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KaiFengPC / public / static / libs / mapbox / extend / XYZLayer.js
@zhangdeliang zhangdeliang on 23 May 93 KB 初始化项目
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ?
        module.exports = factory() :
        typeof define === 'function' && define.amd ? define(factory) :
            (global = typeof globalThis !== 'undefined' ? globalThis :
                global || self, global.mapboxgl1.XYZLayer = factory());
}(window, (function () {
    'use strict';

    /*
 * @namespace Util
 *
 * Various utility functions, used by Leaflet internally.
 */
    Object.freeze = function (obj) {
        return obj;
    };

    // @function create(proto: Object, properties?: Object): Object
    // Compatibility polyfill for [Object.create](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/create)
    var create$3 = Object.create || function () {
        function F() {}
        return function (proto) {
            F.prototype = proto;
            return new F();
        };
    }();

    // @function setOptions(obj: Object, options: Object): Object
    // Merges the given properties to the `options` of the `obj` object, returning the resulting options. See `Class options`. Has an `L.setOptions` shortcut.
    function setOptions(obj, options) {
        if (!obj.hasOwnProperty('options')) {
            obj.options = obj.options ? create$3(obj.options) : {};
        }
        for (var i in options) {
            obj.options[i] = options[i] || obj.options[i];
        }
        return obj.options;
    }

    var templateRe = /\{ *([\w_-]+) *\}/g;

    // @function template(str: String, data: Object): String
    // Simple templating facility, accepts a template string of the form `'Hello {a}, {b}'`
    // and a data object like `{a: 'foo', b: 'bar'}`, returns evaluated string
    // `('Hello foo, bar')`. You can also specify functions instead of strings for
    // data values — they will be evaluated passing `data` as an argument.
    function template(str, data) {
        return str.replace(templateRe, function (str, key) {
            var value = data[key];

            if (value === undefined) {
                throw new Error('No value provided for variable ' + str);
            } else if (typeof value === 'function') {
                value = value(data);
            }
            return value;
        });
    }

    // @function isArray(obj): Boolean
    // Compatibility polyfill for [Array.isArray](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray)
    var isArray = Array.isArray || function (obj) {
        return Object.prototype.toString.call(obj) === '[object Array]';
    };

    //坐标转换
    var pi = 3.1415926535897932384626;
    var a = 6378245.0;
    var ee = 0.00669342162296594323;
    var x_pi = pi * 3000.0 / 180.0;

    /**百度转84*/
    function bd09_To_gps84(lng, lat) {
        if (isArray(lng)) {
            var _lng = lng[0];
            lat = lng[1];
            lng = _lng;
        }
        if (lng instanceof Object) {
            var _lng = lng.lng;
            lat = lng.lat;
            lng = _lng;
        }
        var gcj02 = bd09_To_gcj02(lng, lat);
        var map84 = gcj02_To_gps84(gcj02.lng, gcj02.lat);
        return map84;
    }
    /**84转百度*/
    function gps84_To_bd09(lng, lat) {
        if (isArray(lng)) {
            var _lng = lng[0];
            lat = lng[1];
            lng = _lng;
        }
        if (lng instanceof Object) {
            var _lng = lng.lng;
            lat = lng.lat;
            lng = _lng;
        }
        var gcj02 = gps84_To_gcj02(lng, lat);
        var bd09 = gcj02_To_bd09(gcj02.lng, gcj02.lat);
        return bd09;
    }
    /**84转火星*/
    function gps84_To_gcj02(lng, lat) {
        if (isArray(lng)) {
            var _lng = lng[0];
            lat = lng[1];
            lng = _lng;
        }
        if (lng instanceof Object) {
            var _lng = lng.lng;
            lat = lng.lat;
            lng = _lng;
        }

        var dLat = transformLat(lng - 105.0, lat - 35.0);
        var dLng = transformLng(lng - 105.0, lat - 35.0);
        var radLat = lat / 180.0 * pi;
        var magic = Math.sin(radLat);
        magic = 1 - ee * magic * magic;
        var sqrtMagic = Math.sqrt(magic);
        dLat = dLat * 180.0 / (a * (1 - ee) / (magic * sqrtMagic) * pi);
        dLng = dLng * 180.0 / (a / sqrtMagic * Math.cos(radLat) * pi);
        var mgLat = lat + dLat;
        var mgLng = lng + dLng;
        var newCoord = {
            lng: mgLng,
            lat: mgLat
        };
        return newCoord;
    }
    /**火星转84*/
    function gcj02_To_gps84(lng, lat) {
        if (isArray(lng)) {
            var _lng = lng[0];
            lat = lng[1];
            lng = _lng;
        }
        if (lng instanceof Object) {
            var _lng = lng.lng;
            lat = lng.lat;
            lng = _lng;
        }

        var coord = transform(lng, lat);
        var lontitude = lng * 2 - coord.lng;
        var latitude = lat * 2 - coord.lat;
        var newCoord = {
            lng: lontitude,
            lat: latitude
        };
        return newCoord;
    }
    /**火星转百度*/
    function gcj02_To_bd09(x, y) {
        var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);
        var theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * x_pi);
        var bd_lng = z * Math.cos(theta) + 0.0065;
        var bd_lat = z * Math.sin(theta) + 0.006;
        var newCoord = {
            lng: bd_lng,
            lat: bd_lat
        };
        return newCoord;
    }
    /**百度转火星*/
    function bd09_To_gcj02(bd_lng, bd_lat) {
        var x = bd_lng - 0.0065;
        var y = bd_lat - 0.006;
        var z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * x_pi);
        var theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * x_pi);
        var gg_lng = z * Math.cos(theta);
        var gg_lat = z * Math.sin(theta);
        var newCoord = {
            lng: gg_lng,
            lat: gg_lat
        };
        return newCoord;
    }

    function transform(lng, lat) {
        var dLat = transformLat(lng - 105.0, lat - 35.0);
        var dLng = transformLng(lng - 105.0, lat - 35.0);
        var radLat = lat / 180.0 * pi;
        var magic = Math.sin(radLat);
        magic = 1 - ee * magic * magic;
        var sqrtMagic = Math.sqrt(magic);
        dLat = dLat * 180.0 / (a * (1 - ee) / (magic * sqrtMagic) * pi);
        dLng = dLng * 180.0 / (a / sqrtMagic * Math.cos(radLat) * pi);
        var mgLat = lat + dLat;
        var mgLng = lng + dLng;
        var newCoord = {
            lng: mgLng,
            lat: mgLat
        };
        return newCoord;
    }

    function transformLat(x, y) {
        var ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
        return ret;
    }

    function transformLng(x, y) {
        var ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;
        return ret;
    }

    //经纬度转xyz协议瓦片编号
    function lonLatToTileNumbers(lon_deg, lat_deg, zoom) {
        // 地球半径
        /*	const r = 6378137;

            // 地球周长
            const C = 2 * Math.PI * 6378137;

            // 瓦片像素
            const titleSize = 256;

            // 获取某一层级下的分辨率(X,Y方向适)
            const getResolution = (n) => {
                const tileNums = Math.pow(2, n)
                const tileTotalPx = tileNums * titleSize
                return C / tileTotalPx
            }

            // 4326转3857
            const lngLatMercator = (lng, lat) => {
                //注意先转为为弧度制,弧度=角度*Math.PI/180,弧长=弧度*半径
                let x = lng * (Math.PI / 180) * r;
                let rad = lat * (Math.PI / 180)
                let sin = Math.sin(rad)
                let y = r / 2 * Math.log((1 + sin) / (1 - sin))
                return [x, y]
            }

            // 根据像素坐标及缩放层级计算瓦片行列号
            const getTileRowAndCol = (x, y, z) => {
                   //因为3857与4326坐标原点位于经纬度为零的地方,而瓦片坐标原点位于左上角,所以需要将3857坐标原点转到左上角
                x += C / 2;
                y = C / 2 - y;
                let resolutionX = getResolution(z)//获取某一层级z下的分辨率
                let row = Math.floor(x / resolutionX / tileSize)
                let col = Math.floor(y / resolutionY / tileSize)
                return [row, col]
            }

            return getTileRowAndCol(...lngLatMercator(lon_deg,lat_deg),zoom);*/



        /*		console.log(lon_deg,lat_deg,zoom);
                function lon2tile(lon,zoom) {
                    return (Math.floor((lon+180)/360*Math.pow(2,zoom)));
                }
                function lat2tile(lat,zoom)  {
                    return (Math.floor((1-Math.log(Math.tan(lat*Math.PI/180) + 1/Math.cos(lat*Math.PI/180))/Math.PI)/2 *Math.pow(2,zoom)));
                }

                return [lon2tile(lon_deg,zoom),lat2tile(lat_deg,zoom)];*/



        var lat_rad = pi / 180 * lat_deg; //math.radians(lat_deg)  角度转弧度
        var n = Math.pow(2, zoom);
        var xtile = parseInt((lon_deg + 180.0) / 360.0 * n);
        var ytile = parseInt((1.0 - Math.asinh(Math.tan(lat_rad)) / pi) / 2.0 * n);
        return [xtile, ytile];
    }

    //xyz协议瓦片编号转经纬度
    function tileNumbersToLonLat(xtile, ytile, zoom) {
        /*		function tile2long(x,z) {
                    return (x/Math.pow(2,z)*360-180);
                }

                function tile2lat(y,z) {
                    var n=Math.PI-2*Math.PI*y/Math.pow(2,z);
                    return (180/Math.PI*Math.atan(0.5*(Math.exp(n)-Math.exp(-n))));
                }

                return [tile2long(xtile, zoom),tile2lat(ytile,zoom)];*/


        let n = Math.pow(2, zoom);
        let lon_deg = xtile / n * 360.0 - 180.0;
        let lat_rad = Math.atan(Math.sinh(pi * (1 - 2 * ytile / n)));

        let lat_deg = lat_rad * 180.0 / pi;
        return [lon_deg, lat_deg];
    }
    /*
     * Created by CntChen 2016.05.04
     * 从百度JavaScritp API v2.0 抽取代码,并作少量命名修改
     * http://lbsyun.baidu.com/index.php?title=jspopular
     * http://api.map.baidu.com/getscript?v=2.0&ak=E4805d16520de693a3fe707cdc962045&t=20160503160001
     */

    // ----- Baidu API start

    // util function
    function Extend(a, b) {
        for (var c in b) b.hasOwnProperty(c) && (a[c] = b[c]);
        return a;
    }
    function S(a, b) {
        for (var c in b) a[c] = b[c];
    }

    function Xa(a) {
        return "string" == typeof a;
    }

    var j = void 0,
        p = null;

    // Point
    function H(a, b) {
        isNaN(a) && (a = Ib(a), a = isNaN(a) ? 0 : a);
        Xa(a) && (a = parseFloat(a));
        isNaN(b) && (b = Ib(b), b = isNaN(b) ? 0 : b);
        Xa(b) && (b = parseFloat(b));
        this.lng = a;
        this.lat = b;
    }
    H.TL = function (a) {
        return a && 180 >= a.lng && -180 <= a.lng && 74 >= a.lat && -74 <= a.lat;
    };
    H.prototype.lb = function (a) {
        return a && this.lat == a.lat && this.lng == a.lng;
    };

    // Pixel
    function Q(a, b) {
        this.x = a || 0;
        this.y = b || 0;
        this.x = this.x;
        this.y = this.y;
    }
    Q.prototype.lb = function (a) {
        return a && a.x == this.x && a.y == this.y;
    };

