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

Hierarchy (view full)

Implements

Constructors

constructor

Properties

backgroundColor colorMap computeMinMax disposed extent frozen id interpretation isLayer name noDataOptions resolutionFactor showEmptyTextures showTileBorders source type userData

Accessors

composer loading progress ready visible

Methods

adjustExtent adjustExtentAndPixelSize applyDefaultTexture applyEmptyTextureToNode applyTextureToNode canFetchImages clear contains deleteUnusedTargets dispose getExtent getMemoryUsage getRenderTargetDataType getRenderTargetPixelFormat loadFallbackImages loadFallbackImagesInternal onInitialized onTextureCreated postUpdate unregisterNode update updateMaterial

Constructors

constructor

Properties

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 showEmptyTextures

showEmptyTextures: boolean

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

loading

  • get loading(): boolean

  • Gets whether the object is currently performing an asynchronous operation.

    Returns boolean

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

ready

visible

Methods

Protected adjustExtent

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

Protected applyDefaultTexture

  • applyDefaultTexture(target): void

  • Parameters

    • target: Target

      The target.

    Returns void

Protected Abstract applyEmptyTextureToNode

Protected Abstract applyTextureToNode

  • applyTextureToNode(texture, target, isLastRender): void

  • Parameters

    • texture: TextureAndPitch
    • target: Target
    • isLastRender: boolean

    Returns void

Protected Abstract canFetchImages

clear

  • clear(): void

  • Resets all render targets to a blank state and repaint all the targets.

    Returns void

contains

  • contains(extent): boolean

  • Parameters

    • extent: Extent

      The extent to test.

    Returns boolean

    true if this layer contains the specified extent, false otherwise.

Protected deleteUnusedTargets

dispose

  • dispose(): void

  • Disposes the layer. This releases all resources held by this layer.

    Returns void

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.

getMemoryUsage

Abstract getRenderTargetDataType

Abstract getRenderTargetPixelFormat

loadFallbackImages

loadFallbackImagesInternal

Protected onInitialized

  • onInitialized(): Promise<void>

  • Called when the layer has finished initializing.

    Returns Promise<void>

Protected onTextureCreated

postUpdate

unregisterNode

  • unregisterNode(node): void

  • Removes the node from this layer.

    Parameters

    • node: Node

      The disposed node.

    Returns void

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

Protected updateMaterial

Settings

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constructorbackgroundColorcolorMapcomputeMinMaxdisposedextentfrozenidinterpretationisLayernamenoDataOptionsresolutionFactorshowEmptyTexturesshowTileBorderssourcetypeuserDatacomposerloadingprogressreadyvisibleadjustExtentadjustExtentAndPixelSizeapplyDefaultTextureapplyEmptyTextureToNodeapplyTextureToNodecanFetchImagesclearcontainsdeleteUnusedTargetsdisposegetExtentgetMemoryUsagegetRenderTargetDataTypegetRenderTargetPixelFormatloadFallbackImagesloadFallbackImagesInternalonInitializedonTextureCreatedpostUpdateunregisterNodeupdateupdateMaterial