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cpl_quad_tree.h File Reference
#include "cpl_port.h"

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Classes

struct  CPLRectObj
 

Typedefs

typedef struct _CPLQuadTree CPLQuadTree
 
typedef void(* CPLQuadTreeGetBoundsFunc) (const void *hFeature, CPLRectObj *pBounds)
 
typedef int(* CPLQuadTreeForeachFunc) (void *pElt, void *pUserData)
 
typedef void(* CPLQuadTreeDumpFeatureFunc) (const void *hFeature, int nIndentLevel, void *pUserData)
 

Functions

CPLQuadTree CPL_DLL * CPLQuadTreeCreate (const CPLRectObj *pGlobalBounds, CPLQuadTreeGetBoundsFunc pfnGetBounds)
 
void CPL_DLL CPLQuadTreeDestroy (CPLQuadTree *hQuadtree)
 
void CPL_DLL CPLQuadTreeSetBucketCapacity (CPLQuadTree *hQuadtree, int nBucketCapacity)
 
int CPL_DLL CPLQuadTreeGetAdvisedMaxDepth (int nExpectedFeatures)
 
void CPL_DLL CPLQuadTreeSetMaxDepth (CPLQuadTree *hQuadtree, int nMaxDepth)
 
void CPL_DLL CPLQuadTreeInsert (CPLQuadTree *hQuadtree, void *hFeature)
 
void CPL_DLL CPLQuadTreeInsertWithBounds (CPLQuadTree *hQuadtree, void *hFeature, const CPLRectObj *psBounds)
 
void CPL_DLL ** CPLQuadTreeSearch (const CPLQuadTree *hQuadtree, const CPLRectObj *pAoi, int *pnFeatureCount)
 
void CPL_DLL CPLQuadTreeForeach (const CPLQuadTree *hQuadtree, CPLQuadTreeForeachFunc pfnForeach, void *pUserData)
 
void CPL_DLL CPLQuadTreeDump (const CPLQuadTree *hQuadtree, CPLQuadTreeDumpFeatureFunc pfnDumpFeatureFunc, void *pUserData)
 
void CPL_DLL CPLQuadTreeGetStats (const CPLQuadTree *hQuadtree, int *pnFeatureCount, int *pnNodeCount, int *pnMaxDepth, int *pnMaxBucketCapacity)
 

Detailed Description

Quad tree implementation.

A quadtree is a tree data structure in which each internal node has up to four children. Quadtrees are most often used to partition a two dimensional space by recursively subdividing it into four quadrants or regions

Typedef Documentation

◆ CPLQuadTree

typedef struct _CPLQuadTree CPLQuadTree

Opaque type for a quad tree

◆ CPLQuadTreeDumpFeatureFunc

typedef void(* CPLQuadTreeDumpFeatureFunc) (const void *hFeature, int nIndentLevel, void *pUserData)

CPLQuadTreeDumpFeatureFunc

◆ CPLQuadTreeForeachFunc

typedef int(* CPLQuadTreeForeachFunc) (void *pElt, void *pUserData)

CPLQuadTreeForeachFunc

◆ CPLQuadTreeGetBoundsFunc

typedef void(* CPLQuadTreeGetBoundsFunc) (const void *hFeature, CPLRectObj *pBounds)

CPLQuadTreeGetBoundsFunc

Function Documentation

◆ CPLQuadTreeCreate()

CPLQuadTree CPL_DLL* CPLQuadTreeCreate ( const CPLRectObj pGlobalBounds,
CPLQuadTreeGetBoundsFunc  pfnGetBounds 
)

Create a new quadtree

Parameters
pGlobalBoundsa pointer to the global extent of all the elements that will be inserted
pfnGetBoundsa user provided function to get the bounding box of the inserted elements. If it is set to NULL, then CPLQuadTreeInsertWithBounds() must be used, and extra memory will be used to keep features bounds in the quad tree.
Returns
a newly allocated quadtree

◆ CPLQuadTreeDestroy()

void CPL_DLL CPLQuadTreeDestroy ( CPLQuadTree hQuadTree)

Destroy a quadtree

Parameters
hQuadTreethe quad tree to destroy

◆ CPLQuadTreeDump()

void CPL_DLL CPLQuadTreeDump ( const CPLQuadTree hQuadTree,
CPLQuadTreeDumpFeatureFunc  pfnDumpFeatureFunc,
void *  pUserData 
)

Dump quad tree

◆ CPLQuadTreeForeach()

void CPL_DLL CPLQuadTreeForeach ( const CPLQuadTree hQuadTree,
CPLQuadTreeForeachFunc  pfnForeach,
void *  pUserData 
)

Walk through the quadtree and runs the provided function on all the elements

This function is provided with the user_data argument of pfnForeach. It must return TRUE to go on the walk through the hash set, or FALSE to make it stop.

Note : the structure of the quadtree must NOT be modified during the walk.

Parameters
hQuadTreethe quad tree
pfnForeachthe function called on each element.
pUserDatathe user data provided to the function.

◆ CPLQuadTreeGetAdvisedMaxDepth()

int CPL_DLL CPLQuadTreeGetAdvisedMaxDepth ( int  nExpectedFeatures)

Returns the optimal depth of a quadtree to hold nExpectedFeatures

Parameters
nExpectedFeaturesthe expected maximum number of elements to be inserted.
Returns
the optimal depth of a quadtree to hold nExpectedFeatures

◆ CPLQuadTreeGetStats()

void CPL_DLL CPLQuadTreeGetStats ( const CPLQuadTree hQuadTree,
int *  pnFeatureCount,
int *  pnNodeCount,
int *  pnMaxDepth,
int *  pnMaxBucketCapacity 
)

Get stats

◆ CPLQuadTreeInsert()

void CPL_DLL CPLQuadTreeInsert ( CPLQuadTree hQuadTree,
void *  hFeature 
)

Insert a feature into a quadtree

Parameters
hQuadTreethe quad tree
hFeaturethe feature to insert

◆ CPLQuadTreeInsertWithBounds()

void CPL_DLL CPLQuadTreeInsertWithBounds ( CPLQuadTree hQuadTree,
void *  hFeature,
const CPLRectObj psBounds 
)

Insert a feature into a quadtree

Parameters
hQuadTreethe quad tree
hFeaturethe feature to insert
psBoundsbounds of the feature

◆ CPLQuadTreeSearch()

void CPL_DLL** CPLQuadTreeSearch ( const CPLQuadTree hQuadTree,
const CPLRectObj pAoi,
int *  pnFeatureCount 
)

Returns all the elements inserted whose bounding box intersects the provided area of interest

Parameters
hQuadTreethe quad tree
pAoithe pointer to the area of interest
pnFeatureCountthe user data provided to the function.
Returns
an array of features that must be freed with CPLFree

◆ CPLQuadTreeSetBucketCapacity()

void CPL_DLL CPLQuadTreeSetBucketCapacity ( CPLQuadTree hQuadTree,
int  nBucketCapacity 
)

Set the maximum capacity of a node of a quadtree. The default value is 8. Note that the maximum capacity will only be honoured if the features inserted have a point geometry. Otherwise it may be exceeded.

Parameters
hQuadTreethe quad tree
nBucketCapacitythe maximum capacity of a node of a quadtree

◆ CPLQuadTreeSetMaxDepth()

void CPL_DLL CPLQuadTreeSetMaxDepth ( CPLQuadTree hQuadTree,
int  nMaxDepth 
)

Set the maximum depth of a quadtree. By default, quad trees have no maximum depth, but a maximum bucket capacity.

Parameters
hQuadTreethe quad tree
nMaxDepththe maximum depth allowed