    // MercatorProjection
    function fc() {}
    fc.prototype.nh = function () {
        aa("lngLatToPoint\u65b9\u6cd5\u672a\u5b9e\u73b0");
    };
    fc.prototype.wi = function () {
        aa("pointToLngLat\u65b9\u6cd5\u672a\u5b9e\u73b0");
    };

    function R() {}
    R.prototype = new fc();
    Extend(R, {
        $O: 6370996.81,
        lG: [1.289059486E7, 8362377.87, 5591021, 3481989.83, 1678043.12, 0],
        Au: [75, 60, 45, 30, 15, 0],
        fP: [[1.410526172116255E-8, 8.98305509648872E-6, -1.9939833816331, 200.9824383106796, -187.2403703815547, 91.6087516669843, -23.38765649603339, 2.57121317296198, -0.03801003308653, 1.73379812E7], [-7.435856389565537E-9, 8.983055097726239E-6, -0.78625201886289, 96.32687599759846, -1.85204757529826, -59.36935905485877, 47.40033549296737, -16.50741931063887, 2.28786674699375, 1.026014486E7], [-3.030883460898826E-8, 8.98305509983578E-6, 0.30071316287616, 59.74293618442277, 7.357984074871, -25.38371002664745, 13.45380521110908, -3.29883767235584, 0.32710905363475, 6856817.37], [-1.981981304930552E-8, 8.983055099779535E-6, 0.03278182852591, 40.31678527705744, 0.65659298677277, -4.44255534477492, 0.85341911805263, 0.12923347998204, -0.04625736007561, 4482777.06], [3.09191371068437E-9, 8.983055096812155E-6, 6.995724062E-5, 23.10934304144901, -2.3663490511E-4, -0.6321817810242, -0.00663494467273, 0.03430082397953, -0.00466043876332, 2555164.4], [2.890871144776878E-9, 8.983055095805407E-6, -3.068298E-8, 7.47137025468032, -3.53937994E-6, -0.02145144861037, -1.234426596E-5, 1.0322952773E-4, -3.23890364E-6, 826088.5]],
        iG: [[-0.0015702102444, 111320.7020616939, 1704480524535203, -10338987376042340, 26112667856603880, -35149669176653700, 26595700718403920, -10725012454188240, 1800819912950474, 82.5], [8.277824516172526E-4, 111320.7020463578, 6.477955746671607E8, -4.082003173641316E9, 1.077490566351142E10, -1.517187553151559E10, 1.205306533862167E10, -5.124939663577472E9, 9.133119359512032E8, 67.5], [0.00337398766765, 111320.7020202162, 4481351.045890365, -2.339375119931662E7, 7.968221547186455E7, -1.159649932797253E8, 9.723671115602145E7, -4.366194633752821E7, 8477230.501135234, 52.5], [0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5], [-3.441963504368392E-4, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5], [-3.218135878613132E-4, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45]],
        Z1: function (a, b) {
            if (!a || !b) return 0;
            var c,
                d,
                a = this.Fb(a);
            if (!a) return 0;
            c = this.Tk(a.lng);
            d = this.Tk(a.lat);
            b = this.Fb(b);
            return !b ? 0 : this.Pe(c, this.Tk(b.lng), d, this.Tk(b.lat));
        },
        Vo: function (a, b) {
            if (!a || !b) return 0;
            a.lng = this.JD(a.lng, -180, 180);
            a.lat = this.ND(a.lat, -74, 74);
            b.lng = this.JD(b.lng, -180, 180);
            b.lat = this.ND(b.lat, -74, 74);
            return this.Pe(this.Tk(a.lng), this.Tk(b.lng), this.Tk(a.lat), this.Tk(b.lat));
        },
        Fb: function (a) {
            if (a === p || a === j) return new H(0, 0);
            var b, c;
            b = new H(Math.abs(a.lng), Math.abs(a.lat));
            for (var d = 0; d < this.lG.length; d++) if (b.lat >= this.lG[d]) {
                c = this.fP[d];
                break;
            }
            a = this.gK(a, c);
            return a = new H(a.lng.toFixed(6), a.lat.toFixed(6));
        },
        Eb: function (a) {
            if (a === p || a === j || 180 < a.lng || -180 > a.lng || 90 < a.lat || -90 > a.lat) return new H(0, 0);
            var b, c;
            a.lng = this.JD(a.lng, -180, 180);
            a.lat = this.ND(a.lat, -74, 74);
            b = new H(a.lng, a.lat);
            for (var d = 0; d < this.Au.length; d++) if (b.lat >= this.Au[d]) {
                c = this.iG[d];
                break;
            }

            // 对疑似bug的修改 start
            // by CntChen 2016.05.08
            // @2016-09-19 已经得到官方确认为bug:https://cntchen.github.io/2016/05/09/%E7%99%BE%E5%BA%A6JavaScirpt%20%20API%E4%B8%AD%E7%BB%8F%E7%BA%AC%E5%BA%A6%E5%9D%90%E6%A0%87%E8%BD%AC%E7%93%A6%E7%89%87%E5%9D%90%E6%A0%87bug/
            if (!c) for (d = 0; d < this.Au.length; d++) if (b.lat <= -this.Au[d]) {
                c = this.iG[d];
                break;
            }
            // 对疑似bug的修改 end

            // Baidu JavaScript 中原本代码, 2016.05.08依然如此
            // if (!c)
            //   for (d = this.Au.length - 1; 0 <= d; d--)
            //     if (b.lat <= -this.Au[d]) {
            //       c = this.iG[d];
            //       break
            //     }
            // Baidu JavaScript 中原本代码 end

            a = this.gK(a, c);
            return a = new H(a.lng.toFixed(2), a.lat.toFixed(2));
        },
        gK: function (a, b) {
            if (a && b) {
                var c = b[0] + b[1] * Math.abs(a.lng),
                    d = Math.abs(a.lat) / b[9],
                    d = b[2] + b[3] * d + b[4] * d * d + b[5] * d * d * d + b[6] * d * d * d * d + b[7] * d * d * d * d * d + b[8] * d * d * d * d * d * d,
                    c = c * (0 > a.lng ? -1 : 1),
                    d = d * (0 > a.lat ? -1 : 1);
                return new H(c, d);
            }
        },
        Pe: function (a, b, c, d) {
            return this.$O * Math.acos(Math.sin(c) * Math.sin(d) + Math.cos(c) * Math.cos(d) * Math.cos(b - a));
        },
        Tk: function (a) {
            return Math.PI * a / 180;
        },
        Z3: function (a) {
            return 180 * a / Math.PI;
        },
        ND: function (a, b, c) {
            b != p && (a = Math.max(a, b));
            c != p && (a = Math.min(a, c));
            return a;
        },
        JD: function (a, b, c) {
            for (; a > c;) a -= c - b;
            for (; a < b;) a += c - b;
            return a;
        }
    });
    Extend(R.prototype, {
        Jm: function (a) {
            return R.Eb(a);
        },
        nh: function (a) {
            a = R.Eb(a);
            return new Q(a.lng, a.lat);
        },
        qh: function (a) {
            return R.Fb(a);
        },
        wi: function (a) {
            a = new H(a.x, a.y);
            return R.Fb(a);
        },
        fc: function (a, b, c, d, e) {
            if (a) return a = this.Jm(a, e), b = this.Lc(b), new Q(Math.round((a.lng - c.lng) / b + d.width / 2), Math.round((c.lat - a.lat) / b + d.height / 2));
        },
        zb: function (a, b, c, d, e) {
            if (a) return b = this.Lc(b), this.qh(new H(c.lng + b * (a.x - d.width / 2), c.lat - b * (a.y - d.height / 2)), e);
        },
        Lc: function (a) {
            return Math.pow(2, 18 - a);
        }
    });

    var Je = R.prototype;
    S(Je, {
        lngLatToPoint: Je.nh,
        pointToLngLat: Je.wi
    });

    // ----- Baidu API end

    let BMap = {
        Point: H,
        Pixel: Q,
        MercatorProjection: R
    };

    /*
     * Created by CntChen 2016.05.04
     * 坐标相关参考文章:
     * http://www.cnblogs.com/jz1108/archive/2011/07/02/2095376.html
     * http://www.cnblogs.com/janehlp/archive/2012/08/27/2658106.html
     * 适用地图:百度
     */

    class TransformClassBaidu {
        constructor(levelRange_max, LevelRange_min) {
            this.levelMax = levelRange_max;
            this.levelMin = LevelRange_min;

            this.projection = new BMap.MercatorProjection();
        }

        _getRetain(level) {
            return Math.pow(2, level - 18);
        }

        /*
         * 分辨率,表示水平方向上一个像素点代表的真实距离(m)
         * 百度地图18级时的平面坐标就是地图距离原点的距离(m)
         * 使用{lng:180, lat:0}时候的pointX是否等于地球赤道长一半来验证
         */
        getResolution(latitude, level) {
            return Math.pow(2, 18 - level) * Math.cos(latitude);
        }

        /*
         * 从经纬度到百度平面坐标
         */
        lnglatToPoint(longitude, latitude) {
            let lnglat = new BMap.Point(longitude, latitude);
            let point = this.projection.lngLatToPoint(lnglat);

            // 提取对象的字段并返回
            return {
                pointX: point.x,
                pointY: point.y
            };
        }

        /*
         * 从百度平面坐标到经纬度
         */
        pointToLnglat(pointX, pointY) {
            let point = new BMap.Pixel(pointX, pointY);
            let lnglat = this.projection.pointToLngLat(point);

            // 不直接返回lnglat对象,因为该对象在百SDK中还有其他属性和方法
            // 提取对象的字段后,与其他地图平台统一Lnglat的格式
            return {
                lng: lnglat.lng,
                lat: lnglat.lat
            };
        }

        _lngToTileX(longitude, level) {
            let point = this.lnglatToPoint(longitude, 0);
            let tileX = Math.floor(point.pointX * this._getRetain(level) / 256);

            return tileX;
        }

        _latToTileY(latitude, level) {
            let point = this.lnglatToPoint(0, latitude);
            let tileY = Math.floor(point.pointY * this._getRetain(level) / 256);

            return tileY;
        }

        /*
         * 从经纬度获取某一级别瓦片编号
         */
        lnglatToTile(longitude, latitude, level) {
            let tileX = this._lngToTileX(longitude, level);
            let tileY = this._latToTileY(latitude, level);

            return [tileX, tileY];
        }

        _lngToPixelX(longitude, level) {
            let tileX = this._lngToTileX(longitude, level);
            let point = this.lnglatToPoint(longitude, 0);
            let pixelX = Math.floor(point.pointX * this._getRetain(level) - tileX * 256);

            return pixelX;
        }

        _latToPixelY(latitude, level) {
            let tileY = this._latToTileY(latitude, level);
            let point = this.lnglatToPoint(0, latitude);
            let pixelY = Math.floor(point.pointY * this._getRetain(level) - tileY * 256);

            return pixelY;
        }

        /*
         * 从经纬度到瓦片的像素坐标
         */
        lnglatToPixel(longitude, latitude, level) {
            let pixelX = this._lngToPixelX(longitude, level);
            let pixelY = this._latToPixelY(latitude, level);

            return {
                pixelX,
                pixelY
            };
        }

        _pixelXToLng(pixelX, tileX, level) {
            let pointX = (tileX * 256 + pixelX) / this._getRetain(level);
            let lnglat = this.pointToLnglat(pointX, 0);

            return lnglat.lng;
        }

        _pixelYToLat(pixelY, tileY, level) {
            let pointY = (tileY * 256 + pixelY) / this._getRetain(level);
            let lnglat = this.pointToLnglat(0, pointY);

            return lnglat.lat;
        }

        /*
         * 从某一瓦片的某一像素点到经纬度
         */
        pixelToLnglat(pixelX, pixelY, tileX, tileY, level) {
            let pointX = (tileX * 256 + pixelX) / this._getRetain(level);
            let pointY = (tileY * 256 + pixelY) / this._getRetain(level);
            let lnglat = this.pointToLnglat(pointX, pointY);

            return [lnglat.lng, lnglat.lat];
        }
    }

    function _classCallCheck(instance, Constructor) {
        if (!(instance instanceof Constructor)) {
            throw new TypeError("Cannot call a class as a function");
        }
    }

    function _defineProperties(target, props) {
        for (var i = 0; i < props.length; i++) {
            var descriptor = props[i];
            descriptor.enumerable = descriptor.enumerable || false;
            descriptor.configurable = true;
            if ("value" in descriptor) descriptor.writable = true;
            Object.defineProperty(target, descriptor.key, descriptor);
        }
    }

    function _createClass(Constructor, protoProps, staticProps) {
        if (protoProps) _defineProperties(Constructor.prototype, protoProps);
        if (staticProps) _defineProperties(Constructor, staticProps);
        return Constructor;
    }

    function getDefaultExportFromCjs (x) {
        return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;
    }

    var _typeof$1 = {exports: {}};

