Class Layer<TEvents, TUserData>`Abstract`

Base class of layers. Layers are components of maps or any compatible entity.

The same layer can be added to multiple entities. Don't forget to call dispose when the layer should be destroyed, as removing a layer from an entity will not release memory associated with the layer (such as textures).

Types of layers

Layer is an abstract class. See subclasses for specific information. Main subclasses:

ColorLayer for color information, such as satellite imagery, vector data, etc.
ElevationLayer for elevation and terrain data.
MaskLayer: a special kind of layer that applies a mask on its host map.

The `userData` property

The userData property can be used to attach custom data to the layer, in a type safe manner. It is recommended to use this property instead of attaching arbitrary properties to the object:

type MyCustomUserData = {
  creationDate: Date;
  owner: string;
};
const newLayer = new ColorLayer<MyCustomUserData>({ ... });

newLayer.userData.creationDate = Date.now();
newLayer.userData.owner = 'John Doe';

Reprojection capabilities

When the source of the layer has a different coordinate system (CRS) than the instance, the images from the source will be reprojected to the instance CRS.

Note that doing so will have a performance cost in both CPU and memory.

// Add and create a new Layer to an existing map.
const newLayer = new ColorLayer({ ... });

await map.addLayer(newLayer);

// Change layer's visibilty
newLayer.visible = false;
instance.notifyChange(); // update instance

// Change layer's opacity
newLayer.opacity = 0.5;
instance.notifyChange(); // update instance

// Listen to properties
newLayer.addEventListener('visible-property-changed', (event) => console.log(event));

Type Parameters

TEvents extends LayerEvents = LayerEvents

The event map of the layer.
TUserData extends LayerUserData = LayerUserData

The type of the userData property.

Hierarchy

EventDispatcher<TEvents & LayerEvents>
- Layer
  - ColorLayer
  - ElevationLayer

Implements

Progress

Index

Constructors

constructor

Accessors

composer loading progress ready visible

Constructors

constructor

new Layer<TEvents, TUserData>(options): Layer<TEvents, TUserData>
Creates a layer.
Type Parameters
- TEvents extends LayerEvents = LayerEvents
- TUserData extends LayerUserData = LayerUserData
Parameters
- options: LayerOptions
  
  The layer options.
Returns Layer<TEvents, TUserData>
Overrides EventDispatcher<TEvents & LayerEvents>.constructor
- Defined in core/layer/Layer.ts:345

Properties

`Protected` _composer

_composer: LayerComposer

`Private` `Readonly` _createReadableTextures

_createReadableTextures: boolean

`Private` _fallbackImagesPromise

_fallbackImagesPromise: Promise<void>

`Private` `Readonly` _filter

_filter: ((id) => boolean)

Type declaration

- (id): boolean
- Parameters
  - id: string
  Returns boolean

`Private` _instance

_instance: Instance

`Private` `Readonly` _opCounter

_opCounter: OperationCounter

`Private` `Readonly` _preloadImages

_preloadImages: boolean

`Private` _preprocessOnce

_preprocessOnce: Promise<Layer<TEvents, TUserData>>

`Protected` `Readonly` _queue

_queue: RequestQueue

`Private` _ready

_ready: boolean

`Private` _shouldNotify

_shouldNotify: boolean

`Private` _sortedTargets

_sortedTargets: Target[]

`Private` `Readonly` _targets

_targets: Map<number, Target>

`Private` _visible

_visible: boolean

backgroundColor

backgroundColor: Color

`Readonly` colorMap

colorMap: ColorMap

The colormap of this layer

`Readonly` computeMinMax

computeMinMax: boolean

disposed

disposed: boolean

`Readonly` extent

extent: Extent

The extent of this layer

frozen

frozen: boolean = false

Disables automatic updates of this layer. Useful for debugging purposes.

`Readonly` id

id: string

The unique identifier of this layer.

`Readonly` interpretation

interpretation: Interpretation

`Readonly` isLayer

isLayer: boolean = true

Read-only flag to check if a given object is of type Layer.

`Readonly` name

name: string

Optional name of this layer.

`Readonly` noDataOptions

noDataOptions: NoDataOptions

`Readonly` resolutionFactor

resolutionFactor: number

The resolution factor applied to the textures generated by this layer.

