// Version 1.43.5 force-graph - https://github.com/vasturiano/force-graph
(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global = typeof globalThis !== 'undefined' ? globalThis : global || self, global.ForceGraph = factory());
})(this, (function () { 'use strict';

  function styleInject(css, ref) {
    if ( ref === void 0 ) ref = {};
    var insertAt = ref.insertAt;

    if (!css || typeof document === 'undefined') { return; }

    var head = document.head || document.getElementsByTagName('head')[0];
    var style = document.createElement('style');
    style.type = 'text/css';

    if (insertAt === 'top') {
      if (head.firstChild) {
        head.insertBefore(style, head.firstChild);
      } else {
        head.appendChild(style);
      }
    } else {
      head.appendChild(style);
    }

    if (style.styleSheet) {
      style.styleSheet.cssText = css;
    } else {
      style.appendChild(document.createTextNode(css));
    }
  }

  var css_248z = ".force-graph-container canvas {\n  display: block;\n  user-select: none;\n  outline: none;\n  -webkit-tap-highlight-color: transparent;\n}\n\n.force-graph-container .graph-tooltip {\n  position: absolute;\n  top: 0;\n  font-family: sans-serif;\n  font-size: 16px;\n  padding: 4px;\n  border-radius: 3px;\n  color: #eee;\n  background: rgba(0,0,0,0.65);\n  visibility: hidden; /* by default */\n}\n\n.force-graph-container .clickable {\n  cursor: pointer;\n}\n\n.force-graph-container .grabbable {\n  cursor: move;\n  cursor: grab;\n  cursor: -moz-grab;\n  cursor: -webkit-grab;\n}\n\n.force-graph-container .grabbable:active {\n  cursor: grabbing;\n  cursor: -moz-grabbing;\n  cursor: -webkit-grabbing;\n}\n";
  styleInject(css_248z);

  function _construct(t, e, r) {
    if (_isNativeReflectConstruct()) return Reflect.construct.apply(null, arguments);
    var o = [null];
    o.push.apply(o, e);
    var p = new (t.bind.apply(t, o))();
    return r && _setPrototypeOf(p, r.prototype), p;
  }
  function _isNativeReflectConstruct() {
    try {
      var t = !Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {}));
    } catch (t) {}
    return (_isNativeReflectConstruct = function () {
      return !!t;
    })();
  }
  function _iterableToArrayLimit$2(r, l) {
    var t = null == r ? null : "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"];
    if (null != t) {
      var e,
        n,
        i,
        u,
        a = [],
        f = !0,
        o = !1;
      try {
        if (i = (t = t.call(r)).next, 0 === l) {
          if (Object(t) !== t) return;
          f = !1;
        } else for (; !(f = (e = i.call(t)).done) && (a.push(e.value), a.length !== l); f = !0);
      } catch (r) {
        o = !0, n = r;
      } finally {
        try {
          if (!f && null != t.return && (u = t.return(), Object(u) !== u)) return;
        } finally {
          if (o) throw n;
        }
      }
      return a;
    }
  }
  function ownKeys(e, r) {
    var t = Object.keys(e);
    if (Object.getOwnPropertySymbols) {
      var o = Object.getOwnPropertySymbols(e);
      r && (o = o.filter(function (r) {
        return Object.getOwnPropertyDescriptor(e, r).enumerable;
      })), t.push.apply(t, o);
    }
    return t;
  }
  function _objectSpread2(e) {
    for (var r = 1; r < arguments.length; r++) {
      var t = null != arguments[r] ? arguments[r] : {};
      r % 2 ? ownKeys(Object(t), !0).forEach(function (r) {
        _defineProperty(e, r, t[r]);
      }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) {
        Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r));
      });
    }
    return e;
  }
  function _toPrimitive$3(t, r) {
    if ("object" != typeof t || !t) return t;
    var e = t[Symbol.toPrimitive];
    if (void 0 !== e) {
      var i = e.call(t, r || "default");
      if ("object" != typeof i) return i;
      throw new TypeError("@@toPrimitive must return a primitive value.");
    }
    return ("string" === r ? String : Number)(t);
  }
  function _toPropertyKey$3(t) {
    var i = _toPrimitive$3(t, "string");
    return "symbol" == typeof i ? i : String(i);
  }
  function _typeof$1(o) {
    "@babel/helpers - typeof";

    return _typeof$1 = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) {
      return typeof o;
    } : function (o) {
      return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o;
    }, _typeof$1(o);
  }
  function _defineProperty(obj, key, value) {
    key = _toPropertyKey$3(key);
    if (key in obj) {
      Object.defineProperty(obj, key, {
        value: value,
        enumerable: true,
        configurable: true,
        writable: true
      });
    } else {
      obj[key] = value;
    }
    return obj;
  }
  function _setPrototypeOf(o, p) {
    _setPrototypeOf = Object.setPrototypeOf ? Object.setPrototypeOf.bind() : function _setPrototypeOf(o, p) {
      o.__proto__ = p;
      return o;
    };
    return _setPrototypeOf(o, p);
  }
  function _slicedToArray$2(arr, i) {
    return _arrayWithHoles$2(arr) || _iterableToArrayLimit$2(arr, i) || _unsupportedIterableToArray$3(arr, i) || _nonIterableRest$2();
  }
  function _toConsumableArray$2(arr) {
    return _arrayWithoutHoles$2(arr) || _iterableToArray$2(arr) || _unsupportedIterableToArray$3(arr) || _nonIterableSpread$2();
  }
  function _arrayWithoutHoles$2(arr) {
    if (Array.isArray(arr)) return _arrayLikeToArray$3(arr);
  }
  function _arrayWithHoles$2(arr) {
    if (Array.isArray(arr)) return arr;
  }
  function _iterableToArray$2(iter) {
    if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter);
  }
  function _unsupportedIterableToArray$3(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _arrayLikeToArray$3(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(o);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray$3(o, minLen);
  }
  function _arrayLikeToArray$3(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i];
    return arr2;
  }
  function _nonIterableSpread$2() {
    throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }
  function _nonIterableRest$2() {
    throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }

  var xhtml = "http://www.w3.org/1999/xhtml";

  var namespaces = {
    svg: "http://www.w3.org/2000/svg",
    xhtml: xhtml,
    xlink: "http://www.w3.org/1999/xlink",
    xml: "http://www.w3.org/XML/1998/namespace",
    xmlns: "http://www.w3.org/2000/xmlns/"
  };

  function namespace(name) {
    var prefix = name += "", i = prefix.indexOf(":");
    if (i >= 0 && (prefix = name.slice(0, i)) !== "xmlns") name = name.slice(i + 1);
    return namespaces.hasOwnProperty(prefix) ? {space: namespaces[prefix], local: name} : name; // eslint-disable-line no-prototype-builtins
  }

  function creatorInherit(name) {
    return function() {
      var document = this.ownerDocument,
          uri = this.namespaceURI;
      return uri === xhtml && document.documentElement.namespaceURI === xhtml
          ? document.createElement(name)
          : document.createElementNS(uri, name);
    };
  }

  function creatorFixed(fullname) {
    return function() {
      return this.ownerDocument.createElementNS(fullname.space, fullname.local);
    };
  }

  function creator(name) {
    var fullname = namespace(name);
    return (fullname.local
        ? creatorFixed
        : creatorInherit)(fullname);
  }

  function none() {}

  function selector(selector) {
    return selector == null ? none : function() {
      return this.querySelector(selector);
    };
  }

  function selection_select(select) {
    if (typeof select !== "function") select = selector(select);

    for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
        if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
          if ("__data__" in node) subnode.__data__ = node.__data__;
          subgroup[i] = subnode;
        }
      }
    }

    return new Selection$1(subgroups, this._parents);
  }

  // Given something array like (or null), returns something that is strictly an
  // array. This is used to ensure that array-like objects passed to d3.selectAll
  // or selection.selectAll are converted into proper arrays when creating a
  // selection; we don’t ever want to create a selection backed by a live
  // HTMLCollection or NodeList. However, note that selection.selectAll will use a
  // static NodeList as a group, since it safely derived from querySelectorAll.
  function array(x) {
    return x == null ? [] : Array.isArray(x) ? x : Array.from(x);
  }

  function empty() {
    return [];
  }

  function selectorAll(selector) {
    return selector == null ? empty : function() {
      return this.querySelectorAll(selector);
    };
  }

  function arrayAll(select) {
    return function() {
      return array(select.apply(this, arguments));
    };
  }

  function selection_selectAll(select) {
    if (typeof select === "function") select = arrayAll(select);
    else select = selectorAll(select);

    for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
        if (node = group[i]) {
          subgroups.push(select.call(node, node.__data__, i, group));
          parents.push(node);
        }
      }
    }

    return new Selection$1(subgroups, parents);
  }

  function matcher(selector) {
    return function() {
      return this.matches(selector);
    };
  }

  function childMatcher(selector) {
    return function(node) {
      return node.matches(selector);
    };
  }

  var find$1 = Array.prototype.find;

  function childFind(match) {
    return function() {
      return find$1.call(this.children, match);
    };
  }

  function childFirst() {
    return this.firstElementChild;
  }

  function selection_selectChild(match) {
    return this.select(match == null ? childFirst
        : childFind(typeof match === "function" ? match : childMatcher(match)));
  }

  var filter = Array.prototype.filter;

  function children() {
    return Array.from(this.children);
  }

  function childrenFilter(match) {
    return function() {
      return filter.call(this.children, match);
    };
  }

  function selection_selectChildren(match) {
    return this.selectAll(match == null ? children
        : childrenFilter(typeof match === "function" ? match : childMatcher(match)));
  }

  function selection_filter(match) {
    if (typeof match !== "function") match = matcher(match);

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

    return new Selection$1(subgroups, this._parents);
  }

  function sparse(update) {
    return new Array(update.length);
  }

  function selection_enter() {
    return new Selection$1(this._enter || this._groups.map(sparse), this._parents);
  }

  function EnterNode(parent, datum) {
    this.ownerDocument = parent.ownerDocument;
    this.namespaceURI = parent.namespaceURI;
    this._next = null;
    this._parent = parent;
    this.__data__ = datum;
  }

  EnterNode.prototype = {
    constructor: EnterNode,
    appendChild: function(child) { return this._parent.insertBefore(child, this._next); },
    insertBefore: function(child, next) { return this._parent.insertBefore(child, next); },
    querySelector: function(selector) { return this._parent.querySelector(selector); },
    querySelectorAll: function(selector) { return this._parent.querySelectorAll(selector); }
  };

  function constant$4(x) {
    return function() {
      return x;
    };
  }

  function bindIndex(parent, group, enter, update, exit, data) {
    var i = 0,
        node,
        groupLength = group.length,
        dataLength = data.length;

    // Put any non-null nodes that fit into update.
    // Put any null nodes into enter.
    // Put any remaining data into enter.
    for (; i < dataLength; ++i) {
      if (node = group[i]) {
        node.__data__ = data[i];
        update[i] = node;
      } else {
        enter[i] = new EnterNode(parent, data[i]);
      }
    }

    // Put any non-null nodes that don’t fit into exit.
    for (; i < groupLength; ++i) {
      if (node = group[i]) {
        exit[i] = node;
      }
    }
  }

  function bindKey(parent, group, enter, update, exit, data, key) {
    var i,
        node,
        nodeByKeyValue = new Map,
        groupLength = group.length,
        dataLength = data.length,
        keyValues = new Array(groupLength),
        keyValue;

    // Compute the key for each node.
    // If multiple nodes have the same key, the duplicates are added to exit.
    for (i = 0; i < groupLength; ++i) {
      if (node = group[i]) {
        keyValues[i] = keyValue = key.call(node, node.__data__, i, group) + "";
        if (nodeByKeyValue.has(keyValue)) {
          exit[i] = node;
        } else {
          nodeByKeyValue.set(keyValue, node);
        }
      }
    }

    // Compute the key for each datum.
    // If there a node associated with this key, join and add it to update.
    // If there is not (or the key is a duplicate), add it to enter.
    for (i = 0; i < dataLength; ++i) {
      keyValue = key.call(parent, data[i], i, data) + "";
      if (node = nodeByKeyValue.get(keyValue)) {
        update[i] = node;
        node.__data__ = data[i];
        nodeByKeyValue.delete(keyValue);
      } else {
        enter[i] = new EnterNode(parent, data[i]);
      }
    }

    // Add any remaining nodes that were not bound to data to exit.
    for (i = 0; i < groupLength; ++i) {
      if ((node = group[i]) && (nodeByKeyValue.get(keyValues[i]) === node)) {
        exit[i] = node;
      }
    }
  }

  function datum(node) {
    return node.__data__;
  }

  function selection_data(value, key) {
    if (!arguments.length) return Array.from(this, datum);

    var bind = key ? bindKey : bindIndex,
        parents = this._parents,
        groups = this._groups;

    if (typeof value !== "function") value = constant$4(value);

    for (var m = groups.length, update = new Array(m), enter = new Array(m), exit = new Array(m), j = 0; j < m; ++j) {
      var parent = parents[j],
          group = groups[j],
          groupLength = group.length,
          data = arraylike(value.call(parent, parent && parent.__data__, j, parents)),
          dataLength = data.length,
          enterGroup = enter[j] = new Array(dataLength),
          updateGroup = update[j] = new Array(dataLength),
          exitGroup = exit[j] = new Array(groupLength);

      bind(parent, group, enterGroup, updateGroup, exitGroup, data, key);

      // Now connect the enter nodes to their following update node, such that
      // appendChild can insert the materialized enter node before this node,
      // rather than at the end of the parent node.
      for (var i0 = 0, i1 = 0, previous, next; i0 < dataLength; ++i0) {
        if (previous = enterGroup[i0]) {
          if (i0 >= i1) i1 = i0 + 1;
          while (!(next = updateGroup[i1]) && ++i1 < dataLength);
          previous._next = next || null;
        }
      }
    }

    update = new Selection$1(update, parents);
    update._enter = enter;
    update._exit = exit;
    return update;
  }

  // Given some data, this returns an array-like view of it: an object that
  // exposes a length property and allows numeric indexing. Note that unlike
  // selectAll, this isn’t worried about “live” collections because the resulting
  // array will only be used briefly while data is being bound. (It is possible to
  // cause the data to change while iterating by using a key function, but please
  // don’t; we’d rather avoid a gratuitous copy.)
  function arraylike(data) {
    return typeof data === "object" && "length" in data
      ? data // Array, TypedArray, NodeList, array-like
      : Array.from(data); // Map, Set, iterable, string, or anything else
  }

  function selection_exit() {
    return new Selection$1(this._exit || this._groups.map(sparse), this._parents);
  }

  function selection_join(onenter, onupdate, onexit) {
    var enter = this.enter(), update = this, exit = this.exit();
    if (typeof onenter === "function") {
      enter = onenter(enter);
      if (enter) enter = enter.selection();
    } else {
      enter = enter.append(onenter + "");
    }
    if (onupdate != null) {
      update = onupdate(update);
      if (update) update = update.selection();
    }
    if (onexit == null) exit.remove(); else onexit(exit);
    return enter && update ? enter.merge(update).order() : update;
  }

  function selection_merge(context) {
    var selection = context.selection ? context.selection() : context;

    for (var groups0 = this._groups, groups1 = selection._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
      for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
        if (node = group0[i] || group1[i]) {
          merge[i] = node;
        }
      }
    }

    for (; j < m0; ++j) {
      merges[j] = groups0[j];
    }

    return new Selection$1(merges, this._parents);
  }

  function selection_order() {

    for (var groups = this._groups, j = -1, m = groups.length; ++j < m;) {
      for (var group = groups[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
        if (node = group[i]) {
          if (next && node.compareDocumentPosition(next) ^ 4) next.parentNode.insertBefore(node, next);
          next = node;
        }
      }
    }

    return this;
  }

  function selection_sort(compare) {
    if (!compare) compare = ascending;

    function compareNode(a, b) {
      return a && b ? compare(a.__data__, b.__data__) : !a - !b;
    }

    for (var groups = this._groups, m = groups.length, sortgroups = new Array(m), j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, sortgroup = sortgroups[j] = new Array(n), node, i = 0; i < n; ++i) {
        if (node = group[i]) {
          sortgroup[i] = node;
        }
      }
      sortgroup.sort(compareNode);
    }

    return new Selection$1(sortgroups, this._parents).order();
  }

  function ascending(a, b) {
    return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
  }

  function selection_call() {
    var callback = arguments[0];
    arguments[0] = this;
    callback.apply(null, arguments);
    return this;
  }

  function selection_nodes() {
    return Array.from(this);
  }

  function selection_node() {

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

    return null;
  }

  function selection_size() {
    let size = 0;
    for (const node of this) ++size; // eslint-disable-line no-unused-vars
    return size;
  }

  function selection_empty() {
    return !this.node();
  }

  function selection_each(callback) {

    for (var groups = this._groups, 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.call(node, node.__data__, i, group);
      }
    }

    return this;
  }

  function attrRemove$1(name) {
    return function() {
      this.removeAttribute(name);
    };
  }

  function attrRemoveNS$1(fullname) {
    return function() {
      this.removeAttributeNS(fullname.space, fullname.local);
    };
  }

  function attrConstant$1(name, value) {
    return function() {
      this.setAttribute(name, value);
    };
  }

  function attrConstantNS$1(fullname, value) {
    return function() {
      this.setAttributeNS(fullname.space, fullname.local, value);
    };
  }

  function attrFunction$1(name, value) {
    return function() {
      var v = value.apply(this, arguments);
      if (v == null) this.removeAttribute(name);
      else this.setAttribute(name, v);
    };
  }

  function attrFunctionNS$1(fullname, value) {
    return function() {
      var v = value.apply(this, arguments);
      if (v == null) this.removeAttributeNS(fullname.space, fullname.local);
      else this.setAttributeNS(fullname.space, fullname.local, v);
    };
  }

  function selection_attr(name, value) {
    var fullname = namespace(name);

    if (arguments.length < 2) {
      var node = this.node();
      return fullname.local
          ? node.getAttributeNS(fullname.space, fullname.local)
          : node.getAttribute(fullname);
    }

    return this.each((value == null
        ? (fullname.local ? attrRemoveNS$1 : attrRemove$1) : (typeof value === "function"
        ? (fullname.local ? attrFunctionNS$1 : attrFunction$1)
        : (fullname.local ? attrConstantNS$1 : attrConstant$1)))(fullname, value));
  }

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

  function styleRemove$1(name) {
    return function() {
      this.style.removeProperty(name);
    };
  }

  function styleConstant$1(name, value, priority) {
    return function() {
      this.style.setProperty(name, value, priority);
    };
  }

  function styleFunction$1(name, value, priority) {
    return function() {
      var v = value.apply(this, arguments);
      if (v == null) this.style.removeProperty(name);
      else this.style.setProperty(name, v, priority);
    };
  }

  function selection_style(name, value, priority) {
    return arguments.length > 1
        ? this.each((value == null
              ? styleRemove$1 : typeof value === "function"
              ? styleFunction$1
              : styleConstant$1)(name, value, priority == null ? "" : priority))
        : styleValue(this.node(), name);
  }

  function styleValue(node, name) {
    return node.style.getPropertyValue(name)
        || defaultView(node).getComputedStyle(node, null).getPropertyValue(name);
  }

  function propertyRemove(name) {
    return function() {
      delete this[name];
    };
  }

  function propertyConstant(name, value) {
    return function() {
      this[name] = value;
    };
  }

  function propertyFunction(name, value) {
    return function() {
      var v = value.apply(this, arguments);
      if (v == null) delete this[name];
      else this[name] = v;
    };
  }

  function selection_property(name, value) {
    return arguments.length > 1
        ? this.each((value == null
            ? propertyRemove : typeof value === "function"
            ? propertyFunction
            : propertyConstant)(name, value))
        : this.node()[name];
  }

  function classArray(string) {
    return string.trim().split(/^|\s+/);
  }

  function classList(node) {
    return node.classList || new ClassList(node);
  }

  function ClassList(node) {
    this._node = node;
    this._names = classArray(node.getAttribute("class") || "");
  }

