Files
openlayers/src/ol/source/VectorTile.js

411 lines
15 KiB
JavaScript

/**
* @module ol/source/VectorTile
*/
import TileState from '../TileState.js';
import VectorRenderTile from '../VectorRenderTile.js';
import Tile from '../VectorTile.js';
import {toSize} from '../size.js';
import UrlTile from './UrlTile.js';
import {getKeyZXY, getKey} from '../tilecoord.js';
import {createXYZ, extentFromProjection, createForProjection} from '../tilegrid.js';
import {buffer as bufferExtent, getIntersection, intersects} from '../extent.js';
import {listen, unlistenByKey} from '../events.js';
import EventType from '../events/EventType.js';
import {loadFeaturesXhr} from '../featureloader.js';
import {isEmpty} from '../obj.js';
import {equals} from '../array.js';
/**
* @typedef {Object} Options
* @property {import("./Source.js").AttributionLike} [attributions] Attributions.
* @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
* @property {number} [cacheSize=128] Cache size.
* @property {import("../extent.js").Extent} [extent]
* @property {import("../format/Feature.js").default} [format] Feature format for tiles. Used and required by the default.
* @property {boolean} [overlaps=true] This source may have overlapping geometries. Setting this
* to `false` (e.g. for sources with polygons that represent administrative
* boundaries or TopoJSON sources) allows the renderer to optimise fill and
* stroke operations.
* @property {import("../proj.js").ProjectionLike} [projection='EPSG:3857'] Projection of the tile grid.
* @property {import("./State.js").default} [state] Source state.
* @property {typeof import("../VectorTile.js").default} [tileClass] Class used to instantiate image tiles.
* Default is {@link module:ol/VectorTile}.
* @property {number} [maxZoom=22] Optional max zoom level.
* @property {number} [minZoom] Optional min zoom level.
* @property {number|import("../size.js").Size} [tileSize=512] Optional tile size.
* @property {import("../tilegrid/TileGrid.js").default} [tileGrid] Tile grid.
* @property {import("../Tile.js").LoadFunction} [tileLoadFunction]
* Optional function to load a tile given a URL. Could look like this for pbf tiles:
* ```js
* function(tile, url) {
* tile.setLoader(function(extent, resolution, projection) {
* fetch(url).then(function(response) {
* response.arrayBuffer().then(function(data) {
* const format = tile.getFormat() // ol/format/MVT configured as source format
* const features = format.readFeatures(data, {
* extent: extent,
* featureProjection: projection
* });
* tile.setFeatures(features);
* });
* });
* });
* }
* ```
* @property {import("../Tile.js").UrlFunction} [tileUrlFunction] Optional function to get tile URL given a tile coordinate and the projection.
* @property {string} [url] URL template. Must include `{x}`, `{y}` or `{-y}`, and `{z}` placeholders.
* A `{?-?}` template pattern, for example `subdomain{a-f}.domain.com`, may be
* used instead of defining each one separately in the `urls` option.
* @property {number} [transition] A duration for tile opacity
* transitions in milliseconds. A duration of 0 disables the opacity transition.
* @property {Array<string>} [urls] An array of URL templates.
* @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
* When set to `false`, only one world
* will be rendered. When set to `true`, tiles will be wrapped horizontally to
* render multiple worlds.
* @property {number} [zDirection=1] Indicate which resolution should be used
* by a renderer if the view resolution does not match any resolution of the tile source.
* If 0, the nearest resolution will be used. If 1, the nearest lower resolution
* will be used. If -1, the nearest higher resolution will be used.
*/
/**
* @classdesc
* Class for layer sources providing vector data divided into a tile grid, to be
* used with {@link module:ol/layer/VectorTile~VectorTile}. Although this source receives tiles
* with vector features from the server, it is not meant for feature editing.
* Features are optimized for rendering, their geometries are clipped at or near
* tile boundaries and simplified for a view resolution. See
* {@link module:ol/source/Vector} for vector sources that are suitable for feature
* editing.
*
* @fires import("./Tile.js").TileSourceEvent
* @api
*/
class VectorTile extends UrlTile {
/**
* @param {!Options} options Vector tile options.
