planning

node_modules/ol/TileQueue.js

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+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = function (d, b) {
+        extendStatics = Object.setPrototypeOf ||
+            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+            function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
+        return extendStatics(d, b);
+    };
+    return function (d, b) {
+        if (typeof b !== "function" && b !== null)
+            throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
+/**
+ * @module ol/TileQueue
+ */
+import EventType from './events/EventType.js';
+import PriorityQueue, { DROP } from './structs/PriorityQueue.js';
+import TileState from './TileState.js';
+/**
+ * @typedef {function(import("./Tile.js").default, string, import("./coordinate.js").Coordinate, number): number} PriorityFunction
+ */
+var TileQueue = /** @class */ (function (_super) {
+    __extends(TileQueue, _super);
+    /**
+     * @param {PriorityFunction} tilePriorityFunction Tile priority function.
+     * @param {function(): ?} tileChangeCallback Function called on each tile change event.
+     */
+    function TileQueue(tilePriorityFunction, tileChangeCallback) {
+        var _this = _super.call(this, 
+        /**
+         * @param {Array} element Element.
+         * @return {number} Priority.
+         */
+        function (element) {
+            return tilePriorityFunction.apply(null, element);
+        }, 
+        /**
+         * @param {Array} element Element.
+         * @return {string} Key.
+         */
+        function (element) {
+            return /** @type {import("./Tile.js").default} */ (element[0]).getKey();
+        }) || this;
+        /** @private */
+        _this.boundHandleTileChange_ = _this.handleTileChange.bind(_this);
+        /**
+         * @private
+         * @type {function(): ?}
+         */
+        _this.tileChangeCallback_ = tileChangeCallback;
+        /**
+         * @private
+         * @type {number}
+         */
+        _this.tilesLoading_ = 0;
+        /**
+         * @private
+         * @type {!Object<string,boolean>}
+         */
+        _this.tilesLoadingKeys_ = {};
+        return _this;
+    }
+    /**
+     * @param {Array} element Element.
+     * @return {boolean} The element was added to the queue.
+     */
+    TileQueue.prototype.enqueue = function (element) {
+        var added = _super.prototype.enqueue.call(this, element);
+        if (added) {
+            var tile = element[0];
+            tile.addEventListener(EventType.CHANGE, this.boundHandleTileChange_);
+        }
+        return added;
+    };
+    /**
+     * @return {number} Number of tiles loading.
+     */
+    TileQueue.prototype.getTilesLoading = function () {
+        return this.tilesLoading_;
+    };
+    /**
+     * @param {import("./events/Event.js").default} event Event.
+     * @protected
+     */
+    TileQueue.prototype.handleTileChange = function (event) {
+        var tile = /** @type {import("./Tile.js").default} */ (event.target);
+        var state = tile.getState();
+        if (state === TileState.LOADED ||
+            state === TileState.ERROR ||
+            state === TileState.EMPTY) {
+            tile.removeEventListener(EventType.CHANGE, this.boundHandleTileChange_);
+            var tileKey = tile.getKey();
+            if (tileKey in this.tilesLoadingKeys_) {
+                delete this.tilesLoadingKeys_[tileKey];
+                --this.tilesLoading_;
+            }
+            this.tileChangeCallback_();
+        }
+    };
+    /**
+     * @param {number} maxTotalLoading Maximum number tiles to load simultaneously.
+     * @param {number} maxNewLoads Maximum number of new tiles to load.
+     */
+    TileQueue.prototype.loadMoreTiles = function (maxTotalLoading, maxNewLoads) {
+        var newLoads = 0;
+        var state, tile, tileKey;
+        while (this.tilesLoading_ < maxTotalLoading &&
+            newLoads < maxNewLoads &&
+            this.getCount() > 0) {
+            tile = /** @type {import("./Tile.js").default} */ (this.dequeue()[0]);
+            tileKey = tile.getKey();
+            state = tile.getState();
+            if (state === TileState.IDLE && !(tileKey in this.tilesLoadingKeys_)) {
+                this.tilesLoadingKeys_[tileKey] = true;
+                ++this.tilesLoading_;
+                ++newLoads;
+                tile.load();
+            }
+        }
+    };
+    return TileQueue;
+}(PriorityQueue));
+export default TileQueue;
+/**
+ * @param {import('./PluggableMap.js').FrameState} frameState Frame state.
+ * @param {import("./Tile.js").default} tile Tile.
+ * @param {string} tileSourceKey Tile source key.
+ * @param {import("./coordinate.js").Coordinate} tileCenter Tile center.
+ * @param {number} tileResolution Tile resolution.
+ * @return {number} Tile priority.
+ */
+export function getTilePriority(frameState, tile, tileSourceKey, tileCenter, tileResolution) {
+    // Filter out tiles at higher zoom levels than the current zoom level, or that
+    // are outside the visible extent.
+    if (!frameState || !(tileSourceKey in frameState.wantedTiles)) {
+        return DROP;
+    }
+    if (!frameState.wantedTiles[tileSourceKey][tile.getKey()]) {
+        return DROP;
+    }
+    // Prioritize the highest zoom level tiles closest to the focus.
+    // Tiles at higher zoom levels are prioritized using Math.log(tileResolution).
+    // Within a zoom level, tiles are prioritized by the distance in pixels between
+    // the center of the tile and the center of the viewport.  The factor of 65536
+    // means that the prioritization should behave as desired for tiles up to
+    // 65536 * Math.log(2) = 45426 pixels from the focus.
+    var center = frameState.viewState.center;
+    var deltaX = tileCenter[0] - center[0];
+    var deltaY = tileCenter[1] - center[1];
+    return (65536 * Math.log(tileResolution) +
+        Math.sqrt(deltaX * deltaX + deltaY * deltaY) / tileResolution);
+}
+//# sourceMappingURL=TileQueue.js.map