http://api.map.baidu.com/lbsapi/getpoint/index.html
https://blog.csdn.net/doulejian/article/details/70155080
/**
* 百度经纬度坐标 、 百度墨卡托坐标(ESPG:3857)
*/
var EARTHRADIUS = 6370996.81;
var MCBAND = [12890594.86, 8362377.87, 5591021, 3481989.83, 1678043.12, 0];
var LLBAND = [75, 60, 45, 30, 15, 0];
var MC2LL = [[1.410526172116255e-8, 0.00000898305509648872, -1.9939833816331, 200.9824383106796, -187.2403703815547, 91.6087516669843, -23.38765649603339, 2.57121317296198, -0.03801003308653, 17337981.2], [-7.435856389565537e-9, 0.000008983055097726239, -0.78625201886289, 96.32687599759846, -1.85204757529826, -59.36935905485877, 47.40033549296737, -16.50741931063887, 2.28786674699375, 10260144.86], [-3.030883460898826e-8, 0.00000898305509983578, 0.30071316287616, 59.74293618442277, 7.357984074871, -25.38371002664745, 13.45380521110908, -3.29883767235584, 0.32710905363475, 6856817.37], [-1.981981304930552e-8, 0.000008983055099779535, 0.03278182852591, 40.31678527705744, 0.65659298677277, -4.44255534477492, 0.85341911805263, 0.12923347998204, -0.04625736007561, 4482777.06], [3.09191371068437e-9, 0.000008983055096812155, 0.00006995724062, 23.10934304144901, -0.00023663490511, -0.6321817810242, -0.00663494467273, 0.03430082397953, -0.00466043876332, 2555164.4], [2.890871144776878e-9, 0.000008983055095805407, -3.068298e-8, 7.47137025468032, -0.00000353937994, -0.02145144861037, -0.00001234426596, 0.00010322952773, -0.00000323890364, 826088.5]];
var LL2MC = [[-0.0015702102444, 111320.7020616939, 1704480524535203, -10338987376042340, 26112667856603880, -35149669176653700, 26595700718403920, -10725012454188240, 1800819912950474, 82.5], [0.0008277824516172526, 111320.7020463578, 647795574.6671607, -4082003173.641316, 10774905663.51142, -15171875531.51559, 12053065338.62167, -5124939663.577472, 913311935.9512032, 67.5], [0.00337398766765, 111320.7020202162, 4481351.045890365, -23393751.19931662, 79682215.47186455, -115964993.2797253, 97236711.15602145, -43661946.33752821, 8477230.501135234, 52.5], [0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5], [-0.0003441963504368392, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5], [-0.0003218135878613132, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45]];
function main(args) {
//经纬度坐标
var lng = 116.403891,
lat = 39.914552;
//百度经纬度坐标转百度墨卡托坐标
var location = convertLL2MC(lng, lat);
console.info("bd_mc: " + location[1] + "," + location[0]);
//百度墨卡托坐标转百度经纬度坐标
location = convertMC2LL(location[1],location[0]);
console.info("bd: " + location[1] + "," + location[0]);
}
main();
/**
* 百度墨卡托坐标 转 百度经纬度坐标
* @param x
* @param y
* @return
*/
function convertMC2LL(lng,lat) {
var cF = null;
lng = Math.abs(lng);
lat = Math.abs(lat);
for (var cE = 0; cE < MCBAND.length; cE++) {
if (lat >= MCBAND[cE]) {
cF = MC2LL[cE];
break;
}
}
return converter(lng, lat, cF);
}
/**
* 百度经纬度坐标 转 转百度墨卡托坐标
* @param lng
* @param lat
* @return
*/
function convertLL2MC(lng,lat) {
var cE = null;
lng = getLoop(lng, -180, 180);
lat = getRange(lat, -74, 74);
for (var i = 0; i < LLBAND.length; i++) {
if (lat >= LLBAND[i]) {
cE = LL2MC[i];
break;
}
}
if (cE!=null) {
for (var i = LLBAND.length - 1; i >= 0; i--) {
if (lat <= -LLBAND[i]) {
cE = LL2MC[i];
break;
}
}
}
return converter(lng,lat, cE);
}
function converter(lng, lat, cE) {
var lngTemp = cE[0] + cE[1] * Math.abs(lng);
var cC = Math.abs(lat) / cE[9];
var latTemp = cE[2] + cE[3] * cC + cE[4] * cC * cC + cE[5] * cC * cC * cC + cE[6] * cC * cC * cC * cC + cE[7] * cC * cC * cC * cC * cC + cE[8] * cC * cC * cC * cC * cC * cC;
lngTemp *= (lng < 0 ? -1 : 1);
latTemp *= (lat < 0 ? -1 : 1);
return [latTemp,lngTemp];
}
function getLoop(lng, min, max) {
while (lng > max) {
lng -= max - min;
}
while (lng < min) {
lng += max - min;
}
return lng;
}
function getRange(lat, min, max) {
if (min != null) {
lat = Math.max(lat, min);
}
if (max != null) {
lat = Math.min(lat, max);
}
return lat;
}