  ClassList.prototype = {
    add: function(name) {
      var i = this._names.indexOf(name);
      if (i < 0) {
        this._names.push(name);
        this._node.setAttribute("class", this._names.join(" "));
      }
    },
    remove: function(name) {
      var i = this._names.indexOf(name);
      if (i >= 0) {
        this._names.splice(i, 1);
        this._node.setAttribute("class", this._names.join(" "));
      }
    },
    contains: function(name) {
      return this._names.indexOf(name) >= 0;
    }
  };

  function classedAdd(node, names) {
    var list = classList(node), i = -1, n = names.length;
    while (++i < n) list.add(names[i]);
  }

  function classedRemove(node, names) {
    var list = classList(node), i = -1, n = names.length;
    while (++i < n) list.remove(names[i]);
  }

  function classedTrue(names) {
    return function() {
      classedAdd(this, names);
    };
  }

  function classedFalse(names) {
    return function() {
      classedRemove(this, names);
    };
  }

  function classedFunction(names, value) {
    return function() {
      (value.apply(this, arguments) ? classedAdd : classedRemove)(this, names);
    };
  }

  function selection_classed(name, value) {
    var names = classArray(name + "");

    if (arguments.length < 2) {
      var list = classList(this.node()), i = -1, n = names.length;
      while (++i < n) if (!list.contains(names[i])) return false;
      return true;
    }

    return this.each((typeof value === "function"
        ? classedFunction : value
        ? classedTrue
        : classedFalse)(names, value));
  }

  function textRemove() {
    this.textContent = "";
  }

  function textConstant$1(value) {
    return function() {
      this.textContent = value;
    };
  }

  function textFunction$1(value) {
    return function() {
      var v = value.apply(this, arguments);
      this.textContent = v == null ? "" : v;
    };
  }

  function selection_text(value) {
    return arguments.length
        ? this.each(value == null
            ? textRemove : (typeof value === "function"
            ? textFunction$1
            : textConstant$1)(value))
        : this.node().textContent;
  }

  function htmlRemove() {
    this.innerHTML = "";
  }

  function htmlConstant(value) {
    return function() {
      this.innerHTML = value;
    };
  }

  function htmlFunction(value) {
    return function() {
      var v = value.apply(this, arguments);
      this.innerHTML = v == null ? "" : v;
    };
  }

  function selection_html(value) {
    return arguments.length
        ? this.each(value == null
            ? htmlRemove : (typeof value === "function"
            ? htmlFunction
            : htmlConstant)(value))
        : this.node().innerHTML;
  }

  function raise() {
    if (this.nextSibling) this.parentNode.appendChild(this);
  }

  function selection_raise() {
    return this.each(raise);
  }

  function lower() {
    if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
  }

  function selection_lower() {
    return this.each(lower);
  }

  function selection_append(name) {
    var create = typeof name === "function" ? name : creator(name);
    return this.select(function() {
      return this.appendChild(create.apply(this, arguments));
    });
  }

  function constantNull() {
    return null;
  }

  function selection_insert(name, before) {
    var create = typeof name === "function" ? name : creator(name),
        select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
    return this.select(function() {
      return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
    });
  }

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

  function selection_remove() {
    return this.each(remove);
  }

  function selection_cloneShallow() {
    var clone = this.cloneNode(false), parent = this.parentNode;
    return parent ? parent.insertBefore(clone, this.nextSibling) : clone;
  }

  function selection_cloneDeep() {
    var clone = this.cloneNode(true), parent = this.parentNode;
    return parent ? parent.insertBefore(clone, this.nextSibling) : clone;
  }

  function selection_clone(deep) {
    return this.select(deep ? selection_cloneDeep : selection_cloneShallow);
  }

  function selection_datum(value) {
    return arguments.length
        ? this.property("__data__", value)
        : this.node().__data__;
  }

  function contextListener(listener) {
    return function(event) {
      listener.call(this, event, this.__data__);
    };
  }

  function parseTypenames$1(typenames) {
    return typenames.trim().split(/^|\s+/).map(function(t) {
      var name = "", i = t.indexOf(".");
      if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
      return {type: t, name: name};
    });
  }

  function onRemove(typename) {
    return function() {
      var on = this.__on;
      if (!on) return;
      for (var j = 0, i = -1, m = on.length, o; j < m; ++j) {
        if (o = on[j], (!typename.type || o.type === typename.type) && o.name === typename.name) {
          this.removeEventListener(o.type, o.listener, o.options);
        } else {
          on[++i] = o;
        }
      }
      if (++i) on.length = i;
      else delete this.__on;
    };
  }

  function onAdd(typename, value, options) {
    return function() {
      var on = this.__on, o, listener = contextListener(value);
      if (on) for (var j = 0, m = on.length; j < m; ++j) {
        if ((o = on[j]).type === typename.type && o.name === typename.name) {
          this.removeEventListener(o.type, o.listener, o.options);
          this.addEventListener(o.type, o.listener = listener, o.options = options);
          o.value = value;
          return;
        }
      }
      this.addEventListener(typename.type, listener, options);
      o = {type: typename.type, name: typename.name, value: value, listener: listener, options: options};
      if (!on) this.__on = [o];
      else on.push(o);
    };
  }

  function selection_on(typename, value, options) {
    var typenames = parseTypenames$1(typename + ""), i, n = typenames.length, t;

    if (arguments.length < 2) {
      var on = this.node().__on;
      if (on) for (var j = 0, m = on.length, o; j < m; ++j) {
        for (i = 0, o = on[j]; i < n; ++i) {
          if ((t = typenames[i]).type === o.type && t.name === o.name) {
            return o.value;
          }
        }
      }
      return;
    }

    on = value ? onAdd : onRemove;
    for (i = 0; i < n; ++i) this.each(on(typenames[i], value, options));
    return this;
  }

  function dispatchEvent(node, type, params) {
    var window = defaultView(node),
        event = window.CustomEvent;

    if (typeof event === "function") {
      event = new event(type, params);
    } else {
      event = window.document.createEvent("Event");
      if (params) event.initEvent(type, params.bubbles, params.cancelable), event.detail = params.detail;
      else event.initEvent(type, false, false);
    }

    node.dispatchEvent(event);
  }

  function dispatchConstant(type, params) {
    return function() {
      return dispatchEvent(this, type, params);
    };
  }

  function dispatchFunction(type, params) {
    return function() {
      return dispatchEvent(this, type, params.apply(this, arguments));
    };
  }

  function selection_dispatch(type, params) {
    return this.each((typeof params === "function"
        ? dispatchFunction
        : dispatchConstant)(type, params));
  }

  function* selection_iterator() {
    for (var groups = this._groups, 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]) yield node;
      }
    }
  }

  var root$1 = [null];

  function Selection$1(groups, parents) {
    this._groups = groups;
    this._parents = parents;
  }

  function selection() {
    return new Selection$1([[document.documentElement]], root$1);
  }

  function selection_selection() {
    return this;
  }

  Selection$1.prototype = selection.prototype = {
    constructor: Selection$1,
    select: selection_select,
    selectAll: selection_selectAll,
    selectChild: selection_selectChild,
    selectChildren: selection_selectChildren,
    filter: selection_filter,
    data: selection_data,
    enter: selection_enter,
    exit: selection_exit,
    join: selection_join,
    merge: selection_merge,
    selection: selection_selection,
    order: selection_order,
    sort: selection_sort,
    call: selection_call,
    nodes: selection_nodes,
    node: selection_node,
    size: selection_size,
    empty: selection_empty,
    each: selection_each,
    attr: selection_attr,
    style: selection_style,
    property: selection_property,
    classed: selection_classed,
    text: selection_text,
    html: selection_html,
    raise: selection_raise,
    lower: selection_lower,
    append: selection_append,
    insert: selection_insert,
    remove: selection_remove,
    clone: selection_clone,
    datum: selection_datum,
    on: selection_on,
    dispatch: selection_dispatch,
    [Symbol.iterator]: selection_iterator
  };

  function d3Select(selector) {
    return typeof selector === "string"
        ? new Selection$1([[document.querySelector(selector)]], [document.documentElement])
        : new Selection$1([[selector]], root$1);
  }

  function sourceEvent(event) {
    let sourceEvent;
    while (sourceEvent = event.sourceEvent) event = sourceEvent;
    return event;
  }

  function pointer(event, node) {
    event = sourceEvent(event);
    if (node === undefined) node = event.currentTarget;
    if (node) {
      var svg = node.ownerSVGElement || node;
      if (svg.createSVGPoint) {
        var point = svg.createSVGPoint();
        point.x = event.clientX, point.y = event.clientY;
        point = point.matrixTransform(node.getScreenCTM().inverse());
        return [point.x, point.y];
      }
      if (node.getBoundingClientRect) {
        var rect = node.getBoundingClientRect();
        return [event.clientX - rect.left - node.clientLeft, event.clientY - rect.top - node.clientTop];
      }
    }
    return [event.pageX, event.pageY];
  }

  var noop = {value: () => {}};

  function dispatch() {
    for (var i = 0, n = arguments.length, _ = {}, t; i < n; ++i) {
      if (!(t = arguments[i] + "") || (t in _) || /[\s.]/.test(t)) throw new Error("illegal type: " + t);
      _[t] = [];
    }
    return new Dispatch(_);
  }

  function Dispatch(_) {
    this._ = _;
  }

  function parseTypenames(typenames, types) {
    return typenames.trim().split(/^|\s+/).map(function(t) {
      var name = "", i = t.indexOf(".");
      if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
      if (t && !types.hasOwnProperty(t)) throw new Error("unknown type: " + t);
      return {type: t, name: name};
    });
  }

  Dispatch.prototype = dispatch.prototype = {
    constructor: Dispatch,
    on: function(typename, callback) {
      var _ = this._,
          T = parseTypenames(typename + "", _),
          t,
          i = -1,
          n = T.length;

      // If no callback was specified, return the callback of the given type and name.
      if (arguments.length < 2) {
        while (++i < n) if ((t = (typename = T[i]).type) && (t = get$1(_[t], typename.name))) return t;
        return;
      }

      // If a type was specified, set the callback for the given type and name.
      // Otherwise, if a null callback was specified, remove callbacks of the given name.
      if (callback != null && typeof callback !== "function") throw new Error("invalid callback: " + callback);
      while (++i < n) {
        if (t = (typename = T[i]).type) _[t] = set$1(_[t], typename.name, callback);
        else if (callback == null) for (t in _) _[t] = set$1(_[t], typename.name, null);
      }

      return this;
    },
    copy: function() {
      var copy = {}, _ = this._;
      for (var t in _) copy[t] = _[t].slice();
      return new Dispatch(copy);
    },
    call: function(type, that) {
      if ((n = arguments.length - 2) > 0) for (var args = new Array(n), i = 0, n, t; i < n; ++i) args[i] = arguments[i + 2];
      if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
      for (t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
    },
    apply: function(type, that, args) {
      if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
      for (var t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
    }
  };

  function get$1(type, name) {
    for (var i = 0, n = type.length, c; i < n; ++i) {
      if ((c = type[i]).name === name) {
        return c.value;
      }
    }
  }

  function set$1(type, name, callback) {
    for (var i = 0, n = type.length; i < n; ++i) {
      if (type[i].name === name) {
        type[i] = noop, type = type.slice(0, i).concat(type.slice(i + 1));
        break;
      }
    }
    if (callback != null) type.push({name: name, value: callback});
    return type;
  }

  // These are typically used in conjunction with noevent to ensure that we can
  // preventDefault on the event.
  const nonpassive = {passive: false};
  const nonpassivecapture = {capture: true, passive: false};

  function nopropagation$1(event) {
    event.stopImmediatePropagation();
  }

  function noevent$1(event) {
    event.preventDefault();
    event.stopImmediatePropagation();
  }

  function dragDisable(view) {
    var root = view.document.documentElement,
        selection = d3Select(view).on("dragstart.drag", noevent$1, nonpassivecapture);
    if ("onselectstart" in root) {
      selection.on("selectstart.drag", noevent$1, nonpassivecapture);
    } else {
      root.__noselect = root.style.MozUserSelect;
      root.style.MozUserSelect = "none";
    }
  }

  function yesdrag(view, noclick) {
    var root = view.document.documentElement,
        selection = d3Select(view).on("dragstart.drag", null);
    if (noclick) {
      selection.on("click.drag", noevent$1, nonpassivecapture);
      setTimeout(function() { selection.on("click.drag", null); }, 0);
    }
    if ("onselectstart" in root) {
      selection.on("selectstart.drag", null);
    } else {
      root.style.MozUserSelect = root.__noselect;
      delete root.__noselect;
    }
  }

  var constant$3 = x => () => x;

  function DragEvent(type, {
    sourceEvent,
    subject,
    target,
    identifier,
    active,
    x, y, dx, dy,
    dispatch
  }) {
    Object.defineProperties(this, {
      type: {value: type, enumerable: true, configurable: true},
      sourceEvent: {value: sourceEvent, enumerable: true, configurable: true},
      subject: {value: subject, enumerable: true, configurable: true},
      target: {value: target, enumerable: true, configurable: true},
      identifier: {value: identifier, enumerable: true, configurable: true},
      active: {value: active, enumerable: true, configurable: true},
      x: {value: x, enumerable: true, configurable: true},
      y: {value: y, enumerable: true, configurable: true},
      dx: {value: dx, enumerable: true, configurable: true},
      dy: {value: dy, enumerable: true, configurable: true},
      _: {value: dispatch}
    });
  }

  DragEvent.prototype.on = function() {
    var value = this._.on.apply(this._, arguments);
    return value === this._ ? this : value;
  };

  // Ignore right-click, since that should open the context menu.
  function defaultFilter$1(event) {
    return !event.ctrlKey && !event.button;
  }

  function defaultContainer() {
    return this.parentNode;
  }

  function defaultSubject(event, d) {
    return d == null ? {x: event.x, y: event.y} : d;
  }

  function defaultTouchable$1() {
    return navigator.maxTouchPoints || ("ontouchstart" in this);
  }

  function d3Drag() {
    var filter = defaultFilter$1,
        container = defaultContainer,
        subject = defaultSubject,
        touchable = defaultTouchable$1,
        gestures = {},
        listeners = dispatch("start", "drag", "end"),
        active = 0,
        mousedownx,
        mousedowny,
        mousemoving,
        touchending,
        clickDistance2 = 0;

    function drag(selection) {
      selection
          .on("mousedown.drag", mousedowned)
        .filter(touchable)
          .on("touchstart.drag", touchstarted)
          .on("touchmove.drag", touchmoved, nonpassive)
          .on("touchend.drag touchcancel.drag", touchended)
          .style("touch-action", "none")
          .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
    }

    function mousedowned(event, d) {
      if (touchending || !filter.call(this, event, d)) return;
      var gesture = beforestart(this, container.call(this, event, d), event, d, "mouse");
      if (!gesture) return;
      d3Select(event.view)
        .on("mousemove.drag", mousemoved, nonpassivecapture)
        .on("mouseup.drag", mouseupped, nonpassivecapture);
      dragDisable(event.view);
      nopropagation$1(event);
      mousemoving = false;
      mousedownx = event.clientX;
      mousedowny = event.clientY;
      gesture("start", event);
    }

    function mousemoved(event) {
      noevent$1(event);
      if (!mousemoving) {
        var dx = event.clientX - mousedownx, dy = event.clientY - mousedowny;
        mousemoving = dx * dx + dy * dy > clickDistance2;
      }
      gestures.mouse("drag", event);
    }

    function mouseupped(event) {
      d3Select(event.view).on("mousemove.drag mouseup.drag", null);
      yesdrag(event.view, mousemoving);
      noevent$1(event);
      gestures.mouse("end", event);
    }

    function touchstarted(event, d) {
      if (!filter.call(this, event, d)) return;
      var touches = event.changedTouches,
          c = container.call(this, event, d),
          n = touches.length, i, gesture;

      for (i = 0; i < n; ++i) {
        if (gesture = beforestart(this, c, event, d, touches[i].identifier, touches[i])) {
          nopropagation$1(event);
          gesture("start", event, touches[i]);
        }
      }
    }

    function touchmoved(event) {
      var touches = event.changedTouches,
          n = touches.length, i, gesture;

      for (i = 0; i < n; ++i) {
        if (gesture = gestures[touches[i].identifier]) {
          noevent$1(event);
          gesture("drag", event, touches[i]);
        }
      }
    }

    function touchended(event) {
      var touches = event.changedTouches,
          n = touches.length, i, gesture;

      if (touchending) clearTimeout(touchending);
      touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!
      for (i = 0; i < n; ++i) {
        if (gesture = gestures[touches[i].identifier]) {
          nopropagation$1(event);
          gesture("end", event, touches[i]);
        }
      }
    }

    function beforestart(that, container, event, d, identifier, touch) {
      var dispatch = listeners.copy(),
          p = pointer(touch || event, container), dx, dy,
          s;

      if ((s = subject.call(that, new DragEvent("beforestart", {
          sourceEvent: event,
          target: drag,
          identifier,
          active,
          x: p[0],
          y: p[1],
          dx: 0,
          dy: 0,
          dispatch
        }), d)) == null) return;

      dx = s.x - p[0] || 0;
      dy = s.y - p[1] || 0;

      return function gesture(type, event, touch) {
        var p0 = p, n;
        switch (type) {
          case "start": gestures[identifier] = gesture, n = active++; break;
          case "end": delete gestures[identifier], --active; // falls through
          case "drag": p = pointer(touch || event, container), n = active; break;
        }
        dispatch.call(
          type,
          that,
          new DragEvent(type, {
            sourceEvent: event,
            subject: s,
            target: drag,
            identifier,
            active: n,
            x: p[0] + dx,
            y: p[1] + dy,
            dx: p[0] - p0[0],
            dy: p[1] - p0[1],
            dispatch
          }),
          d
        );
      };
    }

    drag.filter = function(_) {
      return arguments.length ? (filter = typeof _ === "function" ? _ : constant$3(!!_), drag) : filter;
    };

    drag.container = function(_) {
      return arguments.length ? (container = typeof _ === "function" ? _ : constant$3(_), drag) : container;
    };

    drag.subject = function(_) {
      return arguments.length ? (subject = typeof _ === "function" ? _ : constant$3(_), drag) : subject;
    };

    drag.touchable = function(_) {
      return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$3(!!_), drag) : touchable;
    };

    drag.on = function() {
      var value = listeners.on.apply(listeners, arguments);
      return value === listeners ? drag : value;
    };

    drag.clickDistance = function(_) {
      return arguments.length ? (clickDistance2 = (_ = +_) * _, drag) : Math.sqrt(clickDistance2);
    };

    return drag;
  }

  function define(constructor, factory, prototype) {
    constructor.prototype = factory.prototype = prototype;
    prototype.constructor = constructor;
  }

  function extend(parent, definition) {
    var prototype = Object.create(parent.prototype);
    for (var key in definition) prototype[key] = definition[key];
    return prototype;
  }

  function Color() {}

  var darker = 0.7;
  var brighter = 1 / darker;

  var reI = "\\s*([+-]?\\d+)\\s*",
      reN = "\\s*([+-]?(?:\\d*\\.)?\\d+(?:[eE][+-]?\\d+)?)\\s*",
      reP = "\\s*([+-]?(?:\\d*\\.)?\\d+(?:[eE][+-]?\\d+)?)%\\s*",
      reHex = /^#([0-9a-f]{3,8})$/,
      reRgbInteger = new RegExp(`^rgb\\(${reI},${reI},${reI}\\)$`),
      reRgbPercent = new RegExp(`^rgb\\(${reP},${reP},${reP}\\)$`),
      reRgbaInteger = new RegExp(`^rgba\\(${reI},${reI},${reI},${reN}\\)$`),
      reRgbaPercent = new RegExp(`^rgba\\(${reP},${reP},${reP},${reN}\\)$`),
      reHslPercent = new RegExp(`^hsl\\(${reN},${reP},${reP}\\)$`),
      reHslaPercent = new RegExp(`^hsla\\(${reN},${reP},${reP},${reN}\\)$`);

