@allmaps/openlayers

Allmaps plugin for OpenLayers. Plugin that uses WebGL to show warped IIIF images on an OpenLayers map. The plugin works by loading Georeference Annotations.

Allmaps plugin for OpenLayers. This plugin allows displaying georeferenced IIIF images on an OpenLayers map. The plugin works by loading Georeference Annotations and uses WebGL to transform images from a IIIF image server to overlay them on their correct geographical position. See allmaps.org for more information.


Examples:

* Observable notebook
* Observable notebook

How it works

This plugin exports the class WarpedMapLayer. You can add one or multiple Georeference Annotations (or AnnotationPages that contain multiple Georeference Annotations) to a WarpedMapLayer and add the WarpedMapLayer to your OpenLayers map. This will render all georeferenced maps defined by the Georeference Annotations.

To understand what happens under the hood for each georeferenced map, see the @allmaps/render package.

Installation

This package works in browsers and in Node.js as an ESM or an UMD module.

Install with pnpm:

``sh
pnpm install @allmaps/openlayers
`

You can optionally build this package locally by running:

`sh
pnpm run build
`

Usage

Built for OpenLayers 8, but should work with OpenLayers 6 and OpenLayers 7 as well.

$3

Creating a WarpedMapLayer and adding a Georeference Annotation to an OpenLayers map looks like this:

`js
import { WarpedMapLayer } from '@allmaps/openlayers'

const map = new ol.Map({
target: 'map',
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
})
],
view: new ol.View({
center: ol.proj.fromLonLat([-71.00661, 42.37124]),
zoom: 14
})
})

// Create WarpedMapLayer
const warpedMapLayer = new WarpedMapLayer()

// Add the WarpedMapLayer to the map and load a Georeference Annotation
const annotationUrl = 'https://annotations.allmaps.org/maps/a9458d2f895dcdfb'
map.addLayer(warpedMapLayer)
warpedMapLayer.addGeoreferenceAnnotationByUrl(annotationUrl)
`

A Georeference Annotation can be added using the addGeoreferenceAnnotation and addGeoreferenceAnnotationByUrl functions:

`js
fetch(annotationUrl)
.then((response) => response.json())
.then((annotation) => warpedMapLayer.addGeoreferenceAnnotation(annotation))
`

Or:

`js
await warpedMapLayer.addGeoreferenceAnnotationByUrl(annotationUrl)
`

$3

See the @allmaps/warpedmaplayer package for the API documentation of the methods inherited from the WarpedMapLayer class (shared by all Allmaps plugins). It includes a list of all options that can be set on instances of the class and all events which are passed to the native map instance hosting the layer instance.

You can set options on the entire layer, or on a specific map on the layer (overwriting layer options):

`js
warpedMapLayer.setLayerOptions({ visible: true })
warpedMapLayer.setMapOptions(mapId, { visible: true })
`

You can listen to events in the typical way:

`js
map.on('warpedmapadded', (event) => {
console.log(event.mapIds)
})
`

License

MIT

API

$3

###### Parameters

* type (string)
* data (unknown)

###### Returns

OLWarpedMapEvent.

###### Extends

* Event

$3

###### Type

`ts
unknown
`

$3

###### Type

`ts
object & Partial
`

$3

###### Parameters

* type (WarpedMapEventType)
* data? (Partial | undefined)

###### Returns

WarpedMapEvent.

###### Extends

* Event

$3

###### Type

`ts
{
mapIds?: Array | undefined
tileUrl?: string | undefined
optionKeys?: Array | undefined
spritesInfo?: SpritesInfo | undefined
}
`

$3

Creates a WarpedMapLayer instance

###### Parameters

* options? (Partial | undefined)
* the WebGL2 renderer options

###### Returns

WarpedMapLayer.

###### Extends

* Layer
* BaseWarpedMapLayer

$3

###### Parameters

There are no parameters.

###### Returns

void.

$3

Adds a Georeference Annotation

###### Parameters

* annotation (unknown)
* Georeference Annotation
* mapOptions? (Partial | undefined)
* Map options

###### Returns

Map IDs of the maps that were added, or an error per map (Promise>).