    (function (module) {
        function _typeof(obj) {
            "@babel/helpers - typeof";

            if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") {
                module.exports = _typeof = function _typeof(obj) {
                    return typeof obj;
                };

                module.exports["default"] = module.exports, module.exports.__esModule = true;
            } else {
                module.exports = _typeof = function _typeof(obj) {
                    return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
                };

                module.exports["default"] = module.exports, module.exports.__esModule = true;
            }

            return _typeof(obj);
        }

        module.exports = _typeof;
        module.exports["default"] = module.exports, module.exports.__esModule = true;
    }(_typeof$1));

    var _typeof = /*@__PURE__*/getDefaultExportFromCjs(_typeof$1.exports);

    function _assertThisInitialized(self) {
        if (self === void 0) {
            throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
        }

        return self;
    }

    function _possibleConstructorReturn(self, call) {
        if (call && (_typeof(call) === "object" || typeof call === "function")) {
            return call;
        }

        return _assertThisInitialized(self);
    }

    function _getPrototypeOf(o) {
        _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) {
            return o.__proto__ || Object.getPrototypeOf(o);
        };
        return _getPrototypeOf(o);
    }

    function _setPrototypeOf(o, p) {
        _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
            o.__proto__ = p;
            return o;
        };

        return _setPrototypeOf(o, p);
    }

    function _inherits(subClass, superClass) {
        if (typeof superClass !== "function" && superClass !== null) {
            throw new TypeError("Super expression must either be null or a function");
        }

        subClass.prototype = Object.create(superClass && superClass.prototype, {
            constructor: {
                value: subClass,
                writable: true,
                configurable: true
            }
        });
        if (superClass) _setPrototypeOf(subClass, superClass);
    }

    function _arrayWithHoles(arr) {
        if (Array.isArray(arr)) return arr;
    }

    function _iterableToArrayLimit(arr, i) {
        var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"];

        if (_i == null) return;
        var _arr = [];
        var _n = true;
        var _d = false;

        var _s, _e;

        try {
            for (_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true) {
                _arr.push(_s.value);

                if (i && _arr.length === i) break;
            }
        } catch (err) {
            _d = true;
            _e = err;
        } finally {
            try {
                if (!_n && _i["return"] != null) _i["return"]();
            } finally {
                if (_d) throw _e;
            }
        }

        return _arr;
    }

    function _arrayLikeToArray(arr, len) {
        if (len == null || len > arr.length) len = arr.length;

        for (var i = 0, arr2 = new Array(len); i < len; i++) {
            arr2[i] = arr[i];
        }

        return arr2;
    }

    function _unsupportedIterableToArray(o, minLen) {
        if (!o) return;
        if (typeof o === "string") return _arrayLikeToArray(o, minLen);
        var n = Object.prototype.toString.call(o).slice(8, -1);
        if (n === "Object" && o.constructor) n = o.constructor.name;
        if (n === "Map" || n === "Set") return Array.from(o);
        if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen);
    }

    function _nonIterableRest() {
        throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
    }

    function _slicedToArray(arr, i) {
        return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest();
    }

    /**
     * Common utilities
     * @module glMatrix
     */
        // Configuration Constants
    var EPSILON = 0.000001;
    var ARRAY_TYPE = typeof Float32Array !== 'undefined' ? Float32Array : Array;
    if (!Math.hypot) Math.hypot = function () {
        var y = 0,
            i = arguments.length;

        while (i--) {
            y += arguments[i] * arguments[i];
        }

        return Math.sqrt(y);
    };

    /**
     * 4 Dimensional Vector
     * @module vec4
     */

    /**
     * Creates a new, empty vec4
     *
     * @returns {vec4} a new 4D vector
     */

    function create$2() {
        var out = new ARRAY_TYPE(4);

        if (ARRAY_TYPE != Float32Array) {
            out[0] = 0;
            out[1] = 0;
            out[2] = 0;
            out[3] = 0;
        }

        return out;
    }
    /**
     * Scales a vec4 by a scalar number
     *
     * @param {vec4} out the receiving vector
     * @param {ReadonlyVec4} a the vector to scale
     * @param {Number} b amount to scale the vector by
     * @returns {vec4} out
     */

    function scale$1(out, a, b) {
        out[0] = a[0] * b;
        out[1] = a[1] * b;
        out[2] = a[2] * b;
        out[3] = a[3] * b;
        return out;
    }
    /**
     * Transforms the vec4 with a mat4.
     *
     * @param {vec4} out the receiving vector
     * @param {ReadonlyVec4} a the vector to transform
     * @param {ReadonlyMat4} m matrix to transform with
     * @returns {vec4} out
     */

    function transformMat4(out, a, m) {
        var x = a[0],
            y = a[1],
            z = a[2],
            w = a[3];
        out[0] = m[0] * x + m[4] * y + m[8] * z + m[12] * w;
        out[1] = m[1] * x + m[5] * y + m[9] * z + m[13] * w;
        out[2] = m[2] * x + m[6] * y + m[10] * z + m[14] * w;
        out[3] = m[3] * x + m[7] * y + m[11] * z + m[15] * w;
        return out;
    }
    /**
     * Perform some operation over an array of vec4s.
     *
     * @param {Array} a the array of vectors to iterate over
     * @param {Number} stride Number of elements between the start of each vec4. If 0 assumes tightly packed
     * @param {Number} offset Number of elements to skip at the beginning of the array
     * @param {Number} count Number of vec4s to iterate over. If 0 iterates over entire array
     * @param {Function} fn Function to call for each vector in the array
     * @param {Object} [arg] additional argument to pass to fn
     * @returns {Array} a
     * @function
     */

    (function () {
        var vec = create$2();
        return function (a, stride, offset, count, fn, arg) {
            var i, l;

            if (!stride) {
                stride = 4;
            }

            if (!offset) {
                offset = 0;
            }

            if (count) {
                l = Math.min(count * stride + offset, a.length);
            } else {
                l = a.length;
            }

            for (i = offset; i < l; i += stride) {
                vec[0] = a[i];
                vec[1] = a[i + 1];
                vec[2] = a[i + 2];
                vec[3] = a[i + 3];
                fn(vec, vec, arg);
                a[i] = vec[0];
                a[i + 1] = vec[1];
                a[i + 2] = vec[2];
                a[i + 3] = vec[3];
            }

            return a;
        };
    })();

    function createMat4() {
        return [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
    }
    function transformVector(matrix, vector) {
        var result = transformMat4([], vector, matrix);
        scale$1(result, result, 1 / result[3]);
        return result;
    }

    /**
     * Inverts a mat4
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the source matrix
     * @returns {mat4} out
     */

    function invert(out, a) {
        var a00 = a[0],
            a01 = a[1],
            a02 = a[2],
            a03 = a[3];
        var a10 = a[4],
            a11 = a[5],
            a12 = a[6],
            a13 = a[7];
        var a20 = a[8],
            a21 = a[9],
            a22 = a[10],
            a23 = a[11];
        var a30 = a[12],
            a31 = a[13],
            a32 = a[14],
            a33 = a[15];
        var b00 = a00 * a11 - a01 * a10;
        var b01 = a00 * a12 - a02 * a10;
        var b02 = a00 * a13 - a03 * a10;
        var b03 = a01 * a12 - a02 * a11;
        var b04 = a01 * a13 - a03 * a11;
        var b05 = a02 * a13 - a03 * a12;
        var b06 = a20 * a31 - a21 * a30;
        var b07 = a20 * a32 - a22 * a30;
        var b08 = a20 * a33 - a23 * a30;
        var b09 = a21 * a32 - a22 * a31;
        var b10 = a21 * a33 - a23 * a31;
        var b11 = a22 * a33 - a23 * a32; // Calculate the determinant

        var det = b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - b04 * b07 + b05 * b06;

        if (!det) {
            return null;
        }

        det = 1.0 / det;
        out[0] = (a11 * b11 - a12 * b10 + a13 * b09) * det;
        out[1] = (a02 * b10 - a01 * b11 - a03 * b09) * det;
        out[2] = (a31 * b05 - a32 * b04 + a33 * b03) * det;
        out[3] = (a22 * b04 - a21 * b05 - a23 * b03) * det;
        out[4] = (a12 * b08 - a10 * b11 - a13 * b07) * det;
        out[5] = (a00 * b11 - a02 * b08 + a03 * b07) * det;
        out[6] = (a32 * b02 - a30 * b05 - a33 * b01) * det;
        out[7] = (a20 * b05 - a22 * b02 + a23 * b01) * det;
        out[8] = (a10 * b10 - a11 * b08 + a13 * b06) * det;
        out[9] = (a01 * b08 - a00 * b10 - a03 * b06) * det;
        out[10] = (a30 * b04 - a31 * b02 + a33 * b00) * det;
        out[11] = (a21 * b02 - a20 * b04 - a23 * b00) * det;
        out[12] = (a11 * b07 - a10 * b09 - a12 * b06) * det;
        out[13] = (a00 * b09 - a01 * b07 + a02 * b06) * det;
        out[14] = (a31 * b01 - a30 * b03 - a32 * b00) * det;
        out[15] = (a20 * b03 - a21 * b01 + a22 * b00) * det;
        return out;
    }
    /**
     * Multiplies two mat4s
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the first operand
     * @param {ReadonlyMat4} b the second operand
     * @returns {mat4} out
     */

    function multiply(out, a, b) {
        var a00 = a[0],
            a01 = a[1],
            a02 = a[2],
            a03 = a[3];
        var a10 = a[4],
            a11 = a[5],
            a12 = a[6],
            a13 = a[7];
        var a20 = a[8],
            a21 = a[9],
            a22 = a[10],
            a23 = a[11];
        var a30 = a[12],
            a31 = a[13],
            a32 = a[14],
            a33 = a[15]; // Cache only the current line of the second matrix

        var b0 = b[0],
            b1 = b[1],
            b2 = b[2],
            b3 = b[3];
        out[0] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[1] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[2] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[3] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;
        b0 = b[4];
        b1 = b[5];
        b2 = b[6];
        b3 = b[7];
        out[4] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[5] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[6] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[7] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;
        b0 = b[8];
        b1 = b[9];
        b2 = b[10];
        b3 = b[11];
        out[8] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[9] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[10] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[11] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;
        b0 = b[12];
        b1 = b[13];
        b2 = b[14];
        b3 = b[15];
        out[12] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[13] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[14] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[15] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;
        return out;
    }
    /**
     * Translate a mat4 by the given vector
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the matrix to translate
     * @param {ReadonlyVec3} v vector to translate by
     * @returns {mat4} out
     */