  var named = {
    aliceblue: 0xf0f8ff,
    antiquewhite: 0xfaebd7,
    aqua: 0x00ffff,
    aquamarine: 0x7fffd4,
    azure: 0xf0ffff,
    beige: 0xf5f5dc,
    bisque: 0xffe4c4,
    black: 0x000000,
    blanchedalmond: 0xffebcd,
    blue: 0x0000ff,
    blueviolet: 0x8a2be2,
    brown: 0xa52a2a,
    burlywood: 0xdeb887,
    cadetblue: 0x5f9ea0,
    chartreuse: 0x7fff00,
    chocolate: 0xd2691e,
    coral: 0xff7f50,
    cornflowerblue: 0x6495ed,
    cornsilk: 0xfff8dc,
    crimson: 0xdc143c,
    cyan: 0x00ffff,
    darkblue: 0x00008b,
    darkcyan: 0x008b8b,
    darkgoldenrod: 0xb8860b,
    darkgray: 0xa9a9a9,
    darkgreen: 0x006400,
    darkgrey: 0xa9a9a9,
    darkkhaki: 0xbdb76b,
    darkmagenta: 0x8b008b,
    darkolivegreen: 0x556b2f,
    darkorange: 0xff8c00,
    darkorchid: 0x9932cc,
    darkred: 0x8b0000,
    darksalmon: 0xe9967a,
    darkseagreen: 0x8fbc8f,
    darkslateblue: 0x483d8b,
    darkslategray: 0x2f4f4f,
    darkslategrey: 0x2f4f4f,
    darkturquoise: 0x00ced1,
    darkviolet: 0x9400d3,
    deeppink: 0xff1493,
    deepskyblue: 0x00bfff,
    dimgray: 0x696969,
    dimgrey: 0x696969,
    dodgerblue: 0x1e90ff,
    firebrick: 0xb22222,
    floralwhite: 0xfffaf0,
    forestgreen: 0x228b22,
    fuchsia: 0xff00ff,
    gainsboro: 0xdcdcdc,
    ghostwhite: 0xf8f8ff,
    gold: 0xffd700,
    goldenrod: 0xdaa520,
    gray: 0x808080,
    green: 0x008000,
    greenyellow: 0xadff2f,
    grey: 0x808080,
    honeydew: 0xf0fff0,
    hotpink: 0xff69b4,
    indianred: 0xcd5c5c,
    indigo: 0x4b0082,
    ivory: 0xfffff0,
    khaki: 0xf0e68c,
    lavender: 0xe6e6fa,
    lavenderblush: 0xfff0f5,
    lawngreen: 0x7cfc00,
    lemonchiffon: 0xfffacd,
    lightblue: 0xadd8e6,
    lightcoral: 0xf08080,
    lightcyan: 0xe0ffff,
    lightgoldenrodyellow: 0xfafad2,
    lightgray: 0xd3d3d3,
    lightgreen: 0x90ee90,
    lightgrey: 0xd3d3d3,
    lightpink: 0xffb6c1,
    lightsalmon: 0xffa07a,
    lightseagreen: 0x20b2aa,
    lightskyblue: 0x87cefa,
    lightslategray: 0x778899,
    lightslategrey: 0x778899,
    lightsteelblue: 0xb0c4de,
    lightyellow: 0xffffe0,
    lime: 0x00ff00,
    limegreen: 0x32cd32,
    linen: 0xfaf0e6,
    magenta: 0xff00ff,
    maroon: 0x800000,
    mediumaquamarine: 0x66cdaa,
    mediumblue: 0x0000cd,
    mediumorchid: 0xba55d3,
    mediumpurple: 0x9370db,
    mediumseagreen: 0x3cb371,
    mediumslateblue: 0x7b68ee,
    mediumspringgreen: 0x00fa9a,
    mediumturquoise: 0x48d1cc,
    mediumvioletred: 0xc71585,
    midnightblue: 0x191970,
    mintcream: 0xf5fffa,
    mistyrose: 0xffe4e1,
    moccasin: 0xffe4b5,
    navajowhite: 0xffdead,
    navy: 0x000080,
    oldlace: 0xfdf5e6,
    olive: 0x808000,
    olivedrab: 0x6b8e23,
    orange: 0xffa500,
    orangered: 0xff4500,
    orchid: 0xda70d6,
    palegoldenrod: 0xeee8aa,
    palegreen: 0x98fb98,
    paleturquoise: 0xafeeee,
    palevioletred: 0xdb7093,
    papayawhip: 0xffefd5,
    peachpuff: 0xffdab9,
    peru: 0xcd853f,
    pink: 0xffc0cb,
    plum: 0xdda0dd,
    powderblue: 0xb0e0e6,
    purple: 0x800080,
    rebeccapurple: 0x663399,
    red: 0xff0000,
    rosybrown: 0xbc8f8f,
    royalblue: 0x4169e1,
    saddlebrown: 0x8b4513,
    salmon: 0xfa8072,
    sandybrown: 0xf4a460,
    seagreen: 0x2e8b57,
    seashell: 0xfff5ee,
    sienna: 0xa0522d,
    silver: 0xc0c0c0,
    skyblue: 0x87ceeb,
    slateblue: 0x6a5acd,
    slategray: 0x708090,
    slategrey: 0x708090,
    snow: 0xfffafa,
    springgreen: 0x00ff7f,
    steelblue: 0x4682b4,
    tan: 0xd2b48c,
    teal: 0x008080,
    thistle: 0xd8bfd8,
    tomato: 0xff6347,
    turquoise: 0x40e0d0,
    violet: 0xee82ee,
    wheat: 0xf5deb3,
    white: 0xffffff,
    whitesmoke: 0xf5f5f5,
    yellow: 0xffff00,
    yellowgreen: 0x9acd32
  };

  define(Color, color, {
    copy(channels) {
      return Object.assign(new this.constructor, this, channels);
    },
    displayable() {
      return this.rgb().displayable();
    },
    hex: color_formatHex, // Deprecated! Use color.formatHex.
    formatHex: color_formatHex,
    formatHex8: color_formatHex8,
    formatHsl: color_formatHsl,
    formatRgb: color_formatRgb,
    toString: color_formatRgb
  });

  function color_formatHex() {
    return this.rgb().formatHex();
  }

  function color_formatHex8() {
    return this.rgb().formatHex8();
  }

  function color_formatHsl() {
    return hslConvert(this).formatHsl();
  }

  function color_formatRgb() {
    return this.rgb().formatRgb();
  }

  function color(format) {
    var m, l;
    format = (format + "").trim().toLowerCase();
    return (m = reHex.exec(format)) ? (l = m[1].length, m = parseInt(m[1], 16), l === 6 ? rgbn(m) // #ff0000
        : l === 3 ? new Rgb((m >> 8 & 0xf) | (m >> 4 & 0xf0), (m >> 4 & 0xf) | (m & 0xf0), ((m & 0xf) << 4) | (m & 0xf), 1) // #f00
        : l === 8 ? rgba(m >> 24 & 0xff, m >> 16 & 0xff, m >> 8 & 0xff, (m & 0xff) / 0xff) // #ff000000
        : l === 4 ? rgba((m >> 12 & 0xf) | (m >> 8 & 0xf0), (m >> 8 & 0xf) | (m >> 4 & 0xf0), (m >> 4 & 0xf) | (m & 0xf0), (((m & 0xf) << 4) | (m & 0xf)) / 0xff) // #f000
        : null) // invalid hex
        : (m = reRgbInteger.exec(format)) ? new Rgb(m[1], m[2], m[3], 1) // rgb(255, 0, 0)
        : (m = reRgbPercent.exec(format)) ? new Rgb(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, 1) // rgb(100%, 0%, 0%)
        : (m = reRgbaInteger.exec(format)) ? rgba(m[1], m[2], m[3], m[4]) // rgba(255, 0, 0, 1)
        : (m = reRgbaPercent.exec(format)) ? rgba(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, m[4]) // rgb(100%, 0%, 0%, 1)
        : (m = reHslPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, 1) // hsl(120, 50%, 50%)
        : (m = reHslaPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, m[4]) // hsla(120, 50%, 50%, 1)
        : named.hasOwnProperty(format) ? rgbn(named[format]) // eslint-disable-line no-prototype-builtins
        : format === "transparent" ? new Rgb(NaN, NaN, NaN, 0)
        : null;
  }

  function rgbn(n) {
    return new Rgb(n >> 16 & 0xff, n >> 8 & 0xff, n & 0xff, 1);
  }

  function rgba(r, g, b, a) {
    if (a <= 0) r = g = b = NaN;
    return new Rgb(r, g, b, a);
  }

  function rgbConvert(o) {
    if (!(o instanceof Color)) o = color(o);
    if (!o) return new Rgb;
    o = o.rgb();
    return new Rgb(o.r, o.g, o.b, o.opacity);
  }

  function rgb(r, g, b, opacity) {
    return arguments.length === 1 ? rgbConvert(r) : new Rgb(r, g, b, opacity == null ? 1 : opacity);
  }

  function Rgb(r, g, b, opacity) {
    this.r = +r;
    this.g = +g;
    this.b = +b;
    this.opacity = +opacity;
  }

  define(Rgb, rgb, extend(Color, {
    brighter(k) {
      k = k == null ? brighter : Math.pow(brighter, k);
      return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
    },
    darker(k) {
      k = k == null ? darker : Math.pow(darker, k);
      return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
    },
    rgb() {
      return this;
    },
    clamp() {
      return new Rgb(clampi(this.r), clampi(this.g), clampi(this.b), clampa(this.opacity));
    },
    displayable() {
      return (-0.5 <= this.r && this.r < 255.5)
          && (-0.5 <= this.g && this.g < 255.5)
          && (-0.5 <= this.b && this.b < 255.5)
          && (0 <= this.opacity && this.opacity <= 1);
    },
    hex: rgb_formatHex, // Deprecated! Use color.formatHex.
    formatHex: rgb_formatHex,
    formatHex8: rgb_formatHex8,
    formatRgb: rgb_formatRgb,
    toString: rgb_formatRgb
  }));

  function rgb_formatHex() {
    return `#${hex(this.r)}${hex(this.g)}${hex(this.b)}`;
  }

  function rgb_formatHex8() {
    return `#${hex(this.r)}${hex(this.g)}${hex(this.b)}${hex((isNaN(this.opacity) ? 1 : this.opacity) * 255)}`;
  }

  function rgb_formatRgb() {
    const a = clampa(this.opacity);
    return `${a === 1 ? "rgb(" : "rgba("}${clampi(this.r)}, ${clampi(this.g)}, ${clampi(this.b)}${a === 1 ? ")" : `, ${a})`}`;
  }

  function clampa(opacity) {
    return isNaN(opacity) ? 1 : Math.max(0, Math.min(1, opacity));
  }

  function clampi(value) {
    return Math.max(0, Math.min(255, Math.round(value) || 0));
  }

  function hex(value) {
    value = clampi(value);
    return (value < 16 ? "0" : "") + value.toString(16);
  }

  function hsla(h, s, l, a) {
    if (a <= 0) h = s = l = NaN;
    else if (l <= 0 || l >= 1) h = s = NaN;
    else if (s <= 0) h = NaN;
    return new Hsl(h, s, l, a);
  }

  function hslConvert(o) {
    if (o instanceof Hsl) return new Hsl(o.h, o.s, o.l, o.opacity);
    if (!(o instanceof Color)) o = color(o);
    if (!o) return new Hsl;
    if (o instanceof Hsl) return o;
    o = o.rgb();
    var r = o.r / 255,
        g = o.g / 255,
        b = o.b / 255,
        min = Math.min(r, g, b),
        max = Math.max(r, g, b),
        h = NaN,
        s = max - min,
        l = (max + min) / 2;
    if (s) {
      if (r === max) h = (g - b) / s + (g < b) * 6;
      else if (g === max) h = (b - r) / s + 2;
      else h = (r - g) / s + 4;
      s /= l < 0.5 ? max + min : 2 - max - min;
      h *= 60;
    } else {
      s = l > 0 && l < 1 ? 0 : h;
    }
    return new Hsl(h, s, l, o.opacity);
  }

  function hsl(h, s, l, opacity) {
    return arguments.length === 1 ? hslConvert(h) : new Hsl(h, s, l, opacity == null ? 1 : opacity);
  }

  function Hsl(h, s, l, opacity) {
    this.h = +h;
    this.s = +s;
    this.l = +l;
    this.opacity = +opacity;
  }

  define(Hsl, hsl, extend(Color, {
    brighter(k) {
      k = k == null ? brighter : Math.pow(brighter, k);
      return new Hsl(this.h, this.s, this.l * k, this.opacity);
    },
    darker(k) {
      k = k == null ? darker : Math.pow(darker, k);
      return new Hsl(this.h, this.s, this.l * k, this.opacity);
    },
    rgb() {
      var h = this.h % 360 + (this.h < 0) * 360,
          s = isNaN(h) || isNaN(this.s) ? 0 : this.s,
          l = this.l,
          m2 = l + (l < 0.5 ? l : 1 - l) * s,
          m1 = 2 * l - m2;
      return new Rgb(
        hsl2rgb(h >= 240 ? h - 240 : h + 120, m1, m2),
        hsl2rgb(h, m1, m2),
        hsl2rgb(h < 120 ? h + 240 : h - 120, m1, m2),
        this.opacity
      );
    },
    clamp() {
      return new Hsl(clamph(this.h), clampt(this.s), clampt(this.l), clampa(this.opacity));
    },
    displayable() {
      return (0 <= this.s && this.s <= 1 || isNaN(this.s))
          && (0 <= this.l && this.l <= 1)
          && (0 <= this.opacity && this.opacity <= 1);
    },
    formatHsl() {
      const a = clampa(this.opacity);
      return `${a === 1 ? "hsl(" : "hsla("}${clamph(this.h)}, ${clampt(this.s) * 100}%, ${clampt(this.l) * 100}%${a === 1 ? ")" : `, ${a})`}`;
    }
  }));

  function clamph(value) {
    value = (value || 0) % 360;
    return value < 0 ? value + 360 : value;
  }

  function clampt(value) {
    return Math.max(0, Math.min(1, value || 0));
  }

  /* From FvD 13.37, CSS Color Module Level 3 */
  function hsl2rgb(h, m1, m2) {
    return (h < 60 ? m1 + (m2 - m1) * h / 60
        : h < 180 ? m2
        : h < 240 ? m1 + (m2 - m1) * (240 - h) / 60
        : m1) * 255;
  }

  var constant$2 = x => () => x;

  function linear(a, d) {
    return function(t) {
      return a + t * d;
    };
  }

  function exponential(a, b, y) {
    return a = Math.pow(a, y), b = Math.pow(b, y) - a, y = 1 / y, function(t) {
      return Math.pow(a + t * b, y);
    };
  }

  function gamma(y) {
    return (y = +y) === 1 ? nogamma : function(a, b) {
      return b - a ? exponential(a, b, y) : constant$2(isNaN(a) ? b : a);
    };
  }

  function nogamma(a, b) {
    var d = b - a;
    return d ? linear(a, d) : constant$2(isNaN(a) ? b : a);
  }

  var interpolateRgb = (function rgbGamma(y) {
    var color = gamma(y);

    function rgb$1(start, end) {
      var r = color((start = rgb(start)).r, (end = rgb(end)).r),
          g = color(start.g, end.g),
          b = color(start.b, end.b),
          opacity = nogamma(start.opacity, end.opacity);
      return function(t) {
        start.r = r(t);
        start.g = g(t);
        start.b = b(t);
        start.opacity = opacity(t);
        return start + "";
      };
    }

    rgb$1.gamma = rgbGamma;

    return rgb$1;
  })(1);

  function interpolateNumber(a, b) {
    return a = +a, b = +b, function(t) {
      return a * (1 - t) + b * t;
    };
  }

  var reA = /[-+]?(?:\d+\.?\d*|\.?\d+)(?:[eE][-+]?\d+)?/g,
      reB = new RegExp(reA.source, "g");

  function zero(b) {
    return function() {
      return b;
    };
  }

  function one(b) {
    return function(t) {
      return b(t) + "";
    };
  }

  function interpolateString(a, b) {
    var bi = reA.lastIndex = reB.lastIndex = 0, // scan index for next number in b
        am, // current match in a
        bm, // current match in b
        bs, // string preceding current number in b, if any
        i = -1, // index in s
        s = [], // string constants and placeholders
        q = []; // number interpolators

    // Coerce inputs to strings.
    a = a + "", b = b + "";

    // Interpolate pairs of numbers in a & b.
    while ((am = reA.exec(a))
        && (bm = reB.exec(b))) {
      if ((bs = bm.index) > bi) { // a string precedes the next number in b
        bs = b.slice(bi, bs);
        if (s[i]) s[i] += bs; // coalesce with previous string
        else s[++i] = bs;
      }
      if ((am = am[0]) === (bm = bm[0])) { // numbers in a & b match
        if (s[i]) s[i] += bm; // coalesce with previous string
        else s[++i] = bm;
      } else { // interpolate non-matching numbers
        s[++i] = null;
        q.push({i: i, x: interpolateNumber(am, bm)});
      }
      bi = reB.lastIndex;
    }

    // Add remains of b.
    if (bi < b.length) {
      bs = b.slice(bi);
      if (s[i]) s[i] += bs; // coalesce with previous string
      else s[++i] = bs;
    }

    // Special optimization for only a single match.
    // Otherwise, interpolate each of the numbers and rejoin the string.
    return s.length < 2 ? (q[0]
        ? one(q[0].x)
        : zero(b))
        : (b = q.length, function(t) {
            for (var i = 0, o; i < b; ++i) s[(o = q[i]).i] = o.x(t);
            return s.join("");
          });
  }

  var degrees = 180 / Math.PI;

  var identity$1 = {
    translateX: 0,
    translateY: 0,
    rotate: 0,
    skewX: 0,
    scaleX: 1,
    scaleY: 1
  };

  function decompose(a, b, c, d, e, f) {
    var scaleX, scaleY, skewX;
    if (scaleX = Math.sqrt(a * a + b * b)) a /= scaleX, b /= scaleX;
    if (skewX = a * c + b * d) c -= a * skewX, d -= b * skewX;
    if (scaleY = Math.sqrt(c * c + d * d)) c /= scaleY, d /= scaleY, skewX /= scaleY;
    if (a * d < b * c) a = -a, b = -b, skewX = -skewX, scaleX = -scaleX;
    return {
      translateX: e,
      translateY: f,
      rotate: Math.atan2(b, a) * degrees,
      skewX: Math.atan(skewX) * degrees,
      scaleX: scaleX,
      scaleY: scaleY
    };
  }

  var svgNode;

  /* eslint-disable no-undef */
  function parseCss(value) {
    const m = new (typeof DOMMatrix === "function" ? DOMMatrix : WebKitCSSMatrix)(value + "");
    return m.isIdentity ? identity$1 : decompose(m.a, m.b, m.c, m.d, m.e, m.f);
  }

  function parseSvg(value) {
    if (value == null) return identity$1;
    if (!svgNode) svgNode = document.createElementNS("http://www.w3.org/2000/svg", "g");
    svgNode.setAttribute("transform", value);
    if (!(value = svgNode.transform.baseVal.consolidate())) return identity$1;
    value = value.matrix;
    return decompose(value.a, value.b, value.c, value.d, value.e, value.f);
  }

  function interpolateTransform(parse, pxComma, pxParen, degParen) {

    function pop(s) {
      return s.length ? s.pop() + " " : "";
    }

    function translate(xa, ya, xb, yb, s, q) {
      if (xa !== xb || ya !== yb) {
        var i = s.push("translate(", null, pxComma, null, pxParen);
        q.push({i: i - 4, x: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(ya, yb)});
      } else if (xb || yb) {
        s.push("translate(" + xb + pxComma + yb + pxParen);
      }
    }

    function rotate(a, b, s, q) {
      if (a !== b) {
        if (a - b > 180) b += 360; else if (b - a > 180) a += 360; // shortest path
        q.push({i: s.push(pop(s) + "rotate(", null, degParen) - 2, x: interpolateNumber(a, b)});
      } else if (b) {
        s.push(pop(s) + "rotate(" + b + degParen);
      }
    }

    function skewX(a, b, s, q) {
      if (a !== b) {
        q.push({i: s.push(pop(s) + "skewX(", null, degParen) - 2, x: interpolateNumber(a, b)});
      } else if (b) {
        s.push(pop(s) + "skewX(" + b + degParen);
      }
    }

    function scale(xa, ya, xb, yb, s, q) {
      if (xa !== xb || ya !== yb) {
        var i = s.push(pop(s) + "scale(", null, ",", null, ")");
        q.push({i: i - 4, x: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(ya, yb)});
      } else if (xb !== 1 || yb !== 1) {
        s.push(pop(s) + "scale(" + xb + "," + yb + ")");
      }
    }

    return function(a, b) {
      var s = [], // string constants and placeholders
          q = []; // number interpolators
      a = parse(a), b = parse(b);
      translate(a.translateX, a.translateY, b.translateX, b.translateY, s, q);
      rotate(a.rotate, b.rotate, s, q);
      skewX(a.skewX, b.skewX, s, q);
      scale(a.scaleX, a.scaleY, b.scaleX, b.scaleY, s, q);
      a = b = null; // gc
      return function(t) {
        var i = -1, n = q.length, o;
        while (++i < n) s[(o = q[i]).i] = o.x(t);
        return s.join("");
      };
    };
  }

  var interpolateTransformCss = interpolateTransform(parseCss, "px, ", "px)", "deg)");
  var interpolateTransformSvg = interpolateTransform(parseSvg, ", ", ")", ")");

  var epsilon2 = 1e-12;

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

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

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

  var interpolateZoom = (function zoomRho(rho, rho2, rho4) {

    // p0 = [ux0, uy0, w0]
    // p1 = [ux1, uy1, w1]
    function zoom(p0, p1) {
      var ux0 = p0[0], uy0 = p0[1], w0 = p0[2],
          ux1 = p1[0], uy1 = p1[1], w1 = p1[2],
          dx = ux1 - ux0,
          dy = uy1 - uy0,
          d2 = dx * dx + dy * dy,
          i,
          S;

      // Special case for u0 ≅ u1.
      if (d2 < epsilon2) {
        S = Math.log(w1 / w0) / rho;
        i = function(t) {
          return [
            ux0 + t * dx,
            uy0 + t * dy,
            w0 * Math.exp(rho * t * S)
          ];
        };
      }

