213 lines
No EOL
8.6 KiB
TypeScript
213 lines
No EOL
8.6 KiB
TypeScript
import FeatureSource, {FeatureSourceForLayer, IndexedFeatureSource, Tiled} from "../FeatureSource";
|
|
import {Store, UIEventSource} from "../../UIEventSource";
|
|
import FilteredLayer from "../../../Models/FilteredLayer";
|
|
import TileHierarchy from "./TileHierarchy";
|
|
import {Tiles} from "../../../Models/TileRange";
|
|
import {BBox} from "../../BBox";
|
|
|
|
/**
|
|
* Contains all features in a tiled fashion.
|
|
* The data will be automatically broken down into subtiles when there are too much features in a single tile or if the zoomlevel is too high
|
|
*/
|
|
export default class TiledFeatureSource implements Tiled, IndexedFeatureSource, FeatureSourceForLayer, TileHierarchy<IndexedFeatureSource & FeatureSourceForLayer & Tiled> {
|
|
public readonly z: number;
|
|
public readonly x: number;
|
|
public readonly y: number;
|
|
public readonly parent: TiledFeatureSource;
|
|
public readonly root: TiledFeatureSource
|
|
public readonly layer: FilteredLayer;
|
|
/* An index of all known tiles. allTiles[z][x][y].get('layerid') will yield the corresponding tile.
|
|
* Only defined on the root element!
|
|
*/
|
|
public readonly loadedTiles: Map<number, TiledFeatureSource & FeatureSourceForLayer> = undefined;
|
|
|
|
public readonly maxFeatureCount: number;
|
|
public readonly name;
|
|
public readonly features: UIEventSource<{ feature: any, freshness: Date }[]>
|
|
public readonly containedIds: Store<Set<string>>
|
|
|
|
public readonly bbox: BBox;
|
|
public readonly tileIndex: number;
|
|
private upper_left: TiledFeatureSource
|
|
private upper_right: TiledFeatureSource
|
|
private lower_left: TiledFeatureSource
|
|
private lower_right: TiledFeatureSource
|
|
private readonly maxzoom: number;
|
|
private readonly options: TiledFeatureSourceOptions
|
|
|
|
private constructor(z: number, x: number, y: number, parent: TiledFeatureSource, options?: TiledFeatureSourceOptions) {
|
|
this.z = z;
|
|
this.x = x;
|
|
this.y = y;
|
|
this.bbox = BBox.fromTile(z, x, y)
|
|
this.tileIndex = Tiles.tile_index(z, x, y)
|
|
this.name = `TiledFeatureSource(${z},${x},${y})`
|
|
this.parent = parent;
|
|
this.layer = options.layer
|
|
options = options ?? {}
|
|
this.maxFeatureCount = options?.maxFeatureCount ?? 250;
|
|
this.maxzoom = options.maxZoomLevel ?? 18
|
|
this.options = options;
|
|
if (parent === undefined) {
|
|
throw "Parent is not allowed to be undefined. Use null instead"
|
|
}
|
|
if (parent === null && z !== 0 && x !== 0 && y !== 0) {
|
|
throw "Invalid root tile: z, x and y should all be null"
|
|
}
|
|
if (parent === null) {
|
|
this.root = this;
|
|
this.loadedTiles = new Map()
|
|
} else {
|
|
this.root = this.parent.root;
|
|
this.loadedTiles = this.root.loadedTiles;
|
|
const i = Tiles.tile_index(z, x, y)
|
|
this.root.loadedTiles.set(i, this)
|
|
}
|
|
this.features = new UIEventSource<any[]>([])
|
|
this.containedIds = this.features.map(features => {
|
|
if (features === undefined) {
|
|
return undefined;
|
|
}
|
|
return new Set(features.map(f => f.feature.properties.id))
|
|
})
|
|
|
|
// We register this tile, but only when there is some data in it
|
|
if (this.options.registerTile !== undefined) {
|
|
this.features.addCallbackAndRunD(features => {
|
|
if (features.length === 0) {
|
|
return;
|
|
}
|
|
this.options.registerTile(this)
|
|
return true;
|
|
})
|
|
}
|
|
|
|
|
|
}
|
|
|
|
public static createHierarchy(features: FeatureSource, options?: TiledFeatureSourceOptions): TiledFeatureSource {
|
|
options = {
|
|
...options,
|
|
layer: features["layer"] ?? options.layer
|
|
}
|
|
const root = new TiledFeatureSource(0, 0, 0, null, options)
|
|
features.features?.addCallbackAndRunD(feats => root.addFeatures(feats))
|
|
return root;
|
|
}
|
|
|
|
private isSplitNeeded(featureCount: number) {
|
|
if (this.upper_left !== undefined) {
|
|
// This tile has been split previously, so we keep on splitting
|
|
return true;
|
|
}
|
|
if (this.z >= this.maxzoom) {
|
|
// We are not allowed to split any further
|
|
return false
|
|
}
|
|
if (this.options.minZoomLevel !== undefined && this.z < this.options.minZoomLevel) {
|
|
// We must have at least this zoom level before we are allowed to start splitting
|
|
return true
|
|
}
|
|
|
|
// To much features - we split
|
|
return featureCount > this.maxFeatureCount
|
|
|
|
}
|
|
|
|
/***
|
|
* Adds the list of features to this hierarchy.