    function translate(out, a, v) {
        var x = v[0],
            y = v[1],
            z = v[2];
        var a00, a01, a02, a03;
        var a10, a11, a12, a13;
        var a20, a21, a22, a23;

        if (a === out) {
            out[12] = a[0] * x + a[4] * y + a[8] * z + a[12];
            out[13] = a[1] * x + a[5] * y + a[9] * z + a[13];
            out[14] = a[2] * x + a[6] * y + a[10] * z + a[14];
            out[15] = a[3] * x + a[7] * y + a[11] * z + a[15];
        } else {
            a00 = a[0];
            a01 = a[1];
            a02 = a[2];
            a03 = a[3];
            a10 = a[4];
            a11 = a[5];
            a12 = a[6];
            a13 = a[7];
            a20 = a[8];
            a21 = a[9];
            a22 = a[10];
            a23 = a[11];
            out[0] = a00;
            out[1] = a01;
            out[2] = a02;
            out[3] = a03;
            out[4] = a10;
            out[5] = a11;
            out[6] = a12;
            out[7] = a13;
            out[8] = a20;
            out[9] = a21;
            out[10] = a22;
            out[11] = a23;
            out[12] = a00 * x + a10 * y + a20 * z + a[12];
            out[13] = a01 * x + a11 * y + a21 * z + a[13];
            out[14] = a02 * x + a12 * y + a22 * z + a[14];
            out[15] = a03 * x + a13 * y + a23 * z + a[15];
        }

        return out;
    }
    /**
     * Scales the mat4 by the dimensions in the given vec3 not using vectorization
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the matrix to scale
     * @param {ReadonlyVec3} v the vec3 to scale the matrix by
     * @returns {mat4} out
     **/

    function scale(out, a, v) {
        var x = v[0],
            y = v[1],
            z = v[2];
        out[0] = a[0] * x;
        out[1] = a[1] * x;
        out[2] = a[2] * x;
        out[3] = a[3] * x;
        out[4] = a[4] * y;
        out[5] = a[5] * y;
        out[6] = a[6] * y;
        out[7] = a[7] * y;
        out[8] = a[8] * z;
        out[9] = a[9] * z;
        out[10] = a[10] * z;
        out[11] = a[11] * z;
        out[12] = a[12];
        out[13] = a[13];
        out[14] = a[14];
        out[15] = a[15];
        return out;
    }
    /**
     * Rotates a matrix by the given angle around the X axis
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the matrix to rotate
     * @param {Number} rad the angle to rotate the matrix by
     * @returns {mat4} out
     */

    function rotateX(out, a, rad) {
        var s = Math.sin(rad);
        var c = Math.cos(rad);
        var a10 = a[4];
        var a11 = a[5];
        var a12 = a[6];
        var a13 = a[7];
        var a20 = a[8];
        var a21 = a[9];
        var a22 = a[10];
        var a23 = a[11];

        if (a !== out) {
            // If the source and destination differ, copy the unchanged rows
            out[0] = a[0];
            out[1] = a[1];
            out[2] = a[2];
            out[3] = a[3];
            out[12] = a[12];
            out[13] = a[13];
            out[14] = a[14];
            out[15] = a[15];
        } // Perform axis-specific matrix multiplication


        out[4] = a10 * c + a20 * s;
        out[5] = a11 * c + a21 * s;
        out[6] = a12 * c + a22 * s;
        out[7] = a13 * c + a23 * s;
        out[8] = a20 * c - a10 * s;
        out[9] = a21 * c - a11 * s;
        out[10] = a22 * c - a12 * s;
        out[11] = a23 * c - a13 * s;
        return out;
    }
    /**
     * Rotates a matrix by the given angle around the Z axis
     *
     * @param {mat4} out the receiving matrix
     * @param {ReadonlyMat4} a the matrix to rotate
     * @param {Number} rad the angle to rotate the matrix by
     * @returns {mat4} out
     */

    function rotateZ(out, a, rad) {
        var s = Math.sin(rad);
        var c = Math.cos(rad);
        var a00 = a[0];
        var a01 = a[1];
        var a02 = a[2];
        var a03 = a[3];
        var a10 = a[4];
        var a11 = a[5];
        var a12 = a[6];
        var a13 = a[7];

        if (a !== out) {
            // If the source and destination differ, copy the unchanged last row
            out[8] = a[8];
            out[9] = a[9];
            out[10] = a[10];
            out[11] = a[11];
            out[12] = a[12];
            out[13] = a[13];
            out[14] = a[14];
            out[15] = a[15];
        } // Perform axis-specific matrix multiplication


        out[0] = a00 * c + a10 * s;
        out[1] = a01 * c + a11 * s;
        out[2] = a02 * c + a12 * s;
        out[3] = a03 * c + a13 * s;
        out[4] = a10 * c - a00 * s;
        out[5] = a11 * c - a01 * s;
        out[6] = a12 * c - a02 * s;
        out[7] = a13 * c - a03 * s;
        return out;
    }
    /**
     * Generates a perspective projection matrix with the given bounds.
     * Passing null/undefined/no value for far will generate infinite projection matrix.
     *
     * @param {mat4} out mat4 frustum matrix will be written into
     * @param {number} fovy Vertical field of view in radians
     * @param {number} aspect Aspect ratio. typically viewport width/height
     * @param {number} near Near bound of the frustum
     * @param {number} far Far bound of the frustum, can be null or Infinity
     * @returns {mat4} out
     */

    function perspective(out, fovy, aspect, near, far) {
        var f = 1.0 / Math.tan(fovy / 2),
            nf;
        out[0] = f / aspect;
        out[1] = 0;
        out[2] = 0;
        out[3] = 0;
        out[4] = 0;
        out[5] = f;
        out[6] = 0;
        out[7] = 0;
        out[8] = 0;
        out[9] = 0;
        out[11] = -1;
        out[12] = 0;
        out[13] = 0;
        out[15] = 0;

        if (far != null && far !== Infinity) {
            nf = 1 / (near - far);
            out[10] = (far + near) * nf;
            out[14] = 2 * far * near * nf;
        } else {
            out[10] = -1;
            out[14] = -2 * near;
        }

        return out;
    }
    /**
     * Returns whether or not the matrices have approximately the same elements in the same position.
     *
     * @param {ReadonlyMat4} a The first matrix.
     * @param {ReadonlyMat4} b The second matrix.
     * @returns {Boolean} True if the matrices are equal, false otherwise.
     */

    function equals(a, b) {
        var a0 = a[0],
            a1 = a[1],
            a2 = a[2],
            a3 = a[3];
        var a4 = a[4],
            a5 = a[5],
            a6 = a[6],
            a7 = a[7];
        var a8 = a[8],
            a9 = a[9],
            a10 = a[10],
            a11 = a[11];
        var a12 = a[12],
            a13 = a[13],
            a14 = a[14],
            a15 = a[15];
        var b0 = b[0],
            b1 = b[1],
            b2 = b[2],
            b3 = b[3];
        var b4 = b[4],
            b5 = b[5],
            b6 = b[6],
            b7 = b[7];
        var b8 = b[8],
            b9 = b[9],
            b10 = b[10],
            b11 = b[11];
        var b12 = b[12],
            b13 = b[13],
            b14 = b[14],
            b15 = b[15];
        return Math.abs(a0 - b0) <= EPSILON * Math.max(1.0, Math.abs(a0), Math.abs(b0)) && Math.abs(a1 - b1) <= EPSILON * Math.max(1.0, Math.abs(a1), Math.abs(b1)) && Math.abs(a2 - b2) <= EPSILON * Math.max(1.0, Math.abs(a2), Math.abs(b2)) && Math.abs(a3 - b3) <= EPSILON * Math.max(1.0, Math.abs(a3), Math.abs(b3)) && Math.abs(a4 - b4) <= EPSILON * Math.max(1.0, Math.abs(a4), Math.abs(b4)) && Math.abs(a5 - b5) <= EPSILON * Math.max(1.0, Math.abs(a5), Math.abs(b5)) && Math.abs(a6 - b6) <= EPSILON * Math.max(1.0, Math.abs(a6), Math.abs(b6)) && Math.abs(a7 - b7) <= EPSILON * Math.max(1.0, Math.abs(a7), Math.abs(b7)) && Math.abs(a8 - b8) <= EPSILON * Math.max(1.0, Math.abs(a8), Math.abs(b8)) && Math.abs(a9 - b9) <= EPSILON * Math.max(1.0, Math.abs(a9), Math.abs(b9)) && Math.abs(a10 - b10) <= EPSILON * Math.max(1.0, Math.abs(a10), Math.abs(b10)) && Math.abs(a11 - b11) <= EPSILON * Math.max(1.0, Math.abs(a11), Math.abs(b11)) && Math.abs(a12 - b12) <= EPSILON * Math.max(1.0, Math.abs(a12), Math.abs(b12)) && Math.abs(a13 - b13) <= EPSILON * Math.max(1.0, Math.abs(a13), Math.abs(b13)) && Math.abs(a14 - b14) <= EPSILON * Math.max(1.0, Math.abs(a14), Math.abs(b14)) && Math.abs(a15 - b15) <= EPSILON * Math.max(1.0, Math.abs(a15), Math.abs(b15));
    }

    /**
     * 2 Dimensional Vector
     * @module vec2
     */

    /**
     * Creates a new, empty vec2
     *
     * @returns {vec2} a new 2D vector
     */

    function create$1() {
        var out = new ARRAY_TYPE(2);

        if (ARRAY_TYPE != Float32Array) {
            out[0] = 0;
            out[1] = 0;
        }

        return out;
    }
    /**
     * Adds two vec2's
     *
     * @param {vec2} out the receiving vector
     * @param {ReadonlyVec2} a the first operand
     * @param {ReadonlyVec2} b the second operand
     * @returns {vec2} out
     */

    function add(out, a, b) {
        out[0] = a[0] + b[0];
        out[1] = a[1] + b[1];
        return out;
    }
    /**
     * Negates the components of a vec2
     *
     * @param {vec2} out the receiving vector
     * @param {ReadonlyVec2} a vector to negate
     * @returns {vec2} out
     */

    function negate$1(out, a) {
        out[0] = -a[0];
        out[1] = -a[1];
        return out;
    }
    /**
     * Performs a linear interpolation between two vec2's
     *
     * @param {vec2} out the receiving vector
     * @param {ReadonlyVec2} a the first operand
     * @param {ReadonlyVec2} b the second operand
     * @param {Number} t interpolation amount, in the range [0-1], between the two inputs
     * @returns {vec2} out
     */

    function lerp(out, a, b, t) {
        var ax = a[0],
            ay = a[1];
        out[0] = ax + t * (b[0] - ax);
        out[1] = ay + t * (b[1] - ay);
        return out;
    }
    /**
     * Perform some operation over an array of vec2s.
     *
     * @param {Array} a the array of vectors to iterate over
     * @param {Number} stride Number of elements between the start of each vec2. If 0 assumes tightly packed
     * @param {Number} offset Number of elements to skip at the beginning of the array
     * @param {Number} count Number of vec2s to iterate over. If 0 iterates over entire array
     * @param {Function} fn Function to call for each vector in the array
     * @param {Object} [arg] additional argument to pass to fn
     * @returns {Array} a
     * @function
     */

