[rails.git] / vendor / assets / iD / iD.js

(function(exports) {

  var bootstrap = (typeof exports.bootstrap === "object") ?
    exports.bootstrap :
    (exports.bootstrap = {});

  bootstrap.tooltip = function() {

    var tooltip = function(selection) {
        selection.each(setup);
      },
      animation = d3.functor(false),
      html = d3.functor(false),
      title = function() {
        var title = this.getAttribute("data-original-title");
        if (title) {
          return title;
        } else {
          title = this.getAttribute("title");
          this.removeAttribute("title");
          this.setAttribute("data-original-title", title);
        }
        return title;
      },
      over = "mouseenter.tooltip",
      out = "mouseleave.tooltip",
      placements = "top left bottom right".split(" "),
      placement = d3.functor("top");

    tooltip.title = function(_) {
      if (arguments.length) {
        title = d3.functor(_);
        return tooltip;
      } else {
        return title;
      }
    };

    tooltip.html = function(_) {
      if (arguments.length) {
        html = d3.functor(_);
        return tooltip;
      } else {
        return html;
      }
    };

    tooltip.placement = function(_) {
      if (arguments.length) {
        placement = d3.functor(_);
        return tooltip;
      } else {
        return placement;
      }
    };

    tooltip.show = function(selection) {
      selection.each(show);
    };

    tooltip.hide = function(selection) {
      selection.each(hide);
    };

    tooltip.toggle = function(selection) {
      selection.each(toggle);
    };

    tooltip.destroy = function(selection) {
      selection
        .on(over, null)
        .on(out, null)
        .attr("title", function() {
          return this.getAttribute("data-original-title") || this.getAttribute("title");
        })
        .attr("data-original-title", null)
        .select(".tooltip")
        .remove();
    };

    function setup() {
      var root = d3.select(this),
          animate = animation.apply(this, arguments),
          tip = root.append("div")
            .attr("class", "tooltip");

      if (animate) {
        tip.classed("fade", true);
      }

      // TODO "inside" checks?

      tip.append("div")
        .attr("class", "tooltip-arrow");
      tip.append("div")
        .attr("class", "tooltip-inner");

      var place = placement.apply(this, arguments);
      tip.classed(place, true);

      root.on(over, show);
      root.on(out, hide);
    }

    function show() {
      var root = d3.select(this),
          content = title.apply(this, arguments),
          tip = root.select(".tooltip")
            .classed("in", true),
          markup = html.apply(this, arguments),
          innercontent = tip.select(".tooltip-inner")[markup ? "html" : "text"](content),
          place = placement.apply(this, arguments),
          outer = getPosition(root.node()),
          inner = getPosition(tip.node()),
          pos;

      switch (place) {
        case "top":
          pos = {x: outer.x + (outer.w - inner.w) / 2, y: outer.y - inner.h};
          break;
        case "right":
          pos = {x: outer.x + outer.w, y: outer.y + (outer.h - inner.h) / 2};
          break;
        case "left":
          pos = {x: outer.x - inner.w, y: outer.y + (outer.h - inner.h) / 2};
          break;
        case "bottom":
          pos = {x: Math.max(0, outer.x + (outer.w - inner.w) / 2), y: outer.y + outer.h};
          break;
      }

      tip.style(pos ?
        {left: ~~pos.x + "px", top: ~~pos.y + "px"} :
        {left: null, top: null});

      this.tooltipVisible = true;
    }

    function hide() {
      d3.select(this).select(".tooltip")
        .classed("in", false);

      this.tooltipVisible = false;
    }

    function toggle() {
      if (this.tooltipVisible) {
        hide.apply(this, arguments);
      } else {
        show.apply(this, arguments);
      }
    }

    return tooltip;
  };

  function getPosition(node) {
    var mode = d3.select(node).style('position');
    if (mode === 'absolute' || mode === 'static') {
      return {
        x: node.offsetLeft,
        y: node.offsetTop,
        w: node.offsetWidth,
        h: node.offsetHeight
      };
    } else {
      return {
        x: 0,
        y: 0,
        w: node.offsetWidth,
        h: node.offsetHeight
      };
    }
  }

})(this);
!function(){
  var d3 = {version: "3.5.5"}; // semver
d3.ascending = d3_ascending;

function d3_ascending(a, b) {
  return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
}
d3.descending = function(a, b) {
  return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
};
d3.min = function(array, f) {
  var i = -1,
      n = array.length,
      a,
      b;
  if (arguments.length === 1) {
    while (++i < n) if ((b = array[i]) != null && b >= b) { a = b; break; }
    while (++i < n) if ((b = array[i]) != null && a > b) a = b;
  } else {
    while (++i < n) if ((b = f.call(array, array[i], i)) != null && b >= b) { a = b; break; }
    while (++i < n) if ((b = f.call(array, array[i], i)) != null && a > b) a = b;
  }
  return a;
};
d3.max = function(array, f) {
  var i = -1,
      n = array.length,
      a,
      b;
  if (arguments.length === 1) {
    while (++i < n) if ((b = array[i]) != null && b >= b) { a = b; break; }
    while (++i < n) if ((b = array[i]) != null && b > a) a = b;
  } else {
    while (++i < n) if ((b = f.call(array, array[i], i)) != null && b >= b) { a = b; break; }
    while (++i < n) if ((b = f.call(array, array[i], i)) != null && b > a) a = b;
  }
  return a;
};
d3.extent = function(array, f) {
  var i = -1,
      n = array.length,
      a,
      b,
      c;
  if (arguments.length === 1) {
    while (++i < n) if ((b = array[i]) != null && b >= b) { a = c = b; break; }
    while (++i < n) if ((b = array[i]) != null) {
      if (a > b) a = b;
      if (c < b) c = b;
    }
  } else {
    while (++i < n) if ((b = f.call(array, array[i], i)) != null && b >= b) { a = c = b; break; }
    while (++i < n) if ((b = f.call(array, array[i], i)) != null) {
      if (a > b) a = b;
      if (c < b) c = b;
    }
  }
  return [a, c];
};
function d3_number(x) {
  return x === null ? NaN : +x;
}

function d3_numeric(x) {
  return !isNaN(x);
}

d3.sum = function(array, f) {
  var s = 0,
      n = array.length,
      a,
      i = -1;
  if (arguments.length === 1) {
    while (++i < n) if (d3_numeric(a = +array[i])) s += a; // zero and null are equivalent
  } else {
    while (++i < n) if (d3_numeric(a = +f.call(array, array[i], i))) s += a;
  }
  return s;
};

d3.mean = function(array, f) {
  var s = 0,
      n = array.length,
      a,
      i = -1,
      j = n;
  if (arguments.length === 1) {
    while (++i < n) if (d3_numeric(a = d3_number(array[i]))) s += a; else --j;
  } else {
    while (++i < n) if (d3_numeric(a = d3_number(f.call(array, array[i], i)))) s += a; else --j;
  }
  if (j) return s / j;
};
// R-7 per <http://en.wikipedia.org/wiki/Quantile>
d3.quantile = function(values, p) {
  var H = (values.length - 1) * p + 1,
      h = Math.floor(H),
      v = +values[h - 1],
      e = H - h;
  return e ? v + e * (values[h] - v) : v;
};

d3.median = function(array, f) {
  var numbers = [],
      n = array.length,
      a,
      i = -1;
  if (arguments.length === 1) {
    while (++i < n) if (d3_numeric(a = d3_number(array[i]))) numbers.push(a);
  } else {
    while (++i < n) if (d3_numeric(a = d3_number(f.call(array, array[i], i)))) numbers.push(a);
  }
  if (numbers.length) return d3.quantile(numbers.sort(d3_ascending), .5);
};

d3.variance = function(array, f) {
  var n = array.length,
      m = 0,
      a,
      d,
      s = 0,
      i = -1,
      j = 0;
  if (arguments.length === 1) {
    while (++i < n) {
      if (d3_numeric(a = d3_number(array[i]))) {
        d = a - m;
        m += d / ++j;
        s += d * (a - m);
      }
    }
  } else {
    while (++i < n) {
      if (d3_numeric(a = d3_number(f.call(array, array[i], i)))) {
        d = a - m;
        m += d / ++j;
        s += d * (a - m);
      }
    }
  }
  if (j > 1) return s / (j - 1);
};

d3.deviation = function() {
  var v = d3.variance.apply(this, arguments);
  return v ? Math.sqrt(v) : v;
};

function d3_bisector(compare) {
  return {
    left: function(a, x, lo, hi) {
      if (arguments.length < 3) lo = 0;
      if (arguments.length < 4) hi = a.length;
      while (lo < hi) {
        var mid = lo + hi >>> 1;
        if (compare(a[mid], x) < 0) lo = mid + 1;
        else hi = mid;
      }
      return lo;
    },
    right: function(a, x, lo, hi) {
      if (arguments.length < 3) lo = 0;
      if (arguments.length < 4) hi = a.length;
      while (lo < hi) {
        var mid = lo + hi >>> 1;
        if (compare(a[mid], x) > 0) hi = mid;
        else lo = mid + 1;
      }
      return lo;
    }
  };
}

var d3_bisect = d3_bisector(d3_ascending);
d3.bisectLeft = d3_bisect.left;
d3.bisect = d3.bisectRight = d3_bisect.right;

d3.bisector = function(f) {
  return d3_bisector(f.length === 1
      ? function(d, x) { return d3_ascending(f(d), x); }
      : f);
};
d3.shuffle = function(array, i0, i1) {
  if ((m = arguments.length) < 3) { i1 = array.length; if (m < 2) i0 = 0; }
  var m = i1 - i0, t, i;
  while (m) {
    i = Math.random() * m-- | 0;
    t = array[m + i0], array[m + i0] = array[i + i0], array[i + i0] = t;
  }
  return array;
};
d3.permute = function(array, indexes) {
  var i = indexes.length, permutes = new Array(i);
  while (i--) permutes[i] = array[indexes[i]];
  return permutes;
};
d3.pairs = function(array) {
  var i = 0, n = array.length - 1, p0, p1 = array[0], pairs = new Array(n < 0 ? 0 : n);
  while (i < n) pairs[i] = [p0 = p1, p1 = array[++i]];
  return pairs;
};

d3.zip = function() {
  if (!(n = arguments.length)) return [];
  for (var i = -1, m = d3.min(arguments, d3_zipLength), zips = new Array(m); ++i < m;) {
    for (var j = -1, n, zip = zips[i] = new Array(n); ++j < n;) {
      zip[j] = arguments[j][i];
    }
  }
  return zips;
};

function d3_zipLength(d) {
  return d.length;
}

d3.transpose = function(matrix) {
  return d3.zip.apply(d3, matrix);
};
d3.keys = function(map) {
  var keys = [];
  for (var key in map) keys.push(key);
  return keys;
};
d3.values = function(map) {
  var values = [];
  for (var key in map) values.push(map[key]);
  return values;
};
d3.entries = function(map) {
  var entries = [];
  for (var key in map) entries.push({key: key, value: map[key]});
  return entries;
};
d3.merge = function(arrays) {
  var n = arrays.length,
      m,
      i = -1,
      j = 0,
      merged,
      array;

  while (++i < n) j += arrays[i].length;
  merged = new Array(j);

  while (--n >= 0) {
    array = arrays[n];
    m = array.length;
    while (--m >= 0) {
      merged[--j] = array[m];
    }
  }

  return merged;
};
var abs = Math.abs;

d3.range = function(start, stop, step) {
  if (arguments.length < 3) {
    step = 1;
    if (arguments.length < 2) {
      stop = start;
      start = 0;
    }
  }
  if ((stop - start) / step === Infinity) throw new Error("infinite range");
  var range = [],
       k = d3_range_integerScale(abs(step)),
       i = -1,
       j;
  start *= k, stop *= k, step *= k;
  if (step < 0) while ((j = start + step * ++i) > stop) range.push(j / k);
  else while ((j = start + step * ++i) < stop) range.push(j / k);
  return range;
};

function d3_range_integerScale(x) {
  var k = 1;
  while (x * k % 1) k *= 10;
  return k;
}
function d3_class(ctor, properties) {
  for (var key in properties) {
    Object.defineProperty(ctor.prototype, key, {
      value: properties[key],
      enumerable: false
    });
  }
}

d3.map = function(object, f) {
  var map = new d3_Map;
  if (object instanceof d3_Map) {
    object.forEach(function(key, value) { map.set(key, value); });
  } else if (Array.isArray(object)) {
    var i = -1,
        n = object.length,
        o;
    if (arguments.length === 1) while (++i < n) map.set(i, object[i]);
    else while (++i < n) map.set(f.call(object, o = object[i], i), o);
  } else {
    for (var key in object) map.set(key, object[key]);
  }
  return map;
};

function d3_Map() {
  this._ = Object.create(null);
}

var d3_map_proto = "__proto__",
    d3_map_zero = "\0";

d3_class(d3_Map, {
  has: d3_map_has,
  get: function(key) {
    return this._[d3_map_escape(key)];
  },
  set: function(key, value) {
    return this._[d3_map_escape(key)] = value;
  },
  remove: d3_map_remove,
  keys: d3_map_keys,
  values: function() {
    var values = [];
    for (var key in this._) values.push(this._[key]);
    return values;
  },
  entries: function() {
    var entries = [];
    for (var key in this._) entries.push({key: d3_map_unescape(key), value: this._[key]});
    return entries;
  },
  size: d3_map_size,
  empty: d3_map_empty,
  forEach: function(f) {
    for (var key in this._) f.call(this, d3_map_unescape(key), this._[key]);
  }
});

function d3_map_escape(key) {
  return (key += "") === d3_map_proto || key[0] === d3_map_zero ? d3_map_zero + key : key;
}

function d3_map_unescape(key) {
  return (key += "")[0] === d3_map_zero ? key.slice(1) : key;
}

function d3_map_has(key) {
  return d3_map_escape(key) in this._;
}

function d3_map_remove(key) {
  return (key = d3_map_escape(key)) in this._ && delete this._[key];
}

function d3_map_keys() {
  var keys = [];
  for (var key in this._) keys.push(d3_map_unescape(key));
  return keys;
}

function d3_map_size() {
  var size = 0;
  for (var key in this._) ++size;
  return size;
}

function d3_map_empty() {
  for (var key in this._) return false;
  return true;
}

d3.nest = function() {
  var nest = {},
      keys = [],
      sortKeys = [],
      sortValues,
      rollup;

  function map(mapType, array, depth) {
    if (depth >= keys.length) return rollup
        ? rollup.call(nest, array) : (sortValues
        ? array.sort(sortValues)
        : array);

    var i = -1,
        n = array.length,
        key = keys[depth++],
        keyValue,
        object,
        setter,
        valuesByKey = new d3_Map,
        values;

    while (++i < n) {
      if (values = valuesByKey.get(keyValue = key(object = array[i]))) {
        values.push(object);
      } else {
        valuesByKey.set(keyValue, [object]);
      }
    }

    if (mapType) {
      object = mapType();
      setter = function(keyValue, values) {
        object.set(keyValue, map(mapType, values, depth));
      };
    } else {
      object = {};
      setter = function(keyValue, values) {
        object[keyValue] = map(mapType, values, depth);
      };
    }

    valuesByKey.forEach(setter);
    return object;
  }

  function entries(map, depth) {
    if (depth >= keys.length) return map;

    var array = [],
        sortKey = sortKeys[depth++];

    map.forEach(function(key, keyMap) {
      array.push({key: key, values: entries(keyMap, depth)});
    });

    return sortKey
        ? array.sort(function(a, b) { return sortKey(a.key, b.key); })
        : array;
  }

  nest.map = function(array, mapType) {
    return map(mapType, array, 0);
  };

  nest.entries = function(array) {
    return entries(map(d3.map, array, 0), 0);
  };

  nest.key = function(d) {
    keys.push(d);
    return nest;
  };

  // Specifies the order for the most-recently specified key.
  // Note: only applies to entries. Map keys are unordered!
  nest.sortKeys = function(order) {
    sortKeys[keys.length - 1] = order;
    return nest;
  };

  // Specifies the order for leaf values.
  // Applies to both maps and entries array.
  nest.sortValues = function(order) {
    sortValues = order;
    return nest;
  };

  nest.rollup = function(f) {
    rollup = f;
    return nest;
  };

  return nest;
};

d3.set = function(array) {
  var set = new d3_Set;
  if (array) for (var i = 0, n = array.length; i < n; ++i) set.add(array[i]);
  return set;
};

function d3_Set() {
  this._ = Object.create(null);
}

d3_class(d3_Set, {
  has: d3_map_has,
  add: function(key) {
    this._[d3_map_escape(key += "")] = true;
    return key;
  },
  remove: d3_map_remove,
  values: d3_map_keys,
  size: d3_map_size,
  empty: d3_map_empty,
  forEach: function(f) {
    for (var key in this._) f.call(this, d3_map_unescape(key));
  }
});
d3.behavior = {};
var d3_document = this.document;

function d3_documentElement(node) {
  return node
      && (node.ownerDocument // node is a Node
      || node.document // node is a Window
      || node).documentElement; // node is a Document
}

function d3_window(node) {
  return node
      && ((node.ownerDocument && node.ownerDocument.defaultView) // node is a Node
        || (node.document && node) // node is a Window
        || node.defaultView); // node is a Document
}
// Copies a variable number of methods from source to target.
d3.rebind = function(target, source) {
  var i = 1, n = arguments.length, method;
  while (++i < n) target[method = arguments[i]] = d3_rebind(target, source, source[method]);
  return target;
};

