ZarrLayerProvider

Thin Cesium adapter around the framework-independent Zarr tile renderer. Dataset loading, slicing, styling, caching, and WebGL rendering live in zarr-maps-tiling. This class only translates Cesium tile requests.

Implements

• ImageryProvider

Accessors

credit

Get Signature

get credit(): Credit;

Dataset attribution exposed to Cesium.

Returns

Credit

Implementation of

ImageryProvider.credit

---

dimensionValues

Get Signature

get dimensionValues(): DimensionValues;

Coordinate values keyed by normalized dimension name.

Returns

DimensionValues

---

errorEvent

Get Signature

get errorEvent(): Event;

Cesium imagery-provider error event.

Returns

Event

Implementation of

ImageryProvider.errorEvent

---

hasAlphaChannel

Get Signature

get hasAlphaChannel(): boolean;

Whether rendered tiles contain alpha values. Always true.

Returns

boolean

Implementation of

ImageryProvider.hasAlphaChannel

---

maximumLevel

Get Signature

get maximumLevel(): number;

Maximum imagery level requested by Cesium.

Returns

number

Implementation of

ImageryProvider.maximumLevel

---

minimumLevel

Get Signature

get minimumLevel(): number;

Minimum imagery level requested by Cesium.

Returns

number

Implementation of

ImageryProvider.minimumLevel

---

ready

Get Signature

get ready(): boolean;

Whether metadata initialization completed and the provider is usable.

Returns

boolean

---

readyPromise

Get Signature

get readyPromise(): Promise<boolean>;

Promise resolving to the provider readiness state.

Returns

Promise<boolean>

---

rectangle

Get Signature

get rectangle(): Rectangle;

Geographic coverage of the dataset.

Returns

Rectangle

Implementation of

ImageryProvider.rectangle

---

selectors

Get Signature

get selectors(): Record<string, ZarrSelectorsProps>;

Current index-based selectors used for tile rendering and queries.

Returns

Record<string, ZarrSelectorsProps>

---

tileCacheStats

Get Signature

get tileCacheStats(): TileCacheStats;

Current decoded tile-cache usage and lifetime counters.

Returns

TileCacheStats

---

tileHeight

Get Signature

get tileHeight(): number;

Height of rendered imagery tiles in pixels.

Returns

number

Implementation of

ImageryProvider.tileHeight

---

tileWidth

Get Signature

get tileWidth(): number;

Width of rendered imagery tiles in pixels.

Returns

number

Implementation of

ImageryProvider.tileWidth

---

tilingScheme

Get Signature

get tilingScheme(): TilingScheme;

Cesium tiling scheme selected from the detected dataset CRS.

Returns

TilingScheme

Implementation of

ImageryProvider.tilingScheme

Constructors

Constructor

new ZarrLayerProvider(options): ZarrLayerProvider;

Creates a Cesium imagery provider backed by a URL or custom Zarrita store.

Parameters

Parameter	Type	Description
options	LayerOptions	Dataset, tiling, selection, style, and request options.

Returns

ZarrLayerProvider

Remarks

Prefer createLayer when adding the result to a viewer.

Methods

clearTileCache()

clearTileCache(): void;

Removes decoded numeric tiles retained by this imagery provider.

Returns

void

---

destroy()

destroy(): void;

Aborts pending reads and releases tile-renderer resources.

Returns

void

---

getFullTransect()

getFullTransect(
   start, 
   end, 
   selectors?, 
options?): Promise<FullTransectResult>;

Samples all elevation levels along a line between two WGS84 positions.

Parameters

Parameter	Type	Description
start	QueryPosition	Starting [longitude, latitude] coordinate in degrees.
end	QueryPosition	Ending [longitude, latitude] coordinate in degrees.
selectors?	ZarrSelectors	Fixed selectors for dimensions other than elevation.
options?	TransectQueryOptions	Sample count, concurrency, cancellation, and resolution controls.

Returns

Promise<FullTransectResult>

A distance-by-elevation value matrix.

---

getTileCredits()

getTileCredits(): Credit[];

Returns

Credit[]

Credit entries associated with every rendered tile.

Implementation of

ImageryProvider.getTileCredits

---

getTimeSeries()

getTimeSeries(
   position, 
   selectors?, 
options?): Promise<QueryResult>;

Reads every time value at one WGS84 position.

Parameters

Parameter	Type	Description
position	QueryPosition	[longitude, latitude] in degrees.
selectors?	ZarrSelectors	Fixed selectors for dimensions other than time.
options?	QueryOptions	Query controls, including cancellation and resolution.

Returns

Promise<QueryResult>

A query result ordered by the time coordinate.

---

getTransect()

getTransect(
   start, 
   end, 
   selectors?, 
options?): Promise<TransectResult>;

Samples one selected level along a line between two WGS84 positions.

Parameters

Parameter	Type	Description
start	QueryPosition	Starting [longitude, latitude] coordinate in degrees.
end	QueryPosition	Ending [longitude, latitude] coordinate in degrees.
selectors?	ZarrSelectors	Dimension selectors applied to every sample.
options?	TransectQueryOptions	Sample count, concurrency, cancellation, and resolution controls.

Returns

Promise<TransectResult>

Distances, positions, and scalar values along the transect.

---

getVerticalProfile()

getVerticalProfile(
   position, 
   selectors?, 
options?): Promise<QueryResult>;

Reads every elevation value at one WGS84 position.

Parameters

Parameter	Type	Description
position	QueryPosition	[longitude, latitude] in degrees.
selectors?	ZarrSelectors	Fixed selectors for dimensions other than elevation.
options?	QueryOptions	Query controls, including cancellation and resolution.

Returns

Promise<QueryResult>

A query result ordered by the elevation coordinate.

---

pickFeatures()

pickFeatures(
   _x, 
   _y, 
   level, 
   longitude, 
latitude): Promise<ImageryLayerFeatureInfo[]>;

Queries the feature underneath a Cesium imagery pick position.

Parameters

Parameter	Type	Description
_x	number	Tile column; the point query uses the supplied longitude instead.
_y	number	Tile row; the point query uses the supplied latitude instead.
level	number	Resolution level used by the query.
longitude	number	Longitude in radians.
latitude	number	Latitude in radians.

Returns

Promise<ImageryLayerFeatureInfo[]>

Zero or one feature containing the queried value and coordinates.

Implementation of

ImageryProvider.pickFeatures

---

queryData()

queryData(
   geometry, 
   selectors?, 
options?): Promise<QueryResult>;

Queries the nearest raster cell for a WGS84 GeoJSON point.

Parameters

Parameter	Type	Description
geometry	QueryGeometry	Point geometry in [longitude, latitude] degrees.
selectors?	Record<string, ZarrSelectorsProps>	Optional selector overrides for this query only.
options?	QueryOptions	Abort, resolution-level, and coordinate-output controls.

Returns

Promise<QueryResult>

Values and coordinate labels for the selected cell or profile.

Throws

For unsupported geometries, invalid selectors, or failed reads.

---

requestImage()

requestImage(
   x, 
   y, 
   level, 
_request?): Promise<HTMLCanvasElement | ImageBitmap>;

Renders one Cesium imagery tile.

Parameters

Parameter	Type	Description
x	number	Tile column.
y	number	Tile row.
level	number	Cesium imagery level.
_request?	Request	Cesium request metadata; currently unused.

Returns

Promise<HTMLCanvasElement | ImageBitmap>

A vertically oriented canvas or image bitmap suitable for Cesium.

Implementation of

ImageryProvider.requestImage

---

updateSelectors()

updateSelectors(selectors): boolean;

Updates dimension selectors used for subsequent renders and queries.

Parameters

Parameter	Type	Description
selectors	Record<string, ZarrSelectorsProps>	Selectors keyed by normalized dimension name.

Returns

boolean

true when at least one selector changed.

---

updateStyle()

updateStyle(options): boolean;

Updates tile color mapping without recreating the provider.

Parameters

Parameter	Type	Description
options	{ colormap?: string; scale?: [number, number]; }	New scale and/or colormap.
options.colormap?	string	-
options.scale?	[number, number]	-

Returns

boolean

true when the rendered tile output changed.

---

createLayer()

static createLayer(viewer, options): Promise<ZarrImageryLayer>;

Creates and initializes a ZarrImageryLayer ready to add to Cesium.

Parameters

Parameter	Type	Description
viewer	CesiumHost	Viewer or widget that will host the layer.
options	LayerOptions	Zarr dataset and visualization options.

Returns

Promise<ZarrImageryLayer>

A fully initialized imagery layer. Its provider is available as layer.imageryProvider.

Throws

If metadata, dimensions, CRS, or coverage cannot be initialized.

Example

const layer = await ZarrLayerProvider.createLayer(viewer, {
  url: 'https://example.com/data.zarr',
  variable: 'temperature',
  scale: [0, 30]
});
viewer.imageryLayers.add(layer);

Properties

proxy

readonly proxy: DefaultProxy;

Gets the proxy used by this provider.

Implementation of

ImageryProvider.proxy

---

tileDiscardPolicy

readonly tileDiscardPolicy: NeverTileDiscardPolicy;

Gets the tile discard policy. If not undefined, the discard policy is responsible for filtering out "missing" tiles via its shouldDiscardImage function. If this function returns undefined, no tiles are filtered.

Implementation of

ImageryProvider.tileDiscardPolicy