gov.nasa.worldwind.util

Class LevelSet

java.lang.Object

gov.nasa.worldwind.util.LevelSet

public class LevelSet
extends java.lang.Object

Multi-resolution, hierarchical collection of tiles organized into levels of increasing resolution. Applications typically do not interact with this class.

Field Summary

Fields

Modifier and Type	Field and Description
double	firstLevelDelta The geographic width and height in degrees of tiles in the first level (lowest resolution) of this level set.
Sector	sector The sector spanned by this level set.
int	tileHeight The height in pixels of images associated with tiles in this level set, or the number of sample points in the latitudinal direction of elevation tiles associated with this level set.
int	tileWidth The width in pixels of images associated with tiles in this level set, or the number of sample points in the longitudinal direction of elevation tiles associated with this level set.

Constructor Summary

Constructors

Constructor and Description
LevelSet() Constructs an empty level set with no levels.
LevelSet(LevelSetConfig config) Constructs a level set with parameters from a specified configuration.
LevelSet(Sector sector, double firstLevelDelta, int numLevels, int tileWidth, int tileHeight) Constructs a level set with specified parameters.

Method Summary

Modifier and Type	Method and Description
Level	firstLevel() Returns the first level (lowest resolution) of this level set.
Level	lastLevel() Returns the last level (highest resolution) of this level set.
Level	level(int levelNumber) Returns the Level for a specified level number.
Level	levelForResolution(double radiansPerPixel) Returns the level that most closely approximates the specified resolution.
int	numLevels() Returns the number of levels in this level set.

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 level set.

firstLevelDelta

public final double firstLevelDelta

The geographic width and height in degrees of tiles in the first level (lowest resolution) of this level set.

tileWidth

public final int tileWidth

The width in pixels of images associated with tiles in this level set, or the number of sample points in the longitudinal direction of elevation tiles associated with this level set.

tileHeight

public final int tileHeight

The height in pixels of images associated with tiles in this level set, or the number of sample points in the latitudinal direction of elevation tiles associated with this level set.

Constructor Detail

LevelSet

public LevelSet()

Constructs an empty level set with no levels. The methods level, levelForResolution, firstLevel and lastLevel always return null.

LevelSet

public LevelSet(Sector sector,
                double firstLevelDelta,
                int numLevels,
                int tileWidth,
                int tileHeight)

Constructs a level set with specified parameters.

Parameters:

sector - the sector spanned by this level set

firstLevelDelta - the geographic width and height in degrees of tiles in the first level (lowest resolution) of the level set

numLevels - the number of levels in the level set

tileWidth - the height in pixels of images associated with tiles in this level set, or the number of sample points in the longitudinal direction of elevation tiles associate with this level set

tileHeight - the height in pixels of images associated with tiles in this level set, or the number of sample points in the latitudinal direction of elevation tiles associate with this level set

Throws:

java.lang.IllegalArgumentException - If any argument is null, or if any dimension is zero

LevelSet

public LevelSet(LevelSetConfig config)

Constructs a level set with parameters from a specified configuration. The configuration's sector must be non-null, its first level delta must be positive, its number of levels must be 1 or more, and its tile width and tile height must be 1 or greater.

Parameters:

config - the configuration for this level set

Throws:

java.lang.IllegalArgumentException - If the configuration is null, or if any configuration value is invalid

Method Detail

numLevels

public int numLevels()

Returns the number of levels in this level set.

Returns:

the number of levels

level

public Level level(int levelNumber)

Returns the Level for a specified level number.

Parameters:

levelNumber - the number of the desired level

Returns:

the requested level, or null if the level does not exist

levelForResolution

public Level levelForResolution(double radiansPerPixel)

Returns the level that most closely approximates the specified resolution.

Parameters:

radiansPerPixel - the desired resolution in radians per pixel

Returns:

the level for the specified resolution, or null if this level set is empty

Throws:

java.lang.IllegalArgumentException - If the resolution is not positive

firstLevel

public Level firstLevel()

Returns the first level (lowest resolution) of this level set.

Returns:

the level of lowest resolution, or null if this level set is empty

lastLevel

public Level lastLevel()

Returns the last level (highest resolution) of this level set.

Returns:

the level of highest resolution, or null if this level set is empty