      // General case.
      else {
        var d1 = Math.sqrt(d2),
            b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2 * w0 * rho2 * d1),
            b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2 * w1 * rho2 * d1),
            r0 = Math.log(Math.sqrt(b0 * b0 + 1) - b0),
            r1 = Math.log(Math.sqrt(b1 * b1 + 1) - b1);
        S = (r1 - r0) / rho;
        i = function(t) {
          var s = t * S,
              coshr0 = cosh(r0),
              u = w0 / (rho2 * d1) * (coshr0 * tanh(rho * s + r0) - sinh(r0));
          return [
            ux0 + u * dx,
            uy0 + u * dy,
            w0 * coshr0 / cosh(rho * s + r0)
          ];
        };
      }

      i.duration = S * 1000 * rho / Math.SQRT2;

      return i;
    }

    zoom.rho = function(_) {
      var _1 = Math.max(1e-3, +_), _2 = _1 * _1, _4 = _2 * _2;
      return zoomRho(_1, _2, _4);
    };

    return zoom;
  })(Math.SQRT2, 2, 4);

  var frame = 0, // is an animation frame pending?
      timeout$1 = 0, // is a timeout pending?
      interval = 0, // are any timers active?
      pokeDelay = 1000, // how frequently we check for clock skew
      taskHead,
      taskTail,
      clockLast = 0,
      clockNow = 0,
      clockSkew = 0,
      clock = typeof performance === "object" && performance.now ? performance : Date,
      setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : function(f) { setTimeout(f, 17); };

  function now$2() {
    return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
  }

  function clearNow() {
    clockNow = 0;
  }

  function Timer() {
    this._call =
    this._time =
    this._next = null;
  }

  Timer.prototype = timer.prototype = {
    constructor: Timer,
    restart: function(callback, delay, time) {
      if (typeof callback !== "function") throw new TypeError("callback is not a function");
      time = (time == null ? now$2() : +time) + (delay == null ? 0 : +delay);
      if (!this._next && taskTail !== this) {
        if (taskTail) taskTail._next = this;
        else taskHead = this;
        taskTail = this;
      }
      this._call = callback;
      this._time = time;
      sleep();
    },
    stop: function() {
      if (this._call) {
        this._call = null;
        this._time = Infinity;
        sleep();
      }
    }
  };

  function timer(callback, delay, time) {
    var t = new Timer;
    t.restart(callback, delay, time);
    return t;
  }

  function timerFlush() {
    now$2(); // Get the current time, if not already set.
    ++frame; // Pretend we’ve set an alarm, if we haven’t already.
    var t = taskHead, e;
    while (t) {
      if ((e = clockNow - t._time) >= 0) t._call.call(undefined, e);
      t = t._next;
    }
    --frame;
  }

  function wake() {
    clockNow = (clockLast = clock.now()) + clockSkew;
    frame = timeout$1 = 0;
    try {
      timerFlush();
    } finally {
      frame = 0;
      nap();
      clockNow = 0;
    }
  }

  function poke() {
    var now = clock.now(), delay = now - clockLast;
    if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
  }

  function nap() {
    var t0, t1 = taskHead, t2, time = Infinity;
    while (t1) {
      if (t1._call) {
        if (time > t1._time) time = t1._time;
        t0 = t1, t1 = t1._next;
      } else {
        t2 = t1._next, t1._next = null;
        t1 = t0 ? t0._next = t2 : taskHead = t2;
      }
    }
    taskTail = t0;
    sleep(time);
  }

  function sleep(time) {
    if (frame) return; // Soonest alarm already set, or will be.
    if (timeout$1) timeout$1 = clearTimeout(timeout$1);
    var delay = time - clockNow; // Strictly less than if we recomputed clockNow.
    if (delay > 24) {
      if (time < Infinity) timeout$1 = setTimeout(wake, time - clock.now() - clockSkew);
      if (interval) interval = clearInterval(interval);
    } else {
      if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
      frame = 1, setFrame(wake);
    }
  }

  function timeout(callback, delay, time) {
    var t = new Timer;
    delay = delay == null ? 0 : +delay;
    t.restart(elapsed => {
      t.stop();
      callback(elapsed + delay);
    }, delay, time);
    return t;
  }

  var emptyOn = dispatch("start", "end", "cancel", "interrupt");
  var emptyTween = [];

  var CREATED = 0;
  var SCHEDULED = 1;
  var STARTING = 2;
  var STARTED = 3;
  var RUNNING = 4;
  var ENDING = 5;
  var ENDED = 6;

  function schedule(node, name, id, index, group, timing) {
    var schedules = node.__transition;
    if (!schedules) node.__transition = {};
    else if (id in schedules) return;
    create(node, id, {
      name: name,
      index: index, // For context during callback.
      group: group, // For context during callback.
      on: emptyOn,
      tween: emptyTween,
      time: timing.time,
      delay: timing.delay,
      duration: timing.duration,
      ease: timing.ease,
      timer: null,
      state: CREATED
    });
  }

  function init(node, id) {
    var schedule = get(node, id);
    if (schedule.state > CREATED) throw new Error("too late; already scheduled");
    return schedule;
  }

  function set(node, id) {
    var schedule = get(node, id);
    if (schedule.state > STARTED) throw new Error("too late; already running");
    return schedule;
  }

  function get(node, id) {
    var schedule = node.__transition;
    if (!schedule || !(schedule = schedule[id])) throw new Error("transition not found");
    return schedule;
  }

  function create(node, id, self) {
    var schedules = node.__transition,
        tween;

    // Initialize the self timer when the transition is created.
    // Note the actual delay is not known until the first callback!
    schedules[id] = self;
    self.timer = timer(schedule, 0, self.time);

    function schedule(elapsed) {
      self.state = SCHEDULED;
      self.timer.restart(start, self.delay, self.time);

      // If the elapsed delay is less than our first sleep, start immediately.
      if (self.delay <= elapsed) start(elapsed - self.delay);
    }

    function start(elapsed) {
      var i, j, n, o;

      // If the state is not SCHEDULED, then we previously errored on start.
      if (self.state !== SCHEDULED) return stop();

      for (i in schedules) {
        o = schedules[i];
        if (o.name !== self.name) continue;

        // While this element already has a starting transition during this frame,
        // defer starting an interrupting transition until that transition has a
        // chance to tick (and possibly end); see d3/d3-transition#54!
        if (o.state === STARTED) return timeout(start);

        // Interrupt the active transition, if any.
        if (o.state === RUNNING) {
          o.state = ENDED;
          o.timer.stop();
          o.on.call("interrupt", node, node.__data__, o.index, o.group);
          delete schedules[i];
        }

        // Cancel any pre-empted transitions.
        else if (+i < id) {
          o.state = ENDED;
          o.timer.stop();
          o.on.call("cancel", node, node.__data__, o.index, o.group);
          delete schedules[i];
        }
      }

      // Defer the first tick to end of the current frame; see d3/d3#1576.
      // Note the transition may be canceled after start and before the first tick!
      // Note this must be scheduled before the start event; see d3/d3-transition#16!
      // Assuming this is successful, subsequent callbacks go straight to tick.
      timeout(function() {
        if (self.state === STARTED) {
          self.state = RUNNING;
          self.timer.restart(tick, self.delay, self.time);
          tick(elapsed);
        }
      });

      // Dispatch the start event.
      // Note this must be done before the tween are initialized.
      self.state = STARTING;
      self.on.call("start", node, node.__data__, self.index, self.group);
      if (self.state !== STARTING) return; // interrupted
      self.state = STARTED;

      // Initialize the tween, deleting null tween.
      tween = new Array(n = self.tween.length);
      for (i = 0, j = -1; i < n; ++i) {
        if (o = self.tween[i].value.call(node, node.__data__, self.index, self.group)) {
          tween[++j] = o;
        }
      }
      tween.length = j + 1;
    }

    function tick(elapsed) {
      var t = elapsed < self.duration ? self.ease.call(null, elapsed / self.duration) : (self.timer.restart(stop), self.state = ENDING, 1),
          i = -1,
          n = tween.length;

      while (++i < n) {
        tween[i].call(node, t);
      }

      // Dispatch the end event.
      if (self.state === ENDING) {
        self.on.call("end", node, node.__data__, self.index, self.group);
        stop();
      }
    }

    function stop() {
      self.state = ENDED;
      self.timer.stop();
      delete schedules[id];
      for (var i in schedules) return; // eslint-disable-line no-unused-vars
      delete node.__transition;
    }
  }

  function interrupt(node, name) {
    var schedules = node.__transition,
        schedule,
        active,
        empty = true,
        i;

    if (!schedules) return;

    name = name == null ? null : name + "";

    for (i in schedules) {
      if ((schedule = schedules[i]).name !== name) { empty = false; continue; }
      active = schedule.state > STARTING && schedule.state < ENDING;
      schedule.state = ENDED;
      schedule.timer.stop();
      schedule.on.call(active ? "interrupt" : "cancel", node, node.__data__, schedule.index, schedule.group);
      delete schedules[i];
    }

    if (empty) delete node.__transition;
  }

  function selection_interrupt(name) {
    return this.each(function() {
      interrupt(this, name);
    });
  }

  function tweenRemove(id, name) {
    var tween0, tween1;
    return function() {
      var schedule = set(this, id),
          tween = schedule.tween;

      // If this node shared tween with the previous node,
      // just assign the updated shared tween and we’re done!
      // Otherwise, copy-on-write.
      if (tween !== tween0) {
        tween1 = tween0 = tween;
        for (var i = 0, n = tween1.length; i < n; ++i) {
          if (tween1[i].name === name) {
            tween1 = tween1.slice();
            tween1.splice(i, 1);
            break;
          }
        }
      }

      schedule.tween = tween1;
    };
  }

  function tweenFunction(id, name, value) {
    var tween0, tween1;
    if (typeof value !== "function") throw new Error;
    return function() {
      var schedule = set(this, id),
          tween = schedule.tween;

      // If this node shared tween with the previous node,
      // just assign the updated shared tween and we’re done!
      // Otherwise, copy-on-write.
      if (tween !== tween0) {
        tween1 = (tween0 = tween).slice();
        for (var t = {name: name, value: value}, i = 0, n = tween1.length; i < n; ++i) {
          if (tween1[i].name === name) {
            tween1[i] = t;
            break;
          }
        }
        if (i === n) tween1.push(t);
      }

      schedule.tween = tween1;
    };
  }

  function transition_tween(name, value) {
    var id = this._id;

    name += "";

    if (arguments.length < 2) {
      var tween = get(this.node(), id).tween;
      for (var i = 0, n = tween.length, t; i < n; ++i) {
        if ((t = tween[i]).name === name) {
          return t.value;
        }
      }
      return null;
    }

    return this.each((value == null ? tweenRemove : tweenFunction)(id, name, value));
  }

  function tweenValue(transition, name, value) {
    var id = transition._id;

    transition.each(function() {
      var schedule = set(this, id);
      (schedule.value || (schedule.value = {}))[name] = value.apply(this, arguments);
    });

    return function(node) {
      return get(node, id).value[name];
    };
  }

  function interpolate(a, b) {
    var c;
    return (typeof b === "number" ? interpolateNumber
        : b instanceof color ? interpolateRgb
        : (c = color(b)) ? (b = c, interpolateRgb)
        : interpolateString)(a, b);
  }

  function attrRemove(name) {
    return function() {
      this.removeAttribute(name);
    };
  }

  function attrRemoveNS(fullname) {
    return function() {
      this.removeAttributeNS(fullname.space, fullname.local);
    };
  }

  function attrConstant(name, interpolate, value1) {
    var string00,
        string1 = value1 + "",
        interpolate0;
    return function() {
      var string0 = this.getAttribute(name);
      return string0 === string1 ? null
          : string0 === string00 ? interpolate0
          : interpolate0 = interpolate(string00 = string0, value1);
    };
  }

  function attrConstantNS(fullname, interpolate, value1) {
    var string00,
        string1 = value1 + "",
        interpolate0;
    return function() {
      var string0 = this.getAttributeNS(fullname.space, fullname.local);
      return string0 === string1 ? null
          : string0 === string00 ? interpolate0
          : interpolate0 = interpolate(string00 = string0, value1);
    };
  }

  function attrFunction(name, interpolate, value) {
    var string00,
        string10,
        interpolate0;
    return function() {
      var string0, value1 = value(this), string1;
      if (value1 == null) return void this.removeAttribute(name);
      string0 = this.getAttribute(name);
      string1 = value1 + "";
      return string0 === string1 ? null
          : string0 === string00 && string1 === string10 ? interpolate0
          : (string10 = string1, interpolate0 = interpolate(string00 = string0, value1));
    };
  }

  function attrFunctionNS(fullname, interpolate, value) {
    var string00,
        string10,
        interpolate0;
    return function() {
      var string0, value1 = value(this), string1;
      if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
      string0 = this.getAttributeNS(fullname.space, fullname.local);
      string1 = value1 + "";
      return string0 === string1 ? null
          : string0 === string00 && string1 === string10 ? interpolate0
          : (string10 = string1, interpolate0 = interpolate(string00 = string0, value1));
    };
  }

  function transition_attr(name, value) {
    var fullname = namespace(name), i = fullname === "transform" ? interpolateTransformSvg : interpolate;
    return this.attrTween(name, typeof value === "function"
        ? (fullname.local ? attrFunctionNS : attrFunction)(fullname, i, tweenValue(this, "attr." + name, value))
        : value == null ? (fullname.local ? attrRemoveNS : attrRemove)(fullname)
        : (fullname.local ? attrConstantNS : attrConstant)(fullname, i, value));
  }

  function attrInterpolate(name, i) {
    return function(t) {
      this.setAttribute(name, i.call(this, t));
    };
  }

  function attrInterpolateNS(fullname, i) {
    return function(t) {
      this.setAttributeNS(fullname.space, fullname.local, i.call(this, t));
    };
  }

  function attrTweenNS(fullname, value) {
    var t0, i0;
    function tween() {
      var i = value.apply(this, arguments);
      if (i !== i0) t0 = (i0 = i) && attrInterpolateNS(fullname, i);
      return t0;
    }
    tween._value = value;
    return tween;
  }

  function attrTween(name, value) {
    var t0, i0;
    function tween() {
      var i = value.apply(this, arguments);
      if (i !== i0) t0 = (i0 = i) && attrInterpolate(name, i);
      return t0;
    }
    tween._value = value;
    return tween;
  }

  function transition_attrTween(name, value) {
    var key = "attr." + name;
    if (arguments.length < 2) return (key = this.tween(key)) && key._value;
    if (value == null) return this.tween(key, null);
    if (typeof value !== "function") throw new Error;
    var fullname = namespace(name);
    return this.tween(key, (fullname.local ? attrTweenNS : attrTween)(fullname, value));
  }

  function delayFunction(id, value) {
    return function() {
      init(this, id).delay = +value.apply(this, arguments);
    };
  }

  function delayConstant(id, value) {
    return value = +value, function() {
      init(this, id).delay = value;
    };
  }

  function transition_delay(value) {
    var id = this._id;

    return arguments.length
        ? this.each((typeof value === "function"
            ? delayFunction
            : delayConstant)(id, value))
        : get(this.node(), id).delay;
  }

  function durationFunction(id, value) {
    return function() {
      set(this, id).duration = +value.apply(this, arguments);
    };
  }

  function durationConstant(id, value) {
    return value = +value, function() {
      set(this, id).duration = value;
    };
  }

  function transition_duration(value) {
    var id = this._id;

    return arguments.length
        ? this.each((typeof value === "function"
            ? durationFunction
            : durationConstant)(id, value))
        : get(this.node(), id).duration;
  }

  function easeConstant(id, value) {
    if (typeof value !== "function") throw new Error;
    return function() {
      set(this, id).ease = value;
    };
  }

  function transition_ease(value) {
    var id = this._id;

    return arguments.length
        ? this.each(easeConstant(id, value))
        : get(this.node(), id).ease;
  }

  function easeVarying(id, value) {
    return function() {
      var v = value.apply(this, arguments);
      if (typeof v !== "function") throw new Error;
      set(this, id).ease = v;
    };
  }

  function transition_easeVarying(value) {
    if (typeof value !== "function") throw new Error;
    return this.each(easeVarying(this._id, value));
  }

  function transition_filter(match) {
    if (typeof match !== "function") match = matcher(match);

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

    return new Transition(subgroups, this._parents, this._name, this._id);
  }

  function transition_merge(transition) {
    if (transition._id !== this._id) throw new Error;

    for (var groups0 = this._groups, groups1 = transition._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
      for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
        if (node = group0[i] || group1[i]) {
          merge[i] = node;
        }
      }
    }

    for (; j < m0; ++j) {
      merges[j] = groups0[j];
    }

    return new Transition(merges, this._parents, this._name, this._id);
  }

  function start(name) {
    return (name + "").trim().split(/^|\s+/).every(function(t) {
      var i = t.indexOf(".");
      if (i >= 0) t = t.slice(0, i);
      return !t || t === "start";
    });
  }

  function onFunction(id, name, listener) {
    var on0, on1, sit = start(name) ? init : set;
    return function() {
      var schedule = sit(this, id),
          on = schedule.on;

      // If this node shared a dispatch with the previous node,
      // just assign the updated shared dispatch and we’re done!
      // Otherwise, copy-on-write.
      if (on !== on0) (on1 = (on0 = on).copy()).on(name, listener);

      schedule.on = on1;
    };
  }

  function transition_on(name, listener) {
    var id = this._id;

    return arguments.length < 2
        ? get(this.node(), id).on.on(name)
        : this.each(onFunction(id, name, listener));
  }

  function removeFunction(id) {
    return function() {
      var parent = this.parentNode;
      for (var i in this.__transition) if (+i !== id) return;
      if (parent) parent.removeChild(this);
    };
  }

  function transition_remove() {
    return this.on("end.remove", removeFunction(this._id));
  }

  function transition_select(select) {
    var name = this._name,
        id = this._id;

    if (typeof select !== "function") select = selector(select);

    for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
        if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
          if ("__data__" in node) subnode.__data__ = node.__data__;
          subgroup[i] = subnode;
          schedule(subgroup[i], name, id, i, subgroup, get(node, id));
        }
      }
    }

    return new Transition(subgroups, this._parents, name, id);
  }

  function transition_selectAll(select) {
    var name = this._name,
        id = this._id;

    if (typeof select !== "function") select = selectorAll(select);

    for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
        if (node = group[i]) {
          for (var children = select.call(node, node.__data__, i, group), child, inherit = get(node, id), k = 0, l = children.length; k < l; ++k) {
            if (child = children[k]) {
              schedule(child, name, id, k, children, inherit);
            }
          }
          subgroups.push(children);
          parents.push(node);
        }
      }
    }

    return new Transition(subgroups, parents, name, id);
  }

  var Selection = selection.prototype.constructor;

  function transition_selection() {
    return new Selection(this._groups, this._parents);
  }

  function styleNull(name, interpolate) {
    var string00,
        string10,
        interpolate0;
    return function() {
      var string0 = styleValue(this, name),
          string1 = (this.style.removeProperty(name), styleValue(this, name));
      return string0 === string1 ? null
          : string0 === string00 && string1 === string10 ? interpolate0
          : interpolate0 = interpolate(string00 = string0, string10 = string1);
    };
  }

  function styleRemove(name) {
    return function() {
      this.style.removeProperty(name);
    };
  }

  function styleConstant(name, interpolate, value1) {
    var string00,
        string1 = value1 + "",
        interpolate0;
    return function() {
      var string0 = styleValue(this, name);
      return string0 === string1 ? null
          : string0 === string00 ? interpolate0
          : interpolate0 = interpolate(string00 = string0, value1);
    };
  }

  function styleFunction(name, interpolate, value) {
    var string00,
        string10,
        interpolate0;
    return function() {
      var string0 = styleValue(this, name),
          value1 = value(this),
          string1 = value1 + "";
      if (value1 == null) string1 = value1 = (this.style.removeProperty(name), styleValue(this, name));
      return string0 === string1 ? null
          : string0 === string00 && string1 === string10 ? interpolate0
          : (string10 = string1, interpolate0 = interpolate(string00 = string0, value1));
    };
  }

  function styleMaybeRemove(id, name) {
    var on0, on1, listener0, key = "style." + name, event = "end." + key, remove;
    return function() {
      var schedule = set(this, id),
          on = schedule.on,
          listener = schedule.value[key] == null ? remove || (remove = styleRemove(name)) : undefined;