`Readonly` showTileBorders

showTileBorders: boolean

`Readonly` source

source: ImageSource

The source of this layer

type

type: string

`Readonly` userData

userData: TUserData

An object that can be used to store custom data about the Layer.

Accessors

composer

get composer(): Readonly<LayerComposer>
Returns Readonly<LayerComposer>
- Defined in core/layer/Layer.ts:1088

loading

get loading(): boolean
Gets whether the object is currently performing an asynchronous operation.

Returns boolean
Implementation of Progress.loading
- Defined in core/layer/Layer.ts:444

progress

get progress(): number
Returns the percentage of progress, in normalized value (i.e in the [0, 1] range), of the asynchronous operations that are scheduled to run on this object. 1 means that all operations have finished.

Returns number
Implementation of Progress.progress
- Defined in core/layer/Layer.ts:448

ready

get ready(): boolean
Returns boolean
- Defined in core/layer/Layer.ts:336

visible

get visible(): boolean
Gets or sets the visibility of this layer.

Returns boolean
- Defined in core/layer/Layer.ts:433
set visible(v): void
Parameters
- v: boolean
Returns void
- Defined in core/layer/Layer.ts:437

Methods

`Private` _getSortedTargets

_getSortedTargets(): Target[]
Returns Target[]
Targets sorted by extent dimension.
- Defined in core/layer/Layer.ts:781

`Private` acquireRenderTarget

acquireRenderTarget(width, height): WebGLRenderTarget<Texture>
Parameters
- width: number
  
  Width
- height: number
  
  Height
Returns WebGLRenderTarget<Texture>
The render target.
- Defined in core/layer/Layer.ts:1052

addEventListener

addEventListener<T>(type, listener): void
Adds a listener to an event type.
Type Parameters
- T extends string
Parameters
- type: T
  
  The type of event to listen to.
- listener: EventListener<(TEvents & LayerEvents)[T], T, Layer<TEvents, TUserData>>
  
  The function that gets called when the event is fired.
Returns void
Inherited from EventDispatcher.addEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:52
addEventListener<T>(type, listener): void
Type Parameters
- T extends string
Parameters
- type: T
- listener: EventListener<{}, T, Layer<TEvents, TUserData>>
Returns void
Inherited from EventDispatcher.addEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:56

`Private` addToComposer

addToComposer(image, alwaysVisible): void
Parameters
- image: ImageResult
- alwaysVisible: boolean
Returns void
- Defined in core/layer/Layer.ts:585

`Protected` adjustExtent

adjustExtent(extent): Extent
Parameters
- extent: Extent
Returns Extent
- Defined in core/layer/Layer.ts:725

`Protected` adjustExtentAndPixelSize

adjustExtentAndPixelSize(originalExtent, originalWidth, originalHeight): {
    extent: Extent;
    height: number;
    width: number;
}
Adjusts the extent to avoid visual artifacts.
Parameters
- originalExtent: Extent
  
  The original extent.
- originalWidth: number
  
  The width, in pixels, of the original extent.
- originalHeight: number
  
  The height, in pixels, of the original extent.
Returns {
    extent: Extent;
    height: number;
    width: number;
}
And object containing the adjusted extent, as well as adjusted pixel size.
- extent: Extent
- height: number
- width: number
- Defined in core/layer/Layer.ts:738

`Protected` applyDefaultTexture

applyDefaultTexture(target): void
Parameters
- target: Target
  
  The target.
Returns void
- Defined in core/layer/Layer.ts:813

`Protected` `Abstract` applyEmptyTextureToNode

applyEmptyTextureToNode(node): void
Parameters
- node: Node
Returns void
- Defined in core/layer/Layer.ts:1105

`Protected` `Abstract` applyTextureToNode

applyTextureToNode(texture, node, isLastRender): void
Parameters
- texture: TextureAndPitch
- node: Node
- isLastRender: boolean
Returns void
- Defined in core/layer/Layer.ts:1099

`Protected` `Abstract` canFetchImages

canFetchImages(target): boolean
Parameters
- target: Target
Returns boolean
- Defined in core/layer/Layer.ts:1016

clear

clear(): void
Resets all render targets to a blank state and repaint all the targets.

