chat-app/src/utils/index.js

// BD-09 转 GCJ-02
export const bd09togcj02 = (bd_lon, bd_lat) => {
  const x_pi = (3.14159265358979324 * 3000.0) / 180.0;
  const x = bd_lon - 0.0065;
  const y = bd_lat - 0.006;
  const z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * x_pi);
  const theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * x_pi);
  const gg_lon = z * Math.cos(theta);
  const gg_lat = z * Math.sin(theta);
  return [gg_lon, gg_lat];
}
// GCJ-02 转 WGS-84
export const gcj02towgs84 = (lon, lat) => {
  const PI = 3.1415926535897932384626;
  const a = 6378245.0;
  const ee = 0.00669342162296594323;

  const transformLat = (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;
  };

  const transformLon = (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;
  };

  const dLat = transformLat(lon - 105.0, lat - 35.0);
  const dLon = transformLon(lon - 105.0, lat - 35.0);
  const radLat = (lat / 180.0) * PI;
  let magic = Math.sin(radLat);
  magic = 1 - ee * magic * magic;
  const sqrtMagic = Math.sqrt(magic);
  const mgLat =
    lat + (dLat * 180.0) / (((a * (1 - ee)) / (magic * sqrtMagic)) * PI);
  const mgLon =
    lon + (dLon * 180.0) / ((a / sqrtMagic) * Math.cos(radLat) * PI);
  return [lon * 2 - mgLon, lat * 2 - mgLat];
}

export const convertBd09ToWgs84 = (bd_lon, bd_lat) => {
  const gcj02 = this.bd09togcj02(bd_lon, bd_lat);
  const wgs84 = this.gcj02towgs84(gcj02[0], gcj02[1]);
  return {
    longitude: wgs84[0],
    latitude: wgs84[1],
  };
}

export const uniqueId = () => 'id-' + new Date().getTime().toString(36) + '-' + Math.random().toString(36).substr(2, 9);