KBE3D / KBCore / Cesium / ImageryProvider

类: ImageryProvider

Provides imagery to be displayed on the surface of an ellipsoid. This type describes an interface and is not intended to be instantiated directly.

属性

rectangle

readonly rectangle: Rectangle

Gets the rectangle, in radians, of the imagery provided by the instance.

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tileWidth

readonly tileWidth: number

Gets the width of each tile, in pixels.

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tileHeight

readonly tileHeight: number

Gets the height of each tile, in pixels.

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maximumLevel

readonly maximumLevel: number | undefined

Gets the maximum level-of-detail that can be requested.

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minimumLevel

readonly minimumLevel: number

Gets the minimum level-of-detail that can be requested. Generally, a minimum level should only be used when the rectangle of the imagery is small enough that the number of tiles at the minimum level is small. An imagery provider with more than a few tiles at the minimum level will lead to rendering problems.

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tilingScheme

readonly tilingScheme: TilingScheme

Gets the tiling scheme used by the provider.

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tileDiscardPolicy

readonly tileDiscardPolicy: TileDiscardPolicy

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.

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errorEvent

readonly errorEvent: Event

Gets an event that is raised when the imagery provider encounters an asynchronous error. By subscribing to the event, you will be notified of the error and can potentially recover from it. Event listeners are passed an instance of TileProviderError.

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credit

readonly credit: Credit

Gets the credit to display when this imagery provider is active. Typically this is used to credit the source of the imagery.

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proxy

readonly proxy: Proxy

Gets the proxy used by this provider.

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hasAlphaChannel

readonly hasAlphaChannel: boolean

Gets a value indicating whether or not the images provided by this imagery provider include an alpha channel. If this property is false, an alpha channel, if present, will be ignored. If this property is true, any images without an alpha channel will be treated as if their alpha is 1.0 everywhere. When this property is false, memory usage and texture upload time are reduced.

方法

loadImage()

static loadImage(imageryProvider: ImageryProvider, url: string | Resource): Promise<ImageryTypes | CompressedTextureBuffer> | undefined

Loads an image from a given URL. If the server referenced by the URL already has too many requests pending, this function will instead return undefined, indicating that the request should be retried later.

参数

imageryProvider

ImageryProvider

The imagery provider for the URL.

url

The URL of the image.

string | Resource

返回

Promise<ImageryTypes | CompressedTextureBuffer> | undefined

A promise for the image that will resolve when the image is available, or undefined if there are too many active requests to the server, and the request should be retried later.

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getTileCredits()

getTileCredits(x: number, y: number, level: number): Credit[]

Gets the credits to be displayed when a given tile is displayed.

参数

x

number

The tile X coordinate.

y

number

The tile Y coordinate.

level

number

The tile level;

返回

Credit[]

The credits to be displayed when the tile is displayed.

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requestImage()

requestImage(x: number, y: number, level: number, request?: Request): Promise<ImageryTypes> | undefined

Requests the image for a given tile.

参数

x

number

The tile X coordinate.

y

number

The tile Y coordinate.

level

number

The tile level.

request?

Request

The request object. Intended for internal use only.

返回

Promise<ImageryTypes> | undefined

Returns a promise for the image that will resolve when the image is available, or undefined if there are too many active requests to the server, and the request should be retried later.

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pickFeatures()

pickFeatures(x: number, y: number, level: number, longitude: number, latitude: number): Promise<ImageryLayerFeatureInfo[]> | undefined

Asynchronously determines what features, if any, are located at a given longitude and latitude within a tile. This function is optional, so it may not exist on all ImageryProviders.

参数

x

number

The tile X coordinate.

y

number

The tile Y coordinate.

level

number

The tile level.

longitude

number

The longitude at which to pick features.

latitude

number

The latitude at which to pick features.

返回

Promise<ImageryLayerFeatureInfo[]> | undefined

A promise for the picked features that will resolve when the asynchronous picking completes. The resolved value is an array of ImageryLayerFeatureInfo instances. The array may be empty if no features are found at the given location. It may also be undefined if picking is not supported.

构造函数

构造函数

new ImageryProvider(): ImageryProvider

返回

ImageryProvider