Returns void
- Defined in core/layer/Layer.ts:413

contains

contains(extent): boolean
Parameters
- extent: Extent
  
  The extent to test.
Returns boolean
true if this layer contains the specified extent, false otherwise.
- Defined in core/layer/Layer.ts:1022

dispatchEvent

dispatchEvent<T>(event): void
Fire an event type.
Type Parameters
- T extends string
Parameters
- event: BaseEvent<T> & (TEvents & LayerEvents)[T]
  
  The event that gets fired.
Returns void
Inherited from EventDispatcher.dispatchEvent
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:84

dispose

dispose(): void
Disposes the layer. This releases all resources held by this layer.

Returns void
- Defined in core/layer/Layer.ts:1110

`Private` fetchImages

fetchImages(options): Promise<void>
Parameters
- options: {
      extent: Extent;
      height: number;
      target: Target;
      width: number;
  }
  
  Options.
  - extent: Extent
    
    The request extent.
  - height: number
    
    The request height, in pixels.
  - target: Target
    
    The target of the images.
  - width: number
    
    The request width, in pixels.
Returns Promise<void>
A promise that is settled when all images have been fetched.
- Defined in core/layer/Layer.ts:620

getExtent

getExtent(): Extent
Returns the final extent of this layer. If this layer has its own extent defined, this will be used. Otherwise, will return the source extent (if any). May return undefined if not pre-processed yet.

Returns Extent
The layer final extent.
- Defined in core/layer/Layer.ts:534

`Private` getParent

getParent(target): Target
Parameters
- target: Target
  
  The target.
Returns Target
The smallest target that still contains this extent.
- Defined in core/layer/Layer.ts:797

`Abstract` getRenderTargetDataType

getRenderTargetDataType(): TextureDataType
Returns TextureDataType
- Defined in core/layer/Layer.ts:1035

`Abstract` getRenderTargetPixelFormat

getRenderTargetPixelFormat(): PixelFormat
Returns PixelFormat
- Defined in core/layer/Layer.ts:1033

hasEventListener

hasEventListener<T>(type, listener): boolean
Checks if listener is added to an event type.
Type Parameters
- T extends string
Parameters
- type: T
  
  The type of event to listen to.
- listener: EventListener<(TEvents & LayerEvents)[T], T, Layer<TEvents, TUserData>>
  
  The function that gets called when the event is fired.
Returns boolean
Inherited from EventDispatcher.hasEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:63
hasEventListener<T>(type, listener): boolean
Type Parameters
- T extends string
Parameters
- type: T
- listener: EventListener<{}, T, Layer<TEvents, TUserData>>
Returns boolean
Inherited from EventDispatcher.hasEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:67

`Private` initializeOnce

initializeOnce(): Promise<Layer<TEvents, TUserData>>
Perform the initialization. This should be called exactly once in the lifetime of the layer.

Returns Promise<Layer<TEvents, TUserData>>
- Defined in core/layer/Layer.ts:493

loadFallbackImages

loadFallbackImages(): Promise<void>
Returns Promise<void>
- Defined in core/layer/Layer.ts:595

loadFallbackImagesInternal

loadFallbackImagesInternal(): Promise<void>
Returns Promise<void>
- Defined in core/layer/Layer.ts:540

`Protected` onInitialized

onInitialized(): Promise<void>
Called when the layer has finished initializing.

Returns Promise<void>
- Defined in core/layer/Layer.ts:612

`Private` onSourceUpdated

onSourceUpdated(): void
Returns void
- Defined in core/layer/Layer.ts:406

`Protected` onTextureCreated

onTextureCreated(texture): void
Parameters
- texture: Texture
Returns void
- Defined in core/layer/Layer.ts:580

postUpdate

postUpdate(): void
Returns void
- Defined in core/layer/Layer.ts:1077

`Private` processTarget

processTarget(target): void
Processes the target once, fetching all images relevant for this target, then paints those images to the target's texture.
Parameters
- target: Target
  
  The target to paint.
Returns void
- Defined in core/layer/Layer.ts:860

`Abstract` registerNode

registerNode(node, extent): void
Parameters
- node: Node
- extent: Extent
Returns void
- Defined in core/layer/Layer.ts:1097

`Private` releaseRenderTarget

releaseRenderTarget(target): void
Parameters
- target: WebGLRenderTarget<Texture>
  
  The render target to release.
Returns void
- Defined in core/layer/Layer.ts:1040

removeEventListener

removeEventListener<T>(type, listener): void
Removes a listener from an event type.
Type Parameters
- T extends string
Parameters
- type: T
  
