微信小程序地图定位GPS转腾讯地图的坐标系

柔光的暖阳◎ 2022-03-15 17:52 671阅读 0赞

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//s
       var GPS = {
         PI: 3.14159265358979324,
         x_pi: 3.14159265358979324 * 3000.0 / 180.0,
         delta: function (lat, lon) {
           // Krasovsky 1940
           //
           // a = 6378245.0, 1/f = 298.3
           // b = a * (1 - f)
           // ee = (a^2 - b^2) / a^2;
           var 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。
           var ee = 0.00669342162296594323; //  ee: 椭球的偏心率。
           var dLat = this.transformLat(lon - 105.0, lat - 35.0);
           var dLon = this.transformLon(lon - 105.0, lat - 35.0);
           var radLat = lat / 180.0 * this.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) * this.PI);
           dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * this.PI);
           return { 'lat': dLat, 'lon': dLon };
         },
    
         //WGS-84 to GCJ-02
         gcj_encrypt: function (wgsLat, wgsLon) {
           if (this.outOfChina(wgsLat, wgsLon))
             return { 'lat': wgsLat, 'lon': wgsLon };
    
           var d = this.delta(wgsLat, wgsLon);
           return { 'lat': wgsLat + d.lat, 'lon': wgsLon + d.lon };
         },
         //GCJ-02 to WGS-84
         gcj_decrypt: function (gcjLat, gcjLon) {
           if (this.outOfChina(gcjLat, gcjLon))
             return { 'lat': gcjLat, 'lon': gcjLon };
    
           var d = this.delta(gcjLat, gcjLon);
           return { 'lat': gcjLat - d.lat, 'lon': gcjLon - d.lon };
         },
         //GCJ-02 to WGS-84 exactly
         gcj_decrypt_exact: function (gcjLat, gcjLon) {
           var initDelta = 0.01;
           var threshold = 0.000000001;
           var dLat = initDelta, dLon = initDelta;
           var mLat = gcjLat - dLat, mLon = gcjLon - dLon;
           var pLat = gcjLat + dLat, pLon = gcjLon + dLon;
           var wgsLat, wgsLon, i = 0;
           while (1) {
             wgsLat = (mLat + pLat) / 2;
             wgsLon = (mLon + pLon) / 2;
             var tmp = this.gcj_encrypt(wgsLat, wgsLon)
             dLat = tmp.lat - gcjLat;
             dLon = tmp.lon - gcjLon;
             if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold))
               break;
    
             if (dLat > 0) pLat = wgsLat; else mLat = wgsLat;
             if (dLon > 0) pLon = wgsLon; else mLon = wgsLon;
    
             if (++i > 10000) break;
           }
           //console.log(i);
           return { 'lat': wgsLat, 'lon': wgsLon };
         },
         //GCJ-02 to BD-09
         bd_encrypt: function (gcjLat, gcjLon) {
           var x = gcjLon, y = gcjLat;
           var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * this.x_pi);
           var theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * this.x_pi);
           bdLon = z * Math.cos(theta) + 0.0065;
           bdLat = z * Math.sin(theta) + 0.006;
           return { 'lat': bdLat, 'lon': bdLon };
         },
         //BD-09 to GCJ-02
         bd_decrypt: function (bdLat, bdLon) {
           var x = bdLon - 0.0065, y = bdLat - 0.006;
           var z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * this.x_pi);
           var theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * this.x_pi);
           var gcjLon = z * Math.cos(theta);
           var gcjLat = z * Math.sin(theta);
           return { 'lat': gcjLat, 'lon': gcjLon };
         },
         //WGS-84 to Web mercator
         //mercatorLat -> y mercatorLon -> x
         mercator_encrypt: function (wgsLat, wgsLon) {
           var x = wgsLon * 20037508.34 / 180.;
           var y = Math.log(Math.tan((90. + wgsLat) * this.PI / 360.)) / (this.PI / 180.);
           y = y * 20037508.34 / 180.;
           return { 'lat': y, 'lon': x };
           /*
           if ((Math.abs(wgsLon) > 180 || Math.abs(wgsLat) > 90))
               return null;
           var x = 6378137.0 * wgsLon * 0.017453292519943295;
           var a = wgsLat * 0.017453292519943295;
           var y = 3189068.5 * Math.log((1.0 + Math.sin(a)) / (1.0 - Math.sin(a)));
           return {'lat' : y, 'lon' : x};
           //*/
         },
         // Web mercator to WGS-84
         // mercatorLat -> y mercatorLon -> x
         mercator_decrypt: function (mercatorLat, mercatorLon) {
           var x = mercatorLon / 20037508.34 * 180.;
           var y = mercatorLat / 20037508.34 * 180.;
           y = 180 / this.PI * (2 * Math.atan(Math.exp(y * this.PI / 180.)) - this.PI / 2);
           return { 'lat': y, 'lon': x };
           /*
           if (Math.abs(mercatorLon) < 180 && Math.abs(mercatorLat) < 90)
               return null;
           if ((Math.abs(mercatorLon) > 20037508.3427892) || (Math.abs(mercatorLat) > 20037508.3427892))
               return null;
           var a = mercatorLon / 6378137.0 * 57.295779513082323;
           var x = a - (Math.floor(((a + 180.0) / 360.0)) * 360.0);
           var y = (1.5707963267948966 - (2.0 * Math.atan(Math.exp((-1.0 * mercatorLat) / 6378137.0)))) * 57.295779513082323;
           return {'lat' : y, 'lon' : x};
           //*/
         },
         // two point's distance
         distance: function (latA, lonA, latB, lonB) {
           var earthR = 6371000.;
           var x = Math.cos(latA * this.PI / 180.) * Math.cos(latB * this.PI / 180.) * Math.cos((lonA - lonB) * this.PI / 180);
           var y = Math.sin(latA * this.PI / 180.) * Math.sin(latB * this.PI / 180.);
           var s = x + y;
           if (s > 1) s = 1;
           if (s < -1) s = -1;
           var alpha = Math.acos(s);
           var distance = alpha * earthR;
           return distance;
         },
         outOfChina: function (lat, lon) {
           if (lon < 72.004 || lon > 137.8347)
             return true;
           if (lat < 0.8293 || lat > 55.8271)
             return true;
           return false;
         },
         transformLat: function (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 * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
           ret += (20.0 * Math.sin(y * this.PI) + 40.0 * Math.sin(y / 3.0 * this.PI)) * 2.0 / 3.0;
           ret += (160.0 * Math.sin(y / 12.0 * this.PI) + 320 * Math.sin(y * this.PI / 30.0)) * 2.0 / 3.0;
           return ret;
         },
         transformLon: function (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 * this.PI) + 20.0 * Math.sin(2.0 * x * this.PI)) * 2.0 / 3.0;
           ret += (20.0 * Math.sin(x * this.PI) + 40.0 * Math.sin(x / 3.0 * this.PI)) * 2.0 / 3.0;
           ret += (150.0 * Math.sin(x / 12.0 * this.PI) + 300.0 * Math.sin(x / 30.0 * this.PI)) * 2.0 / 3.0;
           return ret;
         }
       };
    
    
       //e

调用参考：  
[http://www.qchcloud.cn/tn/article/23][http_www.qchcloud.cn_tn_article_23]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3llYmljaGFv_size_16_color_FFFFFF_t_70]: /images/20220311/56e77dc0b0fb49a5af6616634f66cefa.png
[http_www.qchcloud.cn_tn_article_23]: http://www.qchcloud.cn/tn/article/23