// Method is assumed to be a standard D3 getter-setter:
// If passed with no arguments, gets the value.
// If passed with arguments, sets the value and returns the target.
function d3_rebind(target, source, method) {
  return function() {
    var value = method.apply(source, arguments);
    return value === source ? target : value;
  };
}
function d3_vendorSymbol(object, name) {
  if (name in object) return name;
  name = name.charAt(0).toUpperCase() + name.slice(1);
  for (var i = 0, n = d3_vendorPrefixes.length; i < n; ++i) {
    var prefixName = d3_vendorPrefixes[i] + name;
    if (prefixName in object) return prefixName;
  }
}

var d3_vendorPrefixes = ["webkit", "ms", "moz", "Moz", "o", "O"];
var d3_arraySlice = [].slice,
    d3_array = function(list) { return d3_arraySlice.call(list); }; // conversion for NodeLists
function d3_noop() {}

d3.dispatch = function() {
  var dispatch = new d3_dispatch,
      i = -1,
      n = arguments.length;
  while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
  return dispatch;
};

function d3_dispatch() {}

d3_dispatch.prototype.on = function(type, listener) {
  var i = type.indexOf("."),
      name = "";

  // Extract optional namespace, e.g., "click.foo"
  if (i >= 0) {
    name = type.slice(i + 1);
    type = type.slice(0, i);
  }

  if (type) return arguments.length < 2
      ? this[type].on(name)
      : this[type].on(name, listener);

  if (arguments.length === 2) {
    if (listener == null) for (type in this) {
      if (this.hasOwnProperty(type)) this[type].on(name, null);
    }
    return this;
  }
};

function d3_dispatch_event(dispatch) {
  var listeners = [],
      listenerByName = new d3_Map;

  function event() {
    var z = listeners, // defensive reference
        i = -1,
        n = z.length,
        l;
    while (++i < n) if (l = z[i].on) l.apply(this, arguments);
    return dispatch;
  }

  event.on = function(name, listener) {
    var l = listenerByName.get(name),
        i;

    // return the current listener, if any
    if (arguments.length < 2) return l && l.on;

    // remove the old listener, if any (with copy-on-write)
    if (l) {
      l.on = null;
      listeners = listeners.slice(0, i = listeners.indexOf(l)).concat(listeners.slice(i + 1));
      listenerByName.remove(name);
    }

    // add the new listener, if any
    if (listener) listeners.push(listenerByName.set(name, {on: listener}));

    return dispatch;
  };

  return event;
}

d3.event = null;

function d3_eventPreventDefault() {
  d3.event.preventDefault();
}

function d3_eventCancel() {
  d3.event.preventDefault();
  d3.event.stopPropagation();
}

function d3_eventSource() {
  var e = d3.event, s;
  while (s = e.sourceEvent) e = s;
  return e;
}

// Like d3.dispatch, but for custom events abstracting native UI events. These
// events have a target component (such as a brush), a target element (such as
// the svg:g element containing the brush) and the standard arguments `d` (the
// target element's data) and `i` (the selection index of the target element).
function d3_eventDispatch(target) {
  var dispatch = new d3_dispatch,
      i = 0,
      n = arguments.length;

  while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);

  // Creates a dispatch context for the specified `thiz` (typically, the target
  // DOM element that received the source event) and `argumentz` (typically, the
  // data `d` and index `i` of the target element). The returned function can be
  // used to dispatch an event to any registered listeners; the function takes a
  // single argument as input, being the event to dispatch. The event must have
  // a "type" attribute which corresponds to a type registered in the
  // constructor. This context will automatically populate the "sourceEvent" and
  // "target" attributes of the event, as well as setting the `d3.event` global
  // for the duration of the notification.
  dispatch.of = function(thiz, argumentz) {
    return function(e1) {
      try {
        var e0 =
        e1.sourceEvent = d3.event;
        e1.target = target;
        d3.event = e1;
        dispatch[e1.type].apply(thiz, argumentz);
      } finally {
        d3.event = e0;
      }
    };
  };

  return dispatch;
}
d3.requote = function(s) {
  return s.replace(d3_requote_re, "\\$&");
};

var d3_requote_re = /[\\\^\$\*\+\?\|\[\]\(\)\.\{\}]/g;
var d3_subclass = {}.__proto__?

// Until ECMAScript supports array subclassing, prototype injection works well.
function(object, prototype) {
  object.__proto__ = prototype;
}:

// And if your browser doesn't support __proto__, we'll use direct extension.
function(object, prototype) {
  for (var property in prototype) object[property] = prototype[property];
};

function d3_selection(groups) {
  d3_subclass(groups, d3_selectionPrototype);
  return groups;
}

var d3_select = function(s, n) { return n.querySelector(s); },
    d3_selectAll = function(s, n) { return n.querySelectorAll(s); },
    d3_selectMatches = function(n, s) {
      var d3_selectMatcher = n.matches || n[d3_vendorSymbol(n, "matchesSelector")];
      d3_selectMatches = function(n, s) {
        return d3_selectMatcher.call(n, s);
      };
      return d3_selectMatches(n, s);
    };

// Prefer Sizzle, if available.
if (typeof Sizzle === "function") {
  d3_select = function(s, n) { return Sizzle(s, n)[0] || null; };
  d3_selectAll = Sizzle;
  d3_selectMatches = Sizzle.matchesSelector;
}

d3.selection = function() {
  return d3.select(d3_document.documentElement);
};

var d3_selectionPrototype = d3.selection.prototype = [];


d3_selectionPrototype.select = function(selector) {
  var subgroups = [],
      subgroup,
      subnode,
      group,
      node;

  selector = d3_selection_selector(selector);

  for (var j = -1, m = this.length; ++j < m;) {
    subgroups.push(subgroup = []);
    subgroup.parentNode = (group = this[j]).parentNode;
    for (var i = -1, n = group.length; ++i < n;) {
      if (node = group[i]) {
        subgroup.push(subnode = selector.call(node, node.__data__, i, j));
        if (subnode && "__data__" in node) subnode.__data__ = node.__data__;
      } else {
        subgroup.push(null);
      }
    }
  }

  return d3_selection(subgroups);
};

function d3_selection_selector(selector) {
  return typeof selector === "function" ? selector : function() {
    return d3_select(selector, this);
  };
}

d3_selectionPrototype.selectAll = function(selector) {
  var subgroups = [],
      subgroup,
      node;

  selector = d3_selection_selectorAll(selector);

  for (var j = -1, m = this.length; ++j < m;) {
    for (var group = this[j], i = -1, n = group.length; ++i < n;) {
      if (node = group[i]) {
        subgroups.push(subgroup = d3_array(selector.call(node, node.__data__, i, j)));
        subgroup.parentNode = node;
      }
    }
  }

  return d3_selection(subgroups);
};

function d3_selection_selectorAll(selector) {
  return typeof selector === "function" ? selector : function() {
    return d3_selectAll(selector, this);
  };
}
var d3_nsPrefix = {
  svg: "http://www.w3.org/2000/svg",
  xhtml: "http://www.w3.org/1999/xhtml",
  xlink: "http://www.w3.org/1999/xlink",
  xml: "http://www.w3.org/XML/1998/namespace",
  xmlns: "http://www.w3.org/2000/xmlns/"
};

d3.ns = {
  prefix: d3_nsPrefix,
  qualify: function(name) {
    var i = name.indexOf(":"),
        prefix = name;
    if (i >= 0) {
      prefix = name.slice(0, i);
      name = name.slice(i + 1);
    }
    return d3_nsPrefix.hasOwnProperty(prefix)
        ? {space: d3_nsPrefix[prefix], local: name}
        : name;
  }
};

d3_selectionPrototype.attr = function(name, value) {
  if (arguments.length < 2) {

    // For attr(string), return the attribute value for the first node.
    if (typeof name === "string") {
      var node = this.node();
      name = d3.ns.qualify(name);
      return name.local
          ? node.getAttributeNS(name.space, name.local)
          : node.getAttribute(name);
    }

    // For attr(object), the object specifies the names and values of the
    // attributes to set or remove. The values may be functions that are
    // evaluated for each element.
    for (value in name) this.each(d3_selection_attr(value, name[value]));
    return this;
  }

  return this.each(d3_selection_attr(name, value));
};

function d3_selection_attr(name, value) {
  name = d3.ns.qualify(name);

  // For attr(string, null), remove the attribute with the specified name.
  function attrNull() {
    this.removeAttribute(name);
  }
  function attrNullNS() {
    this.removeAttributeNS(name.space, name.local);
  }

  // For attr(string, string), set the attribute with the specified name.
  function attrConstant() {
    this.setAttribute(name, value);
  }
  function attrConstantNS() {
    this.setAttributeNS(name.space, name.local, value);
  }

  // For attr(string, function), evaluate the function for each element, and set
  // or remove the attribute as appropriate.
  function attrFunction() {
    var x = value.apply(this, arguments);
    if (x == null) this.removeAttribute(name);
    else this.setAttribute(name, x);
  }
  function attrFunctionNS() {
    var x = value.apply(this, arguments);
    if (x == null) this.removeAttributeNS(name.space, name.local);
    else this.setAttributeNS(name.space, name.local, x);
  }

  return value == null
      ? (name.local ? attrNullNS : attrNull) : (typeof value === "function"
      ? (name.local ? attrFunctionNS : attrFunction)
      : (name.local ? attrConstantNS : attrConstant));
}
function d3_collapse(s) {
  return s.trim().replace(/\s+/g, " ");
}

d3_selectionPrototype.classed = function(name, value) {
  if (arguments.length < 2) {

    // For classed(string), return true only if the first node has the specified
    // class or classes. Note that even if the browser supports DOMTokenList, it
    // probably doesn't support it on SVG elements (which can be animated).
    if (typeof name === "string") {
      var node = this.node(),
          n = (name = d3_selection_classes(name)).length,
          i = -1;
      if (value = node.classList) {
        while (++i < n) if (!value.contains(name[i])) return false;
      } else {
        value = node.getAttribute("class");
        while (++i < n) if (!d3_selection_classedRe(name[i]).test(value)) return false;
      }
      return true;
    }

    // For classed(object), the object specifies the names of classes to add or
    // remove. The values may be functions that are evaluated for each element.
    for (value in name) this.each(d3_selection_classed(value, name[value]));
    return this;
  }

  // Otherwise, both a name and a value are specified, and are handled as below.
  return this.each(d3_selection_classed(name, value));
};

function d3_selection_classedRe(name) {
  return new RegExp("(?:^|\\s+)" + d3.requote(name) + "(?:\\s+|$)", "g");
}

function d3_selection_classes(name) {
  return (name + "").trim().split(/^|\s+/);
}

// Multiple class names are allowed (e.g., "foo bar").
function d3_selection_classed(name, value) {
  name = d3_selection_classes(name).map(d3_selection_classedName);
  var n = name.length;

  function classedConstant() {
    var i = -1;
    while (++i < n) name[i](this, value);
  }

  // When the value is a function, the function is still evaluated only once per
  // element even if there are multiple class names.
  function classedFunction() {
    var i = -1, x = value.apply(this, arguments);
    while (++i < n) name[i](this, x);
  }

  return typeof value === "function"
      ? classedFunction
      : classedConstant;
}

function d3_selection_classedName(name) {
  var re = d3_selection_classedRe(name);
  return function(node, value) {
    if (c = node.classList) return value ? c.add(name) : c.remove(name);
    var c = node.getAttribute("class") || "";
    if (value) {
      re.lastIndex = 0;
      if (!re.test(c)) node.setAttribute("class", d3_collapse(c + " " + name));
    } else {
      node.setAttribute("class", d3_collapse(c.replace(re, " ")));
    }
  };
}

d3_selectionPrototype.style = function(name, value, priority) {
  var n = arguments.length;
  if (n < 3) {

    // For style(object) or style(object, string), the object specifies the
    // names and values of the attributes to set or remove. The values may be
    // functions that are evaluated for each element. The optional string
    // specifies the priority.
    if (typeof name !== "string") {
      if (n < 2) value = "";
      for (priority in name) this.each(d3_selection_style(priority, name[priority], value));
      return this;
    }

    // For style(string), return the computed style value for the first node.
    if (n < 2) {
      var node = this.node();
      return d3_window(node).getComputedStyle(node, null).getPropertyValue(name);
    }

    // For style(string, string) or style(string, function), use the default
    // priority. The priority is ignored for style(string, null).
    priority = "";
  }

  // Otherwise, a name, value and priority are specified, and handled as below.
  return this.each(d3_selection_style(name, value, priority));
};

function d3_selection_style(name, value, priority) {

  // For style(name, null) or style(name, null, priority), remove the style
  // property with the specified name. The priority is ignored.
  function styleNull() {
    this.style.removeProperty(name);
  }

  // For style(name, string) or style(name, string, priority), set the style
  // property with the specified name, using the specified priority.
  function styleConstant() {
    this.style.setProperty(name, value, priority);
  }

  // For style(name, function) or style(name, function, priority), evaluate the
  // function for each element, and set or remove the style property as
  // appropriate. When setting, use the specified priority.
  function styleFunction() {
    var x = value.apply(this, arguments);
    if (x == null) this.style.removeProperty(name);
    else this.style.setProperty(name, x, priority);
  }

  return value == null
      ? styleNull : (typeof value === "function"
      ? styleFunction : styleConstant);
}

d3_selectionPrototype.property = function(name, value) {
  if (arguments.length < 2) {

    // For property(string), return the property value for the first node.
    if (typeof name === "string") return this.node()[name];

    // For property(object), the object specifies the names and values of the
    // properties to set or remove. The values may be functions that are
    // evaluated for each element.
    for (value in name) this.each(d3_selection_property(value, name[value]));
    return this;
  }

  // Otherwise, both a name and a value are specified, and are handled as below.
  return this.each(d3_selection_property(name, value));
};

function d3_selection_property(name, value) {

  // For property(name, null), remove the property with the specified name.
  function propertyNull() {
    delete this[name];
  }

  // For property(name, string), set the property with the specified name.
  function propertyConstant() {
    this[name] = value;
  }

  // For property(name, function), evaluate the function for each element, and
  // set or remove the property as appropriate.
  function propertyFunction() {
    var x = value.apply(this, arguments);
    if (x == null) delete this[name];
    else this[name] = x;
  }

  return value == null
      ? propertyNull : (typeof value === "function"
      ? propertyFunction : propertyConstant);
}

d3_selectionPrototype.text = function(value) {
  return arguments.length
      ? this.each(typeof value === "function"
      ? function() { var v = value.apply(this, arguments); this.textContent = v == null ? "" : v; } : value == null
      ? function() { if (this.textContent !== "") this.textContent = ""; }
      : function() { if (this.textContent !== value) this.textContent = value; })
      : this.node().textContent;
};

d3_selectionPrototype.html = function(value) {
  return arguments.length
      ? this.each(typeof value === "function"
      ? function() { var v = value.apply(this, arguments); this.innerHTML = v == null ? "" : v; } : value == null
      ? function() { this.innerHTML = ""; }
      : function() { this.innerHTML = value; })
      : this.node().innerHTML;
};

d3_selectionPrototype.append = function(name) {
  name = d3_selection_creator(name);
  return this.select(function() {
    return this.appendChild(name.apply(this, arguments));
  });
};

function d3_selection_creator(name) {

  function create() {
    var document = this.ownerDocument,
        namespace = this.namespaceURI;
    return namespace
        ? document.createElementNS(namespace, name)
        : document.createElement(name);
  }

  function createNS() {
    return this.ownerDocument.createElementNS(name.space, name.local);
  }

  return typeof name === "function" ? name
      : (name = d3.ns.qualify(name)).local ? createNS
      : create;
}

d3_selectionPrototype.insert = function(name, before) {
  name = d3_selection_creator(name);
  before = d3_selection_selector(before);
  return this.select(function() {
    return this.insertBefore(name.apply(this, arguments), before.apply(this, arguments) || null);
  });
};

// TODO remove(selector)?
// TODO remove(node)?
// TODO remove(function)?
d3_selectionPrototype.remove = function() {
  return this.each(d3_selectionRemove);
};

function d3_selectionRemove() {
  var parent = this.parentNode;
  if (parent) parent.removeChild(this);
}

d3_selectionPrototype.data = function(value, key) {
  var i = -1,
      n = this.length,
      group,
      node;

