cesiumBack/public/static/js/mvt.js

window.createMVTWithStyle = function createMVTWithStyle(Cesium, ol, createMapboxStreetsV6Style, options) {
    function MVTProvider(options) {
        options = Cesium.defaultValue(options, Cesium.defaultValue.EMPTY_OBJECT);

        this._tilingScheme = Cesium.defined(options.tilingScheme) ? options.tilingScheme : new Cesium.WebMercatorTilingScheme({ ellipsoid: options.ellipsoid });
        this._tileWidth = Cesium.defaultValue(options.tileWidth, 512);
        this._tileHeight = Cesium.defaultValue(options.tileHeight, 512);
        this._readyPromise = Cesium.when.resolve(true);
        this._ol = ol;
        this._mvtParser = new this._ol.format.MVT();

        this._styleFun = createMapboxStreetsV6Style;
        this._key = Cesium.defaultValue(options.key, "");
        this._url = Cesium.defaultValue(options.url, "https://a.tiles.mapbox.com/v4/mapbox.mapbox-streets-v6/{z}/{x}/{y}.vector.pbf?access_token={k}");

        var sw = this._tilingScheme._rectangleSouthwestInMeters;
        var ne = this._tilingScheme._rectangleNortheastInMeters;
        var mapExtent = [sw.x, sw.y, ne.x, ne.y];
        this._resolutions = ol.tilegrid.resolutionsFromExtent(
            mapExtent, 22, this._tileWidth);

        this._pixelRatio = 1;
        this._transform = [0.125, 0, 0, 0.125, 0, 0];
        this._replays = ["Default", "Image", "Polygon", "LineString", "Text"];

        this._tileQueue = new Cesium.TileReplacementQueue();
        this._cacheSize = 1000;
    }

    Cesium.defineProperties(MVTProvider.prototype, {
        proxy: {
            get: function() {
                return undefined;
            }
        },

        tileWidth: {
            get: function() {
                return this._tileWidth;
            }
        },

        tileHeight: {
            get: function() {
                return this._tileHeight;
            }
        },

        maximumLevel: {
            get: function() {
                return undefined;
            }
        },

        minimumLevel: {
            get: function() {
                return undefined;
            }
        },

        tilingScheme: {
            get: function() {
                return this._tilingScheme;
            }
        },

        rectangle: {
            get: function() {
                return this._tilingScheme.rectangle;
            }
        },

        tileDiscardPolicy: {
            get: function() {
                return undefined;
            }
        },

        errorEvent: {
            get: function() {
                return this._errorEvent;
            }
        },

        ready: {
            get: function() {
                return true;
            }
        },

        readyPromise: {
            get: function() {
                return this._readyPromise;
            }
        },

        credit: {
            get: function() {
                return undefined;
            }
        },

        hasAlphaChannel: {
            get: function() {
                return true;
            }
        }
    });

    MVTProvider.prototype.getTileCredits = function(x, y, level) {
        return undefined;
    };

    function findTileInQueue(x, y, level, tileQueue) {
        var item = tileQueue.head;
        while (item != undefined && !(item.xMvt == x && item.yMvt == y && item.zMvt == level)) {
            item = item.replacementNext;
        }
        return item;
    };

    function remove(tileReplacementQueue, item) {
        var previous = item.replacementPrevious;
        var next = item.replacementNext;

        if (item === tileReplacementQueue._lastBeforeStartOfFrame) {
            tileReplacementQueue._lastBeforeStartOfFrame = next;
        }

        if (item === tileReplacementQueue.head) {
            tileReplacementQueue.head = next;
        } else {
            previous.replacementNext = next;
        }

        if (item === tileReplacementQueue.tail) {
            tileReplacementQueue.tail = previous;
        } else {
            next.replacementPrevious = previous;
        }

        item.replacementPrevious = undefined;
        item.replacementNext = undefined;

        --tileReplacementQueue.count;
    }

    function trimTiles(tileQueue, maximumTiles) {
        var tileToTrim = tileQueue.tail;
        while (tileQueue.count > maximumTiles &&
            Cesium.defined(tileToTrim)) {
            var previous = tileToTrim.replacementPrevious;

            remove(tileQueue, tileToTrim);
            delete tileToTrim;
            tileToTrim = null;

            tileToTrim = previous;
        }
    };

    MVTProvider.prototype.requestImage = function(x, y, level, request) {
        var cacheTile = findTileInQueue(x, y, level, this._tileQueue);
        if (cacheTile != undefined) {
            console.log('cache')
            return cacheTile;
        }
        else {
            var that = this;
            var url = this._url;
            url = url.replace('{x}', x).replace('{y}', y).replace('{z}', level).replace('{k}', this._key);
            var tilerequest = async function(x, y, z) {

                var resource = Cesium.Resource.createIfNeeded(url);

                var arrayBuffer = await resource.fetchArrayBuffer()

                console.log(arrayBuffer)

                var canvas = document.createElement('canvas');
                canvas.width = 512;
                canvas.height = 512;


                if (arrayBuffer.byteLength == 0) {
                    canvas.xMvt = x;
                    canvas.yMvt = y;
                    canvas.zMvt = z;

                    that._tileQueue.markTileRendered(canvas);

                    return canvas;
                }

                var vectorContext = canvas.getContext('2d');

                var features = that._mvtParser.readFeatures(arrayBuffer);

                // console.log(features)

                var styleFun = that._styleFun();

                var extent = [0, 0, 4096, 4096];
                var _replayGroup = new ol.render.canvas.ReplayGroup(0, extent,
                    8, true, 100);

                for (var i = 0; i < features.length; i++) {
                    var feature = features[i];
                    // if(!feature.layer){
                    //     feature.properties_.layer = 'road'
                    //     feature.properties_.class = 'path'
                    // }
                    var styles = styleFun(features[i], that._resolutions[level]);

                    for (var j = 0; j < styles.length; j++)
                    {
                        // console.log( styles[j])
                        ol.renderer.vector.renderFeature_(_replayGroup, feature, styles[j], 16);
                    }
                }
                _replayGroup.finish();

                _replayGroup.replay(vectorContext, that._pixelRatio, that._transform, 0, {}, that._replays, true);
                if (that._tileQueue.count > that._cacheSize) {
                    trimTiles(that._tileQueue, that._cacheSize / 2);
                }

                canvas.xMvt = x;
                canvas.yMvt = y;
                canvas.zMvt = z;

                // console.log(arrayBuffer.byteLength,canvas.toDataURL("image/png"));

                that._tileQueue.markTileRendered(canvas);

                delete _replayGroup;
                _replayGroup = null;

                return canvas;

            }(x, y, level);
        }
    };

    MVTProvider.prototype.pickFeatures = function(x, y, level, longitude, latitude) {
        return undefined;
    };

    return new MVTProvider(options);
}