|
|
* If there are too much features, the list will be broken down and distributed over the subtiles (only retaining features that don't fit a subtile on this level)
|
|
* @param features
|
|
* @private
|
|
*/
|
|
private addFeatures(features: { feature: any, freshness: Date }[]) {
|
|
if (features === undefined || features.length === 0) {
|
|
return;
|
|
}
|
|
|
|
if (!this.isSplitNeeded(features.length)) {
|
|
this.features.setData(features)
|
|
return;
|
|
}
|
|
|
|
if (this.upper_left === undefined) {
|
|
this.upper_left = new TiledFeatureSource(this.z + 1, this.x * 2, this.y * 2, this, this.options)
|
|
this.upper_right = new TiledFeatureSource(this.z + 1, this.x * 2 + 1, this.y * 2, this, this.options)
|
|
this.lower_left = new TiledFeatureSource(this.z + 1, this.x * 2, this.y * 2 + 1, this, this.options)
|
|
this.lower_right = new TiledFeatureSource(this.z + 1, this.x * 2 + 1, this.y * 2 + 1, this, this.options)
|
|
}
|
|
|
|
const ulf = []
|
|
const urf = []
|
|
const llf = []
|
|
const lrf = []
|
|
const overlapsboundary = []
|
|
|
|
for (const feature of features) {
|
|
const bbox = BBox.get(feature.feature)
|
|
|
|
// There are a few strategies to deal with features that cross tile boundaries
|
|
|
|
if (this.options.noDuplicates) {
|
|
// Strategy 1: We put the feature into a somewhat matching tile
|
|
if (bbox.overlapsWith(this.upper_left.bbox)) {
|
|
ulf.push(feature)
|
|
} else if (bbox.overlapsWith(this.upper_right.bbox)) {
|
|
urf.push(feature)
|
|
} else if (bbox.overlapsWith(this.lower_left.bbox)) {
|
|
llf.push(feature)
|
|
} else if (bbox.overlapsWith(this.lower_right.bbox)) {
|
|
lrf.push(feature)
|
|
} else {
|
|
overlapsboundary.push(feature)
|
|
}
|
|
} else if (this.options.minZoomLevel === undefined) {
|
|
// Strategy 2: put it into a strictly matching tile (or in this tile, which is slightly too big)
|
|
if (bbox.isContainedIn(this.upper_left.bbox)) {
|
|
ulf.push(feature)
|
|
} else if (bbox.isContainedIn(this.upper_right.bbox)) {
|
|
urf.push(feature)
|
|
} else if (bbox.isContainedIn(this.lower_left.bbox)) {
|
|
llf.push(feature)
|
|
} else if (bbox.isContainedIn(this.lower_right.bbox)) {
|
|
lrf.push(feature)
|
|
} else {
|
|
overlapsboundary.push(feature)
|
|
}
|
|
} else {
|
|
// Strategy 3: We duplicate a feature on a boundary into every tile as we need to get to the minZoomLevel
|
|
if (bbox.overlapsWith(this.upper_left.bbox)) {
|
|
ulf.push(feature)
|
|
}
|
|
if (bbox.overlapsWith(this.upper_right.bbox)) {
|
|
urf.push(feature)
|
|
}
|
|
if (bbox.overlapsWith(this.lower_left.bbox)) {
|
|
llf.push(feature)
|
|
}
|
|
if (bbox.overlapsWith(this.lower_right.bbox)) {
|
|
lrf.push(feature)
|
|
}
|
|
}
|
|
}
|
|
this.upper_left.addFeatures(ulf)
|
|
this.upper_right.addFeatures(urf)
|
|
this.lower_left.addFeatures(llf)
|
|
this.lower_right.addFeatures(lrf)
|
|
this.features.setData(overlapsboundary)
|
|
|
|
}
|
|
}
|
|
|
|
export interface TiledFeatureSourceOptions {
|
|
readonly maxFeatureCount?: number,
|
|
readonly maxZoomLevel?: number,
|
|
readonly minZoomLevel?: number,
|
|
/**
|
|
* IF minZoomLevel is set, and if a feature runs through a tile boundary, it would normally be duplicated.
|
|
* Setting 'dontEnforceMinZoomLevel' will assign to feature to some matching subtile.
|
|
*/
|
|
readonly noDuplicates?: boolean,
|
|
readonly registerTile?: (tile: TiledFeatureSource & FeatureSourceForLayer & Tiled) => void,
|
|
readonly layer?: FilteredLayer
|
|
} |