  // If no value is specified, return the first value.
  if (!arguments.length) {
    value = new Array(n = (group = this[0]).length);
    while (++i < n) {
      if (node = group[i]) {
        value[i] = node.__data__;
      }
    }
    return value;
  }

  function bind(group, groupData) {
    var i,
        n = group.length,
        m = groupData.length,
        n0 = Math.min(n, m),
        updateNodes = new Array(m),
        enterNodes = new Array(m),
        exitNodes = new Array(n),
        node,
        nodeData;

    if (key) {
      var nodeByKeyValue = new d3_Map,
          keyValues = new Array(n),
          keyValue;

      for (i = -1; ++i < n;) {
        if (nodeByKeyValue.has(keyValue = key.call(node = group[i], node.__data__, i))) {
          exitNodes[i] = node; // duplicate selection key
        } else {
          nodeByKeyValue.set(keyValue, node);
        }
        keyValues[i] = keyValue;
      }

      for (i = -1; ++i < m;) {
        if (!(node = nodeByKeyValue.get(keyValue = key.call(groupData, nodeData = groupData[i], i)))) {
          enterNodes[i] = d3_selection_dataNode(nodeData);
        } else if (node !== true) { // no duplicate data key
          updateNodes[i] = node;
          node.__data__ = nodeData;
        }
        nodeByKeyValue.set(keyValue, true);
      }

      for (i = -1; ++i < n;) {
        if (nodeByKeyValue.get(keyValues[i]) !== true) {
          exitNodes[i] = group[i];
        }
      }
    } else {
      for (i = -1; ++i < n0;) {
        node = group[i];
        nodeData = groupData[i];
        if (node) {
          node.__data__ = nodeData;
          updateNodes[i] = node;
        } else {
          enterNodes[i] = d3_selection_dataNode(nodeData);
        }
      }
      for (; i < m; ++i) {
        enterNodes[i] = d3_selection_dataNode(groupData[i]);
      }
      for (; i < n; ++i) {
        exitNodes[i] = group[i];
      }
    }

    enterNodes.update
        = updateNodes;

    enterNodes.parentNode
        = updateNodes.parentNode
        = exitNodes.parentNode
        = group.parentNode;

    enter.push(enterNodes);
    update.push(updateNodes);
    exit.push(exitNodes);
  }

  var enter = d3_selection_enter([]),
      update = d3_selection([]),
      exit = d3_selection([]);

  if (typeof value === "function") {
    while (++i < n) {
      bind(group = this[i], value.call(group, group.parentNode.__data__, i));
    }
  } else {
    while (++i < n) {
      bind(group = this[i], value);
    }
  }

  update.enter = function() { return enter; };
  update.exit = function() { return exit; };
  return update;
};

function d3_selection_dataNode(data) {
  return {__data__: data};
}

d3_selectionPrototype.datum = function(value) {
  return arguments.length
      ? this.property("__data__", value)
      : this.property("__data__");
};

d3_selectionPrototype.filter = function(filter) {
  var subgroups = [],
      subgroup,
      group,
      node;

  if (typeof filter !== "function") filter = d3_selection_filter(filter);

  for (var j = 0, m = this.length; j < m; j++) {
    subgroups.push(subgroup = []);
    subgroup.parentNode = (group = this[j]).parentNode;
    for (var i = 0, n = group.length; i < n; i++) {
      if ((node = group[i]) && filter.call(node, node.__data__, i, j)) {
        subgroup.push(node);
      }
    }
  }

  return d3_selection(subgroups);
};

function d3_selection_filter(selector) {
  return function() {
    return d3_selectMatches(this, selector);
  };
}

d3_selectionPrototype.order = function() {
  for (var j = -1, m = this.length; ++j < m;) {
    for (var group = this[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
      if (node = group[i]) {
        if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
        next = node;
      }
    }
  }
  return this;
};

d3_selectionPrototype.sort = function(comparator) {
  comparator = d3_selection_sortComparator.apply(this, arguments);
  for (var j = -1, m = this.length; ++j < m;) this[j].sort(comparator);
  return this.order();
};

function d3_selection_sortComparator(comparator) {
  if (!arguments.length) comparator = d3_ascending;
  return function(a, b) {
    return a && b ? comparator(a.__data__, b.__data__) : !a - !b;
  };
}

d3_selectionPrototype.each = function(callback) {
  return d3_selection_each(this, function(node, i, j) {
    callback.call(node, node.__data__, i, j);
  });
};

function d3_selection_each(groups, callback) {
  for (var j = 0, m = groups.length; j < m; j++) {
    for (var group = groups[j], i = 0, n = group.length, node; i < n; i++) {
      if (node = group[i]) callback(node, i, j);
    }
  }
  return groups;
}

d3_selectionPrototype.call = function(callback) {
  var args = d3_array(arguments);
  callback.apply(args[0] = this, args);
  return this;
};

d3_selectionPrototype.empty = function() {
  return !this.node();
};

d3_selectionPrototype.node = function() {
  for (var j = 0, m = this.length; j < m; j++) {
    for (var group = this[j], i = 0, n = group.length; i < n; i++) {
      var node = group[i];
      if (node) return node;
    }
  }
  return null;
};

d3_selectionPrototype.size = function() {
  var n = 0;
  d3_selection_each(this, function() { ++n; });
  return n;
};

function d3_selection_enter(selection) {
  d3_subclass(selection, d3_selection_enterPrototype);
  return selection;
}

var d3_selection_enterPrototype = [];

d3.selection.enter = d3_selection_enter;
d3.selection.enter.prototype = d3_selection_enterPrototype;

d3_selection_enterPrototype.append = d3_selectionPrototype.append;
d3_selection_enterPrototype.empty = d3_selectionPrototype.empty;
d3_selection_enterPrototype.node = d3_selectionPrototype.node;
d3_selection_enterPrototype.call = d3_selectionPrototype.call;
d3_selection_enterPrototype.size = d3_selectionPrototype.size;


d3_selection_enterPrototype.select = function(selector) {
  var subgroups = [],
      subgroup,
      subnode,
      upgroup,
      group,
      node;

  for (var j = -1, m = this.length; ++j < m;) {
    upgroup = (group = this[j]).update;
    subgroups.push(subgroup = []);
    subgroup.parentNode = group.parentNode;
    for (var i = -1, n = group.length; ++i < n;) {
      if (node = group[i]) {
        subgroup.push(upgroup[i] = subnode = selector.call(group.parentNode, node.__data__, i, j));
        subnode.__data__ = node.__data__;
      } else {
        subgroup.push(null);
      }
    }
  }

  return d3_selection(subgroups);
};

d3_selection_enterPrototype.insert = function(name, before) {
  if (arguments.length < 2) before = d3_selection_enterInsertBefore(this);
  return d3_selectionPrototype.insert.call(this, name, before);
};

function d3_selection_enterInsertBefore(enter) {
  var i0, j0;
  return function(d, i, j) {
    var group = enter[j].update,
        n = group.length,
        node;
    if (j != j0) j0 = j, i0 = 0;
    if (i >= i0) i0 = i + 1;
    while (!(node = group[i0]) && ++i0 < n);
    return node;
  };
}

// TODO fast singleton implementation?
d3.select = function(node) {
  var group;
  if (typeof node === "string") {
    group = [d3_select(node, d3_document)];
    group.parentNode = d3_document.documentElement;
  } else {
    group = [node];
    group.parentNode = d3_documentElement(node);
  }
  return d3_selection([group]);
};

d3.selectAll = function(nodes) {
  var group;
  if (typeof nodes === "string") {
    group = d3_array(d3_selectAll(nodes, d3_document));
    group.parentNode = d3_document.documentElement;
  } else {
    group = nodes;
    group.parentNode = null;
  }
  return d3_selection([group]);
};

d3_selectionPrototype.on = function(type, listener, capture) {
  var n = arguments.length;
  if (n < 3) {

    // For on(object) or on(object, boolean), the object specifies the event
    // types and listeners to add or remove. The optional boolean specifies
    // whether the listener captures events.
    if (typeof type !== "string") {
      if (n < 2) listener = false;
      for (capture in type) this.each(d3_selection_on(capture, type[capture], listener));
      return this;
    }

    // For on(string), return the listener for the first node.
    if (n < 2) return (n = this.node()["__on" + type]) && n._;

    // For on(string, function), use the default capture.
    capture = false;
  }

  // Otherwise, a type, listener and capture are specified, and handled as below.
  return this.each(d3_selection_on(type, listener, capture));
};

function d3_selection_on(type, listener, capture) {
  var name = "__on" + type,
      i = type.indexOf("."),
      wrap = d3_selection_onListener;

  if (i > 0) type = type.slice(0, i);
  var filter = d3_selection_onFilters.get(type);
  if (filter) type = filter, wrap = d3_selection_onFilter;

  function onRemove() {
    var l = this[name];
    if (l) {
      this.removeEventListener(type, l, l.$);
      delete this[name];
    }
  }

  function onAdd() {
    var l = wrap(listener, d3_array(arguments));
    if (typeof Raven !== 'undefined') l = Raven.wrap(l);
    onRemove.call(this);
    this.addEventListener(type, this[name] = l, l.$ = capture);
    l._ = listener;
  }

  function removeAll() {
    var re = new RegExp("^__on([^.]+)" + d3.requote(type) + "$"),
        match;
    for (var name in this) {
      if (match = name.match(re)) {
        var l = this[name];
        this.removeEventListener(match[1], l, l.$);
        delete this[name];
      }
    }
  }

  return i
      ? listener ? onAdd : onRemove
      : listener ? d3_noop : removeAll;
}

var d3_selection_onFilters = d3.map({
  mouseenter: "mouseover",
  mouseleave: "mouseout"
});

if (d3_document) {
  d3_selection_onFilters.forEach(function(k) {
    if ("on" + k in d3_document) d3_selection_onFilters.remove(k);
  });
}

function d3_selection_onListener(listener, argumentz) {
  return function(e) {
    var o = d3.event; // Events can be reentrant (e.g., focus).
    d3.event = e;
    argumentz[0] = this.__data__;
    try {
      listener.apply(this, argumentz);
    } finally {
      d3.event = o;
    }
  };
}

function d3_selection_onFilter(listener, argumentz) {
  var l = d3_selection_onListener(listener, argumentz);
  return function(e) {
    var target = this, related = e.relatedTarget;
    if (!related || (related !== target && !(related.compareDocumentPosition(target) & 8))) {
      l.call(target, e);
    }
  };
}

var d3_event_dragSelect,
    d3_event_dragId = 0;

function d3_event_dragSuppress(node) {
  var name = ".dragsuppress-" + ++d3_event_dragId,
      click = "click" + name,
      w = d3.select(d3_window(node))
          .on("touchmove" + name, d3_eventPreventDefault)
          .on("dragstart" + name, d3_eventPreventDefault)
          .on("selectstart" + name, d3_eventPreventDefault);

  if (d3_event_dragSelect == null) {
    d3_event_dragSelect = "onselectstart" in node ? false
        : d3_vendorSymbol(node.style, "userSelect");
  }

  if (d3_event_dragSelect) {
    var style = d3_documentElement(node).style,
        select = style[d3_event_dragSelect];
    style[d3_event_dragSelect] = "none";
  }

  return function(suppressClick) {
    w.on(name, null);
    if (d3_event_dragSelect) style[d3_event_dragSelect] = select;
    if (suppressClick) { // suppress the next click, but only if it’s immediate
      var off = function() { w.on(click, null); };
      w.on(click, function() { d3_eventCancel(); off(); }, true);
      setTimeout(off, 0);
    }
  };
}

d3.mouse = function(container) {
  return d3_mousePoint(container, d3_eventSource());
};

// https://bugs.webkit.org/show_bug.cgi?id=44083
var d3_mouse_bug44083 = this.navigator && /WebKit/.test(this.navigator.userAgent) ? -1 : 0;

function d3_mousePoint(container, e) {
  if (e.changedTouches) e = e.changedTouches[0];
  var svg = container.ownerSVGElement || container;
  if (svg.createSVGPoint) {
    var point = svg.createSVGPoint();
    if (d3_mouse_bug44083 < 0) {
      var window = d3_window(container);
      if (window.scrollX || window.scrollY) {
        svg = d3.select("body").append("svg").style({
          position: "absolute",
          top: 0,
          left: 0,
          margin: 0,
          padding: 0,
          border: "none"
        }, "important");
        var ctm = svg[0][0].getScreenCTM();
        d3_mouse_bug44083 = !(ctm.f || ctm.e);
        svg.remove();
      }
    }
    if (d3_mouse_bug44083) point.x = e.pageX, point.y = e.pageY;
    else point.x = e.clientX, point.y = e.clientY;
    point = point.matrixTransform(container.getScreenCTM().inverse());
    return [point.x, point.y];
  }
  var rect = container.getBoundingClientRect();
  return [e.clientX - rect.left - container.clientLeft, e.clientY - rect.top - container.clientTop];
};

d3.touches = function(container, touches) {
  if (arguments.length < 2) touches = d3_eventSource().touches;
  return touches ? d3_array(touches).map(function(touch) {
    var point = d3_mousePoint(container, touch);
    point.identifier = touch.identifier;
    return point;
  }) : [];
};
var ε = 1e-6,
    ε2 = ε * ε,
    π = Math.PI,
    τ = 2 * π,
    τε = τ - ε,
    halfπ = π / 2,
    d3_radians = π / 180,
    d3_degrees = 180 / π;

function d3_sgn(x) {
  return x > 0 ? 1 : x < 0 ? -1 : 0;
}

// Returns the 2D cross product of AB and AC vectors, i.e., the z-component of
// the 3D cross product in a quadrant I Cartesian coordinate system (+x is
// right, +y is up). Returns a positive value if ABC is counter-clockwise,
// negative if clockwise, and zero if the points are collinear.
function d3_cross2d(a, b, c) {
  return (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
}

function d3_acos(x) {
  return x > 1 ? 0 : x < -1 ? π : Math.acos(x);
}

function d3_asin(x) {
  return x > 1 ? halfπ : x < -1 ? -halfπ : Math.asin(x);
}

function d3_sinh(x) {
  return ((x = Math.exp(x)) - 1 / x) / 2;
}

function d3_cosh(x) {
  return ((x = Math.exp(x)) + 1 / x) / 2;
}

function d3_tanh(x) {
  return ((x = Math.exp(2 * x)) - 1) / (x + 1);
}

function d3_haversin(x) {
  return (x = Math.sin(x / 2)) * x;
}

var ρ = Math.SQRT2,
    ρ2 = 2,
    ρ4 = 4;

// p0 = [ux0, uy0, w0]
// p1 = [ux1, uy1, w1]
d3.interpolateZoom = function(p0, p1) {
  var ux0 = p0[0], uy0 = p0[1], w0 = p0[2],
      ux1 = p1[0], uy1 = p1[1], w1 = p1[2];

  var dx = ux1 - ux0,
      dy = uy1 - uy0,
      d2 = dx * dx + dy * dy,
      d1 = Math.sqrt(d2),
      b0 = (w1 * w1 - w0 * w0 + ρ4 * d2) / (2 * w0 * ρ2 * d1),
      b1 = (w1 * w1 - w0 * w0 - ρ4 * d2) / (2 * w1 * ρ2 * d1),
      r0 = Math.log(Math.sqrt(b0 * b0 + 1) - b0),
      r1 = Math.log(Math.sqrt(b1 * b1 + 1) - b1),
      dr = r1 - r0,
      S = (dr || Math.log(w1 / w0)) / ρ;

  function interpolate(t) {
    var s = t * S;
    if (dr) {
      // General case.
      var coshr0 = d3_cosh(r0),
          u = w0 / (ρ2 * d1) * (coshr0 * d3_tanh(ρ * s + r0) - d3_sinh(r0));
      return [
        ux0 + u * dx,
        uy0 + u * dy,
        w0 * coshr0 / d3_cosh(ρ * s + r0)
      ];
    }
    // Special case for u0 ~= u1.
    return [
      ux0 + t * dx,
      uy0 + t * dy,
      w0 * Math.exp(ρ * s)
    ];
  }

  interpolate.duration = S * 1000;

  return interpolate;
};

d3.behavior.zoom = function() {
  var view = {x: 0, y: 0, k: 1},
      translate0, // translate when we started zooming (to avoid drift)
      center0, // implicit desired position of translate0 after zooming
      center, // explicit desired position of translate0 after zooming
      size = [960, 500], // viewport size; required for zoom interpolation
      scaleExtent = d3_behavior_zoomInfinity,
      duration = 250,
      zooming = 0,
      mousedown = "mousedown.zoom",
      mousemove = "mousemove.zoom",
      mouseup = "mouseup.zoom",
      mousewheelTimer,
      touchstart = "touchstart.zoom",
      touchtime, // time of last touchstart (to detect double-tap)
      event = d3_eventDispatch(zoom, "zoomstart", "zoom", "zoomend"),
      x0,
      x1,
      y0,
      y1;

