Class DemTiler

Class representing a Tiler which delivers DEM data.

Hierarchy (View Summary)

Tiler
- DemTiler

Index

Constructors

Properties

dataTiles sphMerc tile url

Methods

getCurrentTiles getData getElevation getElevationFromLonLat getTile lonLatToSphMerc rawTileToStoredTile readTile setZoom update updateByLonLat

Constructors

constructor

new DemTiler(url: string): DemTiler
Create a DemTiler.
Parameters
- url: string
Returns DemTiler
Overrides Tiler.constructor
- Defined in lib/demtiler.ts:19

Properties

dataTiles

dataTiles: Map<string, DataTile>

sphMerc

sphMerc: SphMercProjection

tile

tile: Tile

url

url: string

Methods

getCurrentTiles

getCurrentTiles(): DataTile[]
Obtain the current tiles surrounding the last-requested position.

Returns DataTile[]
array of 9 tiles, including the current tile and the 8 surrounding it.
Inherited from Tiler.getCurrentTiles
- Defined in lib/tiler.ts:88

getData

getData(sphMercPos: EastNorth, z?: number): Promise<Tile>
For a given Spherical Mercator position and zoom, downloads data if necessary and returns the data at the tile corresponding to that position.
Parameters
- sphMercPos: EastNorth
  the Spherical Mercator position.
- z: number = 13
  zoom level to use (default 13)
Returns Promise<Tile>
Promise resolving with the given Tile.
Inherited from Tiler.getData
- Defined in lib/tiler.ts:139

getElevation

getElevation(sphMercPos: EastNorth): number
Obtain the elevation in metres for a given Spherical Mercator position.
Parameters
- sphMercPos: EastNorth
  the Spherical Mercator position.
Returns number
the elevation in metres, or Number.NEGATIVE_INFINITY if this position is outside the extent of the DEM.
- Defined in lib/demtiler.ts:51

getElevationFromLonLat

getElevationFromLonLat(lonLat: LonLat): number
Obtain the elevation in metres for a given longitude/latitude.
Parameters
- lonLat: LonLat
  the longitude/latitude.
Returns number
the elevation in metres, or Number.NEGATIVE_INFINITY if this position is outside the extent of the DEM.
- Defined in lib/demtiler.ts:65

getTile

getTile(sphMercPos: EastNorth, z: number): Tile
Obtain the Tile containing a given Spherical Mercator position.
Parameters
- sphMercPos: EastNorth
- z: number
Returns Tile
the Tile containing the position.
Inherited from Tiler.getTile
- Defined in lib/tiler.ts:47

lonLatToSphMerc

lonLatToSphMerc(lonLat: LonLat): EastNorth
Convert longitude/latitude to Spherical Mercator coordinates.
Parameters
- lonLat: LonLat
  the LonLat to convert.
Returns EastNorth
the EastNorth (Spherical Mercator coordinates).
Inherited from Tiler.lonLatToSphMerc
- Defined in lib/tiler.ts:38

rawTileToStoredTile

rawTileToStoredTile(tile: Tile, data: RawPngData): DataTile
Overridden rawTileToStoredTile() to convert the raw PNG tile to a DEM object.
Parameters
- tile: Tile
  the current tile.
- data: RawPngData
  the raw downloaded data.
Returns DataTile
the DataTile pairing the Tile and the DEM data as a DEM object.
Overrides Tiler.rawTileToStoredTile
- Defined in lib/demtiler.ts:75

readTile

readTile(url: string): Promise<RawPngData>
Overridden readTile() for DemTiler.
Parameters
- url: string
  the URL.
Returns Promise<RawPngData>
a Promise resolving with raw DEM data.
Overrides Tiler.readTile
- Defined in lib/demtiler.ts:28

setZoom

setZoom(z: number): void
Sets the zoom.
Parameters
- z: number
  the zoom to use.
Returns void
Inherited from Tiler.setZoom
- Defined in lib/tiler.ts:29

update

update(pos: EastNorth): Promise<DataTile[]>
Download new tiles for a given Spherical Mercator position.
Parameters
- pos: EastNorth
  the Spherical Mercator position.
Returns Promise<DataTile[]>
a Promise resolving with an array of the newly-downloaded data tiles (only new tiles; existing ones are not returned)
Inherited from Tiler.update
- Defined in lib/tiler.ts:56

updateByLonLat

updateByLonLat(lonLat: LonLat): Promise<DataTile[]>
Download new tiles for a given longitude/latitude.
Parameters
- lonLat: LonLat
  the position.
Returns Promise<DataTile[]>
a Promise resolving with an array of the newly-downloaded data tiles (only new tiles; existing ones are not returned)
Inherited from Tiler.updateByLonLat
- Defined in lib/tiler.ts:80