A spatial index defined by origin, spacing, and resolution. More...

#include </home/docs/checkouts/readthedocs.org/user_builds/axom/checkouts/v0.9.1/src/axom/spin/UniformGrid.hpp>

Inherits policy::DynamicGridStorage< T >.

Classes
struct	QueryObject

Public Types
enum	{ INVALID_BIN_INDEX = -1 }
	A special value indicating any location not in the UniformGrid. More...

using	BoxType = primal::BoundingBox< double, NDIMS >
	The type used for specifying spatial extent of the contents. More...

using	PointType = primal::Point< double, NDIMS >
	The type used to query the index. More...

Public Member Functions
	UniformGrid (const double lower_bound, const double upper_bound, const int *res, int allocatorID=axom::execution_space< ExecSpace >::allocatorID())
	Constructor specifying bounding box (min and max points) and number of bins. More...

	UniformGrid (const BoxType &bbox, const int *res, int allocatorID=axom::execution_space< ExecSpace >::allocatorID())
	Constructor specifying bounding box and number of bins. More...

	UniformGrid (const primal::NumericArray< int, NDIMS > &res, axom::ArrayView< const BoxType > bboxes, axom::ArrayView< const T > objs, int allocatorID=axom::execution_space< ExecSpace >::allocatorID())
	Constructor specifying objects to initialize the UniformGrid with. More...

void	initialize (axom::ArrayView< const BoxType > bboxes, axom::ArrayView< const T > objs)
	Reinitializes a UniformGrid with an array of objects and associated bounding boxes. More...

int	getBinIndex (const PointType &pt) const
	Returns the index of the bin containing the specified point. More...

bool	isBinEmpty (int index) const
	Returns whether the bin specified by index is empty. More...

const std::vector< int >	getBinsForBbox (const BoxType &BB) const
	Returns the indices of the bins for a given bounding box. More...

void	getCandidatesAsArray (axom::ArrayView< const BoxType > queryObjs, axom::ArrayView< IndexType > outOffsets, axom::ArrayView< IndexType > outCounts, axom::Array< IndexType > &outCandidates) const
	Returns a list of candidates in the vicinity of a set of query bounding boxes. More...

void	insert (const BoxType &BB, const T &obj)
	Inserts obj into each bin overlapped by BB. More...

QueryObject	getQueryObject () const

Detailed Description

template<typename T, int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>>
class axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >

A spatial index defined by origin, spacing, and resolution.

Template Parameters

T	The type of object that this UniformGrid will hold
NDIMS	The UniformGrid dimensionality: supported values are 2 or 3
ExecSpace	The execution space in which operations will take place

The UniformGrid class is parameterized on the type of object it will contain and the dimensionality of the grid. Currently the UniformGrid will index 2D and 3D space.

The UniformGrid divides space into a number of bins, extending in a block from an origin point and arranged in row-major order. Each bin extends over an axis-aligned rectangle or parallelepiped. The size of a bin is specified by the spacing constructor argument, and the number of bins is specified by the res constructor argument.

To use this class, a user will instantiate a UniformGrid and insert a number of objects (each with its own bounding box). The insert operation puts the object into some of the bins. The user may retrieve the bin index of any point, then retrieve any objects associated with the bin at that index.

Member Typedef Documentation

◆ BoxType

template<typename T , int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>>

using axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::BoxType = primal::BoundingBox<double, NDIMS>

The type used for specifying spatial extent of the contents.

◆ PointType

template<typename T , int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>>

using axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::PointType = primal::Point<double, NDIMS>

The type used to query the index.

Member Enumeration Documentation

◆ anonymous enum

template<typename T , int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>>

anonymous enum

A special value indicating any location not in the UniformGrid.

Returned by getBinIndex() if that function is passed an exterior point. An error is thrown if getBinContents() is passed INVALID_BIN_INDEX. clear(INVALID_BIN_INDEX) is a no-op; isBinEmpty(INVALID_BIN_INDEX) returns true.

Enumerator
INVALID_BIN_INDEX

Constructor & Destructor Documentation

◆ UniformGrid() [1/3]

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::UniformGrid	(	const double *	lower_bound,
		const double *	upper_bound,
		const int *	res,
		int	allocatorID = `axom::execution_space<ExecSpace>::allocatorID()`
	)

Constructor specifying bounding box (min and max points) and number of bins.

The lower and upper bounds are specified as double arrays. Each argument points to an array of at least length NDIMS. The nth element in each array specifies, for the nth dimension, the lower bound (inclusive), the upper bound (exclusive), and the number of bins. Thus, UniformGrid({0., 0.}, {2., 4.}, {2, 4}); defines an index extending from 0 up to 2 divided into two bins in the x-dimension and from 0 up to 4 divided into four bins in the y dimension.

◆ UniformGrid() [2/3]

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::UniformGrid	(	const BoxType &	bbox,
		const int *	res,
		int	allocatorID = `axom::execution_space<ExecSpace>::allocatorID()`
	)

Constructor specifying bounding box and number of bins.