$3

Adds a Georeference Annotation by URL

###### Parameters

* annotationUrl (string)
* URL of a Georeference Annotation
* mapOptions? (Partial | undefined)
* Map options

###### Returns

Map IDs of the maps that were added, or an error per map (Promise>).

$3

Adds a Georeferenced Map

###### Parameters

* georeferencedMap (unknown)
* Georeferenced Map
* mapOptions? (Partial | undefined)
* Map options

###### Returns

Map ID of the map that was added, or an error (Promise).

$3

Adds image information to the WarpedMapList's image information cache

###### Parameters

* imageInfos (Array)
* Image informations

###### Returns

Image IDs of the image informations that were added (Array).

$3

Adds sprites to the Renderer's sprite tile cache

This adds tiles from sprites to warped maps in WarpedMapList. Load maps before running this function.
This uses the image info of related maps. When using addImageInfos(), call it before calling this function.

###### Parameters

* sprites (Array)
* Sprites
* imageUrl (string)
* Image url
* imageSize ([number, number])
* Image size

###### Returns

Promise.

$3

Bring maps forward

###### Parameters

* mapIds (Iterable)
* IDs of the maps

###### Returns

void.

$3

Bring maps to front

###### Parameters

* mapIds (Iterable)
* IDs of the maps

###### Returns

void.

$3

###### Type

`ts
HTMLCanvasElement
`

$3

###### Type

`ts
[number, number]
`

$3

Removes all warped maps from the layer

###### Parameters

There are no parameters.

###### Returns

void.

$3

###### Type

`ts
HTMLDivElement
`

$3

###### Parameters

* event (Event)

###### Returns

void.

$3

###### Parameters

* event (Event)

###### Returns

void.

$3

###### Type

`ts
object
`

$3

Disposes all WebGL resources and cached tiles

###### Parameters

There are no parameters.

###### Returns

void.

$3

Get the default options the layer

###### Parameters

There are no parameters.

###### Returns

object &
SpecificWarpedMapListOptions &
Partial &
SpecificWebGL2WarpedMapOptions &
SpecificTriangulatedWarpedMapOptions &
WarpedMapOptions.

$3

Get the layer options

###### Parameters

There are no parameters.

###### Returns

{ createRTree?: boolean | undefined; rtreeUpdatedOptions?: Array | undefined; animatedOptions?: Array | undefined; renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; ... 58 more ...; distortionMeasure?: DistortionMeasure | undefined; }.

$3

Return the bounding box of all visible maps in the layer (inside or outside of the Viewport), in longitude/latitude coordinates.

###### Parameters

There are no parameters.

###### Returns

Extent | undefined.

* Bounding box of all warped maps

$3

Get the default options of a map

These come from the default option settings for WebGL2WarpedMaps and the map's georeferenced map proporties

###### Parameters

* mapId (string)
* Map ID for which the options apply

###### Returns

WebGL2WarpedMapOptions | undefined.

$3

Get mapIds for selected maps

Note: more selection options are available on this function of WarpedMapList

###### Parameters

There are no parameters.

###### Returns

Array.

$3

Get the map-specific options of a map

###### Parameters

* mapId (string)
* Map ID for which the options apply

###### Returns

Partial | undefined.

$3

Get the options of a map

These options are the result of merging the default, georeferenced map,
layer and map-specific options of that map.

###### Parameters

* mapId (string)
* Map ID for which the options apply

###### Returns

WebGL2WarpedMapOptions | undefined.

$3

Get the z-index of a map

###### Parameters

* mapId (string)
* Map ID for which to get the z-index

###### Returns

The z-index of a map (number | undefined).

$3

Get the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default
Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

###### Parameters

* mapIds (Array)
* Map IDs
* projectionOptions? (ProjectionOptions | undefined)

###### Returns

The bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Bbox | undefined).

$3

Get the center of the bounding box of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default
Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

###### Parameters

* mapIds (Array)
* Map IDs
* projectionOptions? (ProjectionOptions | undefined)

###### Returns

The center of the bbox of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Point | undefined).

