JS大地坐标与经纬度坐标互转

// JS大地坐标与经纬度坐标互转
let locationFun = {
    GaussToBL: function (X, Y) { // 高斯投影坐标反算成经纬度
        let ProjNo;
        let ZoneWide;
        let output = new Array(2);
        let longitude1, latitude1, longitude0, X0, Y0, xval, yval;
        let e1, e2, f, a, ee, NN, T, C, M, D, R, u, fai, iPI;
        iPI = 3.14159265358979324 / 180.0; // 3.1415926535898 / 180.0;
        // a = 6378245.0; f = 1.0/298.3; //54年北京坐标系参数
        a = 6378140.0;
        f = 1.0 / 298.257; //80年西安坐标系参数
        ZoneWide = 6;
        ProjNo = parseInt(X / 1000000);
        longitude0 = (ProjNo - 1) * ZoneWide + ZoneWide / 2;
        longitude0 = longitude0 * iPI;

        X0 = ProjNo * 1000000 + 500000;
        Y0 = 0;
        xval = X - X0;
        yval = Y - Y0;
        e2 = 2 * f - f * f;
        e1 = (1.0 - Math.sqrt(1 - e2)) / (1.0 + Math.sqrt(1 - e2));
        ee = e2 / (1 - e2);
        M = yval;
        u = M / (a * (1 - e2 / 4 - 3 * e2 * e2 / 64 - 5 * e2 * e2 * e2 / 256));
        fai = u + (3 * e1 / 2 - 27 * e1 * e1 * e1 / 32) * Math.sin(2 * u) + (21 * e1 * e1 / 16 - 55 * e1 * e1 * e1 * e1 / 32) * Math.sin(4 * u) + (151 * e1 * e1 * e1 / 96) * Math.sin(6 * u) + (1097 * e1 * e1 * e1 * e1 / 512) * Math.sin(8 * u);
        C = ee * Math.cos(fai) * Math.cos(fai);
        T = Math.tan(fai) * Math.tan(fai);
        NN = a / Math.sqrt(1.0 - e2 * Math.sin(fai) * Math.sin(fai));
        R = a * (1 - e2) / Math.sqrt((1 - e2 * Math.sin(fai) * Math.sin(fai)) * (1 - e2 * Math.sin(fai) * Math.sin(fai)) * (1 - e2 * Math.sin(fai) * Math.sin(fai)));
        D = xval / NN;
        // 计算经度(Longitude) 纬度(Latitude)
        longitude1 = longitude0 + (D - (1 + 2 * T + C) * D * D * D / 6 + (5 - 2 * C + 28 * T - 3 * C * C + 8 * ee + 24 * T * T) * D * D * D * D * D / 120) / Math.cos(fai);
        latitude1 = fai - (NN * Math.tan(fai) / R) * (D * D / 2 - (5 + 3 * T + 10 * C - 4 * C * C - 9 * ee) * D * D * D * D / 24 + (61 + 90 * T + 298 * C + 45 * T * T - 256 * ee - 3 * C * C) * D * D * D * D * D * D / 720);
        // 转换为度 DD
        output[0] = longitude1 / iPI;
        output[1] = latitude1 / iPI;
        return output;
    },
    BLToGauss: function (longitude, latitude) { //经纬度=>高斯投影
        let ProjNo = 0;
        let ZoneWide;
        let ret = Array(2);
        let longitude1, latitude1, longitude0, latitude0, X0, Y0, xval, yval;
        let a, f, e2, ee, NN, T, C, A, M, iPI;
        iPI = 0.0174532925199433; // 3.1415926535898 / 180.0;
        ZoneWide = 6;
        // a=6378245.0; f=1.0/298.3; //54年北京坐标系参数
        a = 6378140.0;
        f = 1 / 298.257; //80年西安坐标系参数
        ProjNo = parseInt(longitude / ZoneWide);
        longitude0 = ProjNo * ZoneWide + ZoneWide / 2;
        longitude0 = longitude0 * iPI;
        latitude0 = 0;
        longitude1 = longitude * iPI; // 经度转换为弧度
        latitude1 = latitude * iPI; // 纬度转换为弧度
        e2 = 2 * f - f * f;
        ee = e2 * (1.0 - e2);
        NN = a / Math.sqrt(1.0 - e2 * Math.sin(latitude1) * Math.sin(latitude1));
        T = Math.tan(latitude1) * Math.tan(latitude1);
        C = ee * Math.cos(latitude1) * Math.cos(latitude1);
        A = (longitude1 - longitude0) * Math.cos(latitude1);
        M = a * ((1 - e2 / 4 - 3 * e2 * e2 / 64 - 5 * e2 * e2 * e2 / 256) * latitude1 - (3 * e2 / 8 + 3 * e2 * e2 / 32 + 45 * e2 * e2 * e2 / 1024) * Math.sin(2 * latitude1) + (15 * e2 * e2 / 256 + 45 * e2 * e2 * e2 / 1024) * Math.sin(4 * latitude1) - (35 * e2 * e2 * e2 / 3072) * Math.sin(6 * latitude1));
        xval = NN * (A + (1 - T + C) * A * A * A / 6 + (5 - 18 * T + T * T + 72 * C - 58 * ee) * A * A * A * A * A / 120);
        yval = M + NN * Math.tan(latitude1) * (A * A / 2 + (5 - T + 9 * C + 4 * C * C) * A * A * A * A / 24 + (61 - 58 * T + T * T + 600 * C - 330 * ee) * A * A * A * A * A * A / 720);
        X0 = 1000000 * (ProjNo + 1) + 500000;
        Y0 = 0;
        xval = xval + X0;
        yval = yval + Y0;
        ret[0] = xval;
        ret[1] = yval;

        return ret;
    }
}

export default locationFun