  The type of the listener that gets removed.
- listener: EventListener<(TEvents & LayerEvents)[T], T, Layer<TEvents, TUserData>>
  
  The listener function that gets removed.
Returns void
Inherited from EventDispatcher.removeEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:74
removeEventListener<T>(type, listener): void
Type Parameters
- T extends string
Parameters
- type: T
- listener: EventListener<{}, T, Layer<TEvents, TUserData>>
Returns void
Inherited from EventDispatcher.removeEventListener
- Defined in ../node_modules/@types/three/src/core/EventDispatcher.d.ts:78

`Private` shouldCancelRequest

shouldCancelRequest(node): boolean
Parameters
- node: Node
Returns boolean
- Defined in core/layer/Layer.ts:398

unregisterNode

unregisterNode(node): void
Removes the node from this layer.
Parameters
- node: Node
  
  The disposed node.
Returns void
- Defined in core/layer/Layer.ts:712

update

update(context, node): void
Updates the provided node with content from this layer.
Parameters
- context: Context
  
  the context
- node: Node
  
  the node to update
Returns void
- Defined in core/layer/Layer.ts:942

`Protected` updateMaterial

updateMaterial(material): void
Parameters
- material: Material
Returns void
- Defined in core/layer/Layer.ts:1093

Class Layer<TEvents, TUserData>Abstract

Types of layers

The userData property

Reprojection capabilities

Type Parameters

TEvents extends LayerEvents = LayerEvents

TUserData extends LayerUserData = LayerUserData

Hierarchy

Implements

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Type Parameters

TEvents extends LayerEvents = LayerEvents

TUserData extends LayerUserData = LayerUserData

Parameters

options: LayerOptions

Returns Layer<TEvents, TUserData>

Properties

Protected _composer

Private Readonly _createReadableTextures

Private _fallbackImagesPromise

Private Readonly _filter

Type declaration

Parameters

id: string

Returns boolean

Private _instance

Private Readonly _opCounter

Private Readonly _preloadImages

Private _preprocessOnce

Protected Readonly _queue

Private _ready

Private _shouldNotify

Private _sortedTargets

Private Readonly _targets

Private _visible

backgroundColor

Readonly colorMap

Readonly computeMinMax

disposed

Readonly extent

frozen

Readonly id

Readonly interpretation

Readonly isLayer

Readonly name

Readonly noDataOptions

Readonly resolutionFactor

Readonly showTileBorders

Readonly source

type

Readonly userData

Accessors

composer

Returns Readonly<LayerComposer>

loading

Returns boolean

progress

Returns number

ready

Returns boolean

visible

Returns boolean

Parameters

v: boolean

Returns void

Methods

Private _getSortedTargets

Returns Target[]

Private acquireRenderTarget

Parameters

width: number

height: number

Returns WebGLRenderTarget<Texture>

addEventListener

Class Layer<TEvents, TUserData>`Abstract`

The `userData` property

`Protected` _composer

`Private` `Readonly` _createReadableTextures

`Private` _fallbackImagesPromise

`Private` `Readonly` _filter

`Private` _instance

`Private` `Readonly` _opCounter

`Private` `Readonly` _preloadImages

`Private` _preprocessOnce

`Protected` `Readonly` _queue

`Private` _ready

`Private` _shouldNotify

`Private` _sortedTargets

`Private` `Readonly` _targets

`Private` _visible

`Readonly` colorMap

`Readonly` computeMinMax

`Readonly` extent

`Readonly` id

`Readonly` interpretation

`Readonly` isLayer

`Readonly` name

`Readonly` noDataOptions

`Readonly` resolutionFactor

`Readonly` showTileBorders

`Readonly` source

`Readonly` userData

`Private` _getSortedTargets

`Private` acquireRenderTarget

`Private` addToComposer

`Protected` adjustExtent

`Protected` adjustExtentAndPixelSize

Returns {
extent: Extent;
height: number;
width: number;
}

`Protected` applyDefaultTexture

`Protected` `Abstract` applyEmptyTextureToNode

`Protected` `Abstract` applyTextureToNode

`Protected` `Abstract` canFetchImages

`Private` fetchImages

options: {
extent: Extent;
height: number;
target: Target;
width: number;
}