Class TiledGridCoverage.TileIterator

Object

TiledGridCoverage.AOI

TileIterator

Enclosing class:

Tiled­Grid­Coverage

protected final class TiledGridCoverage.TileIterator
extends TiledGridCoverage.AOI

An iterator over the tiles to read. Instances of this class are computed by Tiled­Grid­Coverage.render(Grid­Extent) and given to Tiled­Grid­Coverage.read­Tiles(Tile­Iterator). The latter is the method that subclasses need to override.

Since:

1.7

Field Summary

Fields

Modifier and Type	Field	Description
final int	tile­Count­In­Query	Total number of tiles in the AOI, from tile­Lower inclusive to tile­Upper exclusive.

Method Summary

Modifier and Type	Method	Description
Grid­Extent	get­Full­Region­In­Resource­Coordinates()	Returns the extent of the full region to read (all tiles) in units of the originating resource.
Rectangle	image­To­Resource(Rectangle bounds, boolean tight)	Converts cell coordinates from pixel coordinates to the originating resource.
boolean	next()	Moves the iterator position to next tile.
Rectangle	resource­To­Image(Rectangle bounds, boolean tight)	Converts cell coordinates from the originating resource to pixel coordinates.

Methods inherited from class TiledGridCoverage.AOI

cache, create­Raster, get­Cached­Tile, get­Region­Inside­Tile, get­Region­Inside­Tile, get­Tile­Coordinates­In­Resource, get­Tile­Index­In­Resource, get­Tile­Index­In­Result­Array, get­Tile­Location, get­Uncropped­Tile­Location, move­Raster

Modifier and Type	Method	Description
Raster	cache(Raster tile)	Stores the given raster in the cache for the current AOI position.
Writable­Raster	create­Raster()	Creates an initially empty raster for the tile at the current AOI position.
Raster	get­Cached­Tile()	Returns the cached tile for current AOI position.
Rectangle	get­Region­Inside­Tile(boolean subsampled)	Returns the coordinates of the pixels to read relative to the current tile's upper-left corner.
boolean	get­Region­Inside­Tile(long[] lower, long[] upper, long[] subsampling, boolean subsampled)	Returns the clipped coordinates of the cells to read relative to the tile's upper-left corner.
final long[]	get­Tile­Coordinates­In­Resource()	Returns the current AOI position in the tile matrix of the original resource.
final int	get­Tile­Index­In­Resource()	Returns the current AOI position as an index in the vector of tiles of the original resource.
final int	get­Tile­Index­In­Result­Array()	Returns the current AOI position as an index in the array of tiles to be returned by Tiled­Grid­Coverage.read­Tiles(…).
Point	get­Tile­Location()	Creates the coordinates of the upper-left corner of the tile at the current AOI position.
Optional<Point>	get­Uncropped­Tile­Location()	Returns the location (relative to the cropped tile) of the upper-left corner of the uncropped tile.
Raster	move­Raster(Raster tile)	Returns the given raster relocated at the current AOI position.

Methods inherited from class Object

clone, equals, finalize, get­Class, hash­Code, notify, notify­All, to­String, wait, wait, wait

Field Details

tileCountInQuery

public final int tileCountInQuery

Total number of tiles in the AOI, from tile­Lower inclusive to tile­Upper exclusive. This is the length of the array to be returned by Tiled­Grid­Coverage.read­Tiles(Tile­Iterator).

Method Details

getFullRegionInResourceCoordinates

public GridExtent getFullRegionInResourceCoordinates()

Returns the extent of the full region to read (all tiles) in units of the originating resource. The returned extent does not change during the iteration process (this method is not available in Tiled­Grid­Coverage.Snapshot for that reason). This method is typically invoked only at the beginning of the iteration process, when knowing in advance the full read region allows some optimizations.

The returned region is based on the user's request in her/his call to Tiled­Grid­Coverage.render(Grid­Extent), but is not necessarily identical. The render method may have expanded or clipped the user's request. The returned extent may be larger than the actual resource extent because it may be rounded to an integer number of chunks.

Returns:

extent of all tiles to be traversed by this iterator, in units of the originating resource.

resourceToImage

public Rectangle resourceToImage(Rectangle bounds,
 boolean tight)

Converts cell coordinates from the originating resource to pixel coordinates. If tight is true, this method returns the smallest bounding box of interest for a reader which will apply subsampling. See image­To­Resource(Rectangle, boolean) for a discussion of the trade-off.

Parameters:

bounds - the coordinates to convert.

tight - whether to return the smallest bounding box.

Returns:

the converted coordinates.

Throws:

Arithmetic­Exception - if the result cannot be expressed as 32-bits integers.

imageToResource

public Rectangle imageToResource(Rectangle bounds,
 boolean tight)

Converts cell coordinates from pixel coordinates to the originating resource. If tight is true, this method returns the smallest bounding box of interest for a reader which will apply subsampling. If false, this method uses a more straightforward calculation which may result in a larger bounding box, with right and bottom areas possibly containing pixels that should be skipped by subsampling.

The latter case is sometime desirable when the caller may compute scale factors as the ratio of the size of different rectangles. For such calculations, tight bounding boxes may be confusing.

Parameters:

bounds - the coordinates to convert.

tight - whether to return the smallest bounding box, at the cost of less straightforward rectangle size.

Returns:

the image coordinates converted to resource coordinates.

Throws:

Arithmetic­Exception - if the result cannot be expressed as 32-bits integers.

next

public boolean next()

Moves the iterator position to next tile. This method should be invoked in a loop as below:

do {
    // Process current tile.
} while (domain.next());

Returns:

true on success, or false if the iteration is finished.