Detailed Description

template<int D, class StorageT, class Value, class EmbeddingT = DefaultEmbeddingD<D>>
class IMP::algebra::GridD< D, StorageT, Value, EmbeddingT >

A voxel grid in d-dimensional space.

First some terminology:

a voxel is the data stored at a given location in space
an Index is a way of identifying a particular voxel. That is, given an index, it is easy to get the voxel, but not vice-versa.
an ExtendedIndex identifies a particular region in space, but it may not have a corresponding voxel (if it is outside of the region the grid is built on or if that voxel has not yet been added to the sparse grid).

IMP provides support for a variety of spatial grids. The grid support in C++ is implemented by combining several different layers to specify what capabilities are desired. These layers are:

Data: any type of data can be stored in a voxel of the grid.
Boundedness: By using UnboundedGridStorage3D or BoundedGridStorage3D, one can choose whether you want a grid over a finite region of space or over the whole space.
Storage: by choosing SparseGridStorage3D or DenseGridStorage3D, you can choose whether you want to store all voxels or only a subset of the voxels. The former is faster and more compact when most of the voxels are used, the latter when only a few are used (say <1/4).
Geometry: The Grid3D class itself provides a geometric layer, mapping Vector3D objects into voxels in the grid.

These are implemented as mix-ins, so each layer provides a set of accessible functionality as methods/types in the final class.

Basic operations: Creating a grid with a given cell size and upper and lower bounds
BoundingBox3D bb(Vector3D(10,10,10), Vector3D(100,100,100));

typedef Grid3D<Ints> Grid;

Grid grid(5, bb, 0.0);

Iterate over the set of voxels incident on a bounding box:

BoundingBoxD<3> bb(Vector3D(20.2,20.3,20.5), Vector3D(31.3,32.5,38.9));
for (Grid::IndexIterator it= grid.voxels_begin(bb);
it != grid.voxels_end(bb); ++it) {
it->push_back(1);
}

See Also: DenseGridStorage3D; SparseGridStorageD

Examples:: grid.cpp.

Definition at line 79 of file GridD.h.

Public Types
typedef EmbeddingT	Embedding

typedef StorageT	Storage

typedef VectorD< D >	Vector

Public Member Functions
	GridD (const Ints counts, const BoundingBoxD< D > &bb, Value default_value=Value())

	GridD (double side, const BoundingBoxD< D > &bb, const Value &default_value=Value())

	GridD (const VectorD< D > &sides, const BoundingBoxD< D > &bb, const Value &default_value=Value())

	GridD (const Storage &storage, const Embedding &embed)

	GridD (double side, const VectorD< D > &origin, const Value &default_value=Value())

	GridD (const VectorD< D > &sides, const VectorD< D > &origin, const Value &default_value=Value())

	GridD ()
	An empty, undefined grid. More...

GridIndexD< D >	add_voxel (const VectorD< D > &pt, const Value &vt)

const Value	at (VectorD< D >) const

Value &	at (VectorD< D >)

BoundingBoxD< D >	get_bounding_box () const

ExtendedGridIndexD< D >	get_extended_index (const GridIndexD< D > &index) const
	Convert an index back to an extended index. More...

Value &	operator[] (VectorD< D >)

const Value	operator[] (VectorD< D >) const

void	set_bounding_box (const BoundingBoxD< D > &bb3)
	Change the bounding box but not the grid or contents. More...

void	show (std::ostream &out=std::cout) const

Get nearest
If the point is in the bounding box of the grid, this is the index of the voxel containing the point, otherwise it is the closest one in the bounding box. This can only be used with bounded grids, right now.
GridIndexD< D >	get_nearest_index (const VectorD< D > &pt) const

ExtendedGridIndexD< D >	get_nearest_extended_index (const VectorD< D > &pt) const

Voxel iterators
These iterators go through a range of voxels in the grid. These voxels include any that touch or are contained in the shape passed to the begin/end calls.
typedef internal::GridIndexIterator < ExtendedGridIndexD< D > , internal::AllItHelp < ExtendedGridIndexD< D > , ExtendedGridIndexD< D > > >	ExtendedIndexIterator

typedef boost::iterator_range < typename Storage::IndexIterator >	Indexes

typedef boost::iterator_range < typename Storage::AllIndexIterator >	AllIndexes

typedef boost::iterator_range < ExtendedIndexIterator >	ExtendedIndexes

VoxelIterator	voxels_begin (const BoundingBoxD< D > &bb)

VoxelIterator	voxels_end (const BoundingBoxD< D > &bb)

VoxelConstIterator	voxels_begin (const BoundingBoxD< D > &bb) const

VoxelConstIterator	voxels_end (const BoundingBoxD< D > &bb) const

Storage::IndexIterator	indexes_begin (const BoundingBoxD< D > &bb) const

Storage::IndexIterator	indexes_end (const BoundingBoxD< D > &) const

ExtendedIndexIterator	extended_indexes_begin (const BoundingBoxD< D > &bb) const

ExtendedIndexIterator	extended_indexes_end (const BoundingBoxD< D > &) const

Indexes	get_indexes (const BoundingBoxD< D > &bb) const

AllIndexes	get_all_indexes () const

ExtendedIndexes	get_extended_indexes (const BoundingBoxD< D > &bb) const

Apply
In C++, iterating through all the voxels can be slow, and it can be faster to use functional programming to apply a function to each voxel. The passed apply function takes three arguments, the grid, the Grid::Index of the voxel and the Grid::Vector for the center of the voxel.
template<class Functor >
Functor	apply (const Functor &f) const