      // If this node shared a dispatch with the previous node,
      // just assign the updated shared dispatch and we’re done!
      // Otherwise, copy-on-write.
      if (on !== on0 || listener0 !== listener) (on1 = (on0 = on).copy()).on(event, listener0 = listener);

      schedule.on = on1;
    };
  }

  function transition_style(name, value, priority) {
    var i = (name += "") === "transform" ? interpolateTransformCss : interpolate;
    return value == null ? this
        .styleTween(name, styleNull(name, i))
        .on("end.style." + name, styleRemove(name))
      : typeof value === "function" ? this
        .styleTween(name, styleFunction(name, i, tweenValue(this, "style." + name, value)))
        .each(styleMaybeRemove(this._id, name))
      : this
        .styleTween(name, styleConstant(name, i, value), priority)
        .on("end.style." + name, null);
  }

  function styleInterpolate(name, i, priority) {
    return function(t) {
      this.style.setProperty(name, i.call(this, t), priority);
    };
  }

  function styleTween(name, value, priority) {
    var t, i0;
    function tween() {
      var i = value.apply(this, arguments);
      if (i !== i0) t = (i0 = i) && styleInterpolate(name, i, priority);
      return t;
    }
    tween._value = value;
    return tween;
  }

  function transition_styleTween(name, value, priority) {
    var key = "style." + (name += "");
    if (arguments.length < 2) return (key = this.tween(key)) && key._value;
    if (value == null) return this.tween(key, null);
    if (typeof value !== "function") throw new Error;
    return this.tween(key, styleTween(name, value, priority == null ? "" : priority));
  }

  function textConstant(value) {
    return function() {
      this.textContent = value;
    };
  }

  function textFunction(value) {
    return function() {
      var value1 = value(this);
      this.textContent = value1 == null ? "" : value1;
    };
  }

  function transition_text(value) {
    return this.tween("text", typeof value === "function"
        ? textFunction(tweenValue(this, "text", value))
        : textConstant(value == null ? "" : value + ""));
  }

  function textInterpolate(i) {
    return function(t) {
      this.textContent = i.call(this, t);
    };
  }

  function textTween(value) {
    var t0, i0;
    function tween() {
      var i = value.apply(this, arguments);
      if (i !== i0) t0 = (i0 = i) && textInterpolate(i);
      return t0;
    }
    tween._value = value;
    return tween;
  }

  function transition_textTween(value) {
    var key = "text";
    if (arguments.length < 1) return (key = this.tween(key)) && key._value;
    if (value == null) return this.tween(key, null);
    if (typeof value !== "function") throw new Error;
    return this.tween(key, textTween(value));
  }

  function transition_transition() {
    var name = this._name,
        id0 = this._id,
        id1 = newId();

    for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
        if (node = group[i]) {
          var inherit = get(node, id0);
          schedule(node, name, id1, i, group, {
            time: inherit.time + inherit.delay + inherit.duration,
            delay: 0,
            duration: inherit.duration,
            ease: inherit.ease
          });
        }
      }
    }

    return new Transition(groups, this._parents, name, id1);
  }

  function transition_end() {
    var on0, on1, that = this, id = that._id, size = that.size();
    return new Promise(function(resolve, reject) {
      var cancel = {value: reject},
          end = {value: function() { if (--size === 0) resolve(); }};

      that.each(function() {
        var schedule = set(this, id),
            on = schedule.on;

        // If this node shared a dispatch with the previous node,
        // just assign the updated shared dispatch and we’re done!
        // Otherwise, copy-on-write.
        if (on !== on0) {
          on1 = (on0 = on).copy();
          on1._.cancel.push(cancel);
          on1._.interrupt.push(cancel);
          on1._.end.push(end);
        }

        schedule.on = on1;
      });

      // The selection was empty, resolve end immediately
      if (size === 0) resolve();
    });
  }

  var id = 0;

  function Transition(groups, parents, name, id) {
    this._groups = groups;
    this._parents = parents;
    this._name = name;
    this._id = id;
  }

  function newId() {
    return ++id;
  }

  var selection_prototype = selection.prototype;

  Transition.prototype = {
    constructor: Transition,
    select: transition_select,
    selectAll: transition_selectAll,
    selectChild: selection_prototype.selectChild,
    selectChildren: selection_prototype.selectChildren,
    filter: transition_filter,
    merge: transition_merge,
    selection: transition_selection,
    transition: transition_transition,
    call: selection_prototype.call,
    nodes: selection_prototype.nodes,
    node: selection_prototype.node,
    size: selection_prototype.size,
    empty: selection_prototype.empty,
    each: selection_prototype.each,
    on: transition_on,
    attr: transition_attr,
    attrTween: transition_attrTween,
    style: transition_style,
    styleTween: transition_styleTween,
    text: transition_text,
    textTween: transition_textTween,
    remove: transition_remove,
    tween: transition_tween,
    delay: transition_delay,
    duration: transition_duration,
    ease: transition_ease,
    easeVarying: transition_easeVarying,
    end: transition_end,
    [Symbol.iterator]: selection_prototype[Symbol.iterator]
  };

  function cubicInOut(t) {
    return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
  }

  var defaultTiming = {
    time: null, // Set on use.
    delay: 0,
    duration: 250,
    ease: cubicInOut
  };

  function inherit(node, id) {
    var timing;
    while (!(timing = node.__transition) || !(timing = timing[id])) {
      if (!(node = node.parentNode)) {
        throw new Error(`transition ${id} not found`);
      }
    }
    return timing;
  }

  function selection_transition(name) {
    var id,
        timing;

    if (name instanceof Transition) {
      id = name._id, name = name._name;
    } else {
      id = newId(), (timing = defaultTiming).time = now$2(), name = name == null ? null : name + "";
    }

    for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
      for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
        if (node = group[i]) {
          schedule(node, name, id, i, group, timing || inherit(node, id));
        }
      }
    }

    return new Transition(groups, this._parents, name, id);
  }

  selection.prototype.interrupt = selection_interrupt;
  selection.prototype.transition = selection_transition;

  var constant$1 = x => () => x;

  function ZoomEvent(type, {
    sourceEvent,
    target,
    transform,
    dispatch
  }) {
    Object.defineProperties(this, {
      type: {value: type, enumerable: true, configurable: true},
      sourceEvent: {value: sourceEvent, enumerable: true, configurable: true},
      target: {value: target, enumerable: true, configurable: true},
      transform: {value: transform, enumerable: true, configurable: true},
      _: {value: dispatch}
    });
  }

  function Transform(k, x, y) {
    this.k = k;
    this.x = x;
    this.y = y;
  }

  Transform.prototype = {
    constructor: Transform,
    scale: function(k) {
      return k === 1 ? this : new Transform(this.k * k, this.x, this.y);
    },
    translate: function(x, y) {
      return x === 0 & y === 0 ? this : new Transform(this.k, this.x + this.k * x, this.y + this.k * y);
    },
    apply: function(point) {
      return [point[0] * this.k + this.x, point[1] * this.k + this.y];
    },
    applyX: function(x) {
      return x * this.k + this.x;
    },
    applyY: function(y) {
      return y * this.k + this.y;
    },
    invert: function(location) {
      return [(location[0] - this.x) / this.k, (location[1] - this.y) / this.k];
    },
    invertX: function(x) {
      return (x - this.x) / this.k;
    },
    invertY: function(y) {
      return (y - this.y) / this.k;
    },
    rescaleX: function(x) {
      return x.copy().domain(x.range().map(this.invertX, this).map(x.invert, x));
    },
    rescaleY: function(y) {
      return y.copy().domain(y.range().map(this.invertY, this).map(y.invert, y));
    },
    toString: function() {
      return "translate(" + this.x + "," + this.y + ") scale(" + this.k + ")";
    }
  };

  var identity = new Transform(1, 0, 0);

  transform.prototype = Transform.prototype;

  function transform(node) {
    while (!node.__zoom) if (!(node = node.parentNode)) return identity;
    return node.__zoom;
  }

  function nopropagation(event) {
    event.stopImmediatePropagation();
  }

  function noevent(event) {
    event.preventDefault();
    event.stopImmediatePropagation();
  }

  // Ignore right-click, since that should open the context menu.
  // except for pinch-to-zoom, which is sent as a wheel+ctrlKey event
  function defaultFilter(event) {
    return (!event.ctrlKey || event.type === 'wheel') && !event.button;
  }

  function defaultExtent() {
    var e = this;
    if (e instanceof SVGElement) {
      e = e.ownerSVGElement || e;
      if (e.hasAttribute("viewBox")) {
        e = e.viewBox.baseVal;
        return [[e.x, e.y], [e.x + e.width, e.y + e.height]];
      }
      return [[0, 0], [e.width.baseVal.value, e.height.baseVal.value]];
    }
    return [[0, 0], [e.clientWidth, e.clientHeight]];
  }

  function defaultTransform() {
    return this.__zoom || identity;
  }

  function defaultWheelDelta(event) {
    return -event.deltaY * (event.deltaMode === 1 ? 0.05 : event.deltaMode ? 1 : 0.002) * (event.ctrlKey ? 10 : 1);
  }

  function defaultTouchable() {
    return navigator.maxTouchPoints || ("ontouchstart" in this);
  }

  function defaultConstrain(transform, extent, translateExtent) {
    var dx0 = transform.invertX(extent[0][0]) - translateExtent[0][0],
        dx1 = transform.invertX(extent[1][0]) - translateExtent[1][0],
        dy0 = transform.invertY(extent[0][1]) - translateExtent[0][1],
        dy1 = transform.invertY(extent[1][1]) - translateExtent[1][1];
    return transform.translate(
      dx1 > dx0 ? (dx0 + dx1) / 2 : Math.min(0, dx0) || Math.max(0, dx1),
      dy1 > dy0 ? (dy0 + dy1) / 2 : Math.min(0, dy0) || Math.max(0, dy1)
    );
  }

  function d3Zoom() {
    var filter = defaultFilter,
        extent = defaultExtent,
        constrain = defaultConstrain,
        wheelDelta = defaultWheelDelta,
        touchable = defaultTouchable,
        scaleExtent = [0, Infinity],
        translateExtent = [[-Infinity, -Infinity], [Infinity, Infinity]],
        duration = 250,
        interpolate = interpolateZoom,
        listeners = dispatch("start", "zoom", "end"),
        touchstarting,
        touchfirst,
        touchending,
        touchDelay = 500,
        wheelDelay = 150,
        clickDistance2 = 0,
        tapDistance = 10;

    function zoom(selection) {
      selection
          .property("__zoom", defaultTransform)
          .on("wheel.zoom", wheeled, {passive: false})
          .on("mousedown.zoom", mousedowned)
          .on("dblclick.zoom", dblclicked)
        .filter(touchable)
          .on("touchstart.zoom", touchstarted)
          .on("touchmove.zoom", touchmoved)
          .on("touchend.zoom touchcancel.zoom", touchended)
          .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
    }

    zoom.transform = function(collection, transform, point, event) {
      var selection = collection.selection ? collection.selection() : collection;
      selection.property("__zoom", defaultTransform);
      if (collection !== selection) {
        schedule(collection, transform, point, event);
      } else {
        selection.interrupt().each(function() {
          gesture(this, arguments)
            .event(event)
            .start()
            .zoom(null, typeof transform === "function" ? transform.apply(this, arguments) : transform)
            .end();
        });
      }
    };

    zoom.scaleBy = function(selection, k, p, event) {
      zoom.scaleTo(selection, function() {
        var k0 = this.__zoom.k,
            k1 = typeof k === "function" ? k.apply(this, arguments) : k;
        return k0 * k1;
      }, p, event);
    };

    zoom.scaleTo = function(selection, k, p, event) {
      zoom.transform(selection, function() {
        var e = extent.apply(this, arguments),
            t0 = this.__zoom,
            p0 = p == null ? centroid(e) : typeof p === "function" ? p.apply(this, arguments) : p,
            p1 = t0.invert(p0),
            k1 = typeof k === "function" ? k.apply(this, arguments) : k;
        return constrain(translate(scale(t0, k1), p0, p1), e, translateExtent);
      }, p, event);
    };

    zoom.translateBy = function(selection, x, y, event) {
      zoom.transform(selection, function() {
        return constrain(this.__zoom.translate(
          typeof x === "function" ? x.apply(this, arguments) : x,
          typeof y === "function" ? y.apply(this, arguments) : y
        ), extent.apply(this, arguments), translateExtent);
      }, null, event);
    };

    zoom.translateTo = function(selection, x, y, p, event) {
      zoom.transform(selection, function() {
        var e = extent.apply(this, arguments),
            t = this.__zoom,
            p0 = p == null ? centroid(e) : typeof p === "function" ? p.apply(this, arguments) : p;
        return constrain(identity.translate(p0[0], p0[1]).scale(t.k).translate(
          typeof x === "function" ? -x.apply(this, arguments) : -x,
          typeof y === "function" ? -y.apply(this, arguments) : -y
        ), e, translateExtent);
      }, p, event);
    };

    function scale(transform, k) {
      k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], k));
      return k === transform.k ? transform : new Transform(k, transform.x, transform.y);
    }

    function translate(transform, p0, p1) {
      var x = p0[0] - p1[0] * transform.k, y = p0[1] - p1[1] * transform.k;
      return x === transform.x && y === transform.y ? transform : new Transform(transform.k, x, y);
    }

    function centroid(extent) {
      return [(+extent[0][0] + +extent[1][0]) / 2, (+extent[0][1] + +extent[1][1]) / 2];
    }

    function schedule(transition, transform, point, event) {
      transition
          .on("start.zoom", function() { gesture(this, arguments).event(event).start(); })
          .on("interrupt.zoom end.zoom", function() { gesture(this, arguments).event(event).end(); })
          .tween("zoom", function() {
            var that = this,
                args = arguments,
                g = gesture(that, args).event(event),
                e = extent.apply(that, args),
                p = point == null ? centroid(e) : typeof point === "function" ? point.apply(that, args) : point,
                w = Math.max(e[1][0] - e[0][0], e[1][1] - e[0][1]),
                a = that.__zoom,
                b = typeof transform === "function" ? transform.apply(that, args) : transform,
                i = interpolate(a.invert(p).concat(w / a.k), b.invert(p).concat(w / b.k));
            return function(t) {
              if (t === 1) t = b; // Avoid rounding error on end.
              else { var l = i(t), k = w / l[2]; t = new Transform(k, p[0] - l[0] * k, p[1] - l[1] * k); }
              g.zoom(null, t);
            };
          });
    }

    function gesture(that, args, clean) {
      return (!clean && that.__zooming) || new Gesture(that, args);
    }

    function Gesture(that, args) {
      this.that = that;
      this.args = args;
      this.active = 0;
      this.sourceEvent = null;
      this.extent = extent.apply(that, args);
      this.taps = 0;
    }

    Gesture.prototype = {
      event: function(event) {
        if (event) this.sourceEvent = event;
        return this;
      },
      start: function() {
        if (++this.active === 1) {
          this.that.__zooming = this;
          this.emit("start");
        }
        return this;
      },
      zoom: function(key, transform) {
        if (this.mouse && key !== "mouse") this.mouse[1] = transform.invert(this.mouse[0]);
        if (this.touch0 && key !== "touch") this.touch0[1] = transform.invert(this.touch0[0]);
        if (this.touch1 && key !== "touch") this.touch1[1] = transform.invert(this.touch1[0]);
        this.that.__zoom = transform;
        this.emit("zoom");
        return this;
      },
      end: function() {
        if (--this.active === 0) {
          delete this.that.__zooming;
          this.emit("end");
        }
        return this;
      },
      emit: function(type) {
        var d = d3Select(this.that).datum();
        listeners.call(
          type,
          this.that,
          new ZoomEvent(type, {
            sourceEvent: this.sourceEvent,
            target: zoom,
            type,
            transform: this.that.__zoom,
            dispatch: listeners
          }),
          d
        );
      }
    };

    function wheeled(event, ...args) {
      if (!filter.apply(this, arguments)) return;
      var g = gesture(this, args).event(event),
          t = this.__zoom,
          k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], t.k * Math.pow(2, wheelDelta.apply(this, arguments)))),
          p = pointer(event);

      // If the mouse is in the same location as before, reuse it.
      // If there were recent wheel events, reset the wheel idle timeout.
      if (g.wheel) {
        if (g.mouse[0][0] !== p[0] || g.mouse[0][1] !== p[1]) {
          g.mouse[1] = t.invert(g.mouse[0] = p);
        }
        clearTimeout(g.wheel);
      }

      // If this wheel event won’t trigger a transform change, ignore it.
      else if (t.k === k) return;

      // Otherwise, capture the mouse point and location at the start.
      else {
        g.mouse = [p, t.invert(p)];
        interrupt(this);
        g.start();
      }

      noevent(event);
      g.wheel = setTimeout(wheelidled, wheelDelay);
      g.zoom("mouse", constrain(translate(scale(t, k), g.mouse[0], g.mouse[1]), g.extent, translateExtent));

      function wheelidled() {
        g.wheel = null;
        g.end();
      }
    }

    function mousedowned(event, ...args) {
      if (touchending || !filter.apply(this, arguments)) return;
      var currentTarget = event.currentTarget,
          g = gesture(this, args, true).event(event),
          v = d3Select(event.view).on("mousemove.zoom", mousemoved, true).on("mouseup.zoom", mouseupped, true),
          p = pointer(event, currentTarget),
          x0 = event.clientX,
          y0 = event.clientY;

      dragDisable(event.view);
      nopropagation(event);
      g.mouse = [p, this.__zoom.invert(p)];
      interrupt(this);
      g.start();

      function mousemoved(event) {
        noevent(event);
        if (!g.moved) {
          var dx = event.clientX - x0, dy = event.clientY - y0;
          g.moved = dx * dx + dy * dy > clickDistance2;
        }
        g.event(event)
         .zoom("mouse", constrain(translate(g.that.__zoom, g.mouse[0] = pointer(event, currentTarget), g.mouse[1]), g.extent, translateExtent));
      }

      function mouseupped(event) {
        v.on("mousemove.zoom mouseup.zoom", null);
        yesdrag(event.view, g.moved);
        noevent(event);
        g.event(event).end();
      }
    }

    function dblclicked(event, ...args) {
      if (!filter.apply(this, arguments)) return;
      var t0 = this.__zoom,
          p0 = pointer(event.changedTouches ? event.changedTouches[0] : event, this),
          p1 = t0.invert(p0),
          k1 = t0.k * (event.shiftKey ? 0.5 : 2),
          t1 = constrain(translate(scale(t0, k1), p0, p1), extent.apply(this, args), translateExtent);

      noevent(event);
      if (duration > 0) d3Select(this).transition().duration(duration).call(schedule, t1, p0, event);
      else d3Select(this).call(zoom.transform, t1, p0, event);
    }

    function touchstarted(event, ...args) {
      if (!filter.apply(this, arguments)) return;
      var touches = event.touches,
          n = touches.length,
          g = gesture(this, args, event.changedTouches.length === n).event(event),
          started, i, t, p;

      nopropagation(event);
      for (i = 0; i < n; ++i) {
        t = touches[i], p = pointer(t, this);
        p = [p, this.__zoom.invert(p), t.identifier];
        if (!g.touch0) g.touch0 = p, started = true, g.taps = 1 + !!touchstarting;
        else if (!g.touch1 && g.touch0[2] !== p[2]) g.touch1 = p, g.taps = 0;
      }

      if (touchstarting) touchstarting = clearTimeout(touchstarting);

      if (started) {
        if (g.taps < 2) touchfirst = p[0], touchstarting = setTimeout(function() { touchstarting = null; }, touchDelay);
        interrupt(this);
        g.start();
      }
    }

    function touchmoved(event, ...args) {
      if (!this.__zooming) return;
      var g = gesture(this, args).event(event),
          touches = event.changedTouches,
          n = touches.length, i, t, p, l;

      noevent(event);
      for (i = 0; i < n; ++i) {
        t = touches[i], p = pointer(t, this);
        if (g.touch0 && g.touch0[2] === t.identifier) g.touch0[0] = p;
        else if (g.touch1 && g.touch1[2] === t.identifier) g.touch1[0] = p;
      }
      t = g.that.__zoom;
      if (g.touch1) {
        var p0 = g.touch0[0], l0 = g.touch0[1],
            p1 = g.touch1[0], l1 = g.touch1[1],
            dp = (dp = p1[0] - p0[0]) * dp + (dp = p1[1] - p0[1]) * dp,
            dl = (dl = l1[0] - l0[0]) * dl + (dl = l1[1] - l0[1]) * dl;
        t = scale(t, Math.sqrt(dp / dl));
        p = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
        l = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
      }
      else if (g.touch0) p = g.touch0[0], l = g.touch0[1];
      else return;

      g.zoom("touch", constrain(translate(t, p, l), g.extent, translateExtent));
    }

    function touchended(event, ...args) {
      if (!this.__zooming) return;
      var g = gesture(this, args).event(event),
          touches = event.changedTouches,
          n = touches.length, i, t;

      nopropagation(event);
      if (touchending) clearTimeout(touchending);
      touchending = setTimeout(function() { touchending = null; }, touchDelay);
      for (i = 0; i < n; ++i) {
        t = touches[i];
        if (g.touch0 && g.touch0[2] === t.identifier) delete g.touch0;
        else if (g.touch1 && g.touch1[2] === t.identifier) delete g.touch1;
      }
      if (g.touch1 && !g.touch0) g.touch0 = g.touch1, delete g.touch1;
      if (g.touch0) g.touch0[1] = this.__zoom.invert(g.touch0[0]);
      else {
        g.end();
        // If this was a dbltap, reroute to the (optional) dblclick.zoom handler.
        if (g.taps === 2) {
          t = pointer(t, this);
          if (Math.hypot(touchfirst[0] - t[0], touchfirst[1] - t[1]) < tapDistance) {
            var p = d3Select(this).on("dblclick.zoom");
            if (p) p.apply(this, arguments);
          }
        }
      }
    }

    zoom.wheelDelta = function(_) {
      return arguments.length ? (wheelDelta = typeof _ === "function" ? _ : constant$1(+_), zoom) : wheelDelta;
    };

    zoom.filter = function(_) {
      return arguments.length ? (filter = typeof _ === "function" ? _ : constant$1(!!_), zoom) : filter;
    };

    zoom.touchable = function(_) {
      return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$1(!!_), zoom) : touchable;
    };

