GEOS  3.9.0dev
geos::index::strtree::BoundablePair Class Reference

A pair of Boundables, whose leaf items support a distance metric between them. More...

`#include <BoundablePair.h>`

## Public Types

typedef std::priority_queue
< BoundablePair *, std::vector
< BoundablePair * >
, BoundablePairQueueCompare >
BoundablePairQueue

## Public Member Functions

BoundablePair (const Boundable *boundable1, const Boundable *boundable2, ItemDistance *itemDistance)

const BoundablegetBoundable (int i) const

double distance () const
Computes the distance between the Boundables in this pair. The boundables are either composites or leaves. More...

double getDistance () const
Gets the minimum possible distance between the Boundables in this pair. More...

bool isLeaves () const

double maximumDistance ()
Computes the maximum distance between any two items in the pair of nodes. More...

void expandToQueue (BoundablePairQueue &, double minDistance)

void expand (const Boundable *bndComposite, const Boundable *bndOther, bool isFlipped, BoundablePairQueue &priQ, double minDistance)

## Static Public Member Functions

static bool isComposite (const Boundable *item)

static double area (const Boundable *b)

## Detailed Description

A pair of Boundables, whose leaf items support a distance metric between them.

Used to compute the distance between the members, and to expand a member relative to the other in order to produce new branches of the Branch-and-Bound evaluation tree. Provides an ordering based on the distance between the members, which allows building a priority queue by minimum distance.

## Member Function Documentation

 double geos::index::strtree::BoundablePair::distance ( ) const

Computes the distance between the Boundables in this pair. The boundables are either composites or leaves.

If either is composite, the distance is computed as the minimum distance between the bounds. If both are leaves, the distance is computed by ItemDistance::distance(const ItemBoundable* item1, const ItemBoundable* item2).

Returns
the distance between the items
 const Boundable* geos::index::strtree::BoundablePair::getBoundable ( int i ) const

Gets one of the member Boundables in the pair (indexed by [0, 1]).

Parameters
 i the index of the member to return (0 or 1)
Returns
the chosen member
 double geos::index::strtree::BoundablePair::getDistance ( ) const

Gets the minimum possible distance between the Boundables in this pair.

If the members are both items, this will be the exact distance between them. Otherwise, this distance will be a lower bound on the distances between the items in the members.

Returns
the exact or lower bound distance for this pair
 bool geos::index::strtree::BoundablePair::isLeaves ( ) const

Tests if both elements of the pair are leaf nodes

Returns
true if both pair elements are leaf nodes
 double geos::index::strtree::BoundablePair::maximumDistance ( )

Computes the maximum distance between any two items in the pair of nodes.

Returns
the maximum distance between items in the pair

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