Package gov.nasa.worldwind.util

Class Tile

java.lang.Object

gov.nasa.worldwind.util.Tile

Direct Known Subclasses:

ImageTile, TerrainTile

public class Tile
extends java.lang.Object

Geographically rectangular tile within a LevelSet, typically representing terrain or imagery. Provides a base class for tiles used by tiled image layers and elevation models. Applications typically do not interact with this class.

Field Summary

Fields

Modifier and Type	Field	Description
int	column	The tile's column within its level.
Level	level	The level at which this tile lies within a LevelSet.
int	row	The tile's row within its level.
Sector	sector	The sector spanned by this tile.
java.lang.String	tileKey	A key that uniquely identifies this tile within a level set.

Constructor Summary

Constructors

Constructor	Description
Tile(Sector sector, Level level, int row, int column)	Constructs a tile with a specified sector, level, row and column.

Method Summary

Modifier and Type	Method	Description
static java.util.Collection<Tile>	assembleTilesForLevel(Level level, TileFactory tileFactory, java.util.Collection<Tile> result)	Creates all tiles for a specified level within a LevelSet.
static int	computeColumn(double tileDelta, double longitude, double origin)	Computes a column number for a tile within a level given the tile's longitude.
static int	computeLastColumn(double tileDelta, double maxLongitude, double origin)	Computes the last column number for a tile within a level given the tile's maximum longitude.
static int	computeLastRow(double tileDelta, double maxLatitude, double origin)	Computes the last row number for a tile within a level given the tile's maximum latitude.
static int	computeRow(double tileDelta, double latitude, double origin)	Computes a row number for a tile within a level given the tile's latitude.
boolean	intersectsFrustum(RenderContext rc, Frustum frustum)	Indicates whether this tile's Cartesian extent intersects a specified frustum.
boolean	intersectsSector(Sector sector)	Indicates whether this tile intersects a specified sector.
boolean	mustSubdivide(RenderContext rc, double detailFactor)	Indicates whether this tile should be subdivided based on the current navigation state and a specified detail factor.
Tile[]	subdivide(TileFactory tileFactory)	Returns the four children formed by subdividing this tile.
Tile[]	subdivideToCache(TileFactory tileFactory, LruMemoryCache<java.lang.String,Tile[]> cache, int cacheSize)	Returns the four children formed by subdividing this tile, drawing those children from a specified cache.

Methods inherited from class java.lang.Object

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

Field Detail

sector

public final Sector sector

The sector spanned by this tile.

level

public final Level level

The level at which this tile lies within a LevelSet.

row

public final int row

The tile's row within its level.

column

public final int column

The tile's column within its level.

tileKey

public final java.lang.String tileKey

A key that uniquely identifies this tile within a level set. Tile keys are not unique to a specific level set.

Constructor Detail

Tile

public Tile(Sector sector,
            Level level,
            int row,
            int column)

Constructs a tile with a specified sector, level, row and column.

Parameters:

sector - the sector spanned by the tile

level - the tile's level in a LevelSet

row - the tile's row within the specified level

column - the tile's column within the specified level

Throws:

java.lang.IllegalArgumentException - if either the sector or the level is null

Method Detail

computeRow

public static int computeRow(double tileDelta,
                             double latitude,
                             double origin)

Computes a row number for a tile within a level given the tile's latitude.

Parameters:

tileDelta - the level's tile delta in degrees

latitude - the tile's minimum latitude in degrees

origin - the origin of the grid

Returns:

the computed row number

computeColumn

public static int computeColumn(double tileDelta,
                                double longitude,
                                double origin)

Computes a column number for a tile within a level given the tile's longitude.

Parameters:

tileDelta - the level's tile delta in degrees

longitude - the tile's minimum longitude in degrees

origin - the origin of the grid

Returns:

The computed column number

computeLastRow

public static int computeLastRow(double tileDelta,
                                 double maxLatitude,
                                 double origin)

Computes the last row number for a tile within a level given the tile's maximum latitude.

Parameters:

tileDelta - the level's tile delta in degrees

maxLatitude - the tile's maximum latitude in degrees

origin - the origin of the grid

Returns:

the computed row number

computeLastColumn

public static int computeLastColumn(double tileDelta,
                                    double maxLongitude,
                                    double origin)

Computes the last column number for a tile within a level given the tile's maximum longitude.

Parameters:

tileDelta - the level's tile delta in degrees

maxLongitude - the tile's maximum longitude in degrees

origin - the origin of the grid

Returns:

The computed column number

assembleTilesForLevel

public static java.util.Collection<Tile> assembleTilesForLevel(Level level,
                                                               TileFactory tileFactory,
                                                               java.util.Collection<Tile> result)

Creates all tiles for a specified level within a LevelSet.

Parameters:

level - the level to create the tiles for

tileFactory - the tile factory to use for creating tiles.

result - an pre-allocated Collection in which to store the results

Returns:

the result argument populated with the tiles for the specified level

Throws:

java.lang.IllegalArgumentException - If any argument is null

intersectsFrustum

public boolean intersectsFrustum(RenderContext rc,
                                 Frustum frustum)

Indicates whether this tile's Cartesian extent intersects a specified frustum.

Parameters:

rc - the current render context

frustum - the frustum of interest

Returns:

true if the specified frustum intersects this tile's extent, otherwise false

Throws:

java.lang.IllegalArgumentException - If the frustum is null

intersectsSector

public boolean intersectsSector(Sector sector)

Indicates whether this tile intersects a specified sector.

Parameters:

sector - the sector of interest

Returns:

true if the specified sector intersects this tile's sector, otherwise false

Throws:

java.lang.IllegalArgumentException - If the sector is null

mustSubdivide

public boolean mustSubdivide(RenderContext rc,
                             double detailFactor)

Indicates whether this tile should be subdivided based on the current navigation state and a specified detail factor.

Parameters:

rc - the current render context

detailFactor - the detail factor to consider

Returns:

true if the tile should be subdivided, otherwise false

subdivide

public Tile[] subdivide(TileFactory tileFactory)

Returns the four children formed by subdividing this tile. This tile's sector is subdivided into four quadrants as follows: Southwest; Southeast; Northwest; Northeast. A new tile is then constructed for each quadrant and configured with the next level within this tile's LevelSet and its corresponding row and column within that level. This returns null if this tile's level is the last level within its LevelSet.

Parameters:

tileFactory - the tile factory to use to create the children

Returns:

an array containing the four child tiles, or null if this tile's level is the last level

Throws:

java.lang.IllegalArgumentException - If the tile factory is null

subdivideToCache

public Tile[] subdivideToCache(TileFactory tileFactory,
                               LruMemoryCache<java.lang.String,Tile[]> cache,
                               int cacheSize)

Returns the four children formed by subdividing this tile, drawing those children from a specified cache. The cache is checked for a child collection prior to subdividing. If one exists in the cache it is returned rather than creating a new collection of children. If a new collection is created in the same manner as subdivide(TileFactory) and added to the cache.

Parameters:

tileFactory - the tile factory to use to create the children

cache - a memory cache that may contain pre-existing child tiles.

cacheSize - the cached size of the four child tiles

Returns:

an array containing the four child tiles, or null if this tile's level is the last level

Throws:

java.lang.IllegalArgumentException - If any argument is null