/*
* Mercator projection that takes into account that the Earth is not a perfect sphere.
* Less popular than spherical mercator; used by projections like EPSG:3395.
*/
L.Projection.Mercator = {
MAX_LATITUDE: 85.0840591556,
R_MINOR: 6356752.3142,
R_MAJOR: 6378137,
project: function (latlng) { // (LatLng) -> Point
var d = L.LatLng.DEG_TO_RAD,
max = this.MAX_LATITUDE,
lat = Math.max(Math.min(max, latlng.lat), -max),
r = this.R_MAJOR,
r2 = this.R_MINOR,
x = latlng.lng * d * r,
y = lat * d,
tmp = r2 / r,
eccent = Math.sqrt(1.0 - tmp * tmp),
con = eccent * Math.sin(y);
con = Math.pow((1 - con) / (1 + con), eccent * 0.5);
var ts = Math.tan(0.5 * ((Math.PI * 0.5) - y)) / con;
y = -r2 * Math.log(ts);
return new L.Point(x, y);
},
unproject: function (point) { // (Point, Boolean) -> LatLng
var d = L.LatLng.RAD_TO_DEG,
r = this.R_MAJOR,
r2 = this.R_MINOR,
lng = point.x * d / r,
tmp = r2 / r,
eccent = Math.sqrt(1 - (tmp * tmp)),
ts = Math.exp(- point.y / r2),
phi = (Math.PI / 2) - 2 * Math.atan(ts),
numIter = 15,
tol = 1e-7,
i = numIter,
dphi = 0.1,
con;
while ((Math.abs(dphi) > tol) && (--i > 0)) {
con = eccent * Math.sin(phi);
dphi = (Math.PI / 2) - 2 * Math.atan(ts *
Math.pow((1.0 - con) / (1.0 + con), 0.5 * eccent)) - phi;
phi += dphi;
}
return new L.LatLng(phi * d, lng);
}
};
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