*/
constructor(options) {
const projection = options.projection || 'EPSG:3857';
const extent = options.extent || extentFromProjection(projection);
const tileGrid = options.tileGrid || createXYZ({
extent: extent,
maxZoom: options.maxZoom || 22,
minZoom: options.minZoom,
tileSize: options.tileSize || 512
});
super({
attributions: options.attributions,
attributionsCollapsible: options.attributionsCollapsible,
cacheSize: options.cacheSize,
opaque: false,
projection: projection,
state: options.state,
tileGrid: tileGrid,
tileLoadFunction: options.tileLoadFunction ? options.tileLoadFunction : defaultLoadFunction,
tileUrlFunction: options.tileUrlFunction,
url: options.url,
urls: options.urls,
wrapX: options.wrapX === undefined ? true : options.wrapX,
transition: options.transition,
zDirection: options.zDirection === undefined ? 1 : options.zDirection
});
/**
* @private
* @type {import("../format/Feature.js").default}
*/
this.format_ = options.format ? options.format : null;
/**
* @type {Object<string, import("./VectorTile").default>}
*/
this.loadingTiles_ = {};
/**
* @private
* @type {Object<string, import("../VectorTile.js").default>}
*/
this.sourceTileByCoordKey_ = {};
/**
* @private
* @type {Object<string, Array<import("../VectorTile.js").default>>}
*/
this.sourceTilesByTileKey_ = {};
/**
* @private
* @type {boolean}
*/
this.overlaps_ = options.overlaps == undefined ? true : options.overlaps;
/**
* @protected
* @type {typeof import("../VectorTile.js").default}
*/
this.tileClass = options.tileClass ? options.tileClass : Tile;
/**
* @private
* @type {Object<string, import("../tilegrid/TileGrid.js").default>}
*/
this.tileGrids_ = {};
}
/**
* @return {boolean} The source can have overlapping geometries.
*/
getOverlaps() {
return this.overlaps_;
}
/**
* clear {@link module:ol/TileCache~TileCache} and delete all source tiles
* @api
*/
clear() {
this.tileCache.clear();
this.sourceTileByCoordKey_ = {};
this.sourceTilesByTileKey_ = {};
}
/**
* @param {number} pixelRatio Pixel ratio.
* @param {import("../proj/Projection").default} projection Projection.
* @param {VectorRenderTile} tile Vector image tile.
* @return {Array<import("../VectorTile").default>} Tile keys.
*/
getSourceTiles(pixelRatio, projection, tile) {
const urlTileCoord = tile.wrappedTileCoord;
const tileGrid = this.getTileGridForProjection(projection);
const extent = tileGrid.getTileCoordExtent(urlTileCoord);
const z = urlTileCoord[0];
const resolution = tileGrid.getResolution(z);
// make extent 1 pixel smaller so we don't load tiles for < 0.5 pixel render space
bufferExtent(extent, -resolution, extent);
const sourceTileGrid = this.tileGrid;
const sourceExtent = sourceTileGrid.getExtent();
if (sourceExtent) {
getIntersection(extent, sourceExtent, extent);
}
const sourceZ = sourceTileGrid.getZForResolution(resolution, 1);
const minZoom = sourceTileGrid.getMinZoom();
const previousSourceTiles = this.sourceTilesByTileKey_[tile.getKey()];
let sourceTiles, covered, empty, loadedZ;
if (previousSourceTiles && previousSourceTiles.length > 0 && previousSourceTiles[0].tileCoord[0] === sourceZ) {
sourceTiles = previousSourceTiles;
covered = true;
empty = false;
loadedZ = sourceZ;
} else {
sourceTiles = [];
loadedZ = sourceZ + 1;
do {
--loadedZ;
covered = true;
empty = true;
sourceTileGrid.forEachTileCoord(extent, loadedZ, function(sourceTileCoord) {
const coordKey = getKey(sourceTileCoord);
let sourceTile;
if (coordKey in this.sourceTileByCoordKey_) {
sourceTile = this.sourceTileByCoordKey_[coordKey];
const state = sourceTile.getState();
if (state === TileState.LOADED || state === TileState.ERROR || state === TileState.EMPTY) {
empty = empty && state === TileState.EMPTY;
sourceTiles.push(sourceTile);
return;
}
} else if (loadedZ === sourceZ) {
const tileUrl = this.tileUrlFunction(sourceTileCoord, pixelRatio, projection);
if (tileUrl !== undefined) {
sourceTile = new this.tileClass(sourceTileCoord, TileState.IDLE, tileUrl,
this.format_, this.tileLoadFunction);
sourceTile.extent = sourceTileGrid.getTileCoordExtent(sourceTileCoord);
sourceTile.projection = projection;
sourceTile.resolution = sourceTileGrid.getResolution(sourceTileCoord[0]);
this.sourceTileByCoordKey_[coordKey] = sourceTile;
empty = false;
sourceTile.addEventListener(EventType.CHANGE, this.handleTileChange.bind(this));
sourceTile.load();
}
} else {
empty = false;
}
covered = false;
if (!sourceTile) {
return;
}
if (sourceTile.getState() !== TileState.EMPTY && tile.getState() === TileState.IDLE) {
tile.loadingSourceTiles++;
const key = listen(sourceTile, EventType.CHANGE, function() {
const state = sourceTile.getState();
const sourceTileKey = sourceTile.getKey();
if (state === TileState.LOADED || state === TileState.ERROR) {
if (state === TileState.LOADED) {
unlistenByKey(key);
tile.loadingSourceTiles--;
delete tile.errorSourceTileKeys[sourceTileKey];
} else if (state === TileState.ERROR) {
tile.errorSourceTileKeys[sourceTileKey] = true;
}
if (tile.loadingSourceTiles - Object.keys(tile.errorSourceTileKeys).length === 0) {
tile.hifi = true;
tile.sourceZ = sourceZ;
tile.setState(isEmpty(tile.errorSourceTileKeys) ? TileState.LOADED : TileState.ERROR);
}
}
});
}
}.bind(this));
if (!covered) {
sourceTiles.length = 0;
}
} while (!covered && loadedZ > minZoom);
}
if (!empty && tile.getState() === TileState.IDLE) {
tile.setState(TileState.LOADING);
}
if (covered || empty) {
tile.hifi = sourceZ === loadedZ;
tile.sourceZ = loadedZ;
if (tile.getState() < TileState.LOADED) {
tile.setState(empty ? TileState.EMPTY : TileState.LOADED);
} else if (!previousSourceTiles || !equals(sourceTiles, previousSourceTiles)) {
this.removeSourceTiles(tile);
this.addSourceTiles(tile, sourceTiles);
}
}
return sourceTiles;
}
/**
* @param {VectorRenderTile} tile Tile.