  // Lazily determine the DOM’s support for Wheel events.
  // https://developer.mozilla.org/en-US/docs/Mozilla_event_reference/wheel
  if (!d3_behavior_zoomWheel) {
    d3_behavior_zoomWheel = "onwheel" in d3_document ? (d3_behavior_zoomDelta = function() { return -d3.event.deltaY * (d3.event.deltaMode ? 120 : 1); }, "wheel")
        : "onmousewheel" in d3_document ? (d3_behavior_zoomDelta = function() { return d3.event.wheelDelta; }, "mousewheel")
        : (d3_behavior_zoomDelta = function() { return -d3.event.detail; }, "MozMousePixelScroll");
  }

  function zoom(g) {
    g   .on(mousedown, mousedowned)
        .on(d3_behavior_zoomWheel + ".zoom", mousewheeled)
        .on("dblclick.zoom", dblclicked)
        .on(touchstart, touchstarted);
  }

  zoom.event = function(g) {
    g.each(function() {
      var dispatch = event.of(this, arguments),
          view1 = view;
      if (d3_transitionInheritId) {
        d3.select(this).transition()
            .each("start.zoom", function() {
              view = this.__chart__ || {x: 0, y: 0, k: 1}; // pre-transition state
              zoomstarted(dispatch);
            })
            .tween("zoom:zoom", function() {
              var dx = size[0],
                  dy = size[1],
                  cx = center0 ? center0[0] : dx / 2,
                  cy = center0 ? center0[1] : dy / 2,
                  i = d3.interpolateZoom(
                    [(cx - view.x) / view.k, (cy - view.y) / view.k, dx / view.k],
                    [(cx - view1.x) / view1.k, (cy - view1.y) / view1.k, dx / view1.k]
                  );
              return function(t) {
                var l = i(t), k = dx / l[2];
                this.__chart__ = view = {x: cx - l[0] * k, y: cy - l[1] * k, k: k};
                zoomed(dispatch);
              };
            })
            .each("interrupt.zoom", function() {
              zoomended(dispatch);
            })
            .each("end.zoom", function() {
              zoomended(dispatch);
            });
      } else {
        this.__chart__ = view;
        zoomstarted(dispatch);
        zoomed(dispatch);
        zoomended(dispatch);
      }
    });
  }

  zoom.translate = function(_) {
    if (!arguments.length) return [view.x, view.y];
    view = {x: +_[0], y: +_[1], k: view.k}; // copy-on-write
    rescale();
    return zoom;
  };

  zoom.scale = function(_) {
    if (!arguments.length) return view.k;
    view = {x: view.x, y: view.y, k: +_}; // copy-on-write
    rescale();
    return zoom;
  };

  zoom.scaleExtent = function(_) {
    if (!arguments.length) return scaleExtent;
    scaleExtent = _ == null ? d3_behavior_zoomInfinity : [+_[0], +_[1]];
    return zoom;
  };

  zoom.center = function(_) {
    if (!arguments.length) return center;
    center = _ && [+_[0], +_[1]];
    return zoom;
  };

  zoom.size = function(_) {
    if (!arguments.length) return size;
    size = _ && [+_[0], +_[1]];
    return zoom;
  };

  zoom.duration = function(_) {
    if (!arguments.length) return duration;
    duration = +_; // TODO function based on interpolateZoom distance?
    return zoom;
  };

  zoom.x = function(z) {
    if (!arguments.length) return x1;
    x1 = z;
    x0 = z.copy();
    view = {x: 0, y: 0, k: 1}; // copy-on-write
    return zoom;
  };

  zoom.y = function(z) {
    if (!arguments.length) return y1;
    y1 = z;
    y0 = z.copy();
    view = {x: 0, y: 0, k: 1}; // copy-on-write
    return zoom;
  };

  function location(p) {
    return [(p[0] - view.x) / view.k, (p[1] - view.y) / view.k];
  }

  function point(l) {
    return [l[0] * view.k + view.x, l[1] * view.k + view.y];
  }

  function scaleTo(s) {
    view.k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], s));
  }

  function translateTo(p, l) {
    l = point(l);
    view.x += p[0] - l[0];
    view.y += p[1] - l[1];
  }

  function zoomTo(that, p, l, k) {
    that.__chart__ = {x: view.x, y: view.y, k: view.k};

    scaleTo(Math.pow(2, k));
    translateTo(center0 = p, l);

    that = d3.select(that);
    if (duration > 0) that = that.transition().duration(duration);
    that.call(zoom.event);
  }

  function rescale() {
    if (x1) x1.domain(x0.range().map(function(x) { return (x - view.x) / view.k; }).map(x0.invert));
    if (y1) y1.domain(y0.range().map(function(y) { return (y - view.y) / view.k; }).map(y0.invert));
  }

  function zoomstarted(dispatch) {
    if (!zooming++) dispatch({type: "zoomstart"});
  }

  function zoomed(dispatch) {
    rescale();
    dispatch({type: "zoom", scale: view.k, translate: [view.x, view.y]});
  }

  function zoomended(dispatch) {
    if (!--zooming) dispatch({type: "zoomend"});
    center0 = null;
  }

  function mousedowned() {
    var that = this,
        target = d3.event.target,
        dispatch = event.of(that, arguments),
        dragged = 0,
        subject = d3.select(d3_window(that)).on(mousemove, moved).on(mouseup, ended),
        location0 = location(d3.mouse(that)),
        dragRestore = d3_event_dragSuppress(that);

    d3_selection_interrupt.call(that);
    zoomstarted(dispatch);

    function moved() {
      dragged = 1;
      translateTo(d3.mouse(that), location0);
      zoomed(dispatch);
    }

    function ended() {
      subject.on(mousemove, null).on(mouseup, null);
      dragRestore(dragged && d3.event.target === target);
      zoomended(dispatch);
    }
  }

  // These closures persist for as long as at least one touch is active.
  function touchstarted() {
    var that = this,
        dispatch = event.of(that, arguments),
        locations0 = {}, // touchstart locations
        distance0 = 0, // distance² between initial touches
        scale0, // scale when we started touching
        zoomName = ".zoom-" + d3.event.changedTouches[0].identifier,
        touchmove = "touchmove" + zoomName,
        touchend = "touchend" + zoomName,
        targets = [],
        subject = d3.select(that),
        dragRestore = d3_event_dragSuppress(that);

    started();
    zoomstarted(dispatch);

    // Workaround for Chrome issue 412723: the touchstart listener must be set
    // after the touchmove listener.
    subject.on(mousedown, null).on(touchstart, started); // prevent duplicate events

    // Updates locations of any touches in locations0.
    function relocate() {
      var touches = d3.touches(that);
      scale0 = view.k;
      touches.forEach(function(t) {
        if (t.identifier in locations0) locations0[t.identifier] = location(t);
      });
      return touches;
    }

    // Temporarily override touchstart while gesture is active.
    function started() {

      // Listen for touchmove and touchend on the target of touchstart.
      var target = d3.event.target;
      d3.select(target).on(touchmove, moved).on(touchend, ended);
      targets.push(target);

      // Only track touches started on the same subject element.
      var changed = d3.event.changedTouches;
      for (var i = 0, n = changed.length; i < n; ++i) {
        locations0[changed[i].identifier] = null;
      }

      var touches = relocate(),
          now = Date.now();

      if (touches.length === 1) {
        if (now - touchtime < 500) { // dbltap
          var p = touches[0];
          zoomTo(that, p, locations0[p.identifier], Math.floor(Math.log(view.k) / Math.LN2) + 1);
          d3_eventPreventDefault();
        }
        touchtime = now;
      } else if (touches.length > 1) {
        var p = touches[0], q = touches[1],
            dx = p[0] - q[0], dy = p[1] - q[1];
        distance0 = dx * dx + dy * dy;
      }
    }

    function moved() {
      var touches = d3.touches(that),
          p0, l0,
          p1, l1;

      d3_selection_interrupt.call(that);

      for (var i = 0, n = touches.length; i < n; ++i, l1 = null) {
        p1 = touches[i];
        if (l1 = locations0[p1.identifier]) {
          if (l0) break;
          p0 = p1, l0 = l1;
        }
      }

      if (l1) {
        var distance1 = (distance1 = p1[0] - p0[0]) * distance1 + (distance1 = p1[1] - p0[1]) * distance1,
            scale1 = distance0 && Math.sqrt(distance1 / distance0);
        p0 = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
        l0 = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
        scaleTo(scale1 * scale0);
      }

      touchtime = null;
      translateTo(p0, l0);
      zoomed(dispatch);
    }

    function ended() {
      // If there are any globally-active touches remaining, remove the ended
      // touches from locations0.
      if (d3.event.touches.length) {
        var changed = d3.event.changedTouches;
        for (var i = 0, n = changed.length; i < n; ++i) {
          delete locations0[changed[i].identifier];
        }
        // If locations0 is not empty, then relocate and continue listening for
        // touchmove and touchend.
        for (var identifier in locations0) {
          return void relocate(); // locations may have detached due to rotation
        }
      }
      // Otherwise, remove touchmove and touchend listeners.
      d3.selectAll(targets).on(zoomName, null);
      subject.on(mousedown, mousedowned).on(touchstart, touchstarted);
      dragRestore();
      zoomended(dispatch);
    }
  }

  function mousewheeled() {
    var dispatch = event.of(this, arguments);
    if (mousewheelTimer) clearTimeout(mousewheelTimer);
    else translate0 = location(center0 = center || d3.mouse(this)), d3_selection_interrupt.call(this), zoomstarted(dispatch);
    mousewheelTimer = setTimeout(function() { mousewheelTimer = null; zoomended(dispatch); }, 50);
    d3_eventPreventDefault();
    scaleTo(Math.pow(2, d3_behavior_zoomDelta() * .002) * view.k);
    translateTo(center0, translate0);
    zoomed(dispatch);
  }

  function dblclicked() {
    var p = d3.mouse(this),
        k = Math.log(view.k) / Math.LN2;

    zoomTo(this, p, location(p), d3.event.shiftKey ? Math.ceil(k) - 1 : Math.floor(k) + 1);
  }

  return d3.rebind(zoom, event, "on");
};

var d3_behavior_zoomInfinity = [0, Infinity], // default scale extent
    d3_behavior_zoomDelta, // initialized lazily
    d3_behavior_zoomWheel;
function d3_functor(v) {
  return typeof v === "function" ? v : function() { return v; };
}

d3.functor = d3_functor;

d3.touch = function(container, touches, identifier) {
  if (arguments.length < 3) identifier = touches, touches = d3_eventSource().changedTouches;
  if (touches) for (var i = 0, n = touches.length, touch; i < n; ++i) {
    if ((touch = touches[i]).identifier === identifier) {
      return d3_mousePoint(container, touch);
    }
  }
};

var d3_timer_queueHead,
    d3_timer_queueTail,
    d3_timer_interval, // is an interval (or frame) active?
    d3_timer_timeout, // is a timeout active?
    d3_timer_active, // active timer object
    d3_timer_frame = this[d3_vendorSymbol(this, "requestAnimationFrame")] || function(callback) { setTimeout(callback, 17); };

// The timer will continue to fire until callback returns true.
d3.timer = function(callback, delay, then) {
  var n = arguments.length;
  if (n < 2) delay = 0;
  if (n < 3) then = Date.now();

  // Add the callback to the tail of the queue.
  var time = then + delay, timer = {c: callback, t: time, f: false, n: null};
  if (d3_timer_queueTail) d3_timer_queueTail.n = timer;
  else d3_timer_queueHead = timer;
  d3_timer_queueTail = timer;

  // Start animatin'!
  if (!d3_timer_interval) {
    d3_timer_timeout = clearTimeout(d3_timer_timeout);
    d3_timer_interval = 1;
    d3_timer_frame(d3_timer_step);
  }
};

function d3_timer_step() {
  var now = d3_timer_mark(),
      delay = d3_timer_sweep() - now;
  if (delay > 24) {
    if (isFinite(delay)) {
      clearTimeout(d3_timer_timeout);
      d3_timer_timeout = setTimeout(d3_timer_step, delay);
    }
    d3_timer_interval = 0;
  } else {
    d3_timer_interval = 1;
    d3_timer_frame(d3_timer_step);
  }
}

d3.timer.flush = function() {
  d3_timer_mark();
  d3_timer_sweep();
};

function d3_timer_mark() {
  var now = Date.now();
  d3_timer_active = d3_timer_queueHead;
  while (d3_timer_active) {
    if (now >= d3_timer_active.t) d3_timer_active.f = d3_timer_active.c(now - d3_timer_active.t);
    d3_timer_active = d3_timer_active.n;
  }
  return now;
}

// Flush after callbacks to avoid concurrent queue modification.
// Returns the time of the earliest active timer, post-sweep.
function d3_timer_sweep() {
  var t0,
      t1 = d3_timer_queueHead,
      time = Infinity;
  while (t1) {
    if (t1.f) {
      t1 = t0 ? t0.n = t1.n : d3_timer_queueHead = t1.n;
    } else {
      if (t1.t < time) time = t1.t;
      t1 = (t0 = t1).n;
    }
  }
  d3_timer_queueTail = t0;
  return time;
}
d3.geo = {};

d3.geo.stream = function(object, listener) {
  if (object && d3_geo_streamObjectType.hasOwnProperty(object.type)) {
    d3_geo_streamObjectType[object.type](object, listener);
  } else {
    d3_geo_streamGeometry(object, listener);
  }
};

function d3_geo_streamGeometry(geometry, listener) {
  if (geometry && d3_geo_streamGeometryType.hasOwnProperty(geometry.type)) {
    d3_geo_streamGeometryType[geometry.type](geometry, listener);
  }
}

var d3_geo_streamObjectType = {
  Feature: function(feature, listener) {
    d3_geo_streamGeometry(feature.geometry, listener);
  },
  FeatureCollection: function(object, listener) {
    var features = object.features, i = -1, n = features.length;
    while (++i < n) d3_geo_streamGeometry(features[i].geometry, listener);
  }
};

var d3_geo_streamGeometryType = {
  Sphere: function(object, listener) {
    listener.sphere();
  },
  Point: function(object, listener) {
    object = object.coordinates;
    listener.point(object[0], object[1], object[2]);
  },
  MultiPoint: function(object, listener) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) object = coordinates[i], listener.point(object[0], object[1], object[2]);
  },
  LineString: function(object, listener) {
    d3_geo_streamLine(object.coordinates, listener, 0);
  },
  MultiLineString: function(object, listener) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) d3_geo_streamLine(coordinates[i], listener, 0);
  },
  Polygon: function(object, listener) {
    d3_geo_streamPolygon(object.coordinates, listener);
  },
  MultiPolygon: function(object, listener) {
    var coordinates = object.coordinates, i = -1, n = coordinates.length;
    while (++i < n) d3_geo_streamPolygon(coordinates[i], listener);
  },
  GeometryCollection: function(object, listener) {
    var geometries = object.geometries, i = -1, n = geometries.length;
    while (++i < n) d3_geo_streamGeometry(geometries[i], listener);
  }
};

function d3_geo_streamLine(coordinates, listener, closed) {
  var i = -1, n = coordinates.length - closed, coordinate;
  listener.lineStart();
  while (++i < n) coordinate = coordinates[i], listener.point(coordinate[0], coordinate[1], coordinate[2]);
  listener.lineEnd();
}

function d3_geo_streamPolygon(coordinates, listener) {
  var i = -1, n = coordinates.length;
  listener.polygonStart();
  while (++i < n) d3_geo_streamLine(coordinates[i], listener, 1);
  listener.polygonEnd();
}

d3.geo.length = function(object) {
  d3_geo_lengthSum = 0;
  d3.geo.stream(object, d3_geo_length);
  return d3_geo_lengthSum;
};

var d3_geo_lengthSum;

var d3_geo_length = {
  sphere: d3_noop,
  point: d3_noop,
  lineStart: d3_geo_lengthLineStart,
  lineEnd: d3_noop,
  polygonStart: d3_noop,
  polygonEnd: d3_noop
};

function d3_geo_lengthLineStart() {
  var λ0, sinφ0, cosφ0;

  d3_geo_length.point = function(λ, φ) {
    λ0 = λ * d3_radians, sinφ0 = Math.sin(φ *= d3_radians), cosφ0 = Math.cos(φ);
    d3_geo_length.point = nextPoint;
  };

  d3_geo_length.lineEnd = function() {
    d3_geo_length.point = d3_geo_length.lineEnd = d3_noop;
  };

  function nextPoint(λ, φ) {
    var sinφ = Math.sin(φ *= d3_radians),
        cosφ = Math.cos(φ),
        t = abs((λ *= d3_radians) - λ0),
        cosΔλ = Math.cos(t);
    d3_geo_lengthSum += Math.atan2(Math.sqrt((t = cosφ * Math.sin(t)) * t + (t = cosφ0 * sinφ - sinφ0 * cosφ * cosΔλ) * t), sinφ0 * sinφ + cosφ0 * cosφ * cosΔλ);
    λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ;
  }
}
function d3_identity(d) {
  return d;
}
function d3_true() {
  return true;
}

function d3_geo_spherical(cartesian) {
  return [
    Math.atan2(cartesian[1], cartesian[0]),
    d3_asin(cartesian[2])
  ];
}

function d3_geo_sphericalEqual(a, b) {
  return abs(a[0] - b[0]) < ε && abs(a[1] - b[1]) < ε;
}

// General spherical polygon clipping algorithm: takes a polygon, cuts it into
// visible line segments and rejoins the segments by interpolating along the
// clip edge.
function d3_geo_clipPolygon(segments, compare, clipStartInside, interpolate, listener) {
  var subject = [],
      clip = [];

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

    // 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 (d3_geo_sphericalEqual(p0, p1)) {
      listener.lineStart();
      for (var i = 0; i < n; ++i) listener.point((p0 = segment[i])[0], p0[1]);
      listener.lineEnd();
      return;
    }

    var a = new d3_geo_clipPolygonIntersection(p0, segment, null, true),
        b = new d3_geo_clipPolygonIntersection(p0, null, a, false);
    a.o = b;
    subject.push(a);
    clip.push(b);
    a = new d3_geo_clipPolygonIntersection(p1, segment, null, false);
    b = new d3_geo_clipPolygonIntersection(p1, null, a, true);
    a.o = b;
    subject.push(a);
    clip.push(b);
  });
  clip.sort(compare);
  d3_geo_clipPolygonLinkCircular(subject);
  d3_geo_clipPolygonLinkCircular(clip);
  if (!subject.length) return;

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

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

function d3_geo_clipPolygonLinkCircular(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;
}

function d3_geo_clipPolygonIntersection(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
}

function d3_geo_clip(pointVisible, clipLine, interpolate, clipStart) {
  return function(rotate, listener) {
    var line = clipLine(listener),
        rotatedClipStart = rotate.invert(clipStart[0], clipStart[1]);

    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 = d3.merge(segments);
        var clipStartInside = d3_geo_pointInPolygon(rotatedClipStart, polygon);
        if (segments.length) {
          if (!polygonStarted) listener.polygonStart(), polygonStarted = true;
          d3_geo_clipPolygon(segments, d3_geo_clipSort, clipStartInside, interpolate, listener);
        } else if (clipStartInside) {
          if (!polygonStarted) listener.polygonStart(), polygonStarted = true;
          listener.lineStart();
          interpolate(null, null, 1, listener);
          listener.lineEnd();
        }
        if (polygonStarted) listener.polygonEnd(), polygonStarted = false;
        segments = polygon = null;
      },
      sphere: function() {
        listener.polygonStart();
        listener.lineStart();
        interpolate(null, null, 1, listener);
        listener.lineEnd();
        listener.polygonEnd();
      }
    };

    function point(λ, φ) {
      var point = rotate(λ, φ);
      if (pointVisible(λ = point[0], φ = point[1])) listener.point(λ, φ);
    }
    function pointLine(λ, φ) {
      var point = rotate(λ, φ);
      line.point(point[0], point[1]);
    }
    function lineStart() { clip.point = pointLine; line.lineStart(); }
    function lineEnd() { clip.point = point; line.lineEnd(); }

    var segments;

    var buffer = d3_geo_clipBufferListener(),
        ringListener = clipLine(buffer),
        polygonStarted = false,
        polygon,
        ring;

    function pointRing(λ, φ) {
      ring.push([λ, φ]);
      var point = rotate(λ, φ);
      ringListener.point(point[0], point[1]);
    }

    function ringStart() {
      ringListener.lineStart();
      ring = [];
    }

    function ringEnd() {
      pointRing(ring[0][0], ring[0][1]);
      ringListener.lineEnd();

      var clean = ringListener.clean(),
          ringSegments = buffer.buffer(),
          segment,
          n = ringSegments.length;

      ring.pop();
      polygon.push(ring);
      ring = null;

      if (!n) return;

