node-red-contrib-tak-registration/node_modules/d3-geo/build/d3-geo.js

A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK

// https://d3js.org/d3-geo/ Version 1.7.1. Copyright 2017 Mike Bostock.
(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3-array')) :
	typeof define === 'function' && define.amd ? define(['exports', 'd3-array'], factory) :
	(factory((global.d3 = global.d3 || {}),global.d3));
}(this, (function (exports,d3Array) { 'use strict';

// Adds floating point numbers with twice the normal precision.
// Reference: J. R. Shewchuk, Adaptive Precision Floating-Point Arithmetic and
// Fast Robust Geometric Predicates, Discrete & Computational Geometry 18(3)
// 305–363 (1997).
// Code adapted from GeographicLib by Charles F. F. Karney,
// http://geographiclib.sourceforge.net/

var adder = function() {
  return new Adder;
};

function Adder() {
  this.reset();
}

Adder.prototype = {
  constructor: Adder,
  reset: function() {
    this.s = // rounded value
    this.t = 0; // exact error
  },
  add: function(y) {
    add(temp, y, this.t);
    add(this, temp.s, this.s);
    if (this.s) this.t += temp.t;
    else this.s = temp.t;
  },
  valueOf: function() {
    return this.s;
  }
};

var temp = new Adder;

function add(adder, a, b) {
  var x = adder.s = a + b,
      bv = x - a,
      av = x - bv;
  adder.t = (a - av) + (b - bv);
}

var epsilon = 1e-6;
var epsilon2 = 1e-12;
var pi = Math.PI;
var halfPi = pi / 2;
var quarterPi = pi / 4;
var tau = pi * 2;

var degrees = 180 / pi;
var radians = pi / 180;

var abs = Math.abs;
var atan = Math.atan;
var atan2 = Math.atan2;
var cos = Math.cos;
var ceil = Math.ceil;
var exp = Math.exp;

var log = Math.log;
var pow = Math.pow;
var sin = Math.sin;
var sign = Math.sign || function(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; };
var sqrt = Math.sqrt;
var tan = Math.tan;

function acos(x) {
  return x > 1 ? 0 : x < -1 ? pi : Math.acos(x);
}

function asin(x) {
  return x > 1 ? halfPi : x < -1 ? -halfPi : Math.asin(x);
}

function haversin(x) {
  return (x = sin(x / 2)) * x;
}

function noop() {}

function streamGeometry(geometry, stream) {
  if (geometry && streamGeometryType.hasOwnProperty(geometry.type)) {
    streamGeometryType[geometry.type](geometry, stream);
  }
}

var streamObjectType = {
  Feature: function(object, stream) {
    streamGeometry(object.geometry, stream);
  },
  FeatureCollection: function(object, stream) {
    var features = object.features, i = -1, n = features.length;
    while (++i < n) streamGeometry(features[i].geometry, stream);
  }
};

var streamGeometryType = {
  Sphere: function(object, stream) {
    stream.sphere();
  },
  Point: function(object, stream) {
    object = object.coordinates;
    stream.point(object[0], object[1], object[2]);
  },
  MultiPoint: function(object, stream) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) object = coordinates[i], stream.point(object[0], object[1], object[2]);
  },
  LineString: function(object, stream) {
    streamLine(object.coordinates, stream, 0);
  },
  MultiLineString: function(object, stream) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) streamLine(coordinates[i], stream, 0);
  },
  Polygon: function(object, stream) {
    streamPolygon(object.coordinates, stream);
  },
  MultiPolygon: function(object, stream) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) streamPolygon(coordinates[i], stream);
  },
  GeometryCollection: function(object, stream) {
    var geometries = object.geometries, i = -1, n = geometries.length;
    while (++i < n) streamGeometry(geometries[i], stream);
  }
};

function streamLine(coordinates, stream, closed) {
  var i = -1, n = coordinates.length - closed, coordinate;
  stream.lineStart();
  while (++i < n) coordinate = coordinates[i], stream.point(coordinate[0], coordinate[1], coordinate[2]);
  stream.lineEnd();
}

function streamPolygon(coordinates, stream) {
  var i = -1, n = coordinates.length;
  stream.polygonStart();
  while (++i < n) streamLine(coordinates[i], stream, 1);
  stream.polygonEnd();
}

var geoStream = function(object, stream) {
  if (object && streamObjectType.hasOwnProperty(object.type)) {
    streamObjectType[object.type](object, stream);
  } else {
    streamGeometry(object, stream);
  }
};

var areaRingSum = adder();

var areaSum = adder();
var lambda00;
var phi00;
var lambda0;
var cosPhi0;
var sinPhi0;

var areaStream = {
  point: noop,
  lineStart: noop,
  lineEnd: noop,
  polygonStart: function() {
    areaRingSum.reset();
    areaStream.lineStart = areaRingStart;
    areaStream.lineEnd = areaRingEnd;
  },
  polygonEnd: function() {
    var areaRing = +areaRingSum;
    areaSum.add(areaRing < 0 ? tau + areaRing : areaRing);
    this.lineStart = this.lineEnd = this.point = noop;
  },
  sphere: function() {
    areaSum.add(tau);
  }
};

function areaRingStart() {
  areaStream.point = areaPointFirst;
}

function areaRingEnd() {
  areaPoint(lambda00, phi00);
}

function areaPointFirst(lambda, phi) {
  areaStream.point = areaPoint;
  lambda00 = lambda, phi00 = phi;
  lambda *= radians, phi *= radians;
  lambda0 = lambda, cosPhi0 = cos(phi = phi / 2 + quarterPi), sinPhi0 = sin(phi);
}

function areaPoint(lambda, phi) {
  lambda *= radians, phi *= radians;
  phi = phi / 2 + quarterPi; // half the angular distance from south pole

  // Spherical excess E for a spherical triangle with vertices: south pole,
  // previous point, current point.  Uses a formula derived from Cagnoli’s
  // theorem.  See Todhunter, Spherical Trig. (1871), Sec. 103, Eq. (2).
  var dLambda = lambda - lambda0,
      sdLambda = dLambda >= 0 ? 1 : -1,
      adLambda = sdLambda * dLambda,
      cosPhi = cos(phi),
      sinPhi = sin(phi),
      k = sinPhi0 * sinPhi,
      u = cosPhi0 * cosPhi + k * cos(adLambda),
      v = k * sdLambda * sin(adLambda);
  areaRingSum.add(atan2(v, u));

  // Advance the previous points.
  lambda0 = lambda, cosPhi0 = cosPhi, sinPhi0 = sinPhi;
}

var area = function(object) {
  areaSum.reset();
  geoStream(object, areaStream);
  return areaSum * 2;
};

function spherical(cartesian) {
  return [atan2(cartesian[1], cartesian[0]), asin(cartesian[2])];
}

function cartesian(spherical) {
  var lambda = spherical[0], phi = spherical[1], cosPhi = cos(phi);
  return [cosPhi * cos(lambda), cosPhi * sin(lambda), sin(phi)];
}

function cartesianDot(a, b) {
  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
}

function cartesianCross(a, b) {
  return [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
}

