SpatialIndex Class Reference

#include <SpatialIndex.h>

Public Member Functions
	SpatialIndex (size_t maxlevel, size_t buildlevel=5)
uint64	idByPoint (const SpatialVector &vector) const
void	nodeVertex (const uint64 id, SpatialVector &v1, SpatialVector &v2, SpatialVector &v3) const
void	pointById (SpatialVector &vector, uint64 ID) const

Static Public Member Functions
static uint64	idByName (const char *)
static char *	nameById (uint64 ID, char *name=0)

Detailed Description

The Spatial Index is a quad tree of spherical triangles.

The tree is built in the following way: Start out with 8 triangles on the sphere using the 3 main circles to determine them. Then, every triangle can be decomposed into 4 new triangles by drawing main circles between midpoints of its edges:

.                            /\
.                           /  \
.                          /____\
.                         /\    /\
.                        /  \  /  \
.                       /____\/____\

This is how the quad tree is built up to a certain level by decomposing every triangle again and again.

Definition at line 59 of file SpatialIndex.h.

Constructor & Destructor Documentation

SpatialIndex::SpatialIndex	(	size_t	maxlevel,
		size_t	buildlevel = 5
	)

Constructor.

Give the level of the index and optionally the level to build - i.e. the depth to keep in memory. if maxlevel - buildlevel > 0 , that many levels are generated on the fly each time the index is called.

Definition at line 60 of file SpatialIndex.cpp.

Member Function Documentation

uint64 SpatialIndex::idByName ( const char *  name )

static

NodeName conversion to integer ID.

Definition at line 338 of file SpatialIndex.cpp.

uint64 SpatialIndex::idByPoint

(

const SpatialVector &

vector

)

const

find a node by giving a vector.

The ID of the node is returned.

Definition at line 502 of file SpatialIndex.cpp.

char * SpatialIndex::nameById ( uint64  ID, char *  name = 0  )

static

int32 conversion to a string (name of database).

WARNING: if name is already allocated, a size of at least 17 is required. The conversion is done by directly calculating the name from a number. To calculate the name of a certain level, the mechanism is that the name is given by (#of nodes in that level) + (id of node). So for example, for the first level, there are 8 nodes, and we get the names from numbers 8 through 15 giving S0,S1,S2,S3,N0,N1,N2,N3. The order is always ascending starting from S0000.. to N3333...

Definition at line 395 of file SpatialIndex.cpp.

void SpatialIndex::nodeVertex	(	const uint64	id,
		SpatialVector &	v1,
		SpatialVector &	v2,
		SpatialVector &	v3
	)		const

return the actual vertex vectors

Definition at line 122 of file SpatialIndex.cpp.

void SpatialIndex::pointById	(	SpatialVector &	vector,
		uint64	ID
	)		const

find the vector to the centroid of a triangle represented by the ID

Definition at line 450 of file SpatialIndex.cpp.

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

• SpatialIndex.h
• SpatialIndex.cpp