    (function () {
        var vec = create$1();
        return function (a, stride, offset, count, fn, arg) {
            var i, l;

            if (!stride) {
                stride = 2;
            }

            if (!offset) {
                offset = 0;
            }

            if (count) {
                l = Math.min(count * stride + offset, a.length);
            } else {
                l = a.length;
            }

            for (i = offset; i < l; i += stride) {
                vec[0] = a[i];
                vec[1] = a[i + 1];
                fn(vec, vec, arg);
                a[i] = vec[0];
                a[i + 1] = vec[1];
            }

            return a;
        };
    })();

    /**
     * 3 Dimensional Vector
     * @module vec3
     */

    /**
     * Creates a new, empty vec3
     *
     * @returns {vec3} a new 3D vector
     */

    function create() {
        var out = new ARRAY_TYPE(3);

        if (ARRAY_TYPE != Float32Array) {
            out[0] = 0;
            out[1] = 0;
            out[2] = 0;
        }

        return out;
    }
    /**
     * Negates the components of a vec3
     *
     * @param {vec3} out the receiving vector
     * @param {ReadonlyVec3} a vector to negate
     * @returns {vec3} out
     */

    function negate(out, a) {
        out[0] = -a[0];
        out[1] = -a[1];
        out[2] = -a[2];
        return out;
    }
    /**
     * Perform some operation over an array of vec3s.
     *
     * @param {Array} a the array of vectors to iterate over
     * @param {Number} stride Number of elements between the start of each vec3. If 0 assumes tightly packed
     * @param {Number} offset Number of elements to skip at the beginning of the array
     * @param {Number} count Number of vec3s to iterate over. If 0 iterates over entire array
     * @param {Function} fn Function to call for each vector in the array
     * @param {Object} [arg] additional argument to pass to fn
     * @returns {Array} a
     * @function
     */

    (function () {
        var vec = create();
        return function (a, stride, offset, count, fn, arg) {
            var i, l;

            if (!stride) {
                stride = 3;
            }

            if (!offset) {
                offset = 0;
            }

            if (count) {
                l = Math.min(count * stride + offset, a.length);
            } else {
                l = a.length;
            }

            for (i = offset; i < l; i += stride) {
                vec[0] = a[i];
                vec[1] = a[i + 1];
                vec[2] = a[i + 2];
                fn(vec, vec, arg);
                a[i] = vec[0];
                a[i + 1] = vec[1];
                a[i + 2] = vec[2];
            }

            return a;
        };
    })();

    function assert(condition, message) {
        if (!condition) {
            throw new Error(message || 'viewport-mercator-project: assertion failed.');
        }
    }

    var PI$1 = Math.PI;
    var PI_4 = PI$1 / 4;
    var DEGREES_TO_RADIANS$1 = PI$1 / 180;
    var RADIANS_TO_DEGREES = 180 / PI$1;
    var TILE_SIZE$1 = 512;
    var EARTH_CIRCUMFERENCE$1 = 40.03e6;
    var DEFAULT_ALTITUDE = 1.5;
    function zoomToScale$1(zoom) {
        return Math.pow(2, zoom);
    }
    function lngLatToWorld(_ref, scale) {
        var _ref2 = _slicedToArray(_ref, 2),
            lng = _ref2[0],
            lat = _ref2[1];

        assert(Number.isFinite(lng) && Number.isFinite(scale));
        assert(Number.isFinite(lat) && lat >= -90 && lat <= 90, 'invalid latitude');
        scale *= TILE_SIZE$1;
        var lambda2 = lng * DEGREES_TO_RADIANS$1;
        var phi2 = lat * DEGREES_TO_RADIANS$1;
        var x = scale * (lambda2 + PI$1) / (2 * PI$1);
        var y = scale * (PI$1 - Math.log(Math.tan(PI_4 + phi2 * 0.5))) / (2 * PI$1);
        return [x, y];
    }
    function worldToLngLat(_ref3, scale) {
        var _ref4 = _slicedToArray(_ref3, 2),
            x = _ref4[0],
            y = _ref4[1];

        scale *= TILE_SIZE$1;
        var lambda2 = x / scale * (2 * PI$1) - PI$1;
        var phi2 = 2 * (Math.atan(Math.exp(PI$1 - y / scale * (2 * PI$1))) - PI_4);
        return [lambda2 * RADIANS_TO_DEGREES, phi2 * RADIANS_TO_DEGREES];
    }
    function getDistanceScales$1(_ref6) {
        var latitude = _ref6.latitude,
            longitude = _ref6.longitude,
            zoom = _ref6.zoom,
            scale = _ref6.scale,
            _ref6$highPrecision = _ref6.highPrecision,
            highPrecision = _ref6$highPrecision === void 0 ? false : _ref6$highPrecision;
        scale = scale !== undefined ? scale : zoomToScale$1(zoom);
        assert(Number.isFinite(latitude) && Number.isFinite(longitude) && Number.isFinite(scale));
        var result = {};
        var worldSize = TILE_SIZE$1 * scale;
        var latCosine = Math.cos(latitude * DEGREES_TO_RADIANS$1);
        var pixelsPerDegreeX = worldSize / 360;
        var pixelsPerDegreeY = pixelsPerDegreeX / latCosine;
        var altPixelsPerMeter = worldSize / EARTH_CIRCUMFERENCE$1 / latCosine;
        result.pixelsPerMeter = [altPixelsPerMeter, -altPixelsPerMeter, altPixelsPerMeter];
        result.metersPerPixel = [1 / altPixelsPerMeter, -1 / altPixelsPerMeter, 1 / altPixelsPerMeter];
        result.pixelsPerDegree = [pixelsPerDegreeX, -pixelsPerDegreeY, altPixelsPerMeter];
        result.degreesPerPixel = [1 / pixelsPerDegreeX, -1 / pixelsPerDegreeY, 1 / altPixelsPerMeter];

        if (highPrecision) {
            var latCosine2 = DEGREES_TO_RADIANS$1 * Math.tan(latitude * DEGREES_TO_RADIANS$1) / latCosine;
            var pixelsPerDegreeY2 = pixelsPerDegreeX * latCosine2 / 2;
            var altPixelsPerDegree2 = worldSize / EARTH_CIRCUMFERENCE$1 * latCosine2;
            var altPixelsPerMeter2 = altPixelsPerDegree2 / pixelsPerDegreeY * altPixelsPerMeter;
            result.pixelsPerDegree2 = [0, -pixelsPerDegreeY2, altPixelsPerDegree2];
            result.pixelsPerMeter2 = [altPixelsPerMeter2, 0, altPixelsPerMeter2];
        }

        return result;
    }
    function getViewMatrix(_ref7) {
        var height = _ref7.height,
            pitch = _ref7.pitch,
            bearing = _ref7.bearing,
            altitude = _ref7.altitude,
            _ref7$center = _ref7.center,
            center = _ref7$center === void 0 ? null : _ref7$center,
            _ref7$flipY = _ref7.flipY,
            flipY = _ref7$flipY === void 0 ? false : _ref7$flipY;
        var vm = createMat4();
        translate(vm, vm, [0, 0, -altitude]);
        scale(vm, vm, [1, 1, 1 / height]);
        rotateX(vm, vm, -pitch * DEGREES_TO_RADIANS$1);
        rotateZ(vm, vm, bearing * DEGREES_TO_RADIANS$1);

        if (flipY) {
            scale(vm, vm, [1, -1, 1]);
        }

        if (center) {
            translate(vm, vm, negate([], center));
        }

        return vm;
    }
    function getProjectionParameters(_ref8) {
        var width = _ref8.width,
            height = _ref8.height,
            _ref8$altitude = _ref8.altitude,
            altitude = _ref8$altitude === void 0 ? DEFAULT_ALTITUDE : _ref8$altitude,
            _ref8$pitch = _ref8.pitch,
            pitch = _ref8$pitch === void 0 ? 0 : _ref8$pitch,
            _ref8$nearZMultiplier = _ref8.nearZMultiplier,
            nearZMultiplier = _ref8$nearZMultiplier === void 0 ? 1 : _ref8$nearZMultiplier,
            _ref8$farZMultiplier = _ref8.farZMultiplier,
            farZMultiplier = _ref8$farZMultiplier === void 0 ? 1 : _ref8$farZMultiplier;
        var pitchRadians = pitch * DEGREES_TO_RADIANS$1;
        var halfFov = Math.atan(0.5 / altitude);
        var topHalfSurfaceDistance = Math.sin(halfFov) * altitude / Math.sin(Math.PI / 2 - pitchRadians - halfFov);
        var farZ = Math.cos(Math.PI / 2 - pitchRadians) * topHalfSurfaceDistance + altitude;
        return {
            fov: 2 * Math.atan(height / 2 / altitude),
            aspect: width / height,
            focalDistance: altitude,
            near: nearZMultiplier,
            far: farZ * farZMultiplier
        };
    }
    function getProjectionMatrix(_ref9) {
        var width = _ref9.width,
            height = _ref9.height,
            pitch = _ref9.pitch,
            altitude = _ref9.altitude,
            nearZMultiplier = _ref9.nearZMultiplier,
            farZMultiplier = _ref9.farZMultiplier;

        var _getProjectionParamet = getProjectionParameters({
                width: width,
                height: height,
                altitude: altitude,
                pitch: pitch,
                nearZMultiplier: nearZMultiplier,
                farZMultiplier: farZMultiplier
            }),
            fov = _getProjectionParamet.fov,
            aspect = _getProjectionParamet.aspect,
            near = _getProjectionParamet.near,
            far = _getProjectionParamet.far;

        var projectionMatrix = perspective([], fov, aspect, near, far);
        return projectionMatrix;
    }
    function worldToPixels(xyz, pixelProjectionMatrix) {
        var _xyz2 = _slicedToArray(xyz, 3),
            x = _xyz2[0],
            y = _xyz2[1],
            _xyz2$ = _xyz2[2],
            z = _xyz2$ === void 0 ? 0 : _xyz2$;

        assert(Number.isFinite(x) && Number.isFinite(y) && Number.isFinite(z));
        return transformVector(pixelProjectionMatrix, [x, y, z, 1]);
    }
    function pixelsToWorld(xyz, pixelUnprojectionMatrix) {
        var targetZ = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 0;

        var _xyz3 = _slicedToArray(xyz, 3),
            x = _xyz3[0],
            y = _xyz3[1],
            z = _xyz3[2];

        assert(Number.isFinite(x) && Number.isFinite(y), 'invalid pixel coordinate');

        if (Number.isFinite(z)) {
            var coord = transformVector(pixelUnprojectionMatrix, [x, y, z, 1]);
            return coord;
        }

        var coord0 = transformVector(pixelUnprojectionMatrix, [x, y, 0, 1]);
        var coord1 = transformVector(pixelUnprojectionMatrix, [x, y, 1, 1]);
        var z0 = coord0[2];
        var z1 = coord1[2];
        var t = z0 === z1 ? 0 : ((targetZ || 0) - z0) / (z1 - z0);
        return lerp([], coord0, coord1, t);
    }

    var IDENTITY = createMat4();

    var Viewport = function () {
        function Viewport() {
            var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
                width = _ref.width,
                height = _ref.height,
                _ref$viewMatrix = _ref.viewMatrix,
                viewMatrix = _ref$viewMatrix === void 0 ? IDENTITY : _ref$viewMatrix,
                _ref$projectionMatrix = _ref.projectionMatrix,
                projectionMatrix = _ref$projectionMatrix === void 0 ? IDENTITY : _ref$projectionMatrix;