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

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

    zoom.translateExtent = function(_) {
      return arguments.length ? (translateExtent[0][0] = +_[0][0], translateExtent[1][0] = +_[1][0], translateExtent[0][1] = +_[0][1], translateExtent[1][1] = +_[1][1], zoom) : [[translateExtent[0][0], translateExtent[0][1]], [translateExtent[1][0], translateExtent[1][1]]];
    };

    zoom.constrain = function(_) {
      return arguments.length ? (constrain = _, zoom) : constrain;
    };

    zoom.duration = function(_) {
      return arguments.length ? (duration = +_, zoom) : duration;
    };

    zoom.interpolate = function(_) {
      return arguments.length ? (interpolate = _, zoom) : interpolate;
    };

    zoom.on = function() {
      var value = listeners.on.apply(listeners, arguments);
      return value === listeners ? zoom : value;
    };

    zoom.clickDistance = function(_) {
      return arguments.length ? (clickDistance2 = (_ = +_) * _, zoom) : Math.sqrt(clickDistance2);
    };

    zoom.tapDistance = function(_) {
      return arguments.length ? (tapDistance = +_, zoom) : tapDistance;
    };

    return zoom;
  }

  class InternMap extends Map {
    constructor(entries, key = keyof) {
      super();
      Object.defineProperties(this, {_intern: {value: new Map()}, _key: {value: key}});
      if (entries != null) for (const [key, value] of entries) this.set(key, value);
    }
    get(key) {
      return super.get(intern_get(this, key));
    }
    has(key) {
      return super.has(intern_get(this, key));
    }
    set(key, value) {
      return super.set(intern_set(this, key), value);
    }
    delete(key) {
      return super.delete(intern_delete(this, key));
    }
  }

  function intern_get({_intern, _key}, value) {
    const key = _key(value);
    return _intern.has(key) ? _intern.get(key) : value;
  }

  function intern_set({_intern, _key}, value) {
    const key = _key(value);
    if (_intern.has(key)) return _intern.get(key);
    _intern.set(key, value);
    return value;
  }

  function intern_delete({_intern, _key}, value) {
    const key = _key(value);
    if (_intern.has(key)) {
      value = _intern.get(key);
      _intern.delete(key);
    }
    return value;
  }

  function keyof(value) {
    return value !== null && typeof value === "object" ? value.valueOf() : value;
  }

  function max$1(values, valueof) {
    let max;
    if (valueof === undefined) {
      for (const value of values) {
        if (value != null
            && (max < value || (max === undefined && value >= value))) {
          max = value;
        }
      }
    } else {
      let index = -1;
      for (let value of values) {
        if ((value = valueof(value, ++index, values)) != null
            && (max < value || (max === undefined && value >= value))) {
          max = value;
        }
      }
    }
    return max;
  }

  function min$1(values, valueof) {
    let min;
    if (valueof === undefined) {
      for (const value of values) {
        if (value != null
            && (min > value || (min === undefined && value >= value))) {
          min = value;
        }
      }
    } else {
      let index = -1;
      for (let value of values) {
        if ((value = valueof(value, ++index, values)) != null
            && (min > value || (min === undefined && value >= value))) {
          min = value;
        }
      }
    }
    return min;
  }

  /** Detect free variable `global` from Node.js. */
  var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;

  /** Detect free variable `self`. */
  var freeSelf = typeof self == 'object' && self && self.Object === Object && self;

  /** Used as a reference to the global object. */
  var root = freeGlobal || freeSelf || Function('return this')();

  /** Built-in value references. */
  var Symbol$1 = root.Symbol;

  /** Used for built-in method references. */
  var objectProto$1 = Object.prototype;

  /** Used to check objects for own properties. */
  var hasOwnProperty = objectProto$1.hasOwnProperty;

  /**
   * Used to resolve the
   * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
   * of values.
   */
  var nativeObjectToString$1 = objectProto$1.toString;

  /** Built-in value references. */
  var symToStringTag$1 = Symbol$1 ? Symbol$1.toStringTag : undefined;

  /**
   * A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
   *
   * @private
   * @param {*} value The value to query.
   * @returns {string} Returns the raw `toStringTag`.
   */
  function getRawTag(value) {
    var isOwn = hasOwnProperty.call(value, symToStringTag$1),
        tag = value[symToStringTag$1];

    try {
      value[symToStringTag$1] = undefined;
      var unmasked = true;
    } catch (e) {}

    var result = nativeObjectToString$1.call(value);
    if (unmasked) {
      if (isOwn) {
        value[symToStringTag$1] = tag;
      } else {
        delete value[symToStringTag$1];
      }
    }
    return result;
  }

  /** Used for built-in method references. */
  var objectProto = Object.prototype;

  /**
   * Used to resolve the
   * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
   * of values.
   */
  var nativeObjectToString = objectProto.toString;

  /**
   * Converts `value` to a string using `Object.prototype.toString`.
   *
   * @private
   * @param {*} value The value to convert.
   * @returns {string} Returns the converted string.
   */
  function objectToString(value) {
    return nativeObjectToString.call(value);
  }

  /** `Object#toString` result references. */
  var nullTag = '[object Null]',
      undefinedTag = '[object Undefined]';

  /** Built-in value references. */
  var symToStringTag = Symbol$1 ? Symbol$1.toStringTag : undefined;

  /**
   * The base implementation of `getTag` without fallbacks for buggy environments.
   *
   * @private
   * @param {*} value The value to query.
   * @returns {string} Returns the `toStringTag`.
   */
  function baseGetTag(value) {
    if (value == null) {
      return value === undefined ? undefinedTag : nullTag;
    }
    return (symToStringTag && symToStringTag in Object(value))
      ? getRawTag(value)
      : objectToString(value);
  }

  /**
   * Checks if `value` is object-like. A value is object-like if it's not `null`
   * and has a `typeof` result of "object".
   *
   * @static
   * @memberOf _
   * @since 4.0.0
   * @category Lang
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
   * @example
   *
   * _.isObjectLike({});
   * // => true
   *
   * _.isObjectLike([1, 2, 3]);
   * // => true
   *
   * _.isObjectLike(_.noop);
   * // => false
   *
   * _.isObjectLike(null);
   * // => false
   */
  function isObjectLike(value) {
    return value != null && typeof value == 'object';
  }

  /** `Object#toString` result references. */
  var symbolTag = '[object Symbol]';

  /**
   * Checks if `value` is classified as a `Symbol` primitive or object.
   *
   * @static
   * @memberOf _
   * @since 4.0.0
   * @category Lang
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is a symbol, else `false`.
   * @example
   *
   * _.isSymbol(Symbol.iterator);
   * // => true
   *
   * _.isSymbol('abc');
   * // => false
   */
  function isSymbol(value) {
    return typeof value == 'symbol' ||
      (isObjectLike(value) && baseGetTag(value) == symbolTag);
  }

  /** Used to match a single whitespace character. */
  var reWhitespace = /\s/;

  /**
   * Used by `_.trim` and `_.trimEnd` to get the index of the last non-whitespace
   * character of `string`.
   *
   * @private
   * @param {string} string The string to inspect.
   * @returns {number} Returns the index of the last non-whitespace character.
   */
  function trimmedEndIndex(string) {
    var index = string.length;

    while (index-- && reWhitespace.test(string.charAt(index))) {}
    return index;
  }

  /** Used to match leading whitespace. */
  var reTrimStart = /^\s+/;

  /**
   * The base implementation of `_.trim`.
   *
   * @private
   * @param {string} string The string to trim.
   * @returns {string} Returns the trimmed string.
   */
  function baseTrim(string) {
    return string
      ? string.slice(0, trimmedEndIndex(string) + 1).replace(reTrimStart, '')
      : string;
  }

  /**
   * Checks if `value` is the
   * [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
   * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
   *
   * @static
   * @memberOf _
   * @since 0.1.0
   * @category Lang
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is an object, else `false`.
   * @example
   *
   * _.isObject({});
   * // => true
   *
   * _.isObject([1, 2, 3]);
   * // => true
   *
   * _.isObject(_.noop);
   * // => true
   *
   * _.isObject(null);
   * // => false
   */
  function isObject(value) {
    var type = typeof value;
    return value != null && (type == 'object' || type == 'function');
  }

  /** Used as references for various `Number` constants. */
  var NAN = 0 / 0;

  /** Used to detect bad signed hexadecimal string values. */
  var reIsBadHex = /^[-+]0x[0-9a-f]+$/i;

  /** Used to detect binary string values. */
  var reIsBinary = /^0b[01]+$/i;

  /** Used to detect octal string values. */
  var reIsOctal = /^0o[0-7]+$/i;

  /** Built-in method references without a dependency on `root`. */
  var freeParseInt = parseInt;

  /**
   * Converts `value` to a number.
   *
   * @static
   * @memberOf _
   * @since 4.0.0
   * @category Lang
   * @param {*} value The value to process.
   * @returns {number} Returns the number.
   * @example
   *
   * _.toNumber(3.2);
   * // => 3.2
   *
   * _.toNumber(Number.MIN_VALUE);
   * // => 5e-324
   *
   * _.toNumber(Infinity);
   * // => Infinity
   *
   * _.toNumber('3.2');
   * // => 3.2
   */
  function toNumber(value) {
    if (typeof value == 'number') {
      return value;
    }
    if (isSymbol(value)) {
      return NAN;
    }
    if (isObject(value)) {
      var other = typeof value.valueOf == 'function' ? value.valueOf() : value;
      value = isObject(other) ? (other + '') : other;
    }
    if (typeof value != 'string') {
      return value === 0 ? value : +value;
    }
    value = baseTrim(value);
    var isBinary = reIsBinary.test(value);
    return (isBinary || reIsOctal.test(value))
      ? freeParseInt(value.slice(2), isBinary ? 2 : 8)
      : (reIsBadHex.test(value) ? NAN : +value);
  }

  /**
   * Gets the timestamp of the number of milliseconds that have elapsed since
   * the Unix epoch (1 January 1970 00:00:00 UTC).
   *
   * @static
   * @memberOf _
   * @since 2.4.0
   * @category Date
   * @returns {number} Returns the timestamp.
   * @example
   *
   * _.defer(function(stamp) {
   *   console.log(_.now() - stamp);
   * }, _.now());
   * // => Logs the number of milliseconds it took for the deferred invocation.
   */
  var now$1 = function() {
    return root.Date.now();
  };

  /** Error message constants. */
  var FUNC_ERROR_TEXT$1 = 'Expected a function';

  /* Built-in method references for those with the same name as other `lodash` methods. */
  var nativeMax = Math.max,
      nativeMin = Math.min;

  /**
   * Creates a debounced function that delays invoking `func` until after `wait`
   * milliseconds have elapsed since the last time the debounced function was
   * invoked. The debounced function comes with a `cancel` method to cancel
   * delayed `func` invocations and a `flush` method to immediately invoke them.
   * Provide `options` to indicate whether `func` should be invoked on the
   * leading and/or trailing edge of the `wait` timeout. The `func` is invoked
   * with the last arguments provided to the debounced function. Subsequent
   * calls to the debounced function return the result of the last `func`
   * invocation.
   *
   * **Note:** If `leading` and `trailing` options are `true`, `func` is
   * invoked on the trailing edge of the timeout only if the debounced function
   * is invoked more than once during the `wait` timeout.
   *
   * If `wait` is `0` and `leading` is `false`, `func` invocation is deferred
   * until to the next tick, similar to `setTimeout` with a timeout of `0`.
   *
   * See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/)
   * for details over the differences between `_.debounce` and `_.throttle`.
   *
   * @static
   * @memberOf _
   * @since 0.1.0
   * @category Function
   * @param {Function} func The function to debounce.
   * @param {number} [wait=0] The number of milliseconds to delay.
   * @param {Object} [options={}] The options object.
   * @param {boolean} [options.leading=false]
   *  Specify invoking on the leading edge of the timeout.
   * @param {number} [options.maxWait]
   *  The maximum time `func` is allowed to be delayed before it's invoked.
   * @param {boolean} [options.trailing=true]
   *  Specify invoking on the trailing edge of the timeout.
   * @returns {Function} Returns the new debounced function.
   * @example
   *
   * // Avoid costly calculations while the window size is in flux.
   * jQuery(window).on('resize', _.debounce(calculateLayout, 150));
   *
   * // Invoke `sendMail` when clicked, debouncing subsequent calls.
   * jQuery(element).on('click', _.debounce(sendMail, 300, {
   *   'leading': true,
   *   'trailing': false
   * }));
   *
   * // Ensure `batchLog` is invoked once after 1 second of debounced calls.
   * var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
   * var source = new EventSource('/stream');
   * jQuery(source).on('message', debounced);
   *
   * // Cancel the trailing debounced invocation.
   * jQuery(window).on('popstate', debounced.cancel);
   */
  function debounce(func, wait, options) {
    var lastArgs,
        lastThis,
        maxWait,
        result,
        timerId,
        lastCallTime,
        lastInvokeTime = 0,
        leading = false,
        maxing = false,
        trailing = true;

    if (typeof func != 'function') {
      throw new TypeError(FUNC_ERROR_TEXT$1);
    }
    wait = toNumber(wait) || 0;
    if (isObject(options)) {
      leading = !!options.leading;
      maxing = 'maxWait' in options;
      maxWait = maxing ? nativeMax(toNumber(options.maxWait) || 0, wait) : maxWait;
      trailing = 'trailing' in options ? !!options.trailing : trailing;
    }

    function invokeFunc(time) {
      var args = lastArgs,
          thisArg = lastThis;

      lastArgs = lastThis = undefined;
      lastInvokeTime = time;
      result = func.apply(thisArg, args);
      return result;
    }

    function leadingEdge(time) {
      // Reset any `maxWait` timer.
      lastInvokeTime = time;
      // Start the timer for the trailing edge.
      timerId = setTimeout(timerExpired, wait);
      // Invoke the leading edge.
      return leading ? invokeFunc(time) : result;
    }

    function remainingWait(time) {
      var timeSinceLastCall = time - lastCallTime,
          timeSinceLastInvoke = time - lastInvokeTime,
          timeWaiting = wait - timeSinceLastCall;

      return maxing
        ? nativeMin(timeWaiting, maxWait - timeSinceLastInvoke)
        : timeWaiting;
    }

    function shouldInvoke(time) {
      var timeSinceLastCall = time - lastCallTime,
          timeSinceLastInvoke = time - lastInvokeTime;

      // Either this is the first call, activity has stopped and we're at the
      // trailing edge, the system time has gone backwards and we're treating
      // it as the trailing edge, or we've hit the `maxWait` limit.
      return (lastCallTime === undefined || (timeSinceLastCall >= wait) ||
        (timeSinceLastCall < 0) || (maxing && timeSinceLastInvoke >= maxWait));
    }

    function timerExpired() {
      var time = now$1();
      if (shouldInvoke(time)) {
        return trailingEdge(time);
      }
      // Restart the timer.
      timerId = setTimeout(timerExpired, remainingWait(time));
    }

    function trailingEdge(time) {
      timerId = undefined;

      // Only invoke if we have `lastArgs` which means `func` has been
      // debounced at least once.
      if (trailing && lastArgs) {
        return invokeFunc(time);
      }
      lastArgs = lastThis = undefined;
      return result;
    }

    function cancel() {
      if (timerId !== undefined) {
        clearTimeout(timerId);
      }
      lastInvokeTime = 0;
      lastArgs = lastCallTime = lastThis = timerId = undefined;
    }

    function flush() {
      return timerId === undefined ? result : trailingEdge(now$1());
    }

    function debounced() {
      var time = now$1(),
          isInvoking = shouldInvoke(time);

      lastArgs = arguments;
      lastThis = this;
      lastCallTime = time;

      if (isInvoking) {
        if (timerId === undefined) {
          return leadingEdge(lastCallTime);
        }
        if (maxing) {
          // Handle invocations in a tight loop.
          clearTimeout(timerId);
          timerId = setTimeout(timerExpired, wait);
          return invokeFunc(lastCallTime);
        }
      }
      if (timerId === undefined) {
        timerId = setTimeout(timerExpired, wait);
      }
      return result;
    }
    debounced.cancel = cancel;
    debounced.flush = flush;
    return debounced;
  }

  /** Error message constants. */
  var FUNC_ERROR_TEXT = 'Expected a function';

  /**
   * Creates a throttled function that only invokes `func` at most once per
   * every `wait` milliseconds. The throttled function comes with a `cancel`
   * method to cancel delayed `func` invocations and a `flush` method to
   * immediately invoke them. Provide `options` to indicate whether `func`
   * should be invoked on the leading and/or trailing edge of the `wait`
   * timeout. The `func` is invoked with the last arguments provided to the
   * throttled function. Subsequent calls to the throttled function return the
   * result of the last `func` invocation.
   *
   * **Note:** If `leading` and `trailing` options are `true`, `func` is
   * invoked on the trailing edge of the timeout only if the throttled function
   * is invoked more than once during the `wait` timeout.
   *
   * If `wait` is `0` and `leading` is `false`, `func` invocation is deferred
   * until to the next tick, similar to `setTimeout` with a timeout of `0`.
   *
   * See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/)
   * for details over the differences between `_.throttle` and `_.debounce`.
   *
   * @static
   * @memberOf _
   * @since 0.1.0
   * @category Function
   * @param {Function} func The function to throttle.
   * @param {number} [wait=0] The number of milliseconds to throttle invocations to.
   * @param {Object} [options={}] The options object.
   * @param {boolean} [options.leading=true]
   *  Specify invoking on the leading edge of the timeout.
   * @param {boolean} [options.trailing=true]
   *  Specify invoking on the trailing edge of the timeout.
   * @returns {Function} Returns the new throttled function.
   * @example
   *
   * // Avoid excessively updating the position while scrolling.
   * jQuery(window).on('scroll', _.throttle(updatePosition, 100));
   *
   * // Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
   * var throttled = _.throttle(renewToken, 300000, { 'trailing': false });
   * jQuery(element).on('click', throttled);
   *
   * // Cancel the trailing throttled invocation.
   * jQuery(window).on('popstate', throttled.cancel);
   */
  function throttle(func, wait, options) {
    var leading = true,
        trailing = true;

    if (typeof func != 'function') {
      throw new TypeError(FUNC_ERROR_TEXT);
    }
    if (isObject(options)) {
      leading = 'leading' in options ? !!options.leading : leading;
      trailing = 'trailing' in options ? !!options.trailing : trailing;
    }
    return debounce(func, wait, {
      'leading': leading,
      'maxWait': wait,
      'trailing': trailing
    });
  }