      // No intersections.
      if (clean & 1) {
        segment = ringSegments[0];
        var n = segment.length - 1,
            i = -1,
            point;
        if (n > 0) {
          if (!polygonStarted) listener.polygonStart(), polygonStarted = true;
          listener.lineStart();
          while (++i < n) listener.point((point = segment[i])[0], point[1]);
          listener.lineEnd();
        }
        return;
      }

      // Rejoin connected segments.
      // TODO reuse bufferListener.rejoin()?
      if (n > 1 && clean & 2) ringSegments.push(ringSegments.pop().concat(ringSegments.shift()));

      segments.push(ringSegments.filter(d3_geo_clipSegmentLength1));
    }

    return clip;
  };
}

function d3_geo_clipSegmentLength1(segment) {
  return segment.length > 1;
}

function d3_geo_clipBufferListener() {
  var lines = [],
      line;
  return {
    lineStart: function() { lines.push(line = []); },
    point: function(λ, φ) { line.push([λ, φ]); },
    lineEnd: d3_noop,
    buffer: function() {
      var buffer = lines;
      lines = [];
      line = null;
      return buffer;
    },
    rejoin: function() {
      if (lines.length > 1) lines.push(lines.pop().concat(lines.shift()));
    }
  };
}

// Intersection points are sorted along the clip edge. For both antimeridian
// cutting and circle clipping, the same comparison is used.
function d3_geo_clipSort(a, b) {
  return ((a = a.x)[0] < 0 ? a[1] - halfπ - ε : halfπ - a[1])
       - ((b = b.x)[0] < 0 ? b[1] - halfπ - ε : halfπ - b[1]);
}

var d3_geo_clipAntimeridian = d3_geo_clip(
    d3_true,
    d3_geo_clipAntimeridianLine,
    d3_geo_clipAntimeridianInterpolate,
    [-π, -π / 2]);

// Takes a line and cuts into visible segments. Return values:
//   0: there were intersections or the line was empty.
//   1: no intersections.
//   2: there were intersections, and the first and last segments should be
//      rejoined.
function d3_geo_clipAntimeridianLine(listener) {
  var λ0 = NaN,
      φ0 = NaN,
      sλ0 = NaN,
      clean; // no intersections

  return {
    lineStart: function() {
      listener.lineStart();
      clean = 1;
    },
    point: function(λ1, φ1) {
      var sλ1 = λ1 > 0 ? π : -π,
          dλ = abs(λ1 - λ0);
      if (abs(dλ - π) < ε) { // line crosses a pole
        listener.point(λ0, φ0 = (φ0 + φ1) / 2 > 0 ? halfπ : -halfπ);
        listener.point(sλ0, φ0);
        listener.lineEnd();
        listener.lineStart();
        listener.point(sλ1, φ0);
        listener.point(λ1, φ0);
        clean = 0;
      } else if (sλ0 !== sλ1 && dλ >= π) { // line crosses antimeridian
        // handle degeneracies
        if (abs(λ0 - sλ0) < ε) λ0 -= sλ0 * ε;
        if (abs(λ1 - sλ1) < ε) λ1 -= sλ1 * ε;
        φ0 = d3_geo_clipAntimeridianIntersect(λ0, φ0, λ1, φ1);
        listener.point(sλ0, φ0);
        listener.lineEnd();
        listener.lineStart();
        listener.point(sλ1, φ0);
        clean = 0;
      }
      listener.point(λ0 = λ1, φ0 = φ1);
      sλ0 = sλ1;
    },
    lineEnd: function() {
      listener.lineEnd();
      λ0 = φ0 = NaN;
    },
    // if there are intersections, we always rejoin the first and last segments.
    clean: function() { return 2 - clean; }
  };
}

function d3_geo_clipAntimeridianIntersect(λ0, φ0, λ1, φ1) {
  var cosφ0,
      cosφ1,
      sinλ0_λ1 = Math.sin(λ0 - λ1);
  return abs(sinλ0_λ1) > ε
      ? Math.atan((Math.sin(φ0) * (cosφ1 = Math.cos(φ1)) * Math.sin(λ1)
                 - Math.sin(φ1) * (cosφ0 = Math.cos(φ0)) * Math.sin(λ0))
                 / (cosφ0 * cosφ1 * sinλ0_λ1))
      : (φ0 + φ1) / 2;
}

function d3_geo_clipAntimeridianInterpolate(from, to, direction, listener) {
  var φ;
  if (from == null) {
    φ = direction * halfπ;
    listener.point(-π,  φ);
    listener.point( 0,  φ);
    listener.point( π,  φ);
    listener.point( π,  0);
    listener.point( π, -φ);
    listener.point( 0, -φ);
    listener.point(-π, -φ);
    listener.point(-π,  0);
    listener.point(-π,  φ);
  } else if (abs(from[0] - to[0]) > ε) {
    var s = from[0] < to[0] ? π : -π;
    φ = direction * s / 2;
    listener.point(-s, φ);
    listener.point( 0, φ);
    listener.point( s, φ);
  } else {
    listener.point(to[0], to[1]);
  }
}
// TODO
// cross and scale return new vectors,
// whereas add and normalize operate in-place

function d3_geo_cartesian(spherical) {
  var λ = spherical[0],
      φ = spherical[1],
      cosφ = Math.cos(φ);
  return [
    cosφ * Math.cos(λ),
    cosφ * Math.sin(λ),
    Math.sin(φ)
  ];
}

function d3_geo_cartesianDot(a, b) {
  return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
}

function d3_geo_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]
  ];
}

function d3_geo_cartesianAdd(a, b) {
  a[0] += b[0];
  a[1] += b[1];
  a[2] += b[2];
}

function d3_geo_cartesianScale(vector, k) {
  return [
    vector[0] * k,
    vector[1] * k,
    vector[2] * k
  ];
}

function d3_geo_cartesianNormalize(d) {
  var l = Math.sqrt(d[0] * d[0] + d[1] * d[1] + d[2] * d[2]);
  d[0] /= l;
  d[1] /= l;
  d[2] /= l;
}
function d3_geo_compose(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 d3_geo_equirectangular(λ, φ) {
  return [λ, φ];
}

(d3.geo.equirectangular = function() {
  return d3_geo_projection(d3_geo_equirectangular);
}).raw = d3_geo_equirectangular.invert = d3_geo_equirectangular;

d3.geo.rotation = function(rotate) {
  rotate = d3_geo_rotation(rotate[0] % 360 * d3_radians, rotate[1] * d3_radians, rotate.length > 2 ? rotate[2] * d3_radians : 0);

  function forward(coordinates) {
    coordinates = rotate(coordinates[0] * d3_radians, coordinates[1] * d3_radians);
    return coordinates[0] *= d3_degrees, coordinates[1] *= d3_degrees, coordinates;
  }

  forward.invert = function(coordinates) {
    coordinates = rotate.invert(coordinates[0] * d3_radians, coordinates[1] * d3_radians);
    return coordinates[0] *= d3_degrees, coordinates[1] *= d3_degrees, coordinates;
  };

  return forward;
};

function d3_geo_identityRotation(λ, φ) {
  return [λ > π ? λ - τ : λ < -π ? λ + τ : λ, φ];
}

d3_geo_identityRotation.invert = d3_geo_equirectangular;

// Note: |δλ| must be < 2π
function d3_geo_rotation(δλ, δφ, δγ) {
  return δλ ? (δφ || δγ ? d3_geo_compose(d3_geo_rotationλ(δλ), d3_geo_rotationφγ(δφ, δγ))
    : d3_geo_rotationλ(δλ))
    : (δφ || δγ ? d3_geo_rotationφγ(δφ, δγ)
    : d3_geo_identityRotation);
}

function d3_geo_forwardRotationλ(δλ) {
  return function(λ, φ) {
    return λ += δλ, [λ > π ? λ - τ : λ < -π ? λ + τ : λ, φ];
  };
}

function d3_geo_rotationλ(δλ) {
  var rotation = d3_geo_forwardRotationλ(δλ);
  rotation.invert = d3_geo_forwardRotationλ(-δλ);
  return rotation;
}

function d3_geo_rotationφγ(δφ, δγ) {
  var cosδφ = Math.cos(δφ),
      sinδφ = Math.sin(δφ),
      cosδγ = Math.cos(δγ),
      sinδγ = Math.sin(δγ);

  function rotation(λ, φ) {
    var cosφ = Math.cos(φ),
        x = Math.cos(λ) * cosφ,
        y = Math.sin(λ) * cosφ,
        z = Math.sin(φ),
        k = z * cosδφ + x * sinδφ;
    return [
      Math.atan2(y * cosδγ - k * sinδγ, x * cosδφ - z * sinδφ),
      d3_asin(k * cosδγ + y * sinδγ)
    ];
  }

  rotation.invert = function(λ, φ) {
    var cosφ = Math.cos(φ),
        x = Math.cos(λ) * cosφ,
        y = Math.sin(λ) * cosφ,
        z = Math.sin(φ),
        k = z * cosδγ - y * sinδγ;
    return [
      Math.atan2(y * cosδγ + z * sinδγ, x * cosδφ + k * sinδφ),
      d3_asin(k * cosδφ - x * sinδφ)
    ];
  };

  return rotation;
}

d3.geo.circle = function() {
  var origin = [0, 0],
      angle,
      precision = 6,
      interpolate;

  function circle() {
    var center = typeof origin === "function" ? origin.apply(this, arguments) : origin,
        rotate = d3_geo_rotation(-center[0] * d3_radians, -center[1] * d3_radians, 0).invert,
        ring = [];

    interpolate(null, null, 1, {
      point: function(x, y) {
        ring.push(x = rotate(x, y));
        x[0] *= d3_degrees, x[1] *= d3_degrees;
      }
    });

    return {type: "Polygon", coordinates: [ring]};
  }

  circle.origin = function(x) {
    if (!arguments.length) return origin;
    origin = x;
    return circle;
  };

  circle.angle = function(x) {
    if (!arguments.length) return angle;
    interpolate = d3_geo_circleInterpolate((angle = +x) * d3_radians, precision * d3_radians);
    return circle;
  };

  circle.precision = function(_) {
    if (!arguments.length) return precision;
    interpolate = d3_geo_circleInterpolate(angle * d3_radians, (precision = +_) * d3_radians);
    return circle;
  };

  return circle.angle(90);
};

// Interpolates along a circle centered at [0°, 0°], with a given radius and
// precision.
function d3_geo_circleInterpolate(radius, precision) {
  var cr = Math.cos(radius),
      sr = Math.sin(radius);
  return function(from, to, direction, listener) {
    var step = direction * precision;
    if (from != null) {
      from = d3_geo_circleAngle(cr, from);
      to = d3_geo_circleAngle(cr, to);
      if (direction > 0 ? from < to: from > to) from += direction * τ;
    } else {
      from = radius + direction * τ;
      to = radius - .5 * step;
    }
    for (var point, t = from; direction > 0 ? t > to : t < to; t -= step) {
      listener.point((point = d3_geo_spherical([
        cr,
        -sr * Math.cos(t),
        -sr * Math.sin(t)
      ]))[0], point[1]);
    }
  };
}

// Signed angle of a cartesian point relative to [cr, 0, 0].
function d3_geo_circleAngle(cr, point) {
  var a = d3_geo_cartesian(point);
  a[0] -= cr;
  d3_geo_cartesianNormalize(a);
  var angle = d3_acos(-a[1]);
  return ((-a[2] < 0 ? -angle : angle) + 2 * Math.PI - ε) % (2 * Math.PI);
}
// 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/
// See lib/geographiclib/LICENSE for details.

function d3_adder() {}

d3_adder.prototype = {
  s: 0, // rounded value
  t: 0, // exact error
  add: function(y) {
    d3_adderSum(y, this.t, d3_adderTemp);
    d3_adderSum(d3_adderTemp.s, this.s, this);
    if (this.s) this.t += d3_adderTemp.t;
    else this.s = d3_adderTemp.t;
  },
  reset: function() {
    this.s = this.t = 0;
  },
  valueOf: function() {
    return this.s;
  }
};

var d3_adderTemp = new d3_adder;

function d3_adderSum(a, b, o) {
  var x = o.s = a + b, // a + b
      bv = x - a, av = x - bv; // b_virtual & a_virtual
  o.t = (a - av) + (b - bv); // a_roundoff + b_roundoff
}

d3.geo.area = function(object) {
  d3_geo_areaSum = 0;
  d3.geo.stream(object, d3_geo_area);
  return d3_geo_areaSum;
};

var d3_geo_areaSum,
    d3_geo_areaRingSum = new d3_adder;

var d3_geo_area = {
  sphere: function() { d3_geo_areaSum += 4 * π; },
  point: d3_noop,
  lineStart: d3_noop,
  lineEnd: d3_noop,

  // Only count area for polygon rings.
  polygonStart: function() {
    d3_geo_areaRingSum.reset();
    d3_geo_area.lineStart = d3_geo_areaRingStart;
  },
  polygonEnd: function() {
    var area = 2 * d3_geo_areaRingSum;
    d3_geo_areaSum += area < 0 ? 4 * π + area : area;
    d3_geo_area.lineStart = d3_geo_area.lineEnd = d3_geo_area.point = d3_noop;
  }
};

function d3_geo_areaRingStart() {
  var λ00, φ00, λ0, cosφ0, sinφ0; // start point and previous point

  // For the first point, …
  d3_geo_area.point = function(λ, φ) {
    d3_geo_area.point = nextPoint;
    λ0 = (λ00 = λ) * d3_radians, cosφ0 = Math.cos(φ = (φ00 = φ) * d3_radians / 2 + π / 4), sinφ0 = Math.sin(φ);
  };

  // For subsequent points, …
  function nextPoint(λ, φ) {
    λ *= d3_radians;
    φ = φ * d3_radians / 2 + π / 4; // 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 dλ = λ - λ0,
        sdλ = dλ >= 0 ? 1 : -1,
        adλ = sdλ * dλ,
        cosφ = Math.cos(φ),
        sinφ = Math.sin(φ),
        k = sinφ0 * sinφ,
        u = cosφ0 * cosφ + k * Math.cos(adλ),
        v = k * sdλ * Math.sin(adλ);
    d3_geo_areaRingSum.add(Math.atan2(v, u));

    // Advance the previous points.
    λ0 = λ, cosφ0 = cosφ, sinφ0 = sinφ;
  }

  // For the last point, return to the start.
  d3_geo_area.lineEnd = function() {
    nextPoint(λ00, φ00);
  };
}

function d3_geo_pointInPolygon(point, polygon) {
  var meridian = point[0],
      parallel = point[1],
      meridianNormal = [Math.sin(meridian), -Math.cos(meridian), 0],
      polarAngle = 0,
      winding = 0;
  d3_geo_areaRingSum.reset();

  for (var i = 0, n = polygon.length; i < n; ++i) {
    var ring = polygon[i],
        m = ring.length;
    if (!m) continue;
    var point0 = ring[0],
        λ0 = point0[0],
        φ0 = point0[1] / 2 + π / 4,
        sinφ0 = Math.sin(φ0),
        cosφ0 = Math.cos(φ0),
        j = 1;

    while (true) {
      if (j === m) j = 0;
      point = ring[j];
      var λ = point[0],
          φ = point[1] / 2 + π / 4,
          sinφ = Math.sin(φ),
          cosφ = Math.cos(φ),
          dλ = λ - λ0,
          sdλ = dλ >= 0 ? 1 : -1,
          adλ = sdλ * dλ,
          antimeridian = adλ > π,
          k = sinφ0 * sinφ;
      d3_geo_areaRingSum.add(Math.atan2(k * sdλ * Math.sin(adλ), cosφ0 * cosφ + k * Math.cos(adλ)));

      polarAngle += antimeridian ? dλ + sdλ * τ : dλ;

      // Are the longitudes either side of the point's meridian, and are the
      // latitudes smaller than the parallel?
      if (antimeridian ^ λ0 >= meridian ^ λ >= meridian) {
        var arc = d3_geo_cartesianCross(d3_geo_cartesian(point0), d3_geo_cartesian(point));
        d3_geo_cartesianNormalize(arc);
        var intersection = d3_geo_cartesianCross(meridianNormal, arc);
        d3_geo_cartesianNormalize(intersection);
        var φarc = (antimeridian ^ dλ >= 0 ? -1 : 1) * d3_asin(intersection[2]);
        if (parallel > φarc || parallel === φarc && (arc[0] || arc[1])) {
          winding += antimeridian ^ dλ >= 0 ? 1 : -1;
        }
      }
      if (!j++) break;
      λ0 = λ, sinφ0 = sinφ, cosφ0 = cosφ, point0 = point;
    }
  }

  // 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 meridian
  // from the point to the South pole.  If it is zero, then the point is the
  // same side as the South pole.

