Class CogSource

Provides data from a Cloud Optimized GeoTIFF (COG).

Hierarchy (view full)

ImageSource
- CogSource

Index

Constructors

Properties

containsFn crs datatype flipY isCogSource isImageSource type url version

Accessors

channels colorSpace

Methods

adjustExtentAndPixelSize contains dispose getCrs getExtent getImages getMemoryUsage initialize intersects update computeExtent

Constructors

constructor

new CogSource(options): CogSource
Creates a COG source.
Parameters
- options: CogSourceOptions
  options
Returns CogSource
Overrides ImageSource.constructor
- Defined in sources/CogSource.ts:258

Properties

`Readonly` containsFn

containsFn: CustomContainsFn

`Readonly` crs

crs: string

datatype

datatype: TextureDataType

Gets the datatype of images generated by this source.

`Readonly` flipY

flipY: boolean

Gets whether images generated from this source should be flipped vertically.

`Readonly` isCogSource

isCogSource: boolean = true

`Readonly` isImageSource

isImageSource: boolean = true

type

type: string

`Readonly` url

url: string

version

version: number

Accessors

channels

get channels(): number[]
Gets the channel mapping.

Returns number[]
- Defined in sources/CogSource.ts:550
set channels(value): void
Parameters
- value: number[]
Returns void
- Defined in sources/CogSource.ts:554

colorSpace

get colorSpace(): ColorSpace
Gets the color space of the textures generated by this source.

Returns ColorSpace
Inherited from ImageSource.colorSpace
- Defined in sources/ImageSource.ts:157

Methods

adjustExtentAndPixelSize

adjustExtentAndPixelSize(requestExtent, requestWidth, requestHeight, margin?): {
    extent: Extent;
    height: number;
    width: number;
}
Parameters
- requestExtent: Extent
  The request extent.
- requestWidth: number
  The width, in pixels, of the request extent.
- requestHeight: number
  The height, in pixels, of the request extent.
- margin: number = 0
  The margin, in pixels.
Returns {
    extent: Extent;
    height: number;
    width: number;
}
The adjusted parameters.
- extent: Extent
- height: number
- width: number
Overrides ImageSource.adjustExtentAndPixelSize
- Defined in sources/CogSource.ts:321

contains

contains(extent): boolean
Gets whether this source contains the specified extent. If a custom contains function is provided, it will be used. Otherwise, intersects is used.

This method is mainly used to discard non-relevant requests (i.e don't process regions that are not relevant to this source).
Parameters
- extent: Extent
  The extent to test.
Returns boolean
Inherited from ImageSource.contains
- Defined in sources/ImageSource.ts:224

dispose

dispose(): void
Disposes unmanaged resources of this source.

Returns void
Inherited from ImageSource.dispose
- Defined in sources/ImageSource.ts:279

getCrs

getCrs(): string
Returns the CRS of this source.

Returns string
The CRS.
Overrides ImageSource.getCrs
- Defined in sources/CogSource.ts:297

getExtent

getExtent(): Extent
Returns the extent of this source expressed in the CRS of the source.

Returns Extent
The extent of the source.
Overrides ImageSource.getExtent
- Defined in sources/CogSource.ts:293

getImages

getImages(options): {
id: string;
request: (() => Promise<ImageResult>);
}[]
Gets the images for the specified extent and pixel size.
Parameters
- options: {
      extent: Extent;
      height: number;
      id: string;
      signal?: AbortSignal;
      width: number;
  }
  The options.
  - extent: Extent
  - height: number
  - id: string
  - Optional signal?: AbortSignal
  - width: number
Returns {
id: string;
request: (() => Promise<ImageResult>);
}[]
An array containing the functions to generate the images asynchronously.
Overrides ImageSource.getImages
- Defined in sources/CogSource.ts:745

getMemoryUsage

getMemoryUsage(_, target?): MemoryUsageReport
Returns an approximation of the memory used by this object, in bytes.
Parameters
- _: GetMemoryUsageContext
  The graphics context.
- Optional target: MemoryUsageReport
  If specified, the values computed during this call must be added to the existing values in the target. Otherwise, a new report must be built.
Returns MemoryUsageReport
The memory usage report. If target is specified, then this must be returned.
Overrides ImageSource.getMemoryUsage
- Defined in sources/CogSource.ts:273

initialize

initialize(): Promise<void>
Initializes the source.

Returns Promise<void>
A promise that resolves when the source is initialized.
Overrides ImageSource.initialize
- Defined in sources/CogSource.ts:359

intersects

intersects(extent): boolean
Test the intersection between the specified extent and this source's extent. This method may be overriden to perform special logic.
Parameters
- extent: Extent
  The extent to test.
Returns boolean
true if the extent and this source extent intersects, false otherwise.
Inherited from ImageSource.intersects
- Defined in sources/ImageSource.ts:241

update

update(): void
Raises an event to reload the source.

Returns void
Inherited from ImageSource.update
- Defined in sources/ImageSource.ts:210

`Static` computeExtent

computeExtent(crs, tiffImage): Extent
Attemps to compute the exact extent of the TIFF image.
Parameters
- crs: string
  The CRS.
- tiffImage: GeoTIFFImage
  The TIFF image.
Returns Extent
- Defined in sources/CogSource.ts:307