  /**
   * The Ease class provides a collection of easing functions for use with tween.js.
   */
  var Easing = Object.freeze({
      Linear: Object.freeze({
          None: function (amount) {
              return amount;
          },
          In: function (amount) {
              return this.None(amount);
          },
          Out: function (amount) {
              return this.None(amount);
          },
          InOut: function (amount) {
              return this.None(amount);
          },
      }),
      Quadratic: Object.freeze({
          In: function (amount) {
              return amount * amount;
          },
          Out: function (amount) {
              return amount * (2 - amount);
          },
          InOut: function (amount) {
              if ((amount *= 2) < 1) {
                  return 0.5 * amount * amount;
              }
              return -0.5 * (--amount * (amount - 2) - 1);
          },
      }),
      Cubic: Object.freeze({
          In: function (amount) {
              return amount * amount * amount;
          },
          Out: function (amount) {
              return --amount * amount * amount + 1;
          },
          InOut: function (amount) {
              if ((amount *= 2) < 1) {
                  return 0.5 * amount * amount * amount;
              }
              return 0.5 * ((amount -= 2) * amount * amount + 2);
          },
      }),
      Quartic: Object.freeze({
          In: function (amount) {
              return amount * amount * amount * amount;
          },
          Out: function (amount) {
              return 1 - --amount * amount * amount * amount;
          },
          InOut: function (amount) {
              if ((amount *= 2) < 1) {
                  return 0.5 * amount * amount * amount * amount;
              }
              return -0.5 * ((amount -= 2) * amount * amount * amount - 2);
          },
      }),
      Quintic: Object.freeze({
          In: function (amount) {
              return amount * amount * amount * amount * amount;
          },
          Out: function (amount) {
              return --amount * amount * amount * amount * amount + 1;
          },
          InOut: function (amount) {
              if ((amount *= 2) < 1) {
                  return 0.5 * amount * amount * amount * amount * amount;
              }
              return 0.5 * ((amount -= 2) * amount * amount * amount * amount + 2);
          },
      }),
      Sinusoidal: Object.freeze({
          In: function (amount) {
              return 1 - Math.sin(((1.0 - amount) * Math.PI) / 2);
          },
          Out: function (amount) {
              return Math.sin((amount * Math.PI) / 2);
          },
          InOut: function (amount) {
              return 0.5 * (1 - Math.sin(Math.PI * (0.5 - amount)));
          },
      }),
      Exponential: Object.freeze({
          In: function (amount) {
              return amount === 0 ? 0 : Math.pow(1024, amount - 1);
          },
          Out: function (amount) {
              return amount === 1 ? 1 : 1 - Math.pow(2, -10 * amount);
          },
          InOut: function (amount) {
              if (amount === 0) {
                  return 0;
              }
              if (amount === 1) {
                  return 1;
              }
              if ((amount *= 2) < 1) {
                  return 0.5 * Math.pow(1024, amount - 1);
              }
              return 0.5 * (-Math.pow(2, -10 * (amount - 1)) + 2);
          },
      }),
      Circular: Object.freeze({
          In: function (amount) {
              return 1 - Math.sqrt(1 - amount * amount);
          },
          Out: function (amount) {
              return Math.sqrt(1 - --amount * amount);
          },
          InOut: function (amount) {
              if ((amount *= 2) < 1) {
                  return -0.5 * (Math.sqrt(1 - amount * amount) - 1);
              }
              return 0.5 * (Math.sqrt(1 - (amount -= 2) * amount) + 1);
          },
      }),
      Elastic: Object.freeze({
          In: function (amount) {
              if (amount === 0) {
                  return 0;
              }
              if (amount === 1) {
                  return 1;
              }
              return -Math.pow(2, 10 * (amount - 1)) * Math.sin((amount - 1.1) * 5 * Math.PI);
          },
          Out: function (amount) {
              if (amount === 0) {
                  return 0;
              }
              if (amount === 1) {
                  return 1;
              }
              return Math.pow(2, -10 * amount) * Math.sin((amount - 0.1) * 5 * Math.PI) + 1;
          },
          InOut: function (amount) {
              if (amount === 0) {
                  return 0;
              }
              if (amount === 1) {
                  return 1;
              }
              amount *= 2;
              if (amount < 1) {
                  return -0.5 * Math.pow(2, 10 * (amount - 1)) * Math.sin((amount - 1.1) * 5 * Math.PI);
              }
              return 0.5 * Math.pow(2, -10 * (amount - 1)) * Math.sin((amount - 1.1) * 5 * Math.PI) + 1;
          },
      }),
      Back: Object.freeze({
          In: function (amount) {
              var s = 1.70158;
              return amount === 1 ? 1 : amount * amount * ((s + 1) * amount - s);
          },
          Out: function (amount) {
              var s = 1.70158;
              return amount === 0 ? 0 : --amount * amount * ((s + 1) * amount + s) + 1;
          },
          InOut: function (amount) {
              var s = 1.70158 * 1.525;
              if ((amount *= 2) < 1) {
                  return 0.5 * (amount * amount * ((s + 1) * amount - s));
              }
              return 0.5 * ((amount -= 2) * amount * ((s + 1) * amount + s) + 2);
          },
      }),
      Bounce: Object.freeze({
          In: function (amount) {
              return 1 - Easing.Bounce.Out(1 - amount);
          },
          Out: function (amount) {
              if (amount < 1 / 2.75) {
                  return 7.5625 * amount * amount;
              }
              else if (amount < 2 / 2.75) {
                  return 7.5625 * (amount -= 1.5 / 2.75) * amount + 0.75;
              }
              else if (amount < 2.5 / 2.75) {
                  return 7.5625 * (amount -= 2.25 / 2.75) * amount + 0.9375;
              }
              else {
                  return 7.5625 * (amount -= 2.625 / 2.75) * amount + 0.984375;
              }
          },
          InOut: function (amount) {
              if (amount < 0.5) {
                  return Easing.Bounce.In(amount * 2) * 0.5;
              }
              return Easing.Bounce.Out(amount * 2 - 1) * 0.5 + 0.5;
          },
      }),
      generatePow: function (power) {
          if (power === void 0) { power = 4; }
          power = power < Number.EPSILON ? Number.EPSILON : power;
          power = power > 10000 ? 10000 : power;
          return {
              In: function (amount) {
                  return Math.pow(amount, power);
              },
              Out: function (amount) {
                  return 1 - Math.pow((1 - amount), power);
              },
              InOut: function (amount) {
                  if (amount < 0.5) {
                      return Math.pow((amount * 2), power) / 2;
                  }
                  return (1 - Math.pow((2 - amount * 2), power)) / 2 + 0.5;
              },
          };
      },
  });

  var now = function () { return performance.now(); };

  /**
   * Controlling groups of tweens
   *
   * Using the TWEEN singleton to manage your tweens can cause issues in large apps with many components.
   * In these cases, you may want to create your own smaller groups of tween
   */
  var Group = /** @class */ (function () {
      function Group() {
          this._tweens = {};
          this._tweensAddedDuringUpdate = {};
      }
      Group.prototype.getAll = function () {
          var _this = this;
          return Object.keys(this._tweens).map(function (tweenId) {
              return _this._tweens[tweenId];
          });
      };
      Group.prototype.removeAll = function () {
          this._tweens = {};
      };
      Group.prototype.add = function (tween) {
          this._tweens[tween.getId()] = tween;
          this._tweensAddedDuringUpdate[tween.getId()] = tween;
      };
      Group.prototype.remove = function (tween) {
          delete this._tweens[tween.getId()];
          delete this._tweensAddedDuringUpdate[tween.getId()];
      };
      Group.prototype.update = function (time, preserve) {
          if (time === void 0) { time = now(); }
          if (preserve === void 0) { preserve = false; }
          var tweenIds = Object.keys(this._tweens);
          if (tweenIds.length === 0) {
              return false;
          }
          // Tweens are updated in "batches". If you add a new tween during an
          // update, then the new tween will be updated in the next batch.
          // If you remove a tween during an update, it may or may not be updated.
          // However, if the removed tween was added during the current batch,
          // then it will not be updated.
          while (tweenIds.length > 0) {
              this._tweensAddedDuringUpdate = {};
              for (var i = 0; i < tweenIds.length; i++) {
                  var tween = this._tweens[tweenIds[i]];
                  var autoStart = !preserve;
                  if (tween && tween.update(time, autoStart) === false && !preserve) {
                      delete this._tweens[tweenIds[i]];
                  }
              }
              tweenIds = Object.keys(this._tweensAddedDuringUpdate);
          }
          return true;
      };
      return Group;
  }());

  /**
   *
   */
  var Interpolation = {
      Linear: function (v, k) {
          var m = v.length - 1;
          var f = m * k;
          var i = Math.floor(f);
          var fn = Interpolation.Utils.Linear;
          if (k < 0) {
              return fn(v[0], v[1], f);
          }
          if (k > 1) {
              return fn(v[m], v[m - 1], m - f);
          }
          return fn(v[i], v[i + 1 > m ? m : i + 1], f - i);
      },
      Bezier: function (v, k) {
          var b = 0;
          var n = v.length - 1;
          var pw = Math.pow;
          var bn = Interpolation.Utils.Bernstein;
          for (var i = 0; i <= n; i++) {
              b += pw(1 - k, n - i) * pw(k, i) * v[i] * bn(n, i);
          }
          return b;
      },
      CatmullRom: function (v, k) {
          var m = v.length - 1;
          var f = m * k;
          var i = Math.floor(f);
          var fn = Interpolation.Utils.CatmullRom;
          if (v[0] === v[m]) {
              if (k < 0) {
                  i = Math.floor((f = m * (1 + k)));
              }
              return fn(v[(i - 1 + m) % m], v[i], v[(i + 1) % m], v[(i + 2) % m], f - i);
          }
          else {
              if (k < 0) {
                  return v[0] - (fn(v[0], v[0], v[1], v[1], -f) - v[0]);
              }
              if (k > 1) {
                  return v[m] - (fn(v[m], v[m], v[m - 1], v[m - 1], f - m) - v[m]);
              }
              return fn(v[i ? i - 1 : 0], v[i], v[m < i + 1 ? m : i + 1], v[m < i + 2 ? m : i + 2], f - i);
          }
      },
      Utils: {
          Linear: function (p0, p1, t) {
              return (p1 - p0) * t + p0;
          },
          Bernstein: function (n, i) {
              var fc = Interpolation.Utils.Factorial;
              return fc(n) / fc(i) / fc(n - i);
          },
          Factorial: (function () {
              var a = [1];
              return function (n) {
                  var s = 1;
                  if (a[n]) {
                      return a[n];
                  }
                  for (var i = n; i > 1; i--) {
                      s *= i;
                  }
                  a[n] = s;
                  return s;
              };
          })(),
          CatmullRom: function (p0, p1, p2, p3, t) {
              var v0 = (p2 - p0) * 0.5;
              var v1 = (p3 - p1) * 0.5;
              var t2 = t * t;
              var t3 = t * t2;
              return (2 * p1 - 2 * p2 + v0 + v1) * t3 + (-3 * p1 + 3 * p2 - 2 * v0 - v1) * t2 + v0 * t + p1;
          },
      },
  };

  /**
   * Utils
   */
  var Sequence = /** @class */ (function () {
      function Sequence() {
      }
      Sequence.nextId = function () {
          return Sequence._nextId++;
      };
      Sequence._nextId = 0;
      return Sequence;
  }());

  var mainGroup = new Group();

  /**
   * Tween.js - Licensed under the MIT license
   * https://github.com/tweenjs/tween.js
   * ----------------------------------------------
   *
   * See https://github.com/tweenjs/tween.js/graphs/contributors for the full list of contributors.
   * Thank you all, you're awesome!
   */
  var Tween = /** @class */ (function () {
      function Tween(_object, _group) {
          if (_group === void 0) { _group = mainGroup; }
          this._object = _object;
          this._group = _group;
          this._isPaused = false;
          this._pauseStart = 0;
          this._valuesStart = {};
          this._valuesEnd = {};
          this._valuesStartRepeat = {};
          this._duration = 1000;
          this._isDynamic = false;
          this._initialRepeat = 0;
          this._repeat = 0;
          this._yoyo = false;
          this._isPlaying = false;
          this._reversed = false;
          this._delayTime = 0;
          this._startTime = 0;
          this._easingFunction = Easing.Linear.None;
          this._interpolationFunction = Interpolation.Linear;
          // eslint-disable-next-line
          this._chainedTweens = [];
          this._onStartCallbackFired = false;
          this._onEveryStartCallbackFired = false;
          this._id = Sequence.nextId();
          this._isChainStopped = false;
          this._propertiesAreSetUp = false;
          this._goToEnd = false;
      }
      Tween.prototype.getId = function () {
          return this._id;
      };
      Tween.prototype.isPlaying = function () {
          return this._isPlaying;
      };
      Tween.prototype.isPaused = function () {
          return this._isPaused;
      };
      Tween.prototype.getDuration = function () {
          return this._duration;
      };
      Tween.prototype.to = function (target, duration) {
          if (duration === void 0) { duration = 1000; }
          if (this._isPlaying)
              throw new Error('Can not call Tween.to() while Tween is already started or paused. Stop the Tween first.');
          this._valuesEnd = target;
          this._propertiesAreSetUp = false;
          this._duration = duration < 0 ? 0 : duration;
          return this;
      };
      Tween.prototype.duration = function (duration) {
          if (duration === void 0) { duration = 1000; }
          this._duration = duration < 0 ? 0 : duration;
          return this;
      };
      Tween.prototype.dynamic = function (dynamic) {
          if (dynamic === void 0) { dynamic = false; }
          this._isDynamic = dynamic;
          return this;
      };
      Tween.prototype.start = function (time, overrideStartingValues) {
          if (time === void 0) { time = now(); }
          if (overrideStartingValues === void 0) { overrideStartingValues = false; }
          if (this._isPlaying) {
              return this;
          }
          // eslint-disable-next-line
          this._group && this._group.add(this);
          this._repeat = this._initialRepeat;
          if (this._reversed) {
              // If we were reversed (f.e. using the yoyo feature) then we need to
              // flip the tween direction back to forward.
              this._reversed = false;
              for (var property in this._valuesStartRepeat) {
                  this._swapEndStartRepeatValues(property);
                  this._valuesStart[property] = this._valuesStartRepeat[property];
              }
          }
          this._isPlaying = true;
          this._isPaused = false;
          this._onStartCallbackFired = false;
          this._onEveryStartCallbackFired = false;
          this._isChainStopped = false;
          this._startTime = time;
          this._startTime += this._delayTime;
          if (!this._propertiesAreSetUp || overrideStartingValues) {
              this._propertiesAreSetUp = true;
              // If dynamic is not enabled, clone the end values instead of using the passed-in end values.
              if (!this._isDynamic) {
                  var tmp = {};
                  for (var prop in this._valuesEnd)
                      tmp[prop] = this._valuesEnd[prop];
                  this._valuesEnd = tmp;
              }
              this._setupProperties(this._object, this._valuesStart, this._valuesEnd, this._valuesStartRepeat, overrideStartingValues);
          }
          return this;
      };
      Tween.prototype.startFromCurrentValues = function (time) {
          return this.start(time, true);
      };
      Tween.prototype._setupProperties = function (_object, _valuesStart, _valuesEnd, _valuesStartRepeat, overrideStartingValues) {
          for (var property in _valuesEnd) {
              var startValue = _object[property];
              var startValueIsArray = Array.isArray(startValue);
              var propType = startValueIsArray ? 'array' : typeof startValue;
              var isInterpolationList = !startValueIsArray && Array.isArray(_valuesEnd[property]);
              // If `to()` specifies a property that doesn't exist in the source object,
              // we should not set that property in the object
              if (propType === 'undefined' || propType === 'function') {
                  continue;
              }
              // Check if an Array was provided as property value
              if (isInterpolationList) {
                  var endValues = _valuesEnd[property];
                  if (endValues.length === 0) {
                      continue;
                  }
                  // Handle an array of relative values.
                  // Creates a local copy of the Array with the start value at the front
                  var temp = [startValue];
                  for (var i = 0, l = endValues.length; i < l; i += 1) {
                      var value = this._handleRelativeValue(startValue, endValues[i]);
                      if (isNaN(value)) {
                          isInterpolationList = false;
                          console.warn('Found invalid interpolation list. Skipping.');
                          break;
                      }
                      temp.push(value);
                  }
                  if (isInterpolationList) {
                      // if (_valuesStart[property] === undefined) { // handle end values only the first time. NOT NEEDED? setupProperties is now guarded by _propertiesAreSetUp.
                      _valuesEnd[property] = temp;
                      // }
                  }
              }
              // handle the deepness of the values
              if ((propType === 'object' || startValueIsArray) && startValue && !isInterpolationList) {
                  _valuesStart[property] = startValueIsArray ? [] : {};
                  var nestedObject = startValue;
                  for (var prop in nestedObject) {
                      _valuesStart[property][prop] = nestedObject[prop];
                  }
                  // TODO? repeat nested values? And yoyo? And array values?
                  _valuesStartRepeat[property] = startValueIsArray ? [] : {};
                  var endValues = _valuesEnd[property];
                  // If dynamic is not enabled, clone the end values instead of using the passed-in end values.
                  if (!this._isDynamic) {
                      var tmp = {};
                      for (var prop in endValues)
                          tmp[prop] = endValues[prop];
                      _valuesEnd[property] = endValues = tmp;
                  }
                  this._setupProperties(nestedObject, _valuesStart[property], endValues, _valuesStartRepeat[property], overrideStartingValues);
              }
              else {
                  // Save the starting value, but only once unless override is requested.
                  if (typeof _valuesStart[property] === 'undefined' || overrideStartingValues) {
                      _valuesStart[property] = startValue;
                  }
                  if (!startValueIsArray) {
                      // eslint-disable-next-line
                      // @ts-ignore FIXME?
                      _valuesStart[property] *= 1.0; // Ensures we're using numbers, not strings
                  }
                  if (isInterpolationList) {
                      // eslint-disable-next-line
                      // @ts-ignore FIXME?
                      _valuesStartRepeat[property] = _valuesEnd[property].slice().reverse();
                  }
                  else {
                      _valuesStartRepeat[property] = _valuesStart[property] || 0;
                  }
              }
          }
      };
      Tween.prototype.stop = function () {
          if (!this._isChainStopped) {
              this._isChainStopped = true;
              this.stopChainedTweens();
          }
          if (!this._isPlaying) {
              return this;
          }
          // eslint-disable-next-line
          this._group && this._group.remove(this);
          this._isPlaying = false;
          this._isPaused = false;
          if (this._onStopCallback) {
              this._onStopCallback(this._object);
          }
          return this;
      };
      Tween.prototype.end = function () {
          this._goToEnd = true;
          this.update(Infinity);
          return this;
      };
      Tween.prototype.pause = function (time) {
          if (time === void 0) { time = now(); }
          if (this._isPaused || !this._isPlaying) {
              return this;
          }
          this._isPaused = true;
          this._pauseStart = time;
          // eslint-disable-next-line
          this._group && this._group.remove(this);
          return this;
      };
      Tween.prototype.resume = function (time) {
          if (time === void 0) { time = now(); }
          if (!this._isPaused || !this._isPlaying) {
              return this;
          }
          this._isPaused = false;
          this._startTime += time - this._pauseStart;
          this._pauseStart = 0;
          // eslint-disable-next-line
          this._group && this._group.add(this);
          return this;
      };
      Tween.prototype.stopChainedTweens = function () {
          for (var i = 0, numChainedTweens = this._chainedTweens.length; i < numChainedTweens; i++) {
              this._chainedTweens[i].stop();
          }
          return this;
      };
      Tween.prototype.group = function (group) {
          if (group === void 0) { group = mainGroup; }
          this._group = group;
          return this;
      };
      Tween.prototype.delay = function (amount) {
          if (amount === void 0) { amount = 0; }
          this._delayTime = amount;
          return this;
      };
      Tween.prototype.repeat = function (times) {
          if (times === void 0) { times = 0; }
          this._initialRepeat = times;
          this._repeat = times;
          return this;
      };
      Tween.prototype.repeatDelay = function (amount) {
          this._repeatDelayTime = amount;
          return this;
      };
      Tween.prototype.yoyo = function (yoyo) {
          if (yoyo === void 0) { yoyo = false; }
          this._yoyo = yoyo;
          return this;
      };
      Tween.prototype.easing = function (easingFunction) {
          if (easingFunction === void 0) { easingFunction = Easing.Linear.None; }
          this._easingFunction = easingFunction;
          return this;
      };
      Tween.prototype.interpolation = function (interpolationFunction) {
          if (interpolationFunction === void 0) { interpolationFunction = Interpolation.Linear; }
          this._interpolationFunction = interpolationFunction;
          return this;
      };
      // eslint-disable-next-line
      Tween.prototype.chain = function () {
          var tweens = [];
          for (var _i = 0; _i < arguments.length; _i++) {
              tweens[_i] = arguments[_i];
          }
          this._chainedTweens = tweens;
          return this;
      };
      Tween.prototype.onStart = function (callback) {
          this._onStartCallback = callback;
          return this;
      };
      Tween.prototype.onEveryStart = function (callback) {
          this._onEveryStartCallback = callback;
          return this;
      };
      Tween.prototype.onUpdate = function (callback) {
          this._onUpdateCallback = callback;
          return this;
      };
      Tween.prototype.onRepeat = function (callback) {
          this._onRepeatCallback = callback;
          return this;
      };
      Tween.prototype.onComplete = function (callback) {
          this._onCompleteCallback = callback;
          return this;
      };
      Tween.prototype.onStop = function (callback) {
          this._onStopCallback = callback;
          return this;
      };
      /**
       * @returns true if the tween is still playing after the update, false
       * otherwise (calling update on a paused tween still returns true because
       * it is still playing, just paused).
       */
      Tween.prototype.update = function (time, autoStart) {
          var _this = this;
          var _a;
          if (time === void 0) { time = now(); }
          if (autoStart === void 0) { autoStart = true; }
          if (this._isPaused)
              return true;
          var property;
          var endTime = this._startTime + this._duration;
          if (!this._goToEnd && !this._isPlaying) {
              if (time > endTime)
                  return false;
              if (autoStart)
                  this.start(time, true);
          }
          this._goToEnd = false;
          if (time < this._startTime) {
              return true;
          }
          if (this._onStartCallbackFired === false) {
              if (this._onStartCallback) {
                  this._onStartCallback(this._object);
              }
              this._onStartCallbackFired = true;
          }
          if (this._onEveryStartCallbackFired === false) {
              if (this._onEveryStartCallback) {
                  this._onEveryStartCallback(this._object);
              }
              this._onEveryStartCallbackFired = true;
          }
          var elapsedTime = time - this._startTime;
          var durationAndDelay = this._duration + ((_a = this._repeatDelayTime) !== null && _a !== void 0 ? _a : this._delayTime);
          var totalTime = this._duration + this._repeat * durationAndDelay;
          var calculateElapsedPortion = function () {
              if (_this._duration === 0)
                  return 1;
              if (elapsedTime > totalTime) {
                  return 1;
              }
              var timesRepeated = Math.trunc(elapsedTime / durationAndDelay);
              var timeIntoCurrentRepeat = elapsedTime - timesRepeated * durationAndDelay;
              // TODO use %?
              // const timeIntoCurrentRepeat = elapsedTime % durationAndDelay
              var portion = Math.min(timeIntoCurrentRepeat / _this._duration, 1);
              if (portion === 0 && elapsedTime === _this._duration) {
                  return 1;
              }
              return portion;
          };
          var elapsed = calculateElapsedPortion();
          var value = this._easingFunction(elapsed);
          // properties transformations
          this._updateProperties(this._object, this._valuesStart, this._valuesEnd, value);
          if (this._onUpdateCallback) {
              this._onUpdateCallback(this._object, elapsed);
          }
          if (this._duration === 0 || elapsedTime >= this._duration) {
              if (this._repeat > 0) {
                  var completeCount = Math.min(Math.trunc((elapsedTime - this._duration) / durationAndDelay) + 1, this._repeat);
                  if (isFinite(this._repeat)) {
                      this._repeat -= completeCount;
                  }
                  // Reassign starting values, restart by making startTime = now
                  for (property in this._valuesStartRepeat) {
                      if (!this._yoyo && typeof this._valuesEnd[property] === 'string') {
                          this._valuesStartRepeat[property] =
                              // eslint-disable-next-line
                              // @ts-ignore FIXME?
                              this._valuesStartRepeat[property] + parseFloat(this._valuesEnd[property]);
                      }
                      if (this._yoyo) {
                          this._swapEndStartRepeatValues(property);
                      }
                      this._valuesStart[property] = this._valuesStartRepeat[property];
                  }
                  if (this._yoyo) {
                      this._reversed = !this._reversed;
                  }
                  this._startTime += durationAndDelay * completeCount;
                  if (this._onRepeatCallback) {
                      this._onRepeatCallback(this._object);
                  }
                  this._onEveryStartCallbackFired = false;
                  return true;
              }
              else {
                  if (this._onCompleteCallback) {
                      this._onCompleteCallback(this._object);
                  }
                  for (var i = 0, numChainedTweens = this._chainedTweens.length; i < numChainedTweens; i++) {
                      // Make the chained tweens start exactly at the time they should,
                      // even if the `update()` method was called way past the duration of the tween
                      this._chainedTweens[i].start(this._startTime + this._duration, false);
                  }
                  this._isPlaying = false;
                  return false;
              }
          }
          return true;
      };
      Tween.prototype._updateProperties = function (_object, _valuesStart, _valuesEnd, value) {
          for (var property in _valuesEnd) {
              // Don't update properties that do not exist in the source object
              if (_valuesStart[property] === undefined) {
                  continue;
              }
              var start = _valuesStart[property] || 0;
              var end = _valuesEnd[property];
              var startIsArray = Array.isArray(_object[property]);
              var endIsArray = Array.isArray(end);
              var isInterpolationList = !startIsArray && endIsArray;
              if (isInterpolationList) {
                  _object[property] = this._interpolationFunction(end, value);
              }
              else if (typeof end === 'object' && end) {
                  // eslint-disable-next-line
                  // @ts-ignore FIXME?
                  this._updateProperties(_object[property], start, end, value);
              }
              else {
                  // Parses relative end values with start as base (e.g.: +10, -3)
                  end = this._handleRelativeValue(start, end);
                  // Protect against non numeric properties.
                  if (typeof end === 'number') {
                      // eslint-disable-next-line
                      // @ts-ignore FIXME?
                      _object[property] = start + (end - start) * value;
                  }
              }
          }
      };
      Tween.prototype._handleRelativeValue = function (start, end) {
          if (typeof end !== 'string') {
              return end;
          }
          if (end.charAt(0) === '+' || end.charAt(0) === '-') {
              return start + parseFloat(end);
          }
          return parseFloat(end);
      };
      Tween.prototype._swapEndStartRepeatValues = function (property) {
          var tmp = this._valuesStartRepeat[property];
          var endValue = this._valuesEnd[property];
          if (typeof endValue === 'string') {
              this._valuesStartRepeat[property] = this._valuesStartRepeat[property] + parseFloat(endValue);
          }
          else {
              this._valuesStartRepeat[property] = this._valuesEnd[property];
          }
          this._valuesEnd[property] = tmp;
      };
      return Tween;
  }());
  /**
   * Controlling groups of tweens
   *
   * Using the TWEEN singleton to manage your tweens can cause issues in large apps with many components.
   * In these cases, you may want to create your own smaller groups of tweens.
   */
  var TWEEN = mainGroup;
  // This is the best way to export things in a way that's compatible with both ES
  // Modules and CommonJS, without build hacks, and so as not to break the
  // existing API.
  // https://github.com/rollup/rollup/issues/1961#issuecomment-423037881
  TWEEN.getAll.bind(TWEEN);
  TWEEN.removeAll.bind(TWEEN);
  TWEEN.add.bind(TWEEN);
  TWEEN.remove.bind(TWEEN);
  var update = TWEEN.update.bind(TWEEN);