// TODO return a
function cartesianAddInPlace(a, b) {
  a[0] += b[0], a[1] += b[1], a[2] += b[2];
}

function cartesianScale(vector, k) {
  return [vector[0] * k, vector[1] * k, vector[2] * k];
}

// TODO return d
function cartesianNormalizeInPlace(d) {
  var l = sqrt(d[0] * d[0] + d[1] * d[1] + d[2] * d[2]);
  d[0] /= l, d[1] /= l, d[2] /= l;
}

var lambda0$1;
var phi0;
var lambda1;
var phi1;
var lambda2;
var lambda00$1;
var phi00$1;
var p0;
var deltaSum = adder();
var ranges;
var range$1;

var boundsStream = {
  point: boundsPoint,
  lineStart: boundsLineStart,
  lineEnd: boundsLineEnd,
  polygonStart: function() {
    boundsStream.point = boundsRingPoint;
    boundsStream.lineStart = boundsRingStart;
    boundsStream.lineEnd = boundsRingEnd;
    deltaSum.reset();
    areaStream.polygonStart();
  },
  polygonEnd: function() {
    areaStream.polygonEnd();
    boundsStream.point = boundsPoint;
    boundsStream.lineStart = boundsLineStart;
    boundsStream.lineEnd = boundsLineEnd;
    if (areaRingSum < 0) lambda0$1 = -(lambda1 = 180), phi0 = -(phi1 = 90);
    else if (deltaSum > epsilon) phi1 = 90;
    else if (deltaSum < -epsilon) phi0 = -90;
    range$1[0] = lambda0$1, range$1[1] = lambda1;
  }
};

function boundsPoint(lambda, phi) {
  ranges.push(range$1 = [lambda0$1 = lambda, lambda1 = lambda]);
  if (phi < phi0) phi0 = phi;
  if (phi > phi1) phi1 = phi;
}

function linePoint(lambda, phi) {
  var p = cartesian([lambda * radians, phi * radians]);
  if (p0) {
    var normal = cartesianCross(p0, p),
        equatorial = [normal[1], -normal[0], 0],
        inflection = cartesianCross(equatorial, normal);
    cartesianNormalizeInPlace(inflection);
    inflection = spherical(inflection);
    var delta = lambda - lambda2,
        sign$$1 = delta > 0 ? 1 : -1,
        lambdai = inflection[0] * degrees * sign$$1,
        phii,
        antimeridian = abs(delta) > 180;
    if (antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
      phii = inflection[1] * degrees;
      if (phii > phi1) phi1 = phii;
    } else if (lambdai = (lambdai + 360) % 360 - 180, antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
      phii = -inflection[1] * degrees;
      if (phii < phi0) phi0 = phii;
    } else {
      if (phi < phi0) phi0 = phi;
      if (phi > phi1) phi1 = phi;
    }
    if (antimeridian) {
      if (lambda < lambda2) {
        if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
      } else {
        if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
      }
    } else {
      if (lambda1 >= lambda0$1) {
        if (lambda < lambda0$1) lambda0$1 = lambda;
        if (lambda > lambda1) lambda1 = lambda;
      } else {
        if (lambda > lambda2) {
          if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
        } else {
          if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
        }
      }
    }
  } else {
    ranges.push(range$1 = [lambda0$1 = lambda, lambda1 = lambda]);
  }
  if (phi < phi0) phi0 = phi;
  if (phi > phi1) phi1 = phi;
  p0 = p, lambda2 = lambda;
}

function boundsLineStart() {
  boundsStream.point = linePoint;
}

function boundsLineEnd() {
  range$1[0] = lambda0$1, range$1[1] = lambda1;
  boundsStream.point = boundsPoint;
  p0 = null;
}

function boundsRingPoint(lambda, phi) {
  if (p0) {
    var delta = lambda - lambda2;
    deltaSum.add(abs(delta) > 180 ? delta + (delta > 0 ? 360 : -360) : delta);
  } else {
    lambda00$1 = lambda, phi00$1 = phi;
  }
  areaStream.point(lambda, phi);
  linePoint(lambda, phi);
}

function boundsRingStart() {
  areaStream.lineStart();
}

function boundsRingEnd() {
  boundsRingPoint(lambda00$1, phi00$1);
  areaStream.lineEnd();
  if (abs(deltaSum) > epsilon) lambda0$1 = -(lambda1 = 180);
  range$1[0] = lambda0$1, range$1[1] = lambda1;
  p0 = null;
}

// Finds the left-right distance between two longitudes.
// This is almost the same as (lambda1 - lambda0 + 360°) % 360°, except that we want
// the distance between ±180° to be 360°.
function angle(lambda0, lambda1) {
  return (lambda1 -= lambda0) < 0 ? lambda1 + 360 : lambda1;
}

function rangeCompare(a, b) {
  return a[0] - b[0];
}

function rangeContains(range$$1, x) {
  return range$$1[0] <= range$$1[1] ? range$$1[0] <= x && x <= range$$1[1] : x < range$$1[0] || range$$1[1] < x;
}

var bounds = function(feature) {
  var i, n, a, b, merged, deltaMax, delta;

  phi1 = lambda1 = -(lambda0$1 = phi0 = Infinity);
  ranges = [];
  geoStream(feature, boundsStream);

  // First, sort ranges by their minimum longitudes.
  if (n = ranges.length) {
    ranges.sort(rangeCompare);

    // Then, merge any ranges that overlap.
    for (i = 1, a = ranges[0], merged = [a]; i < n; ++i) {
      b = ranges[i];
      if (rangeContains(a, b[0]) || rangeContains(a, b[1])) {
        if (angle(a[0], b[1]) > angle(a[0], a[1])) a[1] = b[1];
        if (angle(b[0], a[1]) > angle(a[0], a[1])) a[0] = b[0];
      } else {
        merged.push(a = b);
      }
    }

    // Finally, find the largest gap between the merged ranges.
    // The final bounding box will be the inverse of this gap.
    for (deltaMax = -Infinity, n = merged.length - 1, i = 0, a = merged[n]; i <= n; a = b, ++i) {
      b = merged[i];
      if ((delta = angle(a[1], b[0])) > deltaMax) deltaMax = delta, lambda0$1 = b[0], lambda1 = a[1];
    }
  }

  ranges = range$1 = null;

  return lambda0$1 === Infinity || phi0 === Infinity
      ? [[NaN, NaN], [NaN, NaN]]
      : [[lambda0$1, phi0], [lambda1, phi1]];
};

var W0;
var W1;
var X0;
var Y0;
var Z0;
var X1;
var Y1;
var Z1;
var X2;
var Y2;
var Z2;
var lambda00$2;
var phi00$2;
var x0;
var y0;
var z0; // previous point

var centroidStream = {
  sphere: noop,
  point: centroidPoint,
  lineStart: centroidLineStart,
  lineEnd: centroidLineEnd,
  polygonStart: function() {
    centroidStream.lineStart = centroidRingStart;
    centroidStream.lineEnd = centroidRingEnd;
  },
  polygonEnd: function() {
    centroidStream.lineStart = centroidLineStart;
    centroidStream.lineEnd = centroidLineEnd;
  }
};

