(

)

Gets the minimum rectangular Polygon which encloses the input geometry.

The rectangle has width equal to the minimum diameter, and a longer length. If the convex hill of the input is degenerate (a line or point) a LineString or Point is returned. The minimum rectangle can be used as an extremely generalized representation for the given geometry.

Returns

the minimum rectangle enclosing the input (or a line or point if degenerate)

getMinimumRectangle() [2/2]

static std::unique_ptr< geom::Geometry > geos::algorithm::MinimumDiameter::getMinimumRectangle ( geom::Geometry *  geom )

static

Gets the minimum rectangle enclosing a geometry.

Parameters

geom	the geometry

Returns

the minimum rectangle enclosing the geometry

getSupportingSegment()

std::unique_ptr< geom::LineString > geos::algorithm::MinimumDiameter::getSupportingSegment

(

)

Gets the segment forming the base of the minimum diameter.

Returns

the segment forming the base of the minimum diameter

getWidthCoordinate()

const geom::Coordinate & geos::algorithm::MinimumDiameter::getWidthCoordinate

(

)

Gets the geom::Coordinate forming one end of the minimum diameter.

Returns

a coordinate forming one end of the minimum diameter

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

• MinimumDiameter.h