$3

Get the convex hull of the maps

By default the result is returned in the list's projection, which is EPSG:3857 by default
Use {definition: 'EPSG:4326'} to request the result in lon-lat EPSG:4326

Note: more selection options are available on this function of WarpedMapList

###### Parameters

* mapIds (Array)
* Map IDs
* projectionOptions? (ProjectionOptions | undefined)

###### Returns

The convex hull of all selected maps, in the chosen projection, or undefined if there were no maps matching the selection (Ring | undefined).

$3

Get the layer opacity

Returns a number between 0 and 1 (the default)

###### Parameters

There are no parameters.

###### Returns

number.

$3

Get the WarpedMap instance for a map

###### Parameters

* mapId (string)
* Map ID of the requested WarpedMap instance

###### Returns

WebGL2WarpedMap | undefined.

$3

Get the WarpedMapList object that contains a list of the warped maps of all loaded maps

###### Parameters

There are no parameters.

###### Returns

WarpedMapList.

$3

Get the WarpedMap instances for selected maps

Note: more selection options are available on this function of WarpedMapList

###### Parameters

* mapIds? (Array | undefined)
* Map IDs

###### Returns

Iterable.

$3

###### Type

`ts
WebGL2RenderingContext | null | undefined
`

$3

###### Parameters

* event (Event)

###### Returns

void.

$3

###### Parameters

There are no parameters.

###### Returns

void.

$3

###### Type

`ts
object & Partial
`

$3

###### Parameters

There are no parameters.

###### Returns

void.

$3

Removes a Georeference Annotation

###### Parameters

* annotation (unknown)
* Georeference Annotation

###### Returns

Map IDs of the maps that were removed, or an error per map (Promise>).

$3

Removes a Georeference Annotation by URL

###### Parameters

* annotationUrl (string)
* URL of a Georeference Annotation

###### Returns

Map IDs of the maps that were removed, or an error per map (Promise>).

$3

Removes a Georeferenced Map

###### Parameters

* georeferencedMap (unknown)
* Georeferenced Map

###### Returns

Map ID of the map that was removed, or an error (Promise).

$3

Removes a Georeferenced Map by its ID

###### Parameters

* mapId (string)
* Map ID of the georeferenced map to remove

###### Returns

Map ID of the map that was removed, or an error (Promise).

$3

Render the layer.

###### Parameters

* frameState ({ pixelRatio: number; time: number; viewState: State; animate: boolean; coordinateToPixelTransform: Transform; ... 14 more ...; renderTargets: { [x: string]: boolean; }; })
* OpenLayers frame state

###### Returns

The rendered element (HTMLElement).

$3

###### Type

`ts
WebGL2Renderer
`

$3

Reset the layer options

An empty array resets all options, undefined resets no options.
Doesn't reset render options or specific warped map layer options

###### Parameters

* layerOptionKeys? (Array | undefined)
* Keys of the options to reset
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Reset the map-specific options of maps (and the layer options)

An empty array resets all options, undefined resets no options.
Doesn't reset render options or specific warped map layer options

###### Parameters

* mapIds (Array)
* Map IDs for which to reset the options
* mapOptionKeys? (Array | undefined)
* Keys of the map-specific options to reset
* layerOptionKeys? (Array | undefined)
* Keys of the layer options to reset
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Reset the map-specific options of maps by map ID (and the layer options)

An empty array or map resets all options (for all maps), undefined resets no options.
Doesn't reset render options or specific warped map layer options

###### Parameters

* mapOptionkeysByMapId (Map>)
* Keys of map-specific options to reset by map ID
* layerOptionKeys? (Array | undefined)
* Keys of the layer options to reset
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

###### Parameters

* canvas (HTMLCanvasElement)
* undefined ([number, number])

###### Returns

boolean.

$3

###### Type

`ts
ResizeObserver
`

$3

###### Parameters

* entries (Array)

###### Returns

void.

$3

Send maps backward

###### Parameters

* mapIds (Iterable)
* IDs of the maps

###### Returns

void.

$3

Send maps to back

###### Parameters

* mapIds (Array)
* IDs of the maps

###### Returns

void.

