// 两点之间的距离
const EARTH_RADIUS = 6378137.0; //单位M
const PI = Math.PI;
const getRad = (d) => d * PI / 180.0;
function getDistance(lat1, lng1, lat2, lng2) {
[lat1, lng1, lat2, lng2] = [Number(lat1), Number(lng1), Number(lat2), Number(lng2)];
let f = getRad((lat1 + lat2) / 2);
let g = getRad((lat1 - lat2) / 2);
let l = getRad((lng1 - lng2) / 2);
let sg = Math.sin(g);
let sl = Math.sin(l);
let sf = Math.sin(f);
let s, c, w, r, d, h1, h2;
let a = EARTH_RADIUS;
let fl = 1 / 298.257;
sg = sg * sg;
sl = sl * sl;
sf = sf * sf;
s = sg * (1 - sl) + (1 - sf) * sl;
c = (1 - sg) * (1 - sl) + sf * sl;
w = Math.atan(Math.sqrt(s / c));
r = Math.sqrt(s * c) / w;
d = 2 * w * a;
h1 = (3 * r - 1) / 2 / c;
h2 = (3 * r + 1) / 2 / s;
let distance = d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg)); // 单位m
let duration = distance / 1000 * 3600 / 30; // 外卖员送外卖速度 30km/小时,转换km(千米),换算用时s(秒)
return { distance, duration, from: { lng: lng1, lat: lat1 }, to: { lng: lng2, lat: lat2 } }
}
结果如下: