geos::operation::grid::Grid< extent_tag > Class Template Reference

The Grid class represents a grid of constant-size rectangular cells that covers a specified envelope. The width of the cells may be different from the height. If the Grid has an "infinite" extent rather than a "bounded" extent, then an extra row and column will be added on all side of the grid. The size of the cells in these columns may be larger than those in the primary grid, such that the extended grid covers a "domain" that is larger than the extent of the regular grid. More...

#include <Grid.h>

Public Member Functions
	Grid (const geom::Envelope &extent, double dx, double dy)
	Construct a bounded grid covering a specified extent.
	Grid (const geom::Envelope &extent, double dx, double dy, const geom::Envelope &domain)
size_t	getColumn (double x) const
	Get the column in which the specified x coordinate would fall.
size_t	getRow (double y) const
	Get the row in which the specified y coordinate would fall.
std::size_t	getCell (double x, double y) const
bool	isEmpty () const
size_t	getNumRows () const
size_t	getNumCols () const
size_t	getSize () const
double	xmin () const
double	xmax () const
double	ymin () const
double	ymax () const
double	dx () const
double	dy () const
const geom::Envelope &	getExtent () const
size_t	getRowOffset (const Grid &other) const
size_t	getColOffset (const Grid &other) const
double	getColX (size_t col) const
	Get the x coordinate at the center of the specified column.
double	getRowY (size_t row) const
	Get the y coordinate at the center of the specified row.
Grid	crop (const geom::Envelope &e) const
Grid< extent_tag >	shrinkToFit (const geom::Envelope &b, bool calcExtentFromNewGrid=true) const
bool	operator== (const Grid< extent_tag > &b) const
bool	operator!= (const Grid< extent_tag > &b) const
geom::Envelope	getCellEnvelope (size_t row, size_t col) const

Static Public Member Functions
static Grid	makeEmpty ()

Friends
Grid< infinite_extent >	make_infinite (const Grid< bounded_extent > &grid, const geom::Envelope &domain)
Grid< bounded_extent >	make_finite (const Grid< infinite_extent > &grid)

Detailed Description

template<typename extent_tag>
class geos::operation::grid::Grid< extent_tag >

The Grid class represents a grid of constant-size rectangular cells that covers a specified envelope. The width of the cells may be different from the height. If the Grid has an "infinite" extent rather than a "bounded" extent, then an extra row and column will be added on all side of the grid. The size of the cells in these columns may be larger than those in the primary grid, such that the extended grid covers a "domain" that is larger than the extent of the regular grid.

Constructor & Destructor Documentation

Grid()

template<typename extent_tag>

geos::operation::grid::Grid< extent_tag >::Grid ( const geom::Envelope & extent, double dx, double dy, const geom::Envelope & domain )

inline

Construct an infinite grid covering a specified extent with regularly-sized cells, and adding a row and column of variably-sized cells to each edge of the primary grid such that the specified domain is covered.

Member Function Documentation

getCell()

template<typename extent_tag>

std::size_t geos::operation::grid::Grid< extent_tag >::getCell ( double x, double y ) const

inline

Get the cell index in which the specified x and y values would fall. Cells are indexed from left-to-right, then top-to-bottom.

References getColumn(), and getRow().

getColOffset()

template<typename extent_tag>

size_t geos::operation::grid::Grid< extent_tag >::getColOffset ( const Grid< extent_tag > & other ) const

inline

Return the number of columns by which another grid is offset from this Grid. It is assumed that the two grids have the same resolution, and that the minimum x value of the other grid is greater than or equal to the minimum x value of this grid.

References geos::geom::Envelope::getMinX(), and Grid().

Referenced by shrinkToFit().

getRowOffset()

template<typename extent_tag>

size_t geos::operation::grid::Grid< extent_tag >::getRowOffset ( const Grid< extent_tag > & other ) const

inline

Return the number of rows by which another grid is offset from this Grid. It is assumed that the two grids have the same resolution, and that the maximum y value of the other grid is less than or equal to the maximum y value of this grid.

References geos::geom::Envelope::getMaxY(), and Grid().

Referenced by shrinkToFit().

shrinkToFit()

template<typename extent_tag>

Grid< extent_tag > geos::operation::grid::Grid< extent_tag >::shrinkToFit ( const geom::Envelope & b, bool calcExtentFromNewGrid = true ) const

inline

Reduce the size of the grid to contain only the provided Envelope If calcExtentFromNewGrid is true, then the xmax and ymin of the new grid will be calculated relative to the origin point of the original grid rather than the newly cropped grid.

References geos::geom::Envelope::contains(), geos::geom::Envelope::getArea(), getColOffset(), getColumn(), geos::geom::Envelope::getHeight(), geos::geom::Envelope::getMaxX(), geos::geom::Envelope::getMaxY(), geos::geom::Envelope::getMinX(), geos::geom::Envelope::getMinY(), getRow(), getRowOffset(), geos::geom::Envelope::getWidth(), and Grid().

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

• Grid.h