* @param {Array<import("../VectorTile").default>} sourceTiles Source tiles.
*/
addSourceTiles(tile, sourceTiles) {
this.sourceTilesByTileKey_[tile.getKey()] = sourceTiles;
for (let i = 0, ii = sourceTiles.length; i < ii; ++i) {
sourceTiles[i].consumers++;
}
}
/**
* @param {VectorRenderTile} tile Tile.
*/
removeSourceTiles(tile) {
const tileKey = tile.getKey();
if (tileKey in this.sourceTilesByTileKey_) {
const sourceTiles = this.sourceTilesByTileKey_[tileKey];
for (let i = 0, ii = sourceTiles.length; i < ii; ++i) {
const sourceTile = sourceTiles[i];
sourceTile.consumers--;
if (sourceTile.consumers === 0) {
sourceTile.dispose();
delete this.sourceTileByCoordKey_[getKey(sourceTile.tileCoord)];
}
}
}
delete this.sourceTilesByTileKey_[tileKey];
}
/**
* @inheritDoc
*/
getTile(z, x, y, pixelRatio, projection) {
const coordKey = getKeyZXY(z, x, y);
const key = this.getKey();
let tile;
if (this.tileCache.containsKey(coordKey)) {
tile = /** @type {!import("../Tile.js").default} */ (this.tileCache.get(coordKey));
if (tile.key === key) {
return tile;
}
}
const tileCoord = [z, x, y];
let urlTileCoord = this.getTileCoordForTileUrlFunction(tileCoord, projection);
const sourceExtent = this.getTileGrid().getExtent();
if (urlTileCoord && sourceExtent) {
const tileGrid = this.getTileGridForProjection(projection);
const tileExtent = tileGrid.getTileCoordExtent(urlTileCoord);
// make extent 1 pixel smaller so we don't load tiles for < 0.5 pixel render space
bufferExtent(tileExtent, -tileGrid.getResolution(z), tileExtent);
if (!intersects(sourceExtent, tileExtent)) {
urlTileCoord = null;
}
}
const newTile = new VectorRenderTile(
tileCoord,
urlTileCoord !== null ? TileState.IDLE : TileState.EMPTY,
urlTileCoord,
this.tileGrid,
this.getSourceTiles.bind(this, pixelRatio, projection),
this.removeSourceTiles.bind(this));
newTile.key = key;
if (tile) {
newTile.interimTile = tile;
newTile.refreshInterimChain();
this.tileCache.replace(coordKey, newTile);
} else {
this.tileCache.set(coordKey, newTile);
}
return newTile;
}
/**
* @inheritDoc
*/
getTileGridForProjection(projection) {
const code = projection.getCode();
let tileGrid = this.tileGrids_[code];
if (!tileGrid) {
// A tile grid that matches the tile size of the source tile grid is more
// likely to have 1:1 relationships between source tiles and rendered tiles.
const sourceTileGrid = this.tileGrid;
tileGrid = this.tileGrids_[code] = createForProjection(projection, undefined,
sourceTileGrid ? sourceTileGrid.getTileSize(sourceTileGrid.getMinZoom()) : undefined);
}
return tileGrid;
}
/**
* @inheritDoc
*/
getTilePixelRatio(pixelRatio) {
return pixelRatio;
}
/**
* @inheritDoc
*/
getTilePixelSize(z, pixelRatio, projection) {
const tileGrid = this.getTileGridForProjection(projection);
const tileSize = toSize(tileGrid.getTileSize(z), this.tmpSize);
return [Math.round(tileSize[0] * pixelRatio), Math.round(tileSize[1] * pixelRatio)];
}
}
export default VectorTile;
/**
* Sets the loader for a tile.
* @param {import("../VectorTile.js").default} tile Vector tile.
* @param {string} url URL.
*/
export function defaultLoadFunction(tile, url) {
const loader = loadFeaturesXhr(url, tile.getFormat(), tile.onLoad.bind(tile), tile.onError.bind(tile));
tile.setLoader(loader);
}