TileAvailability

Methods

addAvailableTileRange(level, startX, startY, endX, endY)

Core/TileAvailability.js 51

Marks a rectangular range of tiles in a particular level as being available. For best performance, add your ranges in order of increasing level.

Name	Type	Description
level	Number	The level.
startX	Number	The X coordinate of the first available tiles at the level.
startY	Number	The Y coordinate of the first available tiles at the level.
endX	Number	The X coordinate of the last available tiles at the level.
endY	Number	The Y coordinate of the last available tiles at the level.

computeBestAvailableLevelOverRectangle(rectangle) → Number

Core/TileAvailability.js 116

Finds the most detailed level that is available _everywhere_ within a given rectangle. More detailed tiles may be available in parts of the rectangle, but not the whole thing. The return value of this function may be safely passed to sampleTerrain for any position within the rectangle. This function usually completes in time logarithmic to the number of rectangles added with TileAvailability#addAvailableTileRange.

Name	Type	Description
rectangle	Rectangle	The rectangle.

Returns:

The best available level for the entire rectangle.

computeChildMaskForTile(level, x, y) → Number

Core/TileAvailability.js 182

Computes a bit mask indicating which of a tile's four children exist. If a child's bit is set, a tile is available for that child. If it is cleared, the tile is not available. The bit values are as follows:

Bit Position	Bit Value	Child Tile
0	1	Southwest
1	2	Southeast
2	4	Northwest
3	8	Northeast

Name	Type	Description
level	Number	The level of the parent tile.
x	Number	The X coordinate of the parent tile.
y	Number	The Y coordinate of the parent tile.

Returns:

The bit mask indicating child availability.

computeMaximumLevelAtPosition(position) → Number

Core/TileAvailability.js 81

Determines the level of the most detailed tile covering the position. This function usually completes in time logarithmic to the number of rectangles added with TileAvailability#addAvailableTileRange.

Name	Type	Description
position	Cartographic	The position for which to determine the maximum available level. The height component is ignored.

Returns:

The level of the most detailed tile covering the position.

Throws:

• DeveloperError : If position is outside any tile according to the tiling scheme.

isTileAvailable(level, x, y) → Boolean

Core/TileAvailability.js 154

Determines if a particular tile is available.

Name	Type	Description
level	Number	The tile level to check.
x	Number	The X coordinate of the tile to check.
y	Number	The Y coordinate of the tile to check.

Returns:

True if the tile is available; otherwise, false.