// Arithmetic mean of Cartesian vectors.
function centroidPoint(lambda, phi) {
  lambda *= radians, phi *= radians;
  var cosPhi = cos(phi);
  centroidPointCartesian(cosPhi * cos(lambda), cosPhi * sin(lambda), sin(phi));
}

function centroidPointCartesian(x, y, z) {
  ++W0;
  X0 += (x - X0) / W0;
  Y0 += (y - Y0) / W0;
  Z0 += (z - Z0) / W0;
}

function centroidLineStart() {
  centroidStream.point = centroidLinePointFirst;
}

function centroidLinePointFirst(lambda, phi) {
  lambda *= radians, phi *= radians;
  var cosPhi = cos(phi);
  x0 = cosPhi * cos(lambda);
  y0 = cosPhi * sin(lambda);
  z0 = sin(phi);
  centroidStream.point = centroidLinePoint;
  centroidPointCartesian(x0, y0, z0);
}

function centroidLinePoint(lambda, phi) {
  lambda *= radians, phi *= radians;
  var cosPhi = cos(phi),
      x = cosPhi * cos(lambda),
      y = cosPhi * sin(lambda),
      z = sin(phi),
      w = atan2(sqrt((w = y0 * z - z0 * y) * w + (w = z0 * x - x0 * z) * w + (w = x0 * y - y0 * x) * w), x0 * x + y0 * y + z0 * z);
  W1 += w;
  X1 += w * (x0 + (x0 = x));
  Y1 += w * (y0 + (y0 = y));
  Z1 += w * (z0 + (z0 = z));
  centroidPointCartesian(x0, y0, z0);
}

function centroidLineEnd() {
  centroidStream.point = centroidPoint;
}

// See J. E. Brock, The Inertia Tensor for a Spherical Triangle,
// J. Applied Mechanics 42, 239 (1975).
function centroidRingStart() {
  centroidStream.point = centroidRingPointFirst;
}

function centroidRingEnd() {
  centroidRingPoint(lambda00$2, phi00$2);
  centroidStream.point = centroidPoint;
}

function centroidRingPointFirst(lambda, phi) {
  lambda00$2 = lambda, phi00$2 = phi;
  lambda *= radians, phi *= radians;
  centroidStream.point = centroidRingPoint;
  var cosPhi = cos(phi);
  x0 = cosPhi * cos(lambda);
  y0 = cosPhi * sin(lambda);
  z0 = sin(phi);
  centroidPointCartesian(x0, y0, z0);
}

function centroidRingPoint(lambda, phi) {
  lambda *= radians, phi *= radians;
  var cosPhi = cos(phi),
      x = cosPhi * cos(lambda),
      y = cosPhi * sin(lambda),
      z = sin(phi),
      cx = y0 * z - z0 * y,
      cy = z0 * x - x0 * z,
      cz = x0 * y - y0 * x,
      m = sqrt(cx * cx + cy * cy + cz * cz),
      w = asin(m), // line weight = angle
      v = m && -w / m; // area weight multiplier
  X2 += v * cx;
  Y2 += v * cy;
  Z2 += v * cz;
  W1 += w;
  X1 += w * (x0 + (x0 = x));
  Y1 += w * (y0 + (y0 = y));
  Z1 += w * (z0 + (z0 = z));
  centroidPointCartesian(x0, y0, z0);
}

var centroid = function(object) {
  W0 = W1 =
  X0 = Y0 = Z0 =
  X1 = Y1 = Z1 =
  X2 = Y2 = Z2 = 0;
  geoStream(object, centroidStream);

  var x = X2,
      y = Y2,
      z = Z2,
      m = x * x + y * y + z * z;

  // If the area-weighted ccentroid is undefined, fall back to length-weighted ccentroid.
  if (m < epsilon2) {
    x = X1, y = Y1, z = Z1;
    // If the feature has zero length, fall back to arithmetic mean of point vectors.
    if (W1 < epsilon) x = X0, y = Y0, z = Z0;
    m = x * x + y * y + z * z;
    // If the feature still has an undefined ccentroid, then return.
    if (m < epsilon2) return [NaN, NaN];
  }

  return [atan2(y, x) * degrees, asin(z / sqrt(m)) * degrees];
};

var constant = function(x) {
  return function() {
    return x;
  };
};

var compose = function(a, b) {

  function compose(x, y) {
    return x = a(x, y), b(x[0], x[1]);
  }

  if (a.invert && b.invert) compose.invert = function(x, y) {
    return x = b.invert(x, y), x && a.invert(x[0], x[1]);
  };

  return compose;
};

function rotationIdentity(lambda, phi) {
  return [lambda > pi ? lambda - tau : lambda < -pi ? lambda + tau : lambda, phi];
}

rotationIdentity.invert = rotationIdentity;

function rotateRadians(deltaLambda, deltaPhi, deltaGamma) {
  return (deltaLambda %= tau) ? (deltaPhi || deltaGamma ? compose(rotationLambda(deltaLambda), rotationPhiGamma(deltaPhi, deltaGamma))
    : rotationLambda(deltaLambda))
    : (deltaPhi || deltaGamma ? rotationPhiGamma(deltaPhi, deltaGamma)
    : rotationIdentity);
}

function forwardRotationLambda(deltaLambda) {
  return function(lambda, phi) {
    return lambda += deltaLambda, [lambda > pi ? lambda - tau : lambda < -pi ? lambda + tau : lambda, phi];
  };
}

function rotationLambda(deltaLambda) {
  var rotation = forwardRotationLambda(deltaLambda);
  rotation.invert = forwardRotationLambda(-deltaLambda);
  return rotation;
}

function rotationPhiGamma(deltaPhi, deltaGamma) {
  var cosDeltaPhi = cos(deltaPhi),
      sinDeltaPhi = sin(deltaPhi),
      cosDeltaGamma = cos(deltaGamma),
      sinDeltaGamma = sin(deltaGamma);

  function rotation(lambda, phi) {
    var cosPhi = cos(phi),
        x = cos(lambda) * cosPhi,
        y = sin(lambda) * cosPhi,
        z = sin(phi),
        k = z * cosDeltaPhi + x * sinDeltaPhi;
    return [
      atan2(y * cosDeltaGamma - k * sinDeltaGamma, x * cosDeltaPhi - z * sinDeltaPhi),
      asin(k * cosDeltaGamma + y * sinDeltaGamma)
    ];
  }

  rotation.invert = function(lambda, phi) {
    var cosPhi = cos(phi),
        x = cos(lambda) * cosPhi,
        y = sin(lambda) * cosPhi,
        z = sin(phi),
        k = z * cosDeltaGamma - y * sinDeltaGamma;
    return [
      atan2(y * cosDeltaGamma + z * sinDeltaGamma, x * cosDeltaPhi + k * sinDeltaPhi),
      asin(k * cosDeltaPhi - x * sinDeltaPhi)
    ];
  };

  return rotation;
}

var rotation = function(rotate) {
  rotate = rotateRadians(rotate[0] * radians, rotate[1] * radians, rotate.length > 2 ? rotate[2] * radians : 0);

  function forward(coordinates) {
    coordinates = rotate(coordinates[0] * radians, coordinates[1] * radians);
    return coordinates[0] *= degrees, coordinates[1] *= degrees, coordinates;
  }

  forward.invert = function(coordinates) {
    coordinates = rotate.invert(coordinates[0] * radians, coordinates[1] * radians);
    return coordinates[0] *= degrees, coordinates[1] *= degrees, coordinates;
  };

  return forward;
};

