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import {atan, exp, halfPi, log, pi, tan, tau} from "../math.js";
import rotation from "../rotation.js";
import projection from "./index.js";
export function mercatorRaw(lambda, phi) {
return [lambda, log(tan((halfPi + phi) / 2))];
}
mercatorRaw.invert = function(x, y) {
return [x, 2 * atan(exp(y)) - halfPi];
};
export default function() {
return mercatorProjection(mercatorRaw)
.scale(961 / tau);
}
export function mercatorProjection(project) {
var m = projection(project),
center = m.center,
scale = m.scale,
translate = m.translate,
clipExtent = m.clipExtent,
x0 = null, y0, x1, y1; // clip extent
m.scale = function(_) {
return arguments.length ? (scale(_), reclip()) : scale();
};
m.translate = function(_) {
return arguments.length ? (translate(_), reclip()) : translate();
};
m.center = function(_) {
return arguments.length ? (center(_), reclip()) : center();
};
m.clipExtent = function(_) {
return arguments.length ? ((_ == null ? x0 = y0 = x1 = y1 = null : (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1])), reclip()) : x0 == null ? null : [[x0, y0], [x1, y1]];
};
function reclip() {
var k = pi * scale(),
t = m(rotation(m.rotate()).invert([0, 0]));
return clipExtent(x0 == null
? [[t[0] - k, t[1] - k], [t[0] + k, t[1] + k]] : project === mercatorRaw
? [[Math.max(t[0] - k, x0), y0], [Math.min(t[0] + k, x1), y1]]
: [[x0, Math.max(t[1] - k, y0)], [x1, Math.min(t[1] + k, y1)]]);
}
return reclip();
}
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