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import {LatLng} from '../LatLng';
import {Bounds} from '../../geometry/Bounds';
import {Point} from '../../geometry/Point';
/*
* @namespace Projection
* @projection L.Projection.Mercator
*
* Elliptical Mercator projection — more complex than Spherical Mercator. Takes into account that Earth is a geoid, not a perfect sphere. Used by the EPSG:3395 CRS.
*/
export var Mercator = {
R: 6378137,
R_MINOR: 6356752.314245179,
bounds: new Bounds([-20037508.34279, -15496570.73972], [20037508.34279, 18764656.23138]),
project: function (latlng) {
var d = Math.PI / 180,
r = this.R,
y = latlng.lat * d,
tmp = this.R_MINOR / r,
e = Math.sqrt(1 - tmp * tmp),
con = e * Math.sin(y);
var ts = Math.tan(Math.PI / 4 - y / 2) / Math.pow((1 - con) / (1 + con), e / 2);
y = -r * Math.log(Math.max(ts, 1E-10));
return new Point(latlng.lng * d * r, y);
},
unproject: function (point) {
var d = 180 / Math.PI,
r = this.R,
tmp = this.R_MINOR / r,
e = Math.sqrt(1 - tmp * tmp),
ts = Math.exp(-point.y / r),
phi = Math.PI / 2 - 2 * Math.atan(ts);
for (var i = 0, dphi = 0.1, con; i < 15 && Math.abs(dphi) > 1e-7; i++) {
con = e * Math.sin(phi);
con = Math.pow((1 - con) / (1 + con), e / 2);
dphi = Math.PI / 2 - 2 * Math.atan(ts * con) - phi;
phi += dphi;
}
return new LatLng(phi * d, point.x * d / r);
}
};
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