References SLIC_ASSERT.

◆ UniformGrid() [3/3]

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::UniformGrid	(	const primal::NumericArray< int, NDIMS > &	res,
		axom::ArrayView< const BoxType >	bboxes,
		axom::ArrayView< const T >	objs,
		int	allocatorID = `axom::execution_space<ExecSpace>::allocatorID()`
	)

Constructor specifying objects to initialize the UniformGrid with.

References axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::initialize().

Member Function Documentation

◆ initialize()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

void axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::initialize	(	axom::ArrayView< const BoxType >	bboxes,
		axom::ArrayView< const T >	objs
	)

Reinitializes a UniformGrid with an array of objects and associated bounding boxes.

References AXOM_HOST_LAMBDA, AXOM_LAMBDA, axom::Array< T, DIM, SPACE >::fill(), axom::detail::getAllocatorID(), axom::primal::BoundingBox< T, NDIMS >::getMax(), axom::primal::BoundingBox< T, NDIMS >::getMin(), axom::utilities::max(), axom::ArrayView< T, DIM, SPACE >::size(), and SLIC_ASSERT.

◆ getBinIndex()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

int axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::getBinIndex ( const PointType & pt ) const

Returns the index of the bin containing the specified point.

If the specified point is outside the grid, the function returns a special value (INVALID_BIN_INDEX). Note that the upper boundaries of a UniformGrid are not in a bin. Thus, if a UniformGrid divides the region from (0., 0.) to (10., 10.) into 10 x 10 bins, the code getBinIndex(PointType::makePoint(10., 10.)) will return INVALID_BIN_INDEX,

Parameters

[in] pt The point to query.

◆ isBinEmpty()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

bool axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::isBinEmpty ( int index ) const

Returns whether the bin specified by index is empty.

Returns true if index is invalid.

Parameters

[in] index The index of the bin to test.

◆ getBinsForBbox()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

const std::vector< int > axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::getBinsForBbox ( const BoxType & BB ) const

Returns the indices of the bins for a given bounding box.

This method returns the indices of the bins that intersect BB. Any part of BB that falls outside this UniformGrid is disregarded. If BB falls completely outside this UniformGrid, this method returns an empty list.

References axom::primal::BoundingBox< T, NDIMS >::getMax(), and axom::primal::BoundingBox< T, NDIMS >::getMin().

◆ getCandidatesAsArray()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

void axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::getCandidatesAsArray	(	axom::ArrayView< const BoxType >	queryObjs,
		axom::ArrayView< IndexType >	outOffsets,
		axom::ArrayView< IndexType >	outCounts,
		axom::Array< IndexType > &	outCandidates
	)		const

Returns a list of candidates in the vicinity of a set of query bounding boxes.

Parameters

[in]	queryObjs	The array of query objects
[out]	outOffsets	Offsets into the candidates array for each query object
[out]	outCounts	The number of candidates for each query object
[out]	candidates	The candidate IDs for each query object

Note

The output candidate array is allocated inside the function, using the given allocator ID passed in during implicit grid initialization.

Upon completion, the ith query point has:

counts[ i ] candidates
Stored in the candidates array in the following range: [ offsets[ i ], offsets[ i ]+counts[ i ] ]

References AXOM_LAMBDA, axom::Array< T, DIM, SPACE >::data(), axom::ArrayView< T, DIM, SPACE >::data(), axom::detail::getAllocatorID(), axom::Array< T, DIM, SPACE >::push_back(), axom::ArrayView< T, DIM, SPACE >::size(), SLIC_ASSERT, and axom::Array< T, DIM, SPACE >::view().

◆ insert()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

void axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::insert	(	const BoxType &	BB,
		const T &	obj
	)

Inserts obj into each bin overlapped by BB.

No error is signalled if BB falls partly or wholly outside the UniformGrid.

Parameters

[in]	BB	The region in which to record obj
[in]	obj	The object to insert into any bins overlapped by BB

References SLIC_ASSERT.

◆ getQueryObject()

template<typename T , int NDIMS, typename ExecSpace , typename StoragePolicy >

UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::QueryObject axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >::getQueryObject

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

/home/docs/checkouts/readthedocs.org/user_builds/axom/checkouts/v0.9.1/src/axom/spin/UniformGrid.hpp

Classes

Public Types

Public Member Functions

Detailed Description

template<typename T, int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>> class axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >

Member Typedef Documentation

◆ BoxType

◆ PointType

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ UniformGrid() [1/3]

◆ UniformGrid() [2/3]

◆ UniformGrid() [3/3]

Member Function Documentation

◆ initialize()

◆ getBinIndex()

◆ isBinEmpty()

◆ getBinsForBbox()

◆ getCandidatesAsArray()

◆ insert()

◆ getQueryObject()

template<typename T, int NDIMS, typename ExecSpace = axom::SEQ_EXEC, typename StoragePolicy = policy::DynamicGridStorage<T>>
class axom::spin::UniformGrid< T, NDIMS, ExecSpace, StoragePolicy >