  return (polarAngle < -ε || polarAngle < ε && d3_geo_areaRingSum < 0) ^ (winding & 1);
}

// Clip features against a small circle centered at [0°, 0°].
function d3_geo_clipCircle(radius) {
  var cr = Math.cos(radius),
      smallRadius = cr > 0,
      notHemisphere = abs(cr) > ε, // TODO optimise for this common case
      interpolate = d3_geo_circleInterpolate(radius, 6 * d3_radians);

  return d3_geo_clip(visible, clipLine, interpolate, smallRadius ? [0, -radius] : [-π, radius - π]);

  function visible(λ, φ) {
    return Math.cos(λ) * Math.cos(φ) > cr;
  }

  // Takes a line and cuts into visible segments. Return values used for
  // polygon clipping:
  //   0: there were intersections or the line was empty.
  //   1: no intersections.
  //   2: there were intersections, and the first and last segments should be
  //      rejoined.
  function clipLine(listener) {
    var point0, // previous point
        c0, // code for previous point
        v0, // visibility of previous point
        v00, // visibility of first point
        clean; // no intersections
    return {
      lineStart: function() {
        v00 = v0 = false;
        clean = 1;
      },
      point: function(λ, φ) {
        var point1 = [λ, φ],
            point2,
            v = visible(λ, φ),
            c = smallRadius
              ? v ? 0 : code(λ, φ)
              : v ? code(λ + (λ < 0 ? π : -π), φ) : 0;
        if (!point0 && (v00 = v0 = v)) listener.lineStart();
        // Handle degeneracies.
        // TODO ignore if not clipping polygons.
        if (v !== v0) {
          point2 = intersect(point0, point1);
          if (d3_geo_sphericalEqual(point0, point2) || d3_geo_sphericalEqual(point1, point2)) {
            point1[0] += ε;
            point1[1] += ε;
            v = visible(point1[0], point1[1]);
          }
        }
        if (v !== v0) {
          clean = 0;
          if (v) {
            // outside going in
            listener.lineStart();
            point2 = intersect(point1, point0);
            listener.point(point2[0], point2[1]);
          } else {
            // inside going out
            point2 = intersect(point0, point1);
            listener.point(point2[0], point2[1]);
            listener.lineEnd();
          }
          point0 = point2;
        } else if (notHemisphere && point0 && smallRadius ^ v) {
          var t;
          // If the codes for two points are different, or are both zero,
          // and there this segment intersects with the small circle.
          if (!(c & c0) && (t = intersect(point1, point0, true))) {
            clean = 0;
            if (smallRadius) {
              listener.lineStart();
              listener.point(t[0][0], t[0][1]);
              listener.point(t[1][0], t[1][1]);
              listener.lineEnd();
            } else {
              listener.point(t[1][0], t[1][1]);
              listener.lineEnd();
              listener.lineStart();
              listener.point(t[0][0], t[0][1]);
            }
          }
        }
        if (v && (!point0 || !d3_geo_sphericalEqual(point0, point1))) {
          listener.point(point1[0], point1[1]);
        }
        point0 = point1, v0 = v, c0 = c;
      },
      lineEnd: function() {
        if (v0) listener.lineEnd();
        point0 = null;
      },
      // Rejoin first and last segments if there were intersections and the first
      // and last points were visible.
      clean: function() { return clean | ((v00 && v0) << 1); }
    };
  }

  // Intersects the great circle between a and b with the clip circle.
  function intersect(a, b, two) {
    var pa = d3_geo_cartesian(a),
        pb = d3_geo_cartesian(b);

    // We have two planes, n1.p = d1 and n2.p = d2.
    // Find intersection line p(t) = c1 n1 + c2 n2 + t (n1 ⨯ n2).
    var n1 = [1, 0, 0], // normal
        n2 = d3_geo_cartesianCross(pa, pb),
        n2n2 = d3_geo_cartesianDot(n2, n2),
        n1n2 = n2[0], // d3_geo_cartesianDot(n1, n2),
        determinant = n2n2 - n1n2 * n1n2;

    // Two polar points.
    if (!determinant) return !two && a;

    var c1 =  cr * n2n2 / determinant,
        c2 = -cr * n1n2 / determinant,
        n1xn2 = d3_geo_cartesianCross(n1, n2),
        A = d3_geo_cartesianScale(n1, c1),
        B = d3_geo_cartesianScale(n2, c2);
    d3_geo_cartesianAdd(A, B);

    // Solve |p(t)|^2 = 1.
    var u = n1xn2,
        w = d3_geo_cartesianDot(A, u),
        uu = d3_geo_cartesianDot(u, u),
        t2 = w * w - uu * (d3_geo_cartesianDot(A, A) - 1);

    if (t2 < 0) return;

    var t = Math.sqrt(t2),
        q = d3_geo_cartesianScale(u, (-w - t) / uu);
    d3_geo_cartesianAdd(q, A);
    q = d3_geo_spherical(q);
    if (!two) return q;

    // Two intersection points.
    var λ0 = a[0],
        λ1 = b[0],
        φ0 = a[1],
        φ1 = b[1],
        z;
    if (λ1 < λ0) z = λ0, λ0 = λ1, λ1 = z;
    var δλ = λ1 - λ0,
        polar = abs(δλ - π) < ε,
        meridian = polar || δλ < ε;

    if (!polar && φ1 < φ0) z = φ0, φ0 = φ1, φ1 = z;

    // Check that the first point is between a and b.
    if (meridian
        ? polar
          ? φ0 + φ1 > 0 ^ q[1] < (abs(q[0] - λ0) < ε ? φ0 : φ1)
          : φ0 <= q[1] && q[1] <= φ1
        : δλ > π ^ (λ0 <= q[0] && q[0] <= λ1)) {
      var q1 = d3_geo_cartesianScale(u, (-w + t) / uu);
      d3_geo_cartesianAdd(q1, A);
      return [q, d3_geo_spherical(q1)];
    }
  }

  // Generates a 4-bit vector representing the location of a point relative to
  // the small circle's bounding box.
  function code(λ, φ) {
    var r = smallRadius ? radius : π - radius,
        code = 0;
    if (λ < -r) code |= 1; // left
    else if (λ > r) code |= 2; // right
    if (φ < -r) code |= 4; // below
    else if (φ > r) code |= 8; // above
    return code;
  }
}

// Liang–Barsky line clipping.
function d3_geom_clipLine(x0, y0, x1, y1) {
  return function(line) {
    var a = line.a,
        b = line.b,
        ax = a.x,
        ay = a.y,
        bx = b.x,
        by = b.y,
        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) line.a = {x: ax + t0 * dx, y: ay + t0 * dy};
    if (t1 < 1) line.b = {x: ax + t1 * dx, y: ay + t1 * dy};
    return line;
  };
}

var d3_geo_clipExtentMAX = 1e9;

d3.geo.clipExtent = function() {
  var x0, y0, x1, y1,
      stream,
      clip,
      clipExtent = {
        stream: function(output) {
          if (stream) stream.valid = false;
          stream = clip(output);
          stream.valid = true; // allow caching by d3.geo.path
          return stream;
        },
        extent: function(_) {
          if (!arguments.length) return [[x0, y0], [x1, y1]];
          clip = d3_geo_clipExtent(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]);
          if (stream) stream.valid = false, stream = null;
          return clipExtent;
        }
      };
  return clipExtent.extent([[0, 0], [960, 500]]);
};

function d3_geo_clipExtent(x0, y0, x1, y1) {
  return function(listener) {
    var listener_ = listener,
        bufferListener = d3_geo_clipBufferListener(),
        clipLine = d3_geom_clipLine(x0, y0, x1, y1),
        segments,
        polygon,
        ring;

    var clip = {
      point: point,
      lineStart: lineStart,
      lineEnd: lineEnd,
      polygonStart: function() {
        listener = bufferListener;
        segments = [];
        polygon = [];
        clean = true;
      },
      polygonEnd: function() {
        listener = listener_;
        segments = d3.merge(segments);
        var clipStartInside = insidePolygon([x0, y1]),
            inside = clean && clipStartInside,
            visible = segments.length;
        if (inside || visible) {
          listener.polygonStart();
          if (inside) {
            listener.lineStart();
            interpolate(null, null, 1, listener);
            listener.lineEnd();
          }
          if (visible) {
            d3_geo_clipPolygon(segments, compare, clipStartInside, interpolate, listener);
          }
          listener.polygonEnd();
        }
        segments = polygon = ring = null;
      }
    };

    function insidePolygon(p) {
      var wn = 0, // the winding number counter
          n = polygon.length,
          y = p[1];

      for (var i = 0; i < n; ++i) {
        for (var j = 1, v = polygon[i], m = v.length, a = v[0], b; j < m; ++j) {
          b = v[j];
          if (a[1] <= y) {
            if (b[1] >  y && d3_cross2d(a, b, p) > 0) ++wn;
          } else {
            if (b[1] <= y && d3_cross2d(a, b, p) < 0) --wn;
          }
          a = b;
        }
      }
      return wn !== 0;
    }

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

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

    function point(x, y) {
      if (pointVisible(x, y)) listener.point(x, y);
    }

    var x__, y__, v__, // first point
        x_, y_, v_, // previous point
        first,
        clean;

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

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

    function linePoint(x, y) {
      x = Math.max(-d3_geo_clipExtentMAX, Math.min(d3_geo_clipExtentMAX, x));
      y = Math.max(-d3_geo_clipExtentMAX, Math.min(d3_geo_clipExtentMAX, y));
      var v = pointVisible(x, y);
      if (polygon) ring.push([x, y]);
      if (first) {
        x__ = x, y__ = y, v__ = v;
        first = false;
        if (v) {
          listener.lineStart();
          listener.point(x, y);
        }
      } else {
        if (v && v_) listener.point(x, y);
        else {
          var l = {a: {x: x_, y: y_}, b: {x: x, y: y}};
          if (clipLine(l)) {
            if (!v_) {
              listener.lineStart();
              listener.point(l.a.x, l.a.y);
            }
            listener.point(l.b.x, l.b.y);
            if (!v) listener.lineEnd();
            clean = false;
          } else if (v) {
            listener.lineStart();
            listener.point(x, y);
            clean = false;
          }
        }
      }
      x_ = x, y_ = y, v_ = v;
    }

    return clip;
  };

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

  function compare(a, b) {
    return comparePoints(a.x, b.x);
  }

  function comparePoints(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];
  }
}

function d3_geo_conic(projectAt) {
  var φ0 = 0,
      φ1 = π / 3,
      m = d3_geo_projectionMutator(projectAt),
      p = m(φ0, φ1);

  p.parallels = function(_) {
    if (!arguments.length) return [φ0 / π * 180, φ1 / π * 180];
    return m(φ0 = _[0] * π / 180, φ1 = _[1] * π / 180);
  };

  return p;
}

function d3_geo_conicEqualArea(φ0, φ1) {
  var sinφ0 = Math.sin(φ0),
      n = (sinφ0 + Math.sin(φ1)) / 2,
      C = 1 + sinφ0 * (2 * n - sinφ0),
      ρ0 = Math.sqrt(C) / n;

  function forward(λ, φ) {
    var ρ = Math.sqrt(C - 2 * n * Math.sin(φ)) / n;
    return [
      ρ * Math.sin(λ *= n),
      ρ0 - ρ * Math.cos(λ)
    ];
  }

  forward.invert = function(x, y) {
    var ρ0_y = ρ0 - y;
    return [
      Math.atan2(x, ρ0_y) / n,
      d3_asin((C - (x * x + ρ0_y * ρ0_y) * n * n) / (2 * n))
    ];
  };

  return forward;
}

(d3.geo.conicEqualArea = function() {
  return d3_geo_conic(d3_geo_conicEqualArea);
}).raw = d3_geo_conicEqualArea;

// ESRI:102003
d3.geo.albers = function() {
  return d3.geo.conicEqualArea()
      .rotate([96, 0])
      .center([-.6, 38.7])
      .parallels([29.5, 45.5])
      .scale(1070);
};

// A composite projection for the United States, configured by default for
// 960×500. Also works quite well at 960×600 with scale 1285. The set of
// standard parallels for each region comes from USGS, which is published here:
// http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html#albers
d3.geo.albersUsa = function() {
  var lower48 = d3.geo.albers();

  // EPSG:3338
  var alaska = d3.geo.conicEqualArea()
      .rotate([154, 0])
      .center([-2, 58.5])
      .parallels([55, 65]);

  // ESRI:102007
  var hawaii = d3.geo.conicEqualArea()
      .rotate([157, 0])
      .center([-3, 19.9])
      .parallels([8, 18]);

  var point,
      pointStream = {point: function(x, y) { point = [x, y]; }},
      lower48Point,
      alaskaPoint,
      hawaiiPoint;

  function albersUsa(coordinates) {
    var x = coordinates[0], y = coordinates[1];
    point = null;
    (lower48Point(x, y), point)
        || (alaskaPoint(x, y), point)
        || hawaiiPoint(x, y);
    return point;
  }

  albersUsa.invert = function(coordinates) {
    var k = lower48.scale(),
        t = lower48.translate(),
        x = (coordinates[0] - t[0]) / k,
        y = (coordinates[1] - t[1]) / k;
    return (y >= .120 && y < .234 && x >= -.425 && x < -.214 ? alaska
        : y >= .166 && y < .234 && x >= -.214 && x < -.115 ? hawaii
        : lower48).invert(coordinates);
  };

  // A naïve multi-projection stream.
  // The projections must have mutually exclusive clip regions on the sphere,
  // as this will avoid emitting interleaving lines and polygons.
  albersUsa.stream = function(stream) {
    var lower48Stream = lower48.stream(stream),
        alaskaStream = alaska.stream(stream),
        hawaiiStream = hawaii.stream(stream);
    return {
      point: function(x, y) {
        lower48Stream.point(x, y);
        alaskaStream.point(x, y);
        hawaiiStream.point(x, y);
      },
      sphere: function() {
        lower48Stream.sphere();
        alaskaStream.sphere();
        hawaiiStream.sphere();
      },
      lineStart: function() {
        lower48Stream.lineStart();
        alaskaStream.lineStart();
        hawaiiStream.lineStart();
      },
      lineEnd: function() {
        lower48Stream.lineEnd();
        alaskaStream.lineEnd();
        hawaiiStream.lineEnd();
      },
      polygonStart: function() {
        lower48Stream.polygonStart();
        alaskaStream.polygonStart();
        hawaiiStream.polygonStart();
      },
      polygonEnd: function() {
        lower48Stream.polygonEnd();
        alaskaStream.polygonEnd();
        hawaiiStream.polygonEnd();
      }
    };
  };

  albersUsa.precision = function(_) {
    if (!arguments.length) return lower48.precision();
    lower48.precision(_);
    alaska.precision(_);
    hawaii.precision(_);
    return albersUsa;
  };

  albersUsa.scale = function(_) {
    if (!arguments.length) return lower48.scale();
    lower48.scale(_);
    alaska.scale(_ * .35);
    hawaii.scale(_);
    return albersUsa.translate(lower48.translate());
  };

  albersUsa.translate = function(_) {
    if (!arguments.length) return lower48.translate();
    var k = lower48.scale(), x = +_[0], y = +_[1];

    lower48Point = lower48
        .translate(_)
        .clipExtent([[x - .455 * k, y - .238 * k], [x + .455 * k, y + .238 * k]])
        .stream(pointStream).point;

    alaskaPoint = alaska
        .translate([x - .307 * k, y + .201 * k])
        .clipExtent([[x - .425 * k + ε, y + .120 * k + ε], [x - .214 * k - ε, y + .234 * k - ε]])
        .stream(pointStream).point;

    hawaiiPoint = hawaii
        .translate([x - .205 * k, y + .212 * k])
        .clipExtent([[x - .214 * k + ε, y + .166 * k + ε], [x - .115 * k - ε, y + .234 * k - ε]])
        .stream(pointStream).point;

    return albersUsa;
  };

  return albersUsa.scale(1070);
};

d3.geo.bounds = (function() {
  var λ0, φ0, λ1, φ1, // bounds
      λ_, // previous λ-coordinate
      λ__, φ__, // first point
      p0, // previous 3D point
      dλSum,
      ranges,
      range;

  var bound = {
    point: point,
    lineStart: lineStart,
    lineEnd: lineEnd,

    polygonStart: function() {
      bound.point = ringPoint;
      bound.lineStart = ringStart;
      bound.lineEnd = ringEnd;
      dλSum = 0;
      d3_geo_area.polygonStart();
    },
    polygonEnd: function() {
      d3_geo_area.polygonEnd();
      bound.point = point;
      bound.lineStart = lineStart;
      bound.lineEnd = lineEnd;
      if (d3_geo_areaRingSum < 0) λ0 = -(λ1 = 180), φ0 = -(φ1 = 90);
      else if (dλSum > ε) φ1 = 90;
      else if (dλSum < -ε) φ0 = -90;
      range[0] = λ0, range[1] = λ1;
    }
  };

  function point(λ, φ) {
    ranges.push(range = [λ0 = λ, λ1 = λ]);
    if (φ < φ0) φ0 = φ;
    if (φ > φ1) φ1 = φ;
  }

  function linePoint(λ, φ) {
    var p = d3_geo_cartesian([λ * d3_radians, φ * d3_radians]);
    if (p0) {
      var normal = d3_geo_cartesianCross(p0, p),
          equatorial = [normal[1], -normal[0], 0],
          inflection = d3_geo_cartesianCross(equatorial, normal);
      d3_geo_cartesianNormalize(inflection);
      inflection = d3_geo_spherical(inflection);
      var dλ = λ - λ_,
          s = dλ > 0 ? 1 : -1,
          λi = inflection[0] * d3_degrees * s,
          antimeridian = abs(dλ) > 180;
      if (antimeridian ^ (s * λ_ < λi && λi < s * λ)) {
        var φi = inflection[1] * d3_degrees;
        if (φi > φ1) φ1 = φi;
      } else if (λi = (λi + 360) % 360 - 180, antimeridian ^ (s * λ_ < λi && λi < s * λ)) {
        var φi = -inflection[1] * d3_degrees;
        if (φi < φ0) φ0 = φi;
      } else {
        if (φ < φ0) φ0 = φ;
        if (φ > φ1) φ1 = φ;
      }
      if (antimeridian) {
        if (λ < λ_) {
          if (angle(λ0, λ) > angle(λ0, λ1)) λ1 = λ;
        } else {
          if (angle(λ, λ1) > angle(λ0, λ1)) λ0 = λ;
        }
      } else {
        if (λ1 >= λ0) {
          if (λ < λ0) λ0 = λ;
          if (λ > λ1) λ1 = λ;
        } else {
          if (λ > λ_) {
            if (angle(λ0, λ) > angle(λ0, λ1)) λ1 = λ;
          } else {
            if (angle(λ, λ1) > angle(λ0, λ1)) λ0 = λ;
          }
        }
      }
    } else {
      point(λ, φ);
    }
    p0 = p, λ_ = λ;
  }

  function lineStart() { bound.point = linePoint; }
  function lineEnd() {
    range[0] = λ0, range[1] = λ1;
    bound.point = point;
    p0 = null;
  }

  function ringPoint(λ, φ) {
    if (p0) {
      var dλ = λ - λ_;
      dλSum += abs(dλ) > 180 ? dλ + (dλ > 0 ? 360 : -360) : dλ;
    } else λ__ = λ, φ__ = φ;
    d3_geo_area.point(λ, φ);
    linePoint(λ, φ);
  }

  function ringStart() {
    d3_geo_area.lineStart();
  }

  function ringEnd() {
    ringPoint(λ__, φ__);
    d3_geo_area.lineEnd();
    if (abs(dλSum) > ε) λ0 = -(λ1 = 180);
    range[0] = λ0, range[1] = λ1;
    p0 = null;
  }

  // Finds the left-right distance between two longitudes.
  // This is almost the same as (λ1 - λ0 + 360°) % 360°, except that we want
  // the distance between ±180° to be 360°.
  function angle(λ0, λ1) { return (λ1 -= λ0) < 0 ? λ1 + 360 : λ1; }

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

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

  return function(feature) {
    φ1 = λ1 = -(λ0 = φ0 = Infinity);
    ranges = [];

    d3.geo.stream(feature, bound);

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

      // Then, merge any ranges that overlap.
      for (var i = 1, a = ranges[0], b, merged = [a]; i < n; ++i) {
        b = ranges[i];
        if (withinRange(b[0], a) || withinRange(b[1], a)) {
          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.
      var best = -Infinity, dλ;
      for (var n = merged.length - 1, i = 0, a = merged[n], b; i <= n; a = b, ++i) {
        b = merged[i];
        if ((dλ = angle(a[1], b[0])) > best) best = dλ, λ0 = b[0], λ1 = a[1];
      }
    }
    ranges = range = null;

    return λ0 === Infinity || φ0 === Infinity
        ? [[NaN, NaN], [NaN, NaN]]
        : [[λ0, φ0], [λ1, φ1]];
  };
})();

d3.geo.centroid = function(object) {
  d3_geo_centroidW0 = d3_geo_centroidW1 =
  d3_geo_centroidX0 = d3_geo_centroidY0 = d3_geo_centroidZ0 =
  d3_geo_centroidX1 = d3_geo_centroidY1 = d3_geo_centroidZ1 =
  d3_geo_centroidX2 = d3_geo_centroidY2 = d3_geo_centroidZ2 = 0;
  d3.geo.stream(object, d3_geo_centroid);

  var x = d3_geo_centroidX2,
      y = d3_geo_centroidY2,
      z = d3_geo_centroidZ2,
      m = x * x + y * y + z * z;

  // If the area-weighted centroid is undefined, fall back to length-weighted centroid.
  if (m < ε2) {
    x = d3_geo_centroidX1, y = d3_geo_centroidY1, z = d3_geo_centroidZ1;
    // If the feature has zero length, fall back to arithmetic mean of point vectors.
    if (d3_geo_centroidW1 < ε) x = d3_geo_centroidX0, y = d3_geo_centroidY0, z = d3_geo_centroidZ0;
    m = x * x + y * y + z * z;
    // If the feature still has an undefined centroid, then return.
    if (m < ε2) return [NaN, NaN];
  }

  return [Math.atan2(y, x) * d3_degrees, d3_asin(z / Math.sqrt(m)) * d3_degrees];
};

var d3_geo_centroidW0,
    d3_geo_centroidW1,
    d3_geo_centroidX0,
    d3_geo_centroidY0,
    d3_geo_centroidZ0,
    d3_geo_centroidX1,
    d3_geo_centroidY1,
    d3_geo_centroidZ1,
    d3_geo_centroidX2,
    d3_geo_centroidY2,
    d3_geo_centroidZ2;

var d3_geo_centroid = {
  sphere: d3_noop,
  point: d3_geo_centroidPoint,
  lineStart: d3_geo_centroidLineStart,
  lineEnd: d3_geo_centroidLineEnd,
  polygonStart: function() {
    d3_geo_centroid.lineStart = d3_geo_centroidRingStart;
  },
  polygonEnd: function() {
    d3_geo_centroid.lineStart = d3_geo_centroidLineStart;
  }
};

// Arithmetic mean of Cartesian vectors.
function d3_geo_centroidPoint(λ, φ) {
  λ *= d3_radians;
  var cosφ = Math.cos(φ *= d3_radians);
  d3_geo_centroidPointXYZ(cosφ * Math.cos(λ), cosφ * Math.sin(λ), Math.sin(φ));
}

function d3_geo_centroidPointXYZ(x, y, z) {
  ++d3_geo_centroidW0;
  d3_geo_centroidX0 += (x - d3_geo_centroidX0) / d3_geo_centroidW0;
  d3_geo_centroidY0 += (y - d3_geo_centroidY0) / d3_geo_centroidW0;
  d3_geo_centroidZ0 += (z - d3_geo_centroidZ0) / d3_geo_centroidW0;
}

function d3_geo_centroidLineStart() {
  var x0, y0, z0; // previous point

  d3_geo_centroid.point = function(λ, φ) {
    λ *= d3_radians;
    var cosφ = Math.cos(φ *= d3_radians);
    x0 = cosφ * Math.cos(λ);
    y0 = cosφ * Math.sin(λ);
    z0 = Math.sin(φ);
    d3_geo_centroid.point = nextPoint;
    d3_geo_centroidPointXYZ(x0, y0, z0);
  };

  function nextPoint(λ, φ) {
    λ *= d3_radians;
    var cosφ = Math.cos(φ *= d3_radians),
        x = cosφ * Math.cos(λ),
        y = cosφ * Math.sin(λ),
        z = Math.sin(φ),
        w = Math.atan2(
          Math.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);
    d3_geo_centroidW1 += w;
    d3_geo_centroidX1 += w * (x0 + (x0 = x));
    d3_geo_centroidY1 += w * (y0 + (y0 = y));
    d3_geo_centroidZ1 += w * (z0 + (z0 = z));
    d3_geo_centroidPointXYZ(x0, y0, z0);
  }
}

function d3_geo_centroidLineEnd() {
  d3_geo_centroid.point = d3_geo_centroidPoint;
}

// See J. E. Brock, The Inertia Tensor for a Spherical Triangle,
// J. Applied Mechanics 42, 239 (1975).
function d3_geo_centroidRingStart() {
  var λ00, φ00, // first point
      x0, y0, z0; // previous point

  d3_geo_centroid.point = function(λ, φ) {
    λ00 = λ, φ00 = φ;
    d3_geo_centroid.point = nextPoint;
    λ *= d3_radians;
    var cosφ = Math.cos(φ *= d3_radians);
    x0 = cosφ * Math.cos(λ);
    y0 = cosφ * Math.sin(λ);
    z0 = Math.sin(φ);
    d3_geo_centroidPointXYZ(x0, y0, z0);
  };

  d3_geo_centroid.lineEnd = function() {
    nextPoint(λ00, φ00);
    d3_geo_centroid.lineEnd = d3_geo_centroidLineEnd;
    d3_geo_centroid.point = d3_geo_centroidPoint;
  };

  function nextPoint(λ, φ) {
    λ *= d3_radians;
    var cosφ = Math.cos(φ *= d3_radians),
        x = cosφ * Math.cos(λ),
        y = cosφ * Math.sin(λ),
        z = Math.sin(φ),
        cx = y0 * z - z0 * y,
        cy = z0 * x - x0 * z,
        cz = x0 * y - y0 * x,
        m = Math.sqrt(cx * cx + cy * cy + cz * cz),
        u = x0 * x + y0 * y + z0 * z,
        v = m && -d3_acos(u) / m, // area weight
        w = Math.atan2(m, u); // line weight
    d3_geo_centroidX2 += v * cx;
    d3_geo_centroidY2 += v * cy;
    d3_geo_centroidZ2 += v * cz;
    d3_geo_centroidW1 += w;
    d3_geo_centroidX1 += w * (x0 + (x0 = x));
    d3_geo_centroidY1 += w * (y0 + (y0 = y));
    d3_geo_centroidZ1 += w * (z0 + (z0 = z));
    d3_geo_centroidPointXYZ(x0, y0, z0);
  }
}

// TODO Unify this code with d3.geom.polygon area?

var d3_geo_pathAreaSum, d3_geo_pathAreaPolygon, d3_geo_pathArea = {
  point: d3_noop,
  lineStart: d3_noop,
  lineEnd: d3_noop,

  // Only count area for polygon rings.
  polygonStart: function() {
    d3_geo_pathAreaPolygon = 0;
    d3_geo_pathArea.lineStart = d3_geo_pathAreaRingStart;
  },
  polygonEnd: function() {
    d3_geo_pathArea.lineStart = d3_geo_pathArea.lineEnd = d3_geo_pathArea.point = d3_noop;
    d3_geo_pathAreaSum += abs(d3_geo_pathAreaPolygon / 2);
  }
};

function d3_geo_pathAreaRingStart() {
  var x00, y00, x0, y0;

  // For the first point, …
  d3_geo_pathArea.point = function(x, y) {
    d3_geo_pathArea.point = nextPoint;
    x00 = x0 = x, y00 = y0 = y;
  };

  // For subsequent points, …
  function nextPoint(x, y) {
    d3_geo_pathAreaPolygon += y0 * x - x0 * y;
    x0 = x, y0 = y;
  }

  // For the last point, return to the start.
  d3_geo_pathArea.lineEnd = function() {
    nextPoint(x00, y00);
  };
}

var d3_geo_pathBoundsX0,
    d3_geo_pathBoundsY0,
    d3_geo_pathBoundsX1,
    d3_geo_pathBoundsY1;

var d3_geo_pathBounds = {
  point: d3_geo_pathBoundsPoint,
  lineStart: d3_noop,
  lineEnd: d3_noop,
  polygonStart: d3_noop,
  polygonEnd: d3_noop
};

function d3_geo_pathBoundsPoint(x, y) {
  if (x < d3_geo_pathBoundsX0) d3_geo_pathBoundsX0 = x;
  if (x > d3_geo_pathBoundsX1) d3_geo_pathBoundsX1 = x;
  if (y < d3_geo_pathBoundsY0) d3_geo_pathBoundsY0 = y;
  if (y > d3_geo_pathBoundsY1) d3_geo_pathBoundsY1 = y;
}
function d3_geo_pathBuffer() {
  var pointCircle = d3_geo_pathBufferCircle(4.5),
      buffer = [];

  var stream = {
    point: point,

    // While inside a line, override point to moveTo then lineTo.
    lineStart: function() { stream.point = pointLineStart; },
    lineEnd: lineEnd,

    // While inside a polygon, override lineEnd to closePath.
    polygonStart: function() { stream.lineEnd = lineEndPolygon; },
    polygonEnd: function() { stream.lineEnd = lineEnd; stream.point = point; },

    pointRadius: function(_) {
      pointCircle = d3_geo_pathBufferCircle(_);
      return stream;
    },

    result: function() {
      if (buffer.length) {
        var result = buffer.join("");
        buffer = [];
        return result;
      }
    }
  };

  function point(x, y) {
    buffer.push("M", x, ",", y, pointCircle);
  }

  function pointLineStart(x, y) {
    buffer.push("M", x, ",", y);
    stream.point = pointLine;
  }

  function pointLine(x, y) {
    buffer.push("L", x, ",", y);
  }

  function lineEnd() {
    stream.point = point;
  }

  function lineEndPolygon() {
    buffer.push("Z");
  }

  return stream;
}

function d3_geo_pathBufferCircle(radius) {
  return "m0," + radius
      + "a" + radius + "," + radius + " 0 1,1 0," + -2 * radius
      + "a" + radius + "," + radius + " 0 1,1 0," + 2 * radius
      + "z";
}

// TODO Unify this code with d3.geom.polygon centroid?
// TODO Enforce positive area for exterior, negative area for interior?

var d3_geo_pathCentroid = {
  point: d3_geo_pathCentroidPoint,

  // For lines, weight by length.
  lineStart: d3_geo_pathCentroidLineStart,
  lineEnd: d3_geo_pathCentroidLineEnd,

  // For polygons, weight by area.
  polygonStart: function() {
    d3_geo_pathCentroid.lineStart = d3_geo_pathCentroidRingStart;
  },
  polygonEnd: function() {
    d3_geo_pathCentroid.point = d3_geo_pathCentroidPoint;
    d3_geo_pathCentroid.lineStart = d3_geo_pathCentroidLineStart;
    d3_geo_pathCentroid.lineEnd = d3_geo_pathCentroidLineEnd;
  }
};

function d3_geo_pathCentroidPoint(x, y) {
  d3_geo_centroidX0 += x;
  d3_geo_centroidY0 += y;
  ++d3_geo_centroidZ0;
}

function d3_geo_pathCentroidLineStart() {
  var x0, y0;

  d3_geo_pathCentroid.point = function(x, y) {
    d3_geo_pathCentroid.point = nextPoint;
    d3_geo_pathCentroidPoint(x0 = x, y0 = y);
  };

  function nextPoint(x, y) {
    var dx = x - x0, dy = y - y0, z = Math.sqrt(dx * dx + dy * dy);
    d3_geo_centroidX1 += z * (x0 + x) / 2;
    d3_geo_centroidY1 += z * (y0 + y) / 2;
    d3_geo_centroidZ1 += z;
    d3_geo_pathCentroidPoint(x0 = x, y0 = y);
  }
}

function d3_geo_pathCentroidLineEnd() {
  d3_geo_pathCentroid.point = d3_geo_pathCentroidPoint;
}

function d3_geo_pathCentroidRingStart() {
  var x00, y00, x0, y0;

  // For the first point, …
  d3_geo_pathCentroid.point = function(x, y) {
    d3_geo_pathCentroid.point = nextPoint;
    d3_geo_pathCentroidPoint(x00 = x0 = x, y00 = y0 = y);
  };

  // For subsequent points, …
  function nextPoint(x, y) {
    var dx = x - x0, dy = y - y0, z = Math.sqrt(dx * dx + dy * dy);
    d3_geo_centroidX1 += z * (x0 + x) / 2;
    d3_geo_centroidY1 += z * (y0 + y) / 2;
    d3_geo_centroidZ1 += z;

    z = y0 * x - x0 * y;
    d3_geo_centroidX2 += z * (x0 + x);
    d3_geo_centroidY2 += z * (y0 + y);
    d3_geo_centroidZ2 += z * 3;
    d3_geo_pathCentroidPoint(x0 = x, y0 = y);
  }

  // For the last point, return to the start.
  d3_geo_pathCentroid.lineEnd = function() {
    nextPoint(x00, y00);
  };
}

function d3_geo_pathContext(context) {
  var pointRadius = 4.5;

  var stream = {
    point: point,

    // While inside a line, override point to moveTo then lineTo.
    lineStart: function() { stream.point = pointLineStart; },
    lineEnd: lineEnd,