  function _iterableToArrayLimit$1(r, l) {
    var t = null == r ? null : "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"];
    if (null != t) {
      var e,
        n,
        i,
        u,
        a = [],
        f = !0,
        o = !1;
      try {
        if (i = (t = t.call(r)).next, 0 === l) {
          if (Object(t) !== t) return;
          f = !1;
        } else for (; !(f = (e = i.call(t)).done) && (a.push(e.value), a.length !== l); f = !0);
      } catch (r) {
        o = !0, n = r;
      } finally {
        try {
          if (!f && null != t.return && (u = t.return(), Object(u) !== u)) return;
        } finally {
          if (o) throw n;
        }
      }
      return a;
    }
  }
  function _classCallCheck$1(instance, Constructor) {
    if (!(instance instanceof Constructor)) {
      throw new TypeError("Cannot call a class as a function");
    }
  }
  function _defineProperties$1(target, props) {
    for (var i = 0; i < props.length; i++) {
      var descriptor = props[i];
      descriptor.enumerable = descriptor.enumerable || false;
      descriptor.configurable = true;
      if ("value" in descriptor) descriptor.writable = true;
      Object.defineProperty(target, _toPropertyKey$2(descriptor.key), descriptor);
    }
  }
  function _createClass$1(Constructor, protoProps, staticProps) {
    if (protoProps) _defineProperties$1(Constructor.prototype, protoProps);
    if (staticProps) _defineProperties$1(Constructor, staticProps);
    Object.defineProperty(Constructor, "prototype", {
      writable: false
    });
    return Constructor;
  }
  function _slicedToArray$1(arr, i) {
    return _arrayWithHoles$1(arr) || _iterableToArrayLimit$1(arr, i) || _unsupportedIterableToArray$2(arr, i) || _nonIterableRest$1();
  }
  function _arrayWithHoles$1(arr) {
    if (Array.isArray(arr)) return arr;
  }
  function _unsupportedIterableToArray$2(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _arrayLikeToArray$2(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(o);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray$2(o, minLen);
  }
  function _arrayLikeToArray$2(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i];
    return arr2;
  }
  function _nonIterableRest$1() {
    throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }
  function _toPrimitive$2(input, hint) {
    if (typeof input !== "object" || input === null) return input;
    var prim = input[Symbol.toPrimitive];
    if (prim !== undefined) {
      var res = prim.call(input, hint || "default");
      if (typeof res !== "object") return res;
      throw new TypeError("@@toPrimitive must return a primitive value.");
    }
    return (hint === "string" ? String : Number)(input);
  }
  function _toPropertyKey$2(arg) {
    var key = _toPrimitive$2(arg, "string");
    return typeof key === "symbol" ? key : String(key);
  }

  var Prop = /*#__PURE__*/_createClass$1(function Prop(name, _ref) {
    var _ref$default = _ref["default"],
      defaultVal = _ref$default === void 0 ? null : _ref$default,
      _ref$triggerUpdate = _ref.triggerUpdate,
      triggerUpdate = _ref$triggerUpdate === void 0 ? true : _ref$triggerUpdate,
      _ref$onChange = _ref.onChange,
      onChange = _ref$onChange === void 0 ? function (newVal, state) {} : _ref$onChange;
    _classCallCheck$1(this, Prop);
    this.name = name;
    this.defaultVal = defaultVal;
    this.triggerUpdate = triggerUpdate;
    this.onChange = onChange;
  });
  function index$3 (_ref2) {
    var _ref2$stateInit = _ref2.stateInit,
      stateInit = _ref2$stateInit === void 0 ? function () {
        return {};
      } : _ref2$stateInit,
      _ref2$props = _ref2.props,
      rawProps = _ref2$props === void 0 ? {} : _ref2$props,
      _ref2$methods = _ref2.methods,
      methods = _ref2$methods === void 0 ? {} : _ref2$methods,
      _ref2$aliases = _ref2.aliases,
      aliases = _ref2$aliases === void 0 ? {} : _ref2$aliases,
      _ref2$init = _ref2.init,
      initFn = _ref2$init === void 0 ? function () {} : _ref2$init,
      _ref2$update = _ref2.update,
      updateFn = _ref2$update === void 0 ? function () {} : _ref2$update;
    // Parse props into Prop instances
    var props = Object.keys(rawProps).map(function (propName) {
      return new Prop(propName, rawProps[propName]);
    });
    return function () {
      var options = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
      // Holds component state
      var state = Object.assign({}, stateInit instanceof Function ? stateInit(options) : stateInit,
      // Support plain objects for backwards compatibility
      {
        initialised: false
      });

      // keeps track of which props triggered an update
      var changedProps = {};

      // Component constructor
      function comp(nodeElement) {
        initStatic(nodeElement, options);
        digest();
        return comp;
      }
      var initStatic = function initStatic(nodeElement, options) {
        initFn.call(comp, nodeElement, state, options);
        state.initialised = true;
      };
      var digest = debounce(function () {
        if (!state.initialised) {
          return;
        }
        updateFn.call(comp, state, changedProps);
        changedProps = {};
      }, 1);

      // Getter/setter methods
      props.forEach(function (prop) {
        comp[prop.name] = getSetProp(prop);
        function getSetProp(_ref3) {
          var prop = _ref3.name,
            _ref3$triggerUpdate = _ref3.triggerUpdate,
            redigest = _ref3$triggerUpdate === void 0 ? false : _ref3$triggerUpdate,
            _ref3$onChange = _ref3.onChange,
            onChange = _ref3$onChange === void 0 ? function (newVal, state) {} : _ref3$onChange,
            _ref3$defaultVal = _ref3.defaultVal,
            defaultVal = _ref3$defaultVal === void 0 ? null : _ref3$defaultVal;
          return function (_) {
            var curVal = state[prop];
            if (!arguments.length) {
              return curVal;
            } // Getter mode

            var val = _ === undefined ? defaultVal : _; // pick default if value passed is undefined
            state[prop] = val;
            onChange.call(comp, val, state, curVal);

            // track changed props
            !changedProps.hasOwnProperty(prop) && (changedProps[prop] = curVal);
            if (redigest) {
              digest();
            }
            return comp;
          };
        }
      });

      // Other methods
      Object.keys(methods).forEach(function (methodName) {
        comp[methodName] = function () {
          var _methods$methodName;
          for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
            args[_key] = arguments[_key];
          }
          return (_methods$methodName = methods[methodName]).call.apply(_methods$methodName, [comp, state].concat(args));
        };
      });

      // Link aliases
      Object.entries(aliases).forEach(function (_ref4) {
        var _ref5 = _slicedToArray$1(_ref4, 2),
          alias = _ref5[0],
          target = _ref5[1];
        return comp[alias] = comp[target];
      });

      // Reset all component props to their default value
      comp.resetProps = function () {
        props.forEach(function (prop) {
          comp[prop.name](prop.defaultVal);
        });
        return comp;
      };

      //

      comp.resetProps(); // Apply all prop defaults
      state._rerender = digest; // Expose digest method

      return comp;
    };
  }

  var index$2 = (function (p) {
    return typeof p === 'function' ? p // fn
    : typeof p === 'string' ? function (obj) {
      return obj[p];
    } // property name
    : function (obj) {
      return p;
    };
  }); // constant

  // This file is autogenerated. It's used to publish ESM to npm.
  function _typeof(obj) {
    "@babel/helpers - typeof";

    return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) {
      return typeof obj;
    } : function (obj) {
      return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
    }, _typeof(obj);
  }

  // https://github.com/bgrins/TinyColor
  // Brian Grinstead, MIT License

  var trimLeft = /^\s+/;
  var trimRight = /\s+$/;
  function tinycolor(color, opts) {
    color = color ? color : "";
    opts = opts || {};

    // If input is already a tinycolor, return itself
    if (color instanceof tinycolor) {
      return color;
    }
    // If we are called as a function, call using new instead
    if (!(this instanceof tinycolor)) {
      return new tinycolor(color, opts);
    }
    var rgb = inputToRGB(color);
    this._originalInput = color, this._r = rgb.r, this._g = rgb.g, this._b = rgb.b, this._a = rgb.a, this._roundA = Math.round(100 * this._a) / 100, this._format = opts.format || rgb.format;
    this._gradientType = opts.gradientType;

    // Don't let the range of [0,255] come back in [0,1].
    // Potentially lose a little bit of precision here, but will fix issues where
    // .5 gets interpreted as half of the total, instead of half of 1
    // If it was supposed to be 128, this was already taken care of by `inputToRgb`
    if (this._r < 1) this._r = Math.round(this._r);
    if (this._g < 1) this._g = Math.round(this._g);
    if (this._b < 1) this._b = Math.round(this._b);
    this._ok = rgb.ok;
  }
  tinycolor.prototype = {
    isDark: function isDark() {
      return this.getBrightness() < 128;
    },
    isLight: function isLight() {
      return !this.isDark();
    },
    isValid: function isValid() {
      return this._ok;
    },
    getOriginalInput: function getOriginalInput() {
      return this._originalInput;
    },
    getFormat: function getFormat() {
      return this._format;
    },
    getAlpha: function getAlpha() {
      return this._a;
    },
    getBrightness: function getBrightness() {
      //http://www.w3.org/TR/AERT#color-contrast
      var rgb = this.toRgb();
      return (rgb.r * 299 + rgb.g * 587 + rgb.b * 114) / 1000;
    },
    getLuminance: function getLuminance() {
      //http://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
      var rgb = this.toRgb();
      var RsRGB, GsRGB, BsRGB, R, G, B;
      RsRGB = rgb.r / 255;
      GsRGB = rgb.g / 255;
      BsRGB = rgb.b / 255;
      if (RsRGB <= 0.03928) R = RsRGB / 12.92;else R = Math.pow((RsRGB + 0.055) / 1.055, 2.4);
      if (GsRGB <= 0.03928) G = GsRGB / 12.92;else G = Math.pow((GsRGB + 0.055) / 1.055, 2.4);
      if (BsRGB <= 0.03928) B = BsRGB / 12.92;else B = Math.pow((BsRGB + 0.055) / 1.055, 2.4);
      return 0.2126 * R + 0.7152 * G + 0.0722 * B;
    },
    setAlpha: function setAlpha(value) {
      this._a = boundAlpha(value);
      this._roundA = Math.round(100 * this._a) / 100;
      return this;
    },
    toHsv: function toHsv() {
      var hsv = rgbToHsv(this._r, this._g, this._b);
      return {
        h: hsv.h * 360,
        s: hsv.s,
        v: hsv.v,
        a: this._a
      };
    },
    toHsvString: function toHsvString() {
      var hsv = rgbToHsv(this._r, this._g, this._b);
      var h = Math.round(hsv.h * 360),
        s = Math.round(hsv.s * 100),
        v = Math.round(hsv.v * 100);
      return this._a == 1 ? "hsv(" + h + ", " + s + "%, " + v + "%)" : "hsva(" + h + ", " + s + "%, " + v + "%, " + this._roundA + ")";
    },
    toHsl: function toHsl() {
      var hsl = rgbToHsl(this._r, this._g, this._b);
      return {
        h: hsl.h * 360,
        s: hsl.s,
        l: hsl.l,
        a: this._a
      };
    },
    toHslString: function toHslString() {
      var hsl = rgbToHsl(this._r, this._g, this._b);
      var h = Math.round(hsl.h * 360),
        s = Math.round(hsl.s * 100),
        l = Math.round(hsl.l * 100);
      return this._a == 1 ? "hsl(" + h + ", " + s + "%, " + l + "%)" : "hsla(" + h + ", " + s + "%, " + l + "%, " + this._roundA + ")";
    },
    toHex: function toHex(allow3Char) {
      return rgbToHex(this._r, this._g, this._b, allow3Char);
    },
    toHexString: function toHexString(allow3Char) {
      return "#" + this.toHex(allow3Char);
    },
    toHex8: function toHex8(allow4Char) {
      return rgbaToHex(this._r, this._g, this._b, this._a, allow4Char);
    },
    toHex8String: function toHex8String(allow4Char) {
      return "#" + this.toHex8(allow4Char);
    },
    toRgb: function toRgb() {
      return {
        r: Math.round(this._r),
        g: Math.round(this._g),
        b: Math.round(this._b),
        a: this._a
      };
    },
    toRgbString: function toRgbString() {
      return this._a == 1 ? "rgb(" + Math.round(this._r) + ", " + Math.round(this._g) + ", " + Math.round(this._b) + ")" : "rgba(" + Math.round(this._r) + ", " + Math.round(this._g) + ", " + Math.round(this._b) + ", " + this._roundA + ")";
    },
    toPercentageRgb: function toPercentageRgb() {
      return {
        r: Math.round(bound01(this._r, 255) * 100) + "%",
        g: Math.round(bound01(this._g, 255) * 100) + "%",
        b: Math.round(bound01(this._b, 255) * 100) + "%",
        a: this._a
      };
    },
    toPercentageRgbString: function toPercentageRgbString() {
      return this._a == 1 ? "rgb(" + Math.round(bound01(this._r, 255) * 100) + "%, " + Math.round(bound01(this._g, 255) * 100) + "%, " + Math.round(bound01(this._b, 255) * 100) + "%)" : "rgba(" + Math.round(bound01(this._r, 255) * 100) + "%, " + Math.round(bound01(this._g, 255) * 100) + "%, " + Math.round(bound01(this._b, 255) * 100) + "%, " + this._roundA + ")";
    },
    toName: function toName() {
      if (this._a === 0) {
        return "transparent";
      }
      if (this._a < 1) {
        return false;
      }
      return hexNames[rgbToHex(this._r, this._g, this._b, true)] || false;
    },
    toFilter: function toFilter(secondColor) {
      var hex8String = "#" + rgbaToArgbHex(this._r, this._g, this._b, this._a);
      var secondHex8String = hex8String;
      var gradientType = this._gradientType ? "GradientType = 1, " : "";
      if (secondColor) {
        var s = tinycolor(secondColor);
        secondHex8String = "#" + rgbaToArgbHex(s._r, s._g, s._b, s._a);
      }
      return "progid:DXImageTransform.Microsoft.gradient(" + gradientType + "startColorstr=" + hex8String + ",endColorstr=" + secondHex8String + ")";
    },
    toString: function toString(format) {
      var formatSet = !!format;
      format = format || this._format;
      var formattedString = false;
      var hasAlpha = this._a < 1 && this._a >= 0;
      var needsAlphaFormat = !formatSet && hasAlpha && (format === "hex" || format === "hex6" || format === "hex3" || format === "hex4" || format === "hex8" || format === "name");
      if (needsAlphaFormat) {
        // Special case for "transparent", all other non-alpha formats
        // will return rgba when there is transparency.
        if (format === "name" && this._a === 0) {
          return this.toName();
        }
        return this.toRgbString();
      }
      if (format === "rgb") {
        formattedString = this.toRgbString();
      }
      if (format === "prgb") {
        formattedString = this.toPercentageRgbString();
      }
      if (format === "hex" || format === "hex6") {
        formattedString = this.toHexString();
      }
      if (format === "hex3") {
        formattedString = this.toHexString(true);
      }
      if (format === "hex4") {
        formattedString = this.toHex8String(true);
      }
      if (format === "hex8") {
        formattedString = this.toHex8String();
      }
      if (format === "name") {
        formattedString = this.toName();
      }
      if (format === "hsl") {
        formattedString = this.toHslString();
      }
      if (format === "hsv") {
        formattedString = this.toHsvString();
      }
      return formattedString || this.toHexString();
    },
    clone: function clone() {
      return tinycolor(this.toString());
    },
    _applyModification: function _applyModification(fn, args) {
      var color = fn.apply(null, [this].concat([].slice.call(args)));
      this._r = color._r;
      this._g = color._g;
      this._b = color._b;
      this.setAlpha(color._a);
      return this;
    },
    lighten: function lighten() {
      return this._applyModification(_lighten, arguments);
    },
    brighten: function brighten() {
      return this._applyModification(_brighten, arguments);
    },
    darken: function darken() {
      return this._applyModification(_darken, arguments);
    },
    desaturate: function desaturate() {
      return this._applyModification(_desaturate, arguments);
    },
    saturate: function saturate() {
      return this._applyModification(_saturate, arguments);
    },
    greyscale: function greyscale() {
      return this._applyModification(_greyscale, arguments);
    },
    spin: function spin() {
      return this._applyModification(_spin, arguments);
    },
    _applyCombination: function _applyCombination(fn, args) {
      return fn.apply(null, [this].concat([].slice.call(args)));
    },
    analogous: function analogous() {
      return this._applyCombination(_analogous, arguments);
    },
    complement: function complement() {
      return this._applyCombination(_complement, arguments);
    },
    monochromatic: function monochromatic() {
      return this._applyCombination(_monochromatic, arguments);
    },
    splitcomplement: function splitcomplement() {
      return this._applyCombination(_splitcomplement, arguments);
    },
    // Disabled until https://github.com/bgrins/TinyColor/issues/254
    // polyad: function (number) {
    //   return this._applyCombination(polyad, [number]);
    // },
    triad: function triad() {
      return this._applyCombination(polyad, [3]);
    },