// Generates a circle centered at [0°, 0°], with a given radius and precision.
function circleStream(stream, radius, delta, direction, t0, t1) {
  if (!delta) return;
  var cosRadius = cos(radius),
      sinRadius = sin(radius),
      step = direction * delta;
  if (t0 == null) {
    t0 = radius + direction * tau;
    t1 = radius - step / 2;
  } else {
    t0 = circleRadius(cosRadius, t0);
    t1 = circleRadius(cosRadius, t1);
    if (direction > 0 ? t0 < t1 : t0 > t1) t0 += direction * tau;
  }
  for (var point, t = t0; direction > 0 ? t > t1 : t < t1; t -= step) {
    point = spherical([cosRadius, -sinRadius * cos(t), -sinRadius * sin(t)]);
    stream.point(point[0], point[1]);
  }
}

// Returns the signed angle of a cartesian point relative to [cosRadius, 0, 0].
function circleRadius(cosRadius, point) {
  point = cartesian(point), point[0] -= cosRadius;
  cartesianNormalizeInPlace(point);
  var radius = acos(-point[1]);
  return ((-point[2] < 0 ? -radius : radius) + tau - epsilon) % tau;
}

var circle = function() {
  var center = constant([0, 0]),
      radius = constant(90),
      precision = constant(6),
      ring,
      rotate,
      stream = {point: point};

  function point(x, y) {
    ring.push(x = rotate(x, y));
    x[0] *= degrees, x[1] *= degrees;
  }

  function circle() {
    var c = center.apply(this, arguments),
        r = radius.apply(this, arguments) * radians,
        p = precision.apply(this, arguments) * radians;
    ring = [];
    rotate = rotateRadians(-c[0] * radians, -c[1] * radians, 0).invert;
    circleStream(stream, r, p, 1);
    c = {type: "Polygon", coordinates: [ring]};
    ring = rotate = null;
    return c;
  }

  circle.center = function(_) {
    return arguments.length ? (center = typeof _ === "function" ? _ : constant([+_[0], +_[1]]), circle) : center;
  };

  circle.radius = function(_) {
    return arguments.length ? (radius = typeof _ === "function" ? _ : constant(+_), circle) : radius;
  };

  circle.precision = function(_) {
    return arguments.length ? (precision = typeof _ === "function" ? _ : constant(+_), circle) : precision;
  };

  return circle;
};

var clipBuffer = function() {
  var lines = [],
      line;
  return {
    point: function(x, y) {
      line.push([x, y]);
    },
    lineStart: function() {
      lines.push(line = []);
    },
    lineEnd: noop,
    rejoin: function() {
      if (lines.length > 1) lines.push(lines.pop().concat(lines.shift()));
    },
    result: function() {
      var result = lines;
      lines = [];
      line = null;
      return result;
    }
  };
};

var clipLine = function(a, b, x0, y0, x1, y1) {
  var ax = a[0],
      ay = a[1],
      bx = b[0],
      by = b[1],
      t0 = 0,
      t1 = 1,
      dx = bx - ax,
      dy = by - ay,
      r;

  r = x0 - ax;
  if (!dx && r > 0) return;
  r /= dx;
  if (dx < 0) {
    if (r < t0) return;
    if (r < t1) t1 = r;
  } else if (dx > 0) {
    if (r > t1) return;
    if (r > t0) t0 = r;
  }

  r = x1 - ax;
  if (!dx && r < 0) return;
  r /= dx;
  if (dx < 0) {
    if (r > t1) return;
    if (r > t0) t0 = r;
  } else if (dx > 0) {
    if (r < t0) return;
    if (r < t1) t1 = r;
  }

  r = y0 - ay;
  if (!dy && r > 0) return;
  r /= dy;
  if (dy < 0) {
    if (r < t0) return;
    if (r < t1) t1 = r;
  } else if (dy > 0) {
    if (r > t1) return;
    if (r > t0) t0 = r;
  }

  r = y1 - ay;
  if (!dy && r < 0) return;
  r /= dy;
  if (dy < 0) {
    if (r > t1) return;
    if (r > t0) t0 = r;
  } else if (dy > 0) {
    if (r < t0) return;
    if (r < t1) t1 = r;
  }

  if (t0 > 0) a[0] = ax + t0 * dx, a[1] = ay + t0 * dy;
  if (t1 < 1) b[0] = ax + t1 * dx, b[1] = ay + t1 * dy;
  return true;
};

var pointEqual = function(a, b) {
  return abs(a[0] - b[0]) < epsilon && abs(a[1] - b[1]) < epsilon;
};

function Intersection(point, points, other, entry) {
  this.x = point;
  this.z = points;
  this.o = other; // another intersection
  this.e = entry; // is an entry?
  this.v = false; // visited
  this.n = this.p = null; // next & previous
}

// A generalized polygon clipping algorithm: given a polygon that has been cut
// into its visible line segments, and rejoins the segments by interpolating
// along the clip edge.
var clipPolygon = function(segments, compareIntersection, startInside, interpolate, stream) {
  var subject = [],
      clip = [],
      i,
      n;

  segments.forEach(function(segment) {
    if ((n = segment.length - 1) <= 0) return;
    var n, p0 = segment[0], p1 = segment[n], x;

    // If the first and last points of a segment are coincident, then treat as a
    // closed ring. TODO if all rings are closed, then the winding order of the
    // exterior ring should be checked.
    if (pointEqual(p0, p1)) {
      stream.lineStart();
      for (i = 0; i < n; ++i) stream.point((p0 = segment[i])[0], p0[1]);
      stream.lineEnd();
      return;
    }

    subject.push(x = new Intersection(p0, segment, null, true));
    clip.push(x.o = new Intersection(p0, null, x, false));
    subject.push(x = new Intersection(p1, segment, null, false));
    clip.push(x.o = new Intersection(p1, null, x, true));
  });

  if (!subject.length) return;

  clip.sort(compareIntersection);
  link(subject);
  link(clip);

  for (i = 0, n = clip.length; i < n; ++i) {
    clip[i].e = startInside = !startInside;
  }

  var start = subject[0],
      points,
      point;

  while (1) {
    // Find first unvisited intersection.
    var current = start,
        isSubject = true;
    while (current.v) if ((current = current.n) === start) return;
    points = current.z;
    stream.lineStart();
    do {
      current.v = current.o.v = true;
      if (current.e) {
        if (isSubject) {
          for (i = 0, n = points.length; i < n; ++i) stream.point((point = points[i])[0], point[1]);
        } else {
          interpolate(current.x, current.n.x, 1, stream);
        }
        current = current.n;
      } else {
        if (isSubject) {
          points = current.p.z;
          for (i = points.length - 1; i >= 0; --i) stream.point((point = points[i])[0], point[1]);
        } else {
          interpolate(current.x, current.p.x, -1, stream);
        }
        current = current.p;
      }
      current = current.o;
      points = current.z;
      isSubject = !isSubject;
    } while (!current.v);
    stream.lineEnd();
  }
};

function link(array) {
  if (!(n = array.length)) return;
  var n,
      i = 0,
      a = array[0],
      b;
  while (++i < n) {
    a.n = b = array[i];
    b.p = a;
    a = b;
  }
  a.n = b = array[0];
  b.p = a;
}

var clipMax = 1e9;
var clipMin = -clipMax;

