DYT/Tool/OpenSceneGraph-3.6.5/include/geos/index/strtree/SimpleSTRdistance.h
2024-12-25 07:49:36 +08:00

167 lines
4.2 KiB
C++

/**********************************************************************
*
* GEOS - Geometry Engine Open Source
* http://geos.osgeo.org
*
* Copyright (C) 2020 Paul Ramsey
*
* This is free software; you can redistribute and/or modify it under
* the terms of the GNU Lesser General Public Licence as published
* by the Free Software Foundation.
* See the COPYING file for more information.
*
**********************************************************************/
#pragma once
#include <cassert>
#include <cstddef>
#include <geos/export.h>
#include <geos/geom/Envelope.h>
#include <geos/index/strtree/SimpleSTRtree.h>
#include <geos/index/strtree/SimpleSTRnode.h>
#include <vector>
#include <queue>
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4251) // warning C4251: needs to have dll-interface to be used by clients of class
#endif
namespace geos {
namespace index { // geos::index
namespace strtree { // geos::index::strtree
class GEOS_DLL SimpleSTRpair {
private:
SimpleSTRnode* node1;
SimpleSTRnode* node2;
ItemDistance* itemDistance;
double m_distance;
/** \brief
* Computes the distance between the {@link SimpleSTRnode}s in this pair.
* The nodes 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 void* item1, const void* item2).
*
* @return the distance between the items
*/
double distance();
public:
SimpleSTRpair(SimpleSTRnode* p_node1, SimpleSTRnode* p_node2, ItemDistance* p_itemDistance)
: node1(p_node1)
, node2(p_node2)
, itemDistance(p_itemDistance)
{
m_distance = distance();
}
SimpleSTRnode* getNode(int i) const;
/** \brief
* Gets the minimum possible distance between the SimpleSTRnode 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.
*
* @return the exact or lower bound distance for this pair
*/
double getDistance() const;
/**
* Tests if both elements of the pair are leaf nodes
*
* @return true if both pair elements are leaf nodes
*/
bool isLeaves() const;
/** \brief
* Computes the maximum distance between any
* two items in the pair of nodes.
*
* @return the maximum distance between items in the pair
*/
double maximumDistance();
friend std::ostream& operator<<(std::ostream& os, SimpleSTRpair& pair);
};
class GEOS_DLL SimpleSTRdistance {
public:
struct STRpairQueueCompare {
bool
operator()(const SimpleSTRpair* a, const SimpleSTRpair* b)
{
return a->getDistance() > b->getDistance();
}
};
typedef std::priority_queue<SimpleSTRpair*,
std::vector<SimpleSTRpair*>,
STRpairQueueCompare> STRpairQueue;
/* Initialize class */
SimpleSTRdistance(SimpleSTRnode* root1, SimpleSTRnode* root2, ItemDistance* p_itemDistance);
/* Turn over the calculation */
std::pair<const void*, const void*> nearestNeighbour();
bool isWithinDistance(double maxDistance);
private:
std::deque<SimpleSTRpair> pairStore;
SimpleSTRpair* initPair;
ItemDistance* itemDistance;
/* Utility method to store allocated pairs */
SimpleSTRpair* createPair(SimpleSTRnode* p_node1, SimpleSTRnode* p_node2, ItemDistance* p_itemDistance);
std::pair<const void*, const void*> nearestNeighbour(SimpleSTRpair* p_initPair);
std::pair<const void*, const void*> nearestNeighbour(SimpleSTRpair* p_initPair, double maxDistance);
bool isWithinDistance(SimpleSTRpair* p_initPair, double maxDistance);
void expandToQueue(SimpleSTRpair* pair, STRpairQueue&, double minDistance);
void expand(SimpleSTRnode* nodeComposite, SimpleSTRnode* nodeOther,
bool isFlipped, STRpairQueue& priQ, double minDistance);
};
} // namespace geos::index::strtree
} // namespace geos::index
} // namespace geos
#ifdef _MSC_VER
#pragma warning(pop)
#endif