$3

Set the layer options

###### Parameters

* layerOptions (object | Partial)
* Layer options to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

###### Examples

`ts
warpedMapLayer.setLayerOptions({ transformationType: 'thinPlateSpline' })
`

$3

Set the GCPs of a map

This only sets the map-specific gcps option of the map
(or more specifically of the warped map used for rendering),
overwriting the original GCPs inferred from the Georeference Annotation.

The original GCPs can be reset by resetting the map-specific GCPs option,
and stay accessible in the warped map's map property.

###### Parameters

* mapId (string)
* Map ID for which to set the options
* gcps (Array)
* GCPs to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Set the map-specific options of a map (and the layer options)

In general setting a map-specific option
also sets the corresponding option of the map,
since these are the result of merging the default, georeferenced map,
layer and map-specific options of that map.

A special case is setting a map-specific option to undefined:
then the corresponding option is derived from the default, georeferenced map or layer option.
This is equivalent to using the reset function for map-specific option.

###### Parameters

* mapId (string)
* Map ID for which to set the options
* mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
* Map-specific options to set
* layerOptions? (object | Partial | undefined)
* Layer options to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

###### Examples

`ts
warpedMapLayer.setMapOptions(myMapId, { transformationType: 'thinPlateSpline' })
`

$3

Set the resource mask of a map

This only sets the map-specific resourceMask option of the map
(or more specifically of the warped map used for rendering),
overwriting the original resource mask inferred from the Georeference Annotation.

The original resource mask can be reset by resetting the map-specific resource mask option,
and stays accessible in the warped map's map property.

###### Parameters

* mapId (string)
* Map ID for which to set the options
* resourceMask (Array)
* Resource mask to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Set the transformation type of a map

This only sets the map-specific transformationType option of the map
(or more specifically of the warped map used for rendering),
overwriting the original transformation type inferred from the Georeference Annotation.

The original transformation type can be reset by resetting the map-specific transformation type option,
and stays accessible in the warped map's map property.

###### Parameters

* mapId (string)
* Map ID for which to set the options
* transformationType ( | 'straight'
| 'helmert'
| 'polynomial'
| 'polynomial1'
| 'polynomial2'
| 'polynomial3'
| 'thinPlateSpline'
| 'projective'
| 'linear')
* Transformation type to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Set the map-specific options of maps (and the layer options)

In general setting a map-specific option
also sets the corresponding option of the map,
since these are the result of merging the default, georeferenced map,
layer and map-specific options of that map.

A special case is setting a map-specific option to undefined:
then the corresponding option is derived from the default, georeferenced map or layer option.
This is equivalent to using the reset function for map-specific option.

###### Parameters

* mapIds (Array)
* Map IDs for which to set the options
* mapOptions ({ renderMaps?: boolean | undefined; renderLines?: boolean | undefined; renderPoints?: boolean | undefined; renderGcps?: boolean | undefined; renderGcpsColor?: string | undefined; renderGcpsSize?: number | undefined; renderGcpsBorderColor?: string | undefined; ... 54 more ...; distortionMeasure?: DistortionMeasure | ...)
* Map-specific options to set
* layerOptions? (object | Partial | undefined)
* Layer options to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

###### Examples

`ts
warpedMapLayer.setMapsOptions([myMapId], { transformationType: 'thinPlateSpline' })
`

$3

Set the map-specific options of maps by map ID (and the layer options)

In general setting a map-specific option
also sets the corresponding option of the map,
since these are the result of merging the default, georeferenced map,
layer and map-specific options of that map.

A special case is setting a map-specific option to undefined:
then the corresponding option is derived from the default, georeferenced map or layer option.
This is equivalent to using the reset function for map-specific option.

###### Parameters

* mapOptionsByMapId (Map>)
* Map-specific options to set by map ID
* layerOptions? (object | Partial | undefined)
* Layer options to set
* animationOptions? (Partial | undefined)
* Animation options

###### Returns

void.

$3

Set the layer opacity

###### Parameters

* opacity (number)
* Layer opacity to set

###### Returns

void`.