Function mercatorProjection

external/.d3.js:12610–12644

(project)

}

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$1 * 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();
}

function tany(y) {
  return tan((halfPi$1 + y) / 2);