            _classCallCheck(this, Viewport);

            this.width = width || 1;
            this.height = height || 1;
            this.scale = 1;
            this.pixelsPerMeter = 1;
            this.viewMatrix = viewMatrix;
            this.projectionMatrix = projectionMatrix;
            var vpm = createMat4();
            multiply(vpm, vpm, this.projectionMatrix);
            multiply(vpm, vpm, this.viewMatrix);
            this.viewProjectionMatrix = vpm;
            var m = createMat4();
            scale(m, m, [this.width / 2, -this.height / 2, 1]);
            translate(m, m, [1, -1, 0]);
            multiply(m, m, this.viewProjectionMatrix);
            var mInverse = invert(createMat4(), m);

            if (!mInverse) {
                throw new Error('Pixel project matrix not invertible');
            }

            this.pixelProjectionMatrix = m;
            this.pixelUnprojectionMatrix = mInverse;
            this.equals = this.equals.bind(this);
            this.project = this.project.bind(this);
            this.unproject = this.unproject.bind(this);
            this.projectPosition = this.projectPosition.bind(this);
            this.unprojectPosition = this.unprojectPosition.bind(this);
            this.projectFlat = this.projectFlat.bind(this);
            this.unprojectFlat = this.unprojectFlat.bind(this);
        }

        _createClass(Viewport, [{
            key: "equals",
            value: function equals$1(viewport) {
                if (!(viewport instanceof Viewport)) {
                    return false;
                }

                return viewport.width === this.width && viewport.height === this.height && equals(viewport.projectionMatrix, this.projectionMatrix) && equals(viewport.viewMatrix, this.viewMatrix);
            }
        }, {
            key: "project",
            value: function project(xyz) {
                var _ref2 = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
                    _ref2$topLeft = _ref2.topLeft,
                    topLeft = _ref2$topLeft === void 0 ? true : _ref2$topLeft;

                var worldPosition = this.projectPosition(xyz);
                var coord = worldToPixels(worldPosition, this.pixelProjectionMatrix);

                var _coord = _slicedToArray(coord, 2),
                    x = _coord[0],
                    y = _coord[1];

                var y2 = topLeft ? y : this.height - y;
                return xyz.length === 2 ? [x, y2] : [x, y2, coord[2]];
            }
        }, {
            key: "unproject",
            value: function unproject(xyz) {
                var _ref3 = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
                    _ref3$topLeft = _ref3.topLeft,
                    topLeft = _ref3$topLeft === void 0 ? true : _ref3$topLeft,
                    targetZ = _ref3.targetZ;

                var _xyz = _slicedToArray(xyz, 3),
                    x = _xyz[0],
                    y = _xyz[1],
                    z = _xyz[2];

                var y2 = topLeft ? y : this.height - y;
                var targetZWorld = targetZ && targetZ * this.pixelsPerMeter;
                var coord = pixelsToWorld([x, y2, z], this.pixelUnprojectionMatrix, targetZWorld);

                var _this$unprojectPositi = this.unprojectPosition(coord),
                    _this$unprojectPositi2 = _slicedToArray(_this$unprojectPositi, 3),
                    X = _this$unprojectPositi2[0],
                    Y = _this$unprojectPositi2[1],
                    Z = _this$unprojectPositi2[2];

                if (Number.isFinite(z)) {
                    return [X, Y, Z];
                }

                return Number.isFinite(targetZ) ? [X, Y, targetZ] : [X, Y];
            }
        }, {
            key: "projectPosition",
            value: function projectPosition(xyz) {
                var _this$projectFlat = this.projectFlat(xyz),
                    _this$projectFlat2 = _slicedToArray(_this$projectFlat, 2),
                    X = _this$projectFlat2[0],
                    Y = _this$projectFlat2[1];

                var Z = (xyz[2] || 0) * this.pixelsPerMeter;
                return [X, Y, Z];
            }
        }, {
            key: "unprojectPosition",
            value: function unprojectPosition(xyz) {
                var _this$unprojectFlat = this.unprojectFlat(xyz),
                    _this$unprojectFlat2 = _slicedToArray(_this$unprojectFlat, 2),
                    X = _this$unprojectFlat2[0],
                    Y = _this$unprojectFlat2[1];

                var Z = (xyz[2] || 0) / this.pixelsPerMeter;
                return [X, Y, Z];
            }
        }, {
            key: "projectFlat",
            value: function projectFlat(xyz) {
                arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.scale;
                return xyz;
            }
        }, {
            key: "unprojectFlat",
            value: function unprojectFlat(xyz) {
                arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.scale;
                return xyz;
            }
        }]);

        return Viewport;
    }();

    function fitBounds(_ref) {
        var width = _ref.width,
            height = _ref.height,
            bounds = _ref.bounds,
            _ref$minExtent = _ref.minExtent,
            minExtent = _ref$minExtent === void 0 ? 0 : _ref$minExtent,
            _ref$maxZoom = _ref.maxZoom,
            maxZoom = _ref$maxZoom === void 0 ? 24 : _ref$maxZoom,
            _ref$padding = _ref.padding,
            padding = _ref$padding === void 0 ? 0 : _ref$padding,
            _ref$offset = _ref.offset,
            offset = _ref$offset === void 0 ? [0, 0] : _ref$offset;

        var _bounds = _slicedToArray(bounds, 2),
            _bounds$ = _slicedToArray(_bounds[0], 2),
            west = _bounds$[0],
            south = _bounds$[1],
            _bounds$2 = _slicedToArray(_bounds[1], 2),
            east = _bounds$2[0],
            north = _bounds$2[1];

        if (Number.isFinite(padding)) {
            var p = padding;
            padding = {
                top: p,
                bottom: p,
                left: p,
                right: p
            };
        } else {
            assert(Number.isFinite(padding.top) && Number.isFinite(padding.bottom) && Number.isFinite(padding.left) && Number.isFinite(padding.right));
        }

        var viewport = new WebMercatorViewport({
            width: width,
            height: height,
            longitude: 0,
            latitude: 0,
            zoom: 0
        });
        var nw = viewport.project([west, north]);
        var se = viewport.project([east, south]);
        var size = [Math.max(Math.abs(se[0] - nw[0]), minExtent), Math.max(Math.abs(se[1] - nw[1]), minExtent)];
        var targetSize = [width - padding.left - padding.right - Math.abs(offset[0]) * 2, height - padding.top - padding.bottom - Math.abs(offset[1]) * 2];
        assert(targetSize[0] > 0 && targetSize[1] > 0);
        var scaleX = targetSize[0] / size[0];
        var scaleY = targetSize[1] / size[1];
        var offsetX = (padding.right - padding.left) / 2 / scaleX;
        var offsetY = (padding.bottom - padding.top) / 2 / scaleY;
        var center = [(se[0] + nw[0]) / 2 + offsetX, (se[1] + nw[1]) / 2 + offsetY];
        var centerLngLat = viewport.unproject(center);
        var zoom = viewport.zoom + Math.log2(Math.abs(Math.min(scaleX, scaleY)));
        return {
            longitude: centerLngLat[0],
            latitude: centerLngLat[1],
            zoom: Math.min(zoom, maxZoom)
        };
    }

    var WebMercatorViewport = function (_Viewport) {
        _inherits(WebMercatorViewport, _Viewport);

        function WebMercatorViewport() {
            var _this;

            var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
                width = _ref.width,
                height = _ref.height,
                _ref$latitude = _ref.latitude,
                latitude = _ref$latitude === void 0 ? 0 : _ref$latitude,
                _ref$longitude = _ref.longitude,
                longitude = _ref$longitude === void 0 ? 0 : _ref$longitude,
                _ref$zoom = _ref.zoom,
                zoom = _ref$zoom === void 0 ? 0 : _ref$zoom,
                _ref$pitch = _ref.pitch,
                pitch = _ref$pitch === void 0 ? 0 : _ref$pitch,
                _ref$bearing = _ref.bearing,
                bearing = _ref$bearing === void 0 ? 0 : _ref$bearing,
                _ref$altitude = _ref.altitude,
                altitude = _ref$altitude === void 0 ? 1.5 : _ref$altitude,
                nearZMultiplier = _ref.nearZMultiplier,
                farZMultiplier = _ref.farZMultiplier;

            _classCallCheck(this, WebMercatorViewport);

            width = width || 1;
            height = height || 1;
            var scale = zoomToScale$1(zoom);
            altitude = Math.max(0.75, altitude);
            var center = lngLatToWorld([longitude, latitude], scale);
            center[2] = 0;
            var projectionMatrix = getProjectionMatrix({
                width: width,
                height: height,
                pitch: pitch,
                bearing: bearing,
                altitude: altitude,
                nearZMultiplier: nearZMultiplier || 1 / height,
                farZMultiplier: farZMultiplier || 1.01
            });
            var viewMatrix = getViewMatrix({
                height: height,
                center: center,
                pitch: pitch,
                bearing: bearing,
                altitude: altitude,
                flipY: true
            });
            _this = _possibleConstructorReturn(this, _getPrototypeOf(WebMercatorViewport).call(this, {
                width: width,
                height: height,
                viewMatrix: viewMatrix,
                projectionMatrix: projectionMatrix
            }));
            _this.latitude = latitude;
            _this.longitude = longitude;
            _this.zoom = zoom;
            _this.pitch = pitch;
            _this.bearing = bearing;
            _this.altitude = altitude;
            _this.scale = scale;
            _this.center = center;
            _this.pixelsPerMeter = getDistanceScales$1(_assertThisInitialized(_assertThisInitialized(_this))).pixelsPerMeter[2];
            Object.freeze(_assertThisInitialized(_assertThisInitialized(_this)));
            return _this;
        }

        _createClass(WebMercatorViewport, [{
            key: "projectFlat",
            value: function projectFlat(lngLat) {
                var scale = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.scale;
                return lngLatToWorld(lngLat, scale);
            }
        }, {
            key: "unprojectFlat",
            value: function unprojectFlat(xy) {
                var scale = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : this.scale;
                return worldToLngLat(xy, scale);
            }
        }, {
            key: "getMapCenterByLngLatPosition",
            value: function getMapCenterByLngLatPosition(_ref2) {
                var lngLat = _ref2.lngLat,
                    pos = _ref2.pos;
                var fromLocation = pixelsToWorld(pos, this.pixelUnprojectionMatrix);
                var toLocation = lngLatToWorld(lngLat, this.scale);
                var translate = add([], toLocation, negate$1([], fromLocation));
                var newCenter = add([], this.center, translate);
                return worldToLngLat(newCenter, this.scale);
            }
        }, {
            key: "getLocationAtPoint",
            value: function getLocationAtPoint(_ref3) {
                var lngLat = _ref3.lngLat,
                    pos = _ref3.pos;
                return this.getMapCenterByLngLatPosition({
                    lngLat: lngLat,
                    pos: pos
                });
            }
        }, {
            key: "fitBounds",
            value: function fitBounds$1(bounds) {
                var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
                var width = this.width,
                    height = this.height;

                var _fitBounds2 = fitBounds(Object.assign({
                        width: width,
                        height: height,
                        bounds: bounds
                    }, options)),
                    longitude = _fitBounds2.longitude,
                    latitude = _fitBounds2.latitude,
                    zoom = _fitBounds2.zoom;

                return new WebMercatorViewport({
                    width: width,
                    height: height,
                    longitude: longitude,
                    latitude: latitude,
                    zoom: zoom
                });
            }
        }]);

        return WebMercatorViewport;
    }(Viewport);

    /**
     * borrow from
     * https://github.com/uber-common/viewport-mercator-project/blob/master/src/web-mercator-utils.js
     */

    const PI = Math.PI;
    const DEGREES_TO_RADIANS = PI / 180;
    // const RADIANS_TO_DEGREES = 180 / PI;
    const TILE_SIZE = 512;
    // Average circumference (40075 km equatorial, 40007 km meridional)
    const EARTH_CIRCUMFERENCE = 40.03e6;

    // Mapbox default altitude
    // const DEFAULT_ALTITUDE = 1.5;

    function zoomToScale(zoom) {
        return Math.pow(2, zoom);
    }

    /**
     * Calculate distance scales in meters around current lat/lon, both for
     * degrees and pixels.
     * In mercator projection mode, the distance scales vary significantly
     * with latitude.
     */
    function getDistanceScales(options) {
        let {
            latitude = 0, zoom = 1, scale, highPrecision = false
        } = options;

        // Calculate scale from zoom if not provided
        scale = scale !== undefined ? scale : zoomToScale(zoom);

        const result = {};
        const worldSize = TILE_SIZE * scale;
        const latCosine = Math.cos(latitude * DEGREES_TO_RADIANS);

        /**
         * Number of pixels occupied by one degree longitude around current lat/lon:
         pixelsPerDegreeX = d(lngLatToWorld([lng, lat])[0])/d(lng)
         = scale * TILE_SIZE * DEGREES_TO_RADIANS / (2 * PI)
         pixelsPerDegreeY = d(lngLatToWorld([lng, lat])[1])/d(lat)
         = -scale * TILE_SIZE * DEGREES_TO_RADIANS / cos(lat * DEGREES_TO_RADIANS)  / (2 * PI)
         */
        const pixelsPerDegreeX = worldSize / 360;
        const pixelsPerDegreeY = pixelsPerDegreeX / latCosine;

        /**
         * Number of pixels occupied by one meter around current lat/lon:
         */
        const altPixelsPerMeter = worldSize / EARTH_CIRCUMFERENCE / latCosine;

        /**
         * LngLat: longitude -> east and latitude -> north (bottom left)
         * UTM meter offset: x -> east and y -> north (bottom left)
         * World space: x -> east and y -> south (top left)
         *
         * Y needs to be flipped when converting delta degree/meter to delta pixels
         */
        result.pixelsPerMeter = [altPixelsPerMeter, -altPixelsPerMeter, altPixelsPerMeter];
        result.metersPerPixel = [1 / altPixelsPerMeter, -1 / altPixelsPerMeter, 1 / altPixelsPerMeter];

        result.pixelsPerDegree = [pixelsPerDegreeX, -pixelsPerDegreeY, altPixelsPerMeter];
        result.degreesPerPixel = [1 / pixelsPerDegreeX, -1 / pixelsPerDegreeY, 1 / altPixelsPerMeter];

        /**
         * Taylor series 2nd order for 1/latCosine
         f'(a) * (x - a)
         = d(1/cos(lat * DEGREES_TO_RADIANS))/d(lat) * dLat
         = DEGREES_TO_RADIANS * tan(lat * DEGREES_TO_RADIANS) / cos(lat * DEGREES_TO_RADIANS) * dLat
         */
        if (highPrecision) {
            const latCosine2 = DEGREES_TO_RADIANS * Math.tan(latitude * DEGREES_TO_RADIANS) / latCosine;
            const pixelsPerDegreeY2 = pixelsPerDegreeX * latCosine2 / 2;

            const altPixelsPerDegree2 = worldSize / EARTH_CIRCUMFERENCE * latCosine2;
            const altPixelsPerMeter2 = altPixelsPerDegree2 / pixelsPerDegreeY * altPixelsPerMeter;

            result.pixelsPerDegree2 = [0, -pixelsPerDegreeY2, altPixelsPerDegree2];
            result.pixelsPerMeter2 = [altPixelsPerMeter2, 0, altPixelsPerMeter2];
        }

        // Main results, used for converting meters to latlng deltas and scaling offsets
        return result;
    }

    return class  {

        constructor(options) {
            this.id = options.id;
            this.type = "custom";
            this.renderingMode = '2d';
            this.url = options.url;
            if(!!!(options.tileType)){
                let tiles = options.subdomains.map(i => options.url.replaceAll('{s}',i));
                !(tiles.length) && (tiles = [options.url]);
                this.layerParams = {
                    source:{"type": "raster", tiles, "tileSize": 256},
                    layer:{"type": "raster", "source": options.id, "minzoom": options.minZoom || 0, "maxzoom": options.maxZoom || 18}
                }
            }

            this.options = {
                //服务器编号
                subdomains: null,
                minZoom: 3,
                maxZoom: 18,
                tileType: 'xyz' //bd09,xyz
            };
            setOptions(this, options); //合并属性

            //着色器程序
            this.program;

            //存放当前显示的瓦片
            this.showTiles = [];

            //存放所有加载过的瓦片
            this.tileCache = {};

            //存放瓦片号对应的经纬度
            this.gridCache = {};

            //记录渲染时的变换矩阵。
            //如果瓦片因为网速慢,在渲染完成后才加载过来,可以使用这个矩阵主动更新渲染
            this.matrix;

            this.map;

            //记录当前图层是否在显示
            this.isLayerShow;

            this.transformBaidu = new TransformClassBaidu();
        }

        onAdd(map, gl) {
            this.map = map;

            // 着色器程序参考:https://github.com/xiaoiver/custom-mapbox-layer/blob/master/src/shaders/project.glsl
            var vertexSource = "" + "uniform mat4 u_matrix;" + "attribute vec2 a_pos;" + "attribute vec2 a_TextCoord;" + "varying vec2 v_TextCoord;" + "const float TILE_SIZE = 512.0;" + "const float PI = 3.1415926536;" + "const float WORLD_SCALE = TILE_SIZE / (PI * 2.0);" + "uniform float u_project_scale;" + "uniform bool u_is_offset;" + "uniform vec3 u_pixels_per_degree;" + "uniform vec3 u_pixels_per_degree2;" + "uniform vec3 u_pixels_per_meter;" + "uniform vec2 u_viewport_center;" + "uniform vec4 u_viewport_center_projection;" + "uniform vec2 u_viewport_size;" + "float project_scale(float meters) {" + "    return meters * u_pixels_per_meter.z;" + "}" + "vec3 project_scale(vec3 position) {" + "    return position * u_pixels_per_meter;" + "}" + "vec2 project_mercator(vec2 lnglat) {" + "    float x = lnglat.x;" + "    return vec2(" + "    radians(x) + PI, PI - log(tan(PI * 0.25 + radians(lnglat.y) * 0.5))" + "    );" + "}" + "vec4 project_offset(vec4 offset) {" + "    float dy = offset.y;" + "    dy = clamp(dy, -1., 1.);" + "    vec3 pixels_per_unit = u_pixels_per_degree + u_pixels_per_degree2 * dy;" + "    return vec4(offset.xyz * pixels_per_unit, offset.w);" + "}" + "vec4 project_position(vec4 position) {" + "    if (u_is_offset) {" + "        float X = position.x - u_viewport_center.x;" + "        float Y = position.y - u_viewport_center.y;" + "        return project_offset(vec4(X, Y, position.z, position.w));" + "    }" + "    else {" + "        return vec4(" + "        project_mercator(position.xy) * WORLD_SCALE * u_project_scale, project_scale(position.z), position.w" + "        );" + "    }" + "}" + "vec4 project_to_clipping_space(vec3 position) {" + "    vec4 project_pos = project_position(vec4(position, 1.0));" + "    return u_matrix * project_pos + u_viewport_center_projection;" + "}" + "void main() {" + "   vec4 project_pos = project_position(vec4(a_pos, 0.0, 1.0));" + "   gl_Position = u_matrix * project_pos + u_viewport_center_projection;" + "   v_TextCoord = a_TextCoord;" + "}";

            var fragmentSource = "" + "precision mediump float;" + "uniform sampler2D u_Sampler; " + "varying vec2 v_TextCoord; " + "void main() {" + "   gl_FragColor = texture2D(u_Sampler, v_TextCoord);" +
                // "    gl_FragColor = vec4(1.0, 0.0, 0.0, 0.5);" +
                "}";

            //初始化顶点着色器
            var vertexShader = gl.createShader(gl.VERTEX_SHADER);
            gl.shaderSource(vertexShader, vertexSource);
            gl.compileShader(vertexShader);
            //初始化片元着色器
            var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
            gl.shaderSource(fragmentShader, fragmentSource);
            gl.compileShader(fragmentShader);
            //初始化着色器程序
            this.program = gl.createProgram();
            gl.attachShader(this.program, vertexShader);
            gl.attachShader(this.program, fragmentShader);
            gl.linkProgram(this.program);

            //获取顶点位置变量
            this.a_Pos = gl.getAttribLocation(this.program, "a_pos");
            this.a_TextCoord = gl.getAttribLocation(this.program, 'a_TextCoord');

            this.isLayerShow = true;
            map.on('move', () => {
                if (this.isLayerShow) this.update(gl, map);
            });
            this.update(gl, map);
        }

        update(gl, map) {
            var center = map.getCenter();
            var zoom;
            var bounds = map.getBounds();

            var minTile, maxTile;
            if (this.options.tileType === 'xyz') {
                zoom = parseInt(map.getZoom() + 1.4); //解决瓦片上文字偏大的问题
                //把当前显示范围做偏移,后面加载瓦片时会再偏移回来
                //如果不这样做的话,大比例尺时,瓦片偏移后,屏幕边缘会有空白区域
                var northWest = gcj02_To_gps84(bounds.getNorthWest());
                var southEast = gcj02_To_gps84(bounds.getSouthEast());
                //算出当前范围的瓦片编号
                minTile = lonLatToTileNumbers(northWest.lng, northWest.lat, zoom);
                maxTile = lonLatToTileNumbers(southEast.lng, southEast.lat, zoom);
            } else if (this.options.tileType === 'bd09') {
                zoom = parseInt(map.getZoom() + 1.8); //解决瓦片上文字偏大的问题
                var southWest = gps84_To_bd09(bounds.getSouthWest());
                var northEast = gps84_To_bd09(bounds.getNorthEast());
                minTile = this.transformBaidu.lnglatToTile(southWest.lng, southWest.lat, zoom);
                maxTile = this.transformBaidu.lnglatToTile(northEast.lng, northEast.lat, zoom);
            }
            var currentTiles = [];
            for (var x = minTile[0]; x <= maxTile[0]; x++) {
                for (var y = minTile[1]; y <= maxTile[1]; y++) {
                    var xyz = {
                        x: x,
                        y: y,
                        z: zoom
                    };
                    currentTiles.push(xyz);

                    //把瓦片号对应的经纬度缓存起来,
                    //存起来是因为贴纹理时需要瓦片4个角的经纬度,这样可以避免重复计算
                    //行和列向外多计算一个瓦片数,这样保证瓦片4个角都有经纬度可以取到
                    this.addGridCache(xyz, 0, 0);
                    if (x === maxTile[0]) this.addGridCache(xyz, 1, 0);
                    if (y === maxTile[1]) this.addGridCache(xyz, 0, 1);
                    if (x === maxTile[0] && y === maxTile[1]) this.addGridCache(xyz, 1, 1);
                }
            }

            //瓦片设置为从中间向周边的排序
            if (this.options.tileType === 'xyz') var centerTile = lonLatToTileNumbers(center.lng, center.lat, zoom); //计算中心点所在的瓦片号
            else if (this.options.tileType === 'bd09') centerTile = this.transformBaidu.lnglatToTile(center.lng, center.lat, zoom);
            currentTiles.sort((a, b) => {
                return this.tileDistance(a, centerTile) - this.tileDistance(b, centerTile);
            });

            //加载瓦片
            this.showTiles = [];
            for (var xyz of currentTiles) {
                //走缓存或新加载
                if (this.tileCache[this.createTileKey(xyz)]) {
                    this.showTiles.push(this.tileCache[this.createTileKey(xyz)]);
                } else {
                    var tile = this.createTile(gl, xyz);
                    this.showTiles.push(tile);
                    this.tileCache[this.createTileKey(xyz)] = tile;
                }
            }
        }

