var x_pi = 3.14159265358979324 * 3000.0 / 180.0;
var PI = 3.14159265358979324;
const a = 6378245.0;
const ee = 0.00669342162296594323;
var mapZbConvert = {
    // 百度坐标bd09II转火星坐标GCJ02
    baiduTomars: function (baidu_point) {
        var mars_point = { x: 0, y: 0 };
        var x = baidu_point.x - 0.0065;
        var y = baidu_point.y - 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);
        mars_point.x = z * Math.cos(theta);
        mars_point.y = z * Math.sin(theta);
        return mars_point;
    },

    // 火星坐标系GCJ02转地球坐标系WGS84
    transformGCJ2WGS: function (gcjLat, gcjLon) {
        let d = this.delta(gcjLat, gcjLon)
        return {
            'lat': gcjLat - d.lat,
            'lon': gcjLon - d.lon
        }
    },

    delta: function (lat, lon) {
        let a = 6378245.0 //  a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
        let ee = 0.00669342162296594323 //  ee: 椭球的偏心率。
        let dLat = this.transformLat(lon - 105.0, lat - 35.0)
        let dLon = this.transformLon(lon - 105.0, lat - 35.0)
        let radLat = lat / 180.0 * PI
        let magic = Math.sin(radLat)
        magic = 1 - ee * magic * magic
        let sqrtMagic = Math.sqrt(magic)
        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * PI)
        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * PI)
        return {
            'lat': dLat,
            'lon': dLon
        }
    },
    transformLat: function (x, y) {
        let 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
    },
    transformLon: function (x, y) {
        let 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
    },
    // 经纬度转墨卡托
    lonlatTomercator: function (lonlat) {
        var mercator = { x: 0, y: 0 };
        var x = lonlat.x * 20037508.34 / 180;
        var y = Math.log(Math.tan((90 + lonlat.y) * Math.PI / 360)) / (Math.PI / 180);
        y = y * 20037508.34 / 180;
        // mercator.x = x * parseFloat('0.597171361602');
        // mercator.y = y * parseFloat('0.593350031602‬');
        mercator.x = x;
        mercator.y = y;
        return mercator;
    },
    // 墨卡托转 经纬度
    mercatorTolonlat: function (mercator) {
        var lonlat = { x: 0, y: 0 };
        var x = mercator.x / 20037508.34 * 180;
        var y = mercator.y / 20037508.34 * 180;
        y = 180 / Math.PI * (2 * Math.atan(Math.exp(y * Math.PI / 180)) - Math.PI / 2);
        // lonlat.x = x / parseFloat('0.597171361602');
        // lonlat.y = y / parseFloat('0.604060871602‬');
        lonlat.x = x;
        lonlat.y = y;
        return lonlat;
    },
    wgs84togcj02(lng, lat) {
        lat = +lat;
        lng = +lng;
        if (out_of_china(lng, lat)) {
            return [lng, lat]
        } else {
            let dlat = this.transformLat(lng - 105.0, lat - 35.0);
            let dlng = this.transformLon(lng - 105.0, lat - 35.0);
            let radlat = lat / 180.0 * PI;
            let magic = Math.sin(radlat);
            magic = 1 - ee * magic * magic;
            let sqrtmagic = Math.sqrt(magic);
            dlat = (dlat * 180.0) / ((a * (1 - ee)) / (magic * sqrtmagic) * PI);
            dlng = (dlng * 180.0) / (a / sqrtmagic * Math.cos(radlat) * PI);
            let mglat = lat + dlat;
            let mglng = lng + dlng;
            return [mglng, mglat]
        }
    }
}

function out_of_china(lng, lat) {
    lat = +lat;
    lng = +lng;
    // 纬度3.86~53.55,经度73.66~135.05
    return !(lng > 73.66 && lng < 135.05 && lat > 3.86 && lat < 53.55);
}