    // While inside a polygon, override lineEnd to closePath.
    polygonStart: function() { stream.lineEnd = lineEndPolygon; },
    polygonEnd: function() { stream.lineEnd = lineEnd; stream.point = point; },

    pointRadius: function(_) {
      pointRadius = _;
      return stream;
    },

    result: d3_noop
  };

  function point(x, y) {
    context.moveTo(x + pointRadius, y);
    context.arc(x, y, pointRadius, 0, τ);
  }

  function pointLineStart(x, y) {
    context.moveTo(x, y);
    stream.point = pointLine;
  }

  function pointLine(x, y) {
    context.lineTo(x, y);
  }

  function lineEnd() {
    stream.point = point;
  }

  function lineEndPolygon() {
    context.closePath();
  }

  return stream;
}

function d3_geo_resample(project) {
  var δ2 = .5, // precision, px²
      cosMinDistance = Math.cos(30 * d3_radians), // cos(minimum angular distance)
      maxDepth = 16;

  function resample(stream) {
    return (maxDepth ? resampleRecursive : resampleNone)(stream);
  }

  function resampleNone(stream) {
    return d3_geo_transformPoint(stream, function(x, y) {
      x = project(x, y);
      stream.point(x[0], x[1]);
    });
  }

  function resampleRecursive(stream) {
    var λ00, φ00, x00, y00, a00, b00, c00, // first point
        λ0, x0, y0, a0, b0, c0; // previous point

    var resample = {
      point: point,
      lineStart: lineStart,
      lineEnd: lineEnd,
      polygonStart: function() { stream.polygonStart(); resample.lineStart = ringStart; },
      polygonEnd: function() { stream.polygonEnd(); resample.lineStart = lineStart; }
    };

    function point(x, y) {
      x = project(x, y);
      stream.point(x[0], x[1]);
    }

    function lineStart() {
      x0 = NaN;
      resample.point = linePoint;
      stream.lineStart();
    }

    function linePoint(λ, φ) {
      var c = d3_geo_cartesian([λ, φ]), p = project(λ, φ);
      resampleLineTo(x0, y0, λ0, a0, b0, c0, x0 = p[0], y0 = p[1], λ0 = λ, a0 = c[0], b0 = c[1], c0 = c[2], maxDepth, stream);
      stream.point(x0, y0);
    }

    function lineEnd() {
      resample.point = point;
      stream.lineEnd();
    }

    function ringStart() {
      lineStart();
      resample.point = ringPoint;
      resample.lineEnd = ringEnd;
    }

    function ringPoint(λ, φ) {
      linePoint(λ00 = λ, φ00 = φ), x00 = x0, y00 = y0, a00 = a0, b00 = b0, c00 = c0;
      resample.point = linePoint;
    }

    function ringEnd() {
      resampleLineTo(x0, y0, λ0, a0, b0, c0, x00, y00, λ00, a00, b00, c00, maxDepth, stream);
      resample.lineEnd = lineEnd;
      lineEnd();
    }

    return resample;
  }

  function resampleLineTo(x0, y0, λ0, a0, b0, c0, x1, y1, λ1, a1, b1, c1, depth, stream) {
    var dx = x1 - x0,
        dy = y1 - y0,
        d2 = dx * dx + dy * dy;
    if (d2 > 4 * δ2 && depth--) {
      var a = a0 + a1,
          b = b0 + b1,
          c = c0 + c1,
          m = Math.sqrt(a * a + b * b + c * c),
          φ2 = Math.asin(c /= m),
          λ2 = abs(abs(c) - 1) < ε || abs(λ0 - λ1) < ε ? (λ0 + λ1) / 2 : Math.atan2(b, a),
          p = project(λ2, φ2),
          x2 = p[0],
          y2 = p[1],
          dx2 = x2 - x0,
          dy2 = y2 - y0,
          dz = dy * dx2 - dx * dy2;
      if (dz * dz / d2 > δ2 // perpendicular projected distance
          || abs((dx * dx2 + dy * dy2) / d2 - .5) > .3 // midpoint close to an end
          || a0 * a1 + b0 * b1 + c0 * c1 < cosMinDistance) { // angular distance
        resampleLineTo(x0, y0, λ0, a0, b0, c0, x2, y2, λ2, a /= m, b /= m, c, depth, stream);
        stream.point(x2, y2);
        resampleLineTo(x2, y2, λ2, a, b, c, x1, y1, λ1, a1, b1, c1, depth, stream);
      }
    }
  }

  resample.precision = function(_) {
    if (!arguments.length) return Math.sqrt(δ2);
    maxDepth = (δ2 = _ * _) > 0 && 16;
    return resample;
  };

  return resample;
}

d3.geo.path = function() {
  var pointRadius = 4.5,
      projection,
      context,
      projectStream,
      contextStream,
      cacheStream;

  function path(object) {
    if (object) {
      if (typeof pointRadius === "function") contextStream.pointRadius(+pointRadius.apply(this, arguments));
      if (!cacheStream || !cacheStream.valid) cacheStream = projectStream(contextStream);
      d3.geo.stream(object, cacheStream);
    }
    return contextStream.result();
  }

  path.area = function(object) {
    d3_geo_pathAreaSum = 0;
    d3.geo.stream(object, projectStream(d3_geo_pathArea));
    return d3_geo_pathAreaSum;
  };

  path.centroid = function(object) {
    d3_geo_centroidX0 = d3_geo_centroidY0 = d3_geo_centroidZ0 =
    d3_geo_centroidX1 = d3_geo_centroidY1 = d3_geo_centroidZ1 =
    d3_geo_centroidX2 = d3_geo_centroidY2 = d3_geo_centroidZ2 = 0;
    d3.geo.stream(object, projectStream(d3_geo_pathCentroid));
    return d3_geo_centroidZ2 ? [d3_geo_centroidX2 / d3_geo_centroidZ2, d3_geo_centroidY2 / d3_geo_centroidZ2]
        : d3_geo_centroidZ1 ? [d3_geo_centroidX1 / d3_geo_centroidZ1, d3_geo_centroidY1 / d3_geo_centroidZ1]
        : d3_geo_centroidZ0 ? [d3_geo_centroidX0 / d3_geo_centroidZ0, d3_geo_centroidY0 / d3_geo_centroidZ0]
        : [NaN, NaN];
  };

  path.bounds = function(object) {
    d3_geo_pathBoundsX1 = d3_geo_pathBoundsY1 = -(d3_geo_pathBoundsX0 = d3_geo_pathBoundsY0 = Infinity);
    d3.geo.stream(object, projectStream(d3_geo_pathBounds));
    return [[d3_geo_pathBoundsX0, d3_geo_pathBoundsY0], [d3_geo_pathBoundsX1, d3_geo_pathBoundsY1]];
  };

  path.projection = function(_) {
    if (!arguments.length) return projection;
    projectStream = (projection = _) ? _.stream || d3_geo_pathProjectStream(_) : d3_identity;
    return reset();
  };

  path.context = function(_) {
    if (!arguments.length) return context;
    contextStream = (context = _) == null ? new d3_geo_pathBuffer : new d3_geo_pathContext(_);
    if (typeof pointRadius !== "function") contextStream.pointRadius(pointRadius);
    return reset();
  };

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

  function reset() {
    cacheStream = null;
    return path;
  }

  return path.projection(d3.geo.albersUsa()).context(null);
};

function d3_geo_pathProjectStream(project) {
  var resample = d3_geo_resample(function(x, y) { return project([x * d3_degrees, y * d3_degrees]); });
  return function(stream) { return d3_geo_projectionRadians(resample(stream)); };
}

d3.geo.transform = function(methods) {
  return {
    stream: function(stream) {
      var transform = new d3_geo_transform(stream);
      for (var k in methods) transform[k] = methods[k];
      return transform;
    }
  };
};

function d3_geo_transform(stream) {
  this.stream = stream;
}

d3_geo_transform.prototype = {
  point: function(x, y) { this.stream.point(x, y); },
  sphere: function() { this.stream.sphere(); },
  lineStart: function() { this.stream.lineStart(); },
  lineEnd: function() { this.stream.lineEnd(); },
  polygonStart: function() { this.stream.polygonStart(); },
  polygonEnd: function() { this.stream.polygonEnd(); }
};

function d3_geo_transformPoint(stream, point) {
  return {
    point: point,
    sphere: function() { stream.sphere(); },
    lineStart: function() { stream.lineStart(); },
    lineEnd: function() { stream.lineEnd(); },
    polygonStart: function() { stream.polygonStart(); },
    polygonEnd: function() { stream.polygonEnd(); },
  };
}

d3.geo.projection = d3_geo_projection;
d3.geo.projectionMutator = d3_geo_projectionMutator;

function d3_geo_projection(project) {
  return d3_geo_projectionMutator(function() { return project; })();
}

function d3_geo_projectionMutator(projectAt) {
  var project,
      rotate,
      projectRotate,
      projectResample = d3_geo_resample(function(x, y) { x = project(x, y); return [x[0] * k + δx, δy - x[1] * k]; }),
      k = 150, // scale
      x = 480, y = 250, // translate
      λ = 0, φ = 0, // center
      δλ = 0, δφ = 0, δγ = 0, // rotate
      δx, δy, // center
      preclip = d3_geo_clipAntimeridian,
      postclip = d3_identity,
      clipAngle = null,
      clipExtent = null,
      stream;

  function projection(point) {
    point = projectRotate(point[0] * d3_radians, point[1] * d3_radians);
    return [point[0] * k + δx, δy - point[1] * k];
  }

  function invert(point) {
    point = projectRotate.invert((point[0] - δx) / k, (δy - point[1]) / k);
    return point && [point[0] * d3_degrees, point[1] * d3_degrees];
  }

  projection.stream = function(output) {
    if (stream) stream.valid = false;
    stream = d3_geo_projectionRadians(preclip(rotate, projectResample(postclip(output))));
    stream.valid = true; // allow caching by d3.geo.path
    return stream;
  };

  projection.clipAngle = function(_) {
    if (!arguments.length) return clipAngle;
    preclip = _ == null ? (clipAngle = _, d3_geo_clipAntimeridian) : d3_geo_clipCircle((clipAngle = +_) * d3_radians);
    return invalidate();
  };

  projection.clipExtent = function(_) {
    if (!arguments.length) return clipExtent;
    clipExtent = _;
    postclip = _ ? d3_geo_clipExtent(_[0][0], _[0][1], _[1][0], _[1][1]) : d3_identity;
    return invalidate();
  };

  projection.scale = function(_) {
    if (!arguments.length) return k;
    k = +_;
    return reset();
  };

  projection.translate = function(_) {
    if (!arguments.length) return [x, y];
    x = +_[0];
    y = +_[1];
    return reset();
  };

  projection.center = function(_) {
    if (!arguments.length) return [λ * d3_degrees, φ * d3_degrees];
    λ = _[0] % 360 * d3_radians;
    φ = _[1] % 360 * d3_radians;
    return reset();
  };

  projection.rotate = function(_) {
    if (!arguments.length) return [δλ * d3_degrees, δφ * d3_degrees, δγ * d3_degrees];
    δλ = _[0] % 360 * d3_radians;
    δφ = _[1] % 360 * d3_radians;
    δγ = _.length > 2 ? _[2] % 360 * d3_radians : 0;
    return reset();
  };

  d3.rebind(projection, projectResample, "precision");

  function reset() {
    projectRotate = d3_geo_compose(rotate = d3_geo_rotation(δλ, δφ, δγ), project);
    var center = project(λ, φ);
    δx = x - center[0] * k;
    δy = y + center[1] * k;
    return invalidate();
  }

  function invalidate() {
    if (stream) stream.valid = false, stream = null;
    return projection;
  }

  return function() {
    project = projectAt.apply(this, arguments);
    projection.invert = project.invert && invert;
    return reset();
  };
}

function d3_geo_projectionRadians(stream) {
  return d3_geo_transformPoint(stream, function(x, y) {
    stream.point(x * d3_radians, y * d3_radians);
  });
}

function d3_geo_mercator(λ, φ) {
  return [λ, Math.log(Math.tan(π / 4 + φ / 2))];
}

d3_geo_mercator.invert = function(x, y) {
  return [x, 2 * Math.atan(Math.exp(y)) - halfπ];
};

function d3_geo_mercatorProjection(project) {
  var m = d3_geo_projection(project),
      scale = m.scale,
      translate = m.translate,
      clipExtent = m.clipExtent,
      clipAuto;

  m.scale = function() {
    var v = scale.apply(m, arguments);
    return v === m ? (clipAuto ? m.clipExtent(null) : m) : v;
  };

  m.translate = function() {
    var v = translate.apply(m, arguments);
    return v === m ? (clipAuto ? m.clipExtent(null) : m) : v;
  };

  m.clipExtent = function(_) {
    var v = clipExtent.apply(m, arguments);
    if (v === m) {
      if (clipAuto = _ == null) {
        var k = π * scale(), t = translate();
        clipExtent([[t[0] - k, t[1] - k], [t[0] + k, t[1] + k]]);
      }
    } else if (clipAuto) {
      v = null;
    }
    return v;
  };

  return m.clipExtent(null);
}

(d3.geo.mercator = function() {
  return d3_geo_mercatorProjection(d3_geo_mercator);
}).raw = d3_geo_mercator;
d3.geom = {};

d3.geom.polygon = function(coordinates) {
  d3_subclass(coordinates, d3_geom_polygonPrototype);
  return coordinates;
};

var d3_geom_polygonPrototype = d3.geom.polygon.prototype = [];

d3_geom_polygonPrototype.area = function() {
  var i = -1,
      n = this.length,
      a,
      b = this[n - 1],
      area = 0;

  while (++i < n) {
    a = b;
    b = this[i];
    area += a[1] * b[0] - a[0] * b[1];
  }

  return area * .5;
};

d3_geom_polygonPrototype.centroid = function(k) {
  var i = -1,
      n = this.length,
      x = 0,
      y = 0,
      a,
      b = this[n - 1],
      c;

  if (!arguments.length) k = -1 / (6 * this.area());

  while (++i < n) {
    a = b;
    b = this[i];
    c = a[0] * b[1] - b[0] * a[1];
    x += (a[0] + b[0]) * c;
    y += (a[1] + b[1]) * c;
  }

  return [x * k, y * k];
};

// The Sutherland-Hodgman clipping algorithm.
// Note: requires the clip polygon to be counterclockwise and convex.
d3_geom_polygonPrototype.clip = function(subject) {
  var input,
      closed = d3_geom_polygonClosed(subject),
      i = -1,
      n = this.length - d3_geom_polygonClosed(this),
      j,
      m,
      a = this[n - 1],
      b,
      c,
      d;

  while (++i < n) {
    input = subject.slice();
    subject.length = 0;
    b = this[i];
    c = input[(m = input.length - closed) - 1];
    j = -1;
    while (++j < m) {
      d = input[j];
      if (d3_geom_polygonInside(d, a, b)) {
        if (!d3_geom_polygonInside(c, a, b)) {
          subject.push(d3_geom_polygonIntersect(c, d, a, b));
        }
        subject.push(d);
      } else if (d3_geom_polygonInside(c, a, b)) {
        subject.push(d3_geom_polygonIntersect(c, d, a, b));
      }
      c = d;
    }
    if (closed) subject.push(subject[0]);
    a = b;
  }

  return subject;
};

function d3_geom_polygonInside(p, a, b) {
  return (b[0] - a[0]) * (p[1] - a[1]) < (b[1] - a[1]) * (p[0] - a[0]);
}

// Intersect two infinite lines cd and ab.
function d3_geom_polygonIntersect(c, d, a, b) {
  var x1 = c[0], x3 = a[0], x21 = d[0] - x1, x43 = b[0] - x3,
      y1 = c[1], y3 = a[1], y21 = d[1] - y1, y43 = b[1] - y3,
      ua = (x43 * (y1 - y3) - y43 * (x1 - x3)) / (y43 * x21 - x43 * y21);
  return [x1 + ua * x21, y1 + ua * y21];
}

// Returns true if the polygon is closed.
function d3_geom_polygonClosed(coordinates) {
  var a = coordinates[0],
      b = coordinates[coordinates.length - 1];
  return !(a[0] - b[0] || a[1] - b[1]);
}
function d3_geom_pointX(d) {
  return d[0];
}

function d3_geom_pointY(d) {
  return d[1];
}

/**
 * Computes the 2D convex hull of a set of points using the monotone chain
 * algorithm:
 * http://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain)
 *
 * The runtime of this algorithm is O(n log n), where n is the number of input
 * points. However in practice it outperforms other O(n log n) hulls.
 *
 * @param vertices [[x1, y1], [x2, y2], ...]
 * @returns polygon [[x1, y1], [x2, y2], ...]
 */
d3.geom.hull = function(vertices) {
  var x = d3_geom_pointX,
      y = d3_geom_pointY;

  if (arguments.length) return hull(vertices);

  function hull(data) {
    // Hull of < 3 points is not well-defined
    if (data.length < 3) return [];

    var fx = d3_functor(x),
        fy = d3_functor(y),
        i,
        n = data.length,
        points = [], // of the form [[x0, y0, 0], ..., [xn, yn, n]]
        flippedPoints = [];

    for (i = 0 ; i < n; i++) {
      points.push([+fx.call(this, data[i], i), +fy.call(this, data[i], i), i]);
    }

    // sort ascending by x-coord first, y-coord second
    points.sort(d3_geom_hullOrder);

    // we flip bottommost points across y axis so we can use the upper hull routine on both
    for (i = 0; i < n; i++) flippedPoints.push([points[i][0], -points[i][1]]);

    var upper = d3_geom_hullUpper(points),
        lower = d3_geom_hullUpper(flippedPoints);

    // construct the polygon, removing possible duplicate endpoints
    var skipLeft = lower[0] === upper[0],
        skipRight  = lower[lower.length - 1] === upper[upper.length - 1],
        polygon = [];

    // add upper hull in r->l order
    // then add lower hull in l->r order
    for (i = upper.length - 1; i >= 0; --i) polygon.push(data[points[upper[i]][2]]);
    for (i = +skipLeft; i < lower.length - skipRight; ++i) polygon.push(data[points[lower[i]][2]]);

    return polygon;
  }

  hull.x = function(_) {
    return arguments.length ? (x = _, hull) : x;
  };

  hull.y = function(_) {
    return arguments.length ? (y = _, hull) : y;
  };

  return hull;
};

// finds the 'upper convex hull' (see wiki link above)
// assumes points arg has >=3 elements, is sorted by x, unique in y
// returns array of indices into points in left to right order
function d3_geom_hullUpper(points) {
  var n = points.length,
      hull = [0, 1],
      hs = 2; // hull size

  for (var i = 2; i < n; i++) {
    while (hs > 1 && d3_cross2d(points[hull[hs-2]], points[hull[hs-1]], points[i]) <= 0) --hs;
    hull[hs++] = i;
  }

  // we slice to make sure that the points we 'popped' from hull don't stay behind
  return hull.slice(0, hs);
}

// comparator for ascending sort by x-coord first, y-coord second
function d3_geom_hullOrder(a, b) {
  return a[0] - b[0] || a[1] - b[1];
}