        //缓存瓦片号对应的经纬度
        addGridCache(xyz, xPlus, yPlus) {
            var key = this.createTileKey(xyz.x + xPlus, xyz.y + yPlus, xyz.z);
            if (!this.gridCache[key]) {
                if (this.options.tileType === 'xyz') this.gridCache[key] = gps84_To_gcj02(tileNumbersToLonLat(xyz.x + xPlus, xyz.y + yPlus, xyz.z));else if (this.options.tileType === 'bd09') this.gridCache[key] = bd09_To_gps84(this.transformBaidu.pixelToLnglat(0, 0, xyz.x + xPlus, xyz.y + yPlus, xyz.z));
            }
        }

        //计算两个瓦片编号的距离
        tileDistance(tile1, tile2) {
            //计算直角三角形斜边长度,c(斜边)=√(a²+b²)。(a,b为两直角边)
            return Math.sqrt(Math.pow(tile1.x - tile2[0], 2) + Math.pow(tile1.y - tile2[1], 2));
        }

        //创建瓦片id
        createTileKey(xyz, y, z) {
            if (xyz instanceof Object) {
                return xyz.z + '/' + xyz.x + '/' + xyz.y;
            } else {
                var x = xyz;
                return z + '/' + x + '/' + y;
            }
        }

        //创建瓦片
        createTile(gl, xyz) {
            //替换请求地址中的变量
            var _url = template(this.url, {
                s: this.options.subdomains[Math.abs(xyz.x + xyz.y) % this.options.subdomains.length],
                x: xyz.x,
                y: xyz.y,
                z: xyz.z
            });

            var tile = {
                xyz: xyz
            };

            //瓦片编号转经纬度,并进行偏移
            var leftTop, rightTop, leftBottom, rightBottom;
            if (this.options.tileType === 'xyz') {
                leftTop = this.gridCache[this.createTileKey(xyz)];
                rightTop = this.gridCache[this.createTileKey(xyz.x + 1, xyz.y, xyz.z)];
                leftBottom = this.gridCache[this.createTileKey(xyz.x, xyz.y + 1, xyz.z)];
                rightBottom = this.gridCache[this.createTileKey(xyz.x + 1, xyz.y + 1, xyz.z)];
            } else if (this.options.tileType === 'bd09') {
                leftTop = this.gridCache[this.createTileKey(xyz.x, xyz.y + 1, xyz.z)];
                rightTop = this.gridCache[this.createTileKey(xyz.x + 1, xyz.y + 1, xyz.z)];
                leftBottom = this.gridCache[this.createTileKey(xyz)];
                rightBottom = this.gridCache[this.createTileKey(xyz.x + 1, xyz.y, xyz.z)];
            }

            //顶点坐标+纹理坐标
            var attrData = new Float32Array([leftTop.lng, leftTop.lat, 0.0, 1.0, leftBottom.lng, leftBottom.lat, 0.0, 0.0, rightTop.lng, rightTop.lat, 1.0, 1.0, rightBottom.lng, rightBottom.lat, 1.0, 0.0]);
            // var attrData = new Float32Array([
            //     116.38967958133532, 39.90811009556515, 0.0, 1.0,
            //     116.38967958133532, 39.90294980726742, 0.0, 0.0,
            //     116.39486013141436, 39.90811009556515, 1.0, 1.0,
            //     116.39486013141436, 39.90294980726742, 1.0, 0.0
            // ])
            var FSIZE = attrData.BYTES_PER_ELEMENT;
            //创建缓冲区并传入数据
            var buffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
            gl.bufferData(gl.ARRAY_BUFFER, attrData, gl.STATIC_DRAW);
            tile.buffer = buffer;
            //从缓冲区中获取顶点数据的参数
            tile.PosParam = {
                size: 2,
                stride: FSIZE * 4,
                offset: 0
                //从缓冲区中获取纹理数据的参数
            };tile.TextCoordParam = {
                size: 2,
                stride: FSIZE * 4,
                offset: FSIZE * 2

                //加载瓦片
            };var img = new Image();
            img.onload = () => {
                // 创建纹理对象
                tile.texture = gl.createTexture();
                //向target绑定纹理对象
                gl.bindTexture(gl.TEXTURE_2D, tile.texture);
                //对纹理进行Y轴反转
                gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, 1);
                //配置纹理图像
                gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, img);

                tile.isLoad = true;

                this.map.triggerRepaint(); //主动让地图重绘
            };
            img.crossOrigin = true;
            img.src = _url;

            return tile;
        }

        //渲染
        render(gl, matrix) {

            if (this.map.getZoom() < this.options.minZoom || this.map.getZoom() > this.options.maxZoom) return;

            //记录变换矩阵,用于瓦片加载后主动绘制
            this.matrix = matrix;

            //应用着色程序
            //必须写到这里,不能写到onAdd中,不然gl中的着色程序可能不是上面写的,会导致下面的变量获取不到
            gl.useProgram(this.program);

            for (var tile of this.showTiles) {
                if (!tile.isLoad) continue;

                //向target绑定纹理对象
                gl.bindTexture(gl.TEXTURE_2D, tile.texture);
                //开启0号纹理单元
                gl.activeTexture(gl.TEXTURE0);
                //配置纹理参数
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
                gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.MIRRORED_REPEAT);
                // 获取纹理的存储位置
                var u_Sampler = gl.getUniformLocation(this.program, 'u_Sampler');
                //将0号纹理传递给着色器
                gl.uniform1i(u_Sampler, 0);

                gl.bindBuffer(gl.ARRAY_BUFFER, tile.buffer);
                //设置从缓冲区获取顶点数据的规则
                gl.vertexAttribPointer(this.a_Pos, tile.PosParam.size, gl.FLOAT, false, tile.PosParam.stride, tile.PosParam.offset);
                gl.vertexAttribPointer(this.a_TextCoord, tile.TextCoordParam.size, gl.FLOAT, false, tile.TextCoordParam.stride, tile.TextCoordParam.offset);
                //激活顶点数据缓冲区
                gl.enableVertexAttribArray(this.a_Pos);
                gl.enableVertexAttribArray(this.a_TextCoord);

                // 设置位置的顶点参数
                this.setVertex(gl);

                //开启阿尔法混合,实现注记半透明效果
                gl.enable(gl.BLEND);
                gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);

                //绘制图形
                gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
            }
        }

        // 设置位置的顶点参数
        //参考:https://github.com/xiaoiver/custom-mapbox-layer/blob/master/src/layers/PointCloudLayer2.ts
        setVertex(gl) {
            const currentZoomLevel = this.map.getZoom();
            const bearing = this.map.getBearing();
            const pitch = this.map.getPitch();
            const center = this.map.getCenter();

            const viewport = new WebMercatorViewport({
                // width: gl.drawingBufferWidth*1.11,
                // height: gl.drawingBufferHeight*1.11,
                width: gl.drawingBufferWidth,
                height: gl.drawingBufferHeight,

                longitude: center.lng,
                latitude: center.lat,
                zoom: currentZoomLevel,
                pitch,
                bearing
            });

            // @ts-ignore
            const { viewProjectionMatrix, projectionMatrix, viewMatrix, viewMatrixUncentered } = viewport;

            let drawParams = {
                // @ts-ignore
                'u_matrix': viewProjectionMatrix,
                'u_point_size': this.pointSize,
                'u_is_offset': false,
                'u_pixels_per_degree': [0, 0, 0],
                'u_pixels_per_degree2': [0, 0, 0],
                'u_viewport_center': [0, 0],
                'u_pixels_per_meter': [0, 0, 0],
                'u_project_scale': zoomToScale(currentZoomLevel),
                'u_viewport_center_projection': [0, 0, 0, 0]
            };

            if (currentZoomLevel > 12) {
                const { pixelsPerDegree, pixelsPerDegree2 } = getDistanceScales({
                    longitude: center.lng,
                    latitude: center.lat,
                    zoom: currentZoomLevel,
                    highPrecision: true
                });

                const positionPixels = viewport.projectFlat([Math.fround(center.lng), Math.fround(center.lat)], Math.pow(2, currentZoomLevel));

                const projectionCenter = transformMat4([], [positionPixels[0], positionPixels[1], 0.0, 1.0], viewProjectionMatrix);

                // Always apply uncentered projection matrix if available (shader adds center)
                let viewMatrix2 = viewMatrixUncentered || viewMatrix;

                // Zero out 4th coordinate ("after" model matrix) - avoids further translations
                // viewMatrix = new Matrix4(viewMatrixUncentered || viewMatrix)
                //   .multiplyRight(VECTOR_TO_POINT_MATRIX);
                let viewProjectionMatrix2 = multiply([], projectionMatrix, viewMatrix2);
                const VECTOR_TO_POINT_MATRIX = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0];
                viewProjectionMatrix2 = multiply([], viewProjectionMatrix2, VECTOR_TO_POINT_MATRIX);

                drawParams['u_matrix'] = viewProjectionMatrix2;
                drawParams['u_is_offset'] = true;
                drawParams['u_viewport_center'] = [Math.fround(center.lng), Math.fround(center.lat)];
                // @ts-ignore
                drawParams['u_viewport_center_projection'] = projectionCenter;
                drawParams['u_pixels_per_degree'] = pixelsPerDegree && pixelsPerDegree.map(p => Math.fround(p));
                drawParams['u_pixels_per_degree2'] = pixelsPerDegree2 && pixelsPerDegree2.map(p => Math.fround(p));
            }

            gl.uniformMatrix4fv(gl.getUniformLocation(this.program, "u_matrix"), false, drawParams['u_matrix']);

            gl.uniform1f(gl.getUniformLocation(this.program, "u_project_scale"), drawParams['u_project_scale']);
            gl.uniform1i(gl.getUniformLocation(this.program, "u_is_offset"), drawParams['u_is_offset'] ? 1 : 0);
            gl.uniform3fv(gl.getUniformLocation(this.program, "u_pixels_per_degree"), drawParams['u_pixels_per_degree']);
            gl.uniform3fv(gl.getUniformLocation(this.program, "u_pixels_per_degree2"), drawParams['u_pixels_per_degree2']);
            gl.uniform3fv(gl.getUniformLocation(this.program, "u_pixels_per_meter"), drawParams['u_pixels_per_meter']);
            gl.uniform2fv(gl.getUniformLocation(this.program, "u_viewport_center"), drawParams['u_viewport_center']);
            gl.uniform4fv(gl.getUniformLocation(this.program, "u_viewport_center_projection"), drawParams['u_viewport_center_projection']);
        }

        //当map移除当前图层时调用
        onRemove(map, gl) {
            this.isLayerShow = false;
        }

        addTo(map){
            this.map = map;
            if(!this.layerParams) return map.addLayer(this);
            this.map.addSource(this.id,this.layerParams.source);
            this.map.addLayer({id:this.id,...this.layerParams.layer});
        }

        remove(map, gl) {
            if(!this.map) return console.warn(`Please trigger "addTo" This method is called after the "map" instance is passed in;`);
            let layer = this.map.getLayer(this.id);
            if(!layer) return console.warn(`The current layer has not been added to the map;`);
            this.map.removeLayer(this.id);
        }

        hide(){
            this.isLayerShow = false;
            this.map.setLayoutProperty(this.id, 'visibility', 'none');
        }

        show(){
            this.isLayerShow = true;
            this.map.setLayoutProperty(this.id, 'visibility', 'visible');
        }
    }
})));