// TODO Use d3-polygon’s polygonContains here for the ring check?
// TODO Eliminate duplicate buffering in clipBuffer and polygon.push?

function clipExtent(x0, y0, x1, y1) {

  function visible(x, y) {
    return x0 <= x && x <= x1 && y0 <= y && y <= y1;
  }

  function interpolate(from, to, direction, stream) {
    var a = 0, a1 = 0;
    if (from == null
        || (a = corner(from, direction)) !== (a1 = corner(to, direction))
        || comparePoint(from, to) < 0 ^ direction > 0) {
      do stream.point(a === 0 || a === 3 ? x0 : x1, a > 1 ? y1 : y0);
      while ((a = (a + direction + 4) % 4) !== a1);
    } else {
      stream.point(to[0], to[1]);
    }
  }

  function corner(p, direction) {
    return abs(p[0] - x0) < epsilon ? direction > 0 ? 0 : 3
        : abs(p[0] - x1) < epsilon ? direction > 0 ? 2 : 1
        : abs(p[1] - y0) < epsilon ? direction > 0 ? 1 : 0
        : direction > 0 ? 3 : 2; // abs(p[1] - y1) < epsilon
  }

  function compareIntersection(a, b) {
    return comparePoint(a.x, b.x);
  }

  function comparePoint(a, b) {
    var ca = corner(a, 1),
        cb = corner(b, 1);
    return ca !== cb ? ca - cb
        : ca === 0 ? b[1] - a[1]
        : ca === 1 ? a[0] - b[0]
        : ca === 2 ? a[1] - b[1]
        : b[0] - a[0];
  }

  return function(stream) {
    var activeStream = stream,
        bufferStream = clipBuffer(),
        segments,
        polygon,
        ring,
        x__, y__, v__, // first point
        x_, y_, v_, // previous point
        first,
        clean;

    var clipStream = {
      point: point,
      lineStart: lineStart,
      lineEnd: lineEnd,
      polygonStart: polygonStart,
      polygonEnd: polygonEnd
    };

    function point(x, y) {
      if (visible(x, y)) activeStream.point(x, y);
    }

    function polygonInside() {
      var winding = 0;

      for (var i = 0, n = polygon.length; i < n; ++i) {
        for (var ring = polygon[i], j = 1, m = ring.length, point = ring[0], a0, a1, b0 = point[0], b1 = point[1]; j < m; ++j) {
          a0 = b0, a1 = b1, point = ring[j], b0 = point[0], b1 = point[1];
          if (a1 <= y1) { if (b1 > y1 && (b0 - a0) * (y1 - a1) > (b1 - a1) * (x0 - a0)) ++winding; }
          else { if (b1 <= y1 && (b0 - a0) * (y1 - a1) < (b1 - a1) * (x0 - a0)) --winding; }
        }
      }

      return winding;
    }

    // Buffer geometry within a polygon and then clip it en masse.
    function polygonStart() {
      activeStream = bufferStream, segments = [], polygon = [], clean = true;
    }

    function polygonEnd() {
      var startInside = polygonInside(),
          cleanInside = clean && startInside,
          visible = (segments = d3Array.merge(segments)).length;
      if (cleanInside || visible) {
        stream.polygonStart();
        if (cleanInside) {
          stream.lineStart();
          interpolate(null, null, 1, stream);
          stream.lineEnd();
        }
        if (visible) {
          clipPolygon(segments, compareIntersection, startInside, interpolate, stream);
        }
        stream.polygonEnd();
      }
      activeStream = stream, segments = polygon = ring = null;
    }

    function lineStart() {
      clipStream.point = linePoint;
      if (polygon) polygon.push(ring = []);
      first = true;
      v_ = false;
      x_ = y_ = NaN;
    }

    // TODO rather than special-case polygons, simply handle them separately.
    // Ideally, coincident intersection points should be jittered to avoid
    // clipping issues.
    function lineEnd() {
      if (segments) {
        linePoint(x__, y__);
        if (v__ && v_) bufferStream.rejoin();
        segments.push(bufferStream.result());
      }
      clipStream.point = point;
      if (v_) activeStream.lineEnd();
    }

    function linePoint(x, y) {
      var v = visible(x, y);
      if (polygon) ring.push([x, y]);
      if (first) {
        x__ = x, y__ = y, v__ = v;
        first = false;
        if (v) {
          activeStream.lineStart();
          activeStream.point(x, y);
        }
      } else {
        if (v && v_) activeStream.point(x, y);
        else {
          var a = [x_ = Math.max(clipMin, Math.min(clipMax, x_)), y_ = Math.max(clipMin, Math.min(clipMax, y_))],
              b = [x = Math.max(clipMin, Math.min(clipMax, x)), y = Math.max(clipMin, Math.min(clipMax, y))];
          if (clipLine(a, b, x0, y0, x1, y1)) {
            if (!v_) {
              activeStream.lineStart();
              activeStream.point(a[0], a[1]);
            }
            activeStream.point(b[0], b[1]);
            if (!v) activeStream.lineEnd();
            clean = false;
          } else if (v) {
            activeStream.lineStart();
            activeStream.point(x, y);
            clean = false;
          }
        }
      }
      x_ = x, y_ = y, v_ = v;
    }

    return clipStream;
  };
}

var extent = function() {
  var x0 = 0,
      y0 = 0,
      x1 = 960,
      y1 = 500,
      cache,
      cacheStream,
      clip;

  return clip = {
    stream: function(stream) {
      return cache && cacheStream === stream ? cache : cache = clipExtent(x0, y0, x1, y1)(cacheStream = stream);
    },
    extent: function(_) {
      return arguments.length ? (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1], cache = cacheStream = null, clip) : [[x0, y0], [x1, y1]];
    }
  };
};

var sum = adder();

var polygonContains = function(polygon, point) {
  var lambda = point[0],
      phi = point[1],
      normal = [sin(lambda), -cos(lambda), 0],
      angle = 0,
      winding = 0;

  sum.reset();

  for (var i = 0, n = polygon.length; i < n; ++i) {
    if (!(m = (ring = polygon[i]).length)) continue;
    var ring,
        m,
        point0 = ring[m - 1],
        lambda0 = point0[0],
        phi0 = point0[1] / 2 + quarterPi,
        sinPhi0 = sin(phi0),
        cosPhi0 = cos(phi0);

    for (var j = 0; j < m; ++j, lambda0 = lambda1, sinPhi0 = sinPhi1, cosPhi0 = cosPhi1, point0 = point1) {
      var point1 = ring[j],
          lambda1 = point1[0],
          phi1 = point1[1] / 2 + quarterPi,
          sinPhi1 = sin(phi1),
          cosPhi1 = cos(phi1),
          delta = lambda1 - lambda0,
          sign$$1 = delta >= 0 ? 1 : -1,
          absDelta = sign$$1 * delta,
          antimeridian = absDelta > pi,
          k = sinPhi0 * sinPhi1;

      sum.add(atan2(k * sign$$1 * sin(absDelta), cosPhi0 * cosPhi1 + k * cos(absDelta)));
      angle += antimeridian ? delta + sign$$1 * tau : delta;

      // Are the longitudes either side of the point’s meridian (lambda),
      // and are the latitudes smaller than the parallel (phi)?
      if (antimeridian ^ lambda0 >= lambda ^ lambda1 >= lambda) {
        var arc = cartesianCross(cartesian(point0), cartesian(point1));
        cartesianNormalizeInPlace(arc);
        var intersection = cartesianCross(normal, arc);
        cartesianNormalizeInPlace(intersection);
        var phiArc = (antimeridian ^ delta >= 0 ? -1 : 1) * asin(intersection[2]);
        if (phi > phiArc || phi === phiArc && (arc[0] || arc[1])) {
          winding += antimeridian ^ delta >= 0 ? 1 : -1;
        }
      }
    }
  }

  // First, determine whether the South pole is inside or outside:
  //
  // It is inside if:
  // * the polygon winds around it in a clockwise direction.
  // * the polygon does not (cumulatively) wind around it, but has a negative
  //   (counter-clockwise) area.
  //
  // Second, count the (signed) number of times a segment crosses a lambda
  // from the point to the South pole.  If it is zero, then the point is the
  // same side as the South pole.

  return (angle < -epsilon || angle < epsilon && sum < -epsilon) ^ (winding & 1);
};

var lengthSum = adder();
var lambda0$2;
var sinPhi0$1;
var cosPhi0$1;

var lengthStream = {
  sphere: noop,
  point: noop,
  lineStart: lengthLineStart,
  lineEnd: noop,
  polygonStart: noop,
  polygonEnd: noop
};

function lengthLineStart() {
  lengthStream.point = lengthPointFirst;
  lengthStream.lineEnd = lengthLineEnd;
}

function lengthLineEnd() {
  lengthStream.point = lengthStream.lineEnd = noop;
}

function lengthPointFirst(lambda, phi) {
  lambda *= radians, phi *= radians;
  lambda0$2 = lambda, sinPhi0$1 = sin(phi), cosPhi0$1 = cos(phi);
  lengthStream.point = lengthPoint;
}

function lengthPoint(lambda, phi) {
  lambda *= radians, phi *= radians;
  var sinPhi = sin(phi),
      cosPhi = cos(phi),
      delta = abs(lambda - lambda0$2),
      cosDelta = cos(delta),
      sinDelta = sin(delta),
      x = cosPhi * sinDelta,
      y = cosPhi0$1 * sinPhi - sinPhi0$1 * cosPhi * cosDelta,
      z = sinPhi0$1 * sinPhi + cosPhi0$1 * cosPhi * cosDelta;
  lengthSum.add(atan2(sqrt(x * x + y * y), z));
  lambda0$2 = lambda, sinPhi0$1 = sinPhi, cosPhi0$1 = cosPhi;
}

var length = function(object) {
  lengthSum.reset();
  geoStream(object, lengthStream);
  return +lengthSum;
};

var coordinates = [null, null];
var object = {type: "LineString", coordinates: coordinates};

var distance = function(a, b) {
  coordinates[0] = a;
  coordinates[1] = b;
  return length(object);
};

var containsObjectType = {
  Feature: function(object, point) {
    return containsGeometry(object.geometry, point);
  },
  FeatureCollection: function(object, point) {
    var features = object.features, i = -1, n = features.length;
    while (++i < n) if (containsGeometry(features[i].geometry, point)) return true;
    return false;
  }
};

var containsGeometryType = {
  Sphere: function() {
    return true;
  },
  Point: function(object, point) {
    return containsPoint(object.coordinates, point);
  },
  MultiPoint: function(object, point) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) if (containsPoint(coordinates[i], point)) return true;
    return false;
  },
  LineString: function(object, point) {
    return containsLine(object.coordinates, point);
  },
  MultiLineString: function(object, point) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) if (containsLine(coordinates[i], point)) return true;
    return false;
  },
  Polygon: function(object, point) {
    return containsPolygon(object.coordinates, point);
  },
  MultiPolygon: function(object, point) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) if (containsPolygon(coordinates[i], point)) return true;
    return false;
  },
  GeometryCollection: function(object, point) {
    var geometries = object.geometries, i = -1, n = geometries.length;
    while (++i < n) if (containsGeometry(geometries[i], point)) return true;
    return false;
  }
};

function containsGeometry(geometry, point) {
  return geometry && containsGeometryType.hasOwnProperty(geometry.type)
      ? containsGeometryType[geometry.type](geometry, point)
      : false;
}

function containsPoint(coordinates, point) {
  return distance(coordinates, point) === 0;
}

function containsLine(coordinates, point) {
  var ab = distance(coordinates[0], coordinates[1]),
      ao = distance(coordinates[0], point),
      ob = distance(point, coordinates[1]);
  return ao + ob <= ab + epsilon;
}

function containsPolygon(coordinates, point) {
  return !!polygonContains(coordinates.map(ringRadians), pointRadians(point));
}

function ringRadians(ring) {
  return ring = ring.map(pointRadians), ring.pop(), ring;
}

function pointRadians(point) {
  return [point[0] * radians, point[1] * radians];
}

var contains = function(object, point) {
  return (object && containsObjectType.hasOwnProperty(object.type)
      ? containsObjectType[object.type]
      : containsGeometry)(object, point);
};

function graticuleX(y0, y1, dy) {
  var y = d3Array.range(y0, y1 - epsilon, dy).concat(y1);
  return function(x) { return y.map(function(y) { return [x, y]; }); };
}

function graticuleY(x0, x1, dx) {
  var x = d3Array.range(x0, x1 - epsilon, dx).concat(x1);
  return function(y) { return x.map(function(x) { return [x, y]; }); };
}

function graticule() {
  var x1, x0, X1, X0,
      y1, y0, Y1, Y0,
      dx = 10, dy = dx, DX = 90, DY = 360,
      x, y, X, Y,
      precision = 2.5;

  function graticule() {
    return {type: "MultiLineString", coordinates: lines()};
  }

  function lines() {
    return d3Array.range(ceil(X0 / DX) * DX, X1, DX).map(X)
        .concat(d3Array.range(ceil(Y0 / DY) * DY, Y1, DY).map(Y))
        .concat(d3Array.range(ceil(x0 / dx) * dx, x1, dx).filter(function(x) { return abs(x % DX) > epsilon; }).map(x))
        .concat(d3Array.range(ceil(y0 / dy) * dy, y1, dy).filter(function(y) { return abs(y % DY) > epsilon; }).map(y));
  }

  graticule.lines = function() {
    return lines().map(function(coordinates) { return {type: "LineString", coordinates: coordinates}; });
  };

  graticule.outline = function() {
    return {
      type: "Polygon",
      coordinates: [
        X(X0).concat(
        Y(Y1).slice(1),
        X(X1).reverse().slice(1),
        Y(Y0).reverse().slice(1))
      ]
    };
  };

  graticule.extent = function(_) {
    if (!arguments.length) return graticule.extentMinor();
    return graticule.extentMajor(_).extentMinor(_);
  };

  graticule.extentMajor = function(_) {
    if (!arguments.length) return [[X0, Y0], [X1, Y1]];
    X0 = +_[0][0], X1 = +_[1][0];
    Y0 = +_[0][1], Y1 = +_[1][1];
    if (X0 > X1) _ = X0, X0 = X1, X1 = _;
    if (Y0 > Y1) _ = Y0, Y0 = Y1, Y1 = _;
    return graticule.precision(precision);
  };

  graticule.extentMinor = function(_) {
    if (!arguments.length) return [[x0, y0], [x1, y1]];
    x0 = +_[0][0], x1 = +_[1][0];
    y0 = +_[0][1], y1 = +_[1][1];
    if (x0 > x1) _ = x0, x0 = x1, x1 = _;
    if (y0 > y1) _ = y0, y0 = y1, y1 = _;
    return graticule.precision(precision);
  };

  graticule.step = function(_) {
    if (!arguments.length) return graticule.stepMinor();
    return graticule.stepMajor(_).stepMinor(_);
  };

  graticule.stepMajor = function(_) {
    if (!arguments.length) return [DX, DY];
    DX = +_[0], DY = +_[1];
    return graticule;
  };

  graticule.stepMinor = function(_) {
    if (!arguments.length) return [dx, dy];
    dx = +_[0], dy = +_[1];
    return graticule;
  };

  graticule.precision = function(_) {
    if (!arguments.length) return precision;
    precision = +_;
    x = graticuleX(y0, y1, 90);
    y = graticuleY(x0, x1, precision);
    X = graticuleX(Y0, Y1, 90);
    Y = graticuleY(X0, X1, precision);
    return graticule;
  };

  return graticule
      .extentMajor([[-180, -90 + epsilon], [180, 90 - epsilon]])
      .extentMinor([[-180, -80 - epsilon], [180, 80 + epsilon]]);
}

function graticule10() {
  return graticule()();
}

var interpolate = function(a, b) {
  var x0 = a[0] * radians,
      y0 = a[1] * radians,
      x1 = b[0] * radians,
      y1 = b[1] * radians,
      cy0 = cos(y0),
      sy0 = sin(y0),
      cy1 = cos(y1),
      sy1 = sin(y1),
      kx0 = cy0 * cos(x0),
      ky0 = cy0 * sin(x0),
      kx1 = cy1 * cos(x1),
      ky1 = cy1 * sin(x1),
      d = 2 * asin(sqrt(haversin(y1 - y0) + cy0 * cy1 * haversin(x1 - x0))),
      k = sin(d);

  var interpolate = d ? function(t) {
    var B = sin(t *= d) / k,
        A = sin(d - t) / k,
        x = A * kx0 + B * kx1,
        y = A * ky0 + B * ky1,
        z = A * sy0 + B * sy1;
    return [
      atan2(y, x) * degrees,
      atan2(z, sqrt(x * x + y * y)) * degrees
    ];
  } : function() {
    return [x0 * degrees, y0 * degrees];
  };

  interpolate.distance = d;

  return interpolate;
};

var identity = function(x) {
  return x;
};

var areaSum$1 = adder();
var areaRingSum$1 = adder();
var x00;
var y00;
var x0$1;
var y0$1;

var areaStream$1 = {
  point: noop,
  lineStart: noop,
  lineEnd: noop,
  polygonStart: function() {
    areaStream$1.lineStart = areaRingStart$1;
    areaStream$1.lineEnd = areaRingEnd$1;
  },
  polygonEnd: function() {
    areaStream$1.lineStart = areaStream$1.lineEnd = areaStream$1.point = noop;
    areaSum$1.add(abs(areaRingSum$1));
    areaRingSum$1.reset();
  },
  result: function() {
    var area = areaSum$1 / 2;
    areaSum$1.reset();
    return area;
  }
};

function areaRingStart$1() {
  areaStream$1.point = areaPointFirst$1;
}

function areaPointFirst$1(x, y) {
  areaStream$1.point = areaPoint$1;
  x00 = x0$1 = x, y00 = y0$1 = y;
}

function areaPoint$1(x, y) {
  areaRingSum$1.add(y0$1 * x - x0$1 * y);
  x0$1 = x, y0$1 = y;
}

function areaRingEnd$1() {
  areaPoint$1(x00, y00);
}

var x0$2 = Infinity;
var y0$2 = x0$2;
var x1 = -x0$2;
var y1 = x1;

var boundsStream$1 = {
  point: boundsPoint$1,
  lineStart: noop,
  lineEnd: noop,
  polygonStart: noop,
  polygonEnd: noop,
  result: function() {
    var bounds = [[x0$2, y0$2], [x1, y1]];
    x1 = y1 = -(y0$2 = x0$2 = Infinity);
    return bounds;
  }
};

function boundsPoint$1(x, y) {
  if (x < x0$2) x0$2 = x;
  if (x > x1) x1 = x;
  if (y < y0$2) y0$2 = y;
  if (y > y1) y1 = y;
}

// TODO Enforce positive area for exterior, negative area for interior?

var X0$1 = 0;
var Y0$1 = 0;
var Z0$1 = 0;
var X1$1 = 0;
var Y1$1 = 0;
var Z1$1 = 0;
var X2$1 = 0;
var Y2$1 = 0;
var Z2$1 = 0;
var x00$1;
var y00$1;
var x0$3;
var y0$3;

var centroidStream$1 = {
  point: centroidPoint$1,
  lineStart: centroidLineStart$1,
  lineEnd: centroidLineEnd$1,
  polygonStart: function() {
    centroidStream$1.lineStart = centroidRingStart$1;
    centroidStream$1.lineEnd = centroidRingEnd$1;
  },
  polygonEnd: function() {
    centroidStream$1.point = centroidPoint$1;
    centroidStream$1.lineStart = centroidLineStart$1;
    centroidStream$1.lineEnd = centroidLineEnd$1;
  },
  result: function() {
    var centroid = Z2$1 ? [X2$1 / Z2$1, Y2$1 / Z2$1]
        : Z1$1 ? [X1$1 / Z1$1, Y1$1 / Z1$1]
        : Z0$1 ? [X0$1 / Z0$1, Y0$1 / Z0$1]
        : [NaN, NaN];
    X0$1 = Y0$1 = Z0$1 =
    X1$1 = Y1$1 = Z1$1 =
    X2$1 = Y2$1 = Z2$1 = 0;
    return centroid;
  }
};

function centroidPoint$1(x, y) {
  X0$1 += x;
  Y0$1 += y;
  ++Z0$1;
}

function centroidLineStart$1() {
  centroidStream$1.point = centroidPointFirstLine;
}

function centroidPointFirstLine(x, y) {
  centroidStream$1.point = centroidPointLine;
  centroidPoint$1(x0$3 = x, y0$3 = y);
}

function centroidPointLine(x, y) {
  var dx = x - x0$3, dy = y - y0$3, z = sqrt(dx * dx + dy * dy);
  X1$1 += z * (x0$3 + x) / 2;
  Y1$1 += z * (y0$3 + y) / 2;
  Z1$1 += z;
  centroidPoint$1(x0$3 = x, y0$3 = y);
}

function centroidLineEnd$1() {
  centroidStream$1.point = centroidPoint$1;
}

function centroidRingStart$1() {
  centroidStream$1.point = centroidPointFirstRing;
}

function centroidRingEnd$1() {
  centroidPointRing(x00$1, y00$1);
}

function centroidPointFirstRing(x, y) {
  centroidStream$1.point = centroidPointRing;
  centroidPoint$1(x00$1 = x0$3 = x, y00$1 = y0$3 = y);
}

function centroidPointRing(x, y) {
  var dx = x - x0$3,
      dy = y - y0$3,
      z = sqrt(dx * dx + dy * dy);

  X1$1 += z * (x0$3 + x) / 2;
  Y1$1 += z * (y0$3 + y) / 2;
  Z1$1 += z;

  z = y0$3 * x - x0$3 * y;
  X2$1 += z * (x0$3 + x);
  Y2$1 += z * (y0$3 + y);
  Z2$1 += z * 3;
  centroidPoint$1(x0$3 = x, y0$3 = y);
}

function PathContext(context) {
  this._context = context;
}

PathContext.prototype = {
  _radius: 4.5,
  pointRadius: function(_) {
    return this._radius = _, this;
  },
  polygonStart: function() {
    this._line = 0;
  },
  polygonEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line === 0) this._context.closePath();
    this._point = NaN;
  },
  point: function(x, y) {
    switch (this._point) {
      case 0: {
        this._context.moveTo(x, y);
        this._point = 1;
        break;
      }
      case 1: {
        this._context.lineTo(x, y);
        break;
      }
      default: {
        this._context.moveTo(x + this._radius, y);
        this._context.arc(x, y, this._radius, 0, tau);
        break;
      }
    }
  },
  result: noop
};

var lengthSum$1 = adder();
var lengthRing;
var x00$2;
var y00$2;
var x0$4;
var y0$4;

var lengthStream$1 = {
  point: noop,
  lineStart: function() {
    lengthStream$1.point = lengthPointFirst$1;
  },
  lineEnd: function() {
    if (lengthRing) lengthPoint$1(x00$2, y00$2);
    lengthStream$1.point = noop;
  },
  polygonStart: function() {
    lengthRing = true;
  },
  polygonEnd: function() {
    lengthRing = null;
  },
  result: function() {
    var length = +lengthSum$1;
    lengthSum$1.reset();
    return length;
  }
};

function lengthPointFirst$1(x, y) {
  lengthStream$1.point = lengthPoint$1;
  x00$2 = x0$4 = x, y00$2 = y0$4 = y;
}

function lengthPoint$1(x, y) {
  x0$4 -= x, y0$4 -= y;
  lengthSum$1.add(sqrt(x0$4 * x0$4 + y0$4 * y0$4));
  x0$4 = x, y0$4 = y;
}

function PathString() {
  this._string = [];
}

PathString.prototype = {
  _radius: 4.5,
  _circle: circle$1(4.5),
  pointRadius: function(_) {
    if ((_ = +_) !== this._radius) this._radius = _, this._circle = null;
    return this;
  },
  polygonStart: function() {
    this._line = 0;
  },
  polygonEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line === 0) this._string.push("Z");
    this._point = NaN;
  },
  point: function(x, y) {
    switch (this._point) {
      case 0: {
        this._string.push("M", x, ",", y);
        this._point = 1;
        break;
      }
      case 1: {
        this._string.push("L", x, ",", y);
        break;
      }
      default: {
        if (this._circle == null) this._circle = circle$1(this._radius);
        this._string.push("M", x, ",", y, this._circle);
        break;
      }
    }
  },
  result: function() {
    if (this._string.length) {
      var result = this._string.join("");
      this._string = [];
      return result;
    } else {
      return null;
    }
  }
};

function circle$1(radius) {
  return "m0," + radius
      + "a" + radius + "," + radius + " 0 1,1 0," + -2 * radius
      + "a" + radius + "," + radius + " 0 1,1 0," + 2 * radius
      + "z";
}

var index = function(projection, context) {
  var pointRadius = 4.5,
      projectionStream,
      contextStream;

  function path(object) {
    if (object) {
      if (typeof pointRadius === "function") contextStream.pointRadius(+pointRadius.apply(this, arguments));
      geoStream(object, projectionStream(contextStream));
    }
    return contextStream.result();
  }

  path.area = function(object) {
    geoStream(object, projectionStream(areaStream$1));
    return areaStream$1.result();
  };

  path.measure = function(object) {
    geoStream(object, projectionStream(lengthStream$1));
    return lengthStream$1.result();
  };

  path.bounds = function(object) {
    geoStream(object, projectionStream(boundsStream$1));
    return boundsStream$1.result();
  };

  path.centroid = function(object) {
    geoStream(object, projectionStream(centroidStream$1));
    return centroidStream$1.result();
  };

  path.projection = function(_) {
    return arguments.length ? (projectionStream = _ == null ? (projection = null, identity) : (projection = _).stream, path) : projection;
  };

  path.context = function(_) {
    if (!arguments.length) return context;
    contextStream = _ == null ? (context = null, new PathString) : new PathContext(context = _);
    if (typeof pointRadius !== "function") contextStream.pointRadius(pointRadius);
    return path;
  };

  path.pointRadius = function(_) {
    if (!arguments.length) return pointRadius;
    pointRadius = typeof _ === "function" ? _ : (contextStream.pointRadius(+_), +_);
    return path;
  };

  return path.projection(projection).context(context);
};

var clip = function(pointVisible, clipLine, interpolate, start) {
  return function(rotate, sink) {
    var line = clipLine(sink),
        rotatedStart = rotate.invert(start[0], start[1]),
        ringBuffer = clipBuffer(),
        ringSink = clipLine(ringBuffer),
        polygonStarted = false,
        polygon,
        segments,
        ring;

    var clip = {
      point: point,
      lineStart: lineStart,
      lineEnd: lineEnd,
      polygonStart: function() {
        clip.point = pointRing;
        clip.lineStart = ringStart;
        clip.lineEnd = ringEnd;
        segments = [];
        polygon = [];
      },
      polygonEnd: function() {
        clip.point = point;
        clip.lineStart = lineStart;
        clip.lineEnd = lineEnd;
        segments = d3Array.merge(segments);
        var startInside = polygonContains(polygon, rotatedStart);
        if (segments.length) {
          if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
          clipPolygon(segments, compareIntersection, startInside, interpolate, sink);
        } else if (startInside) {
          if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
          sink.lineStart();
          interpolate(null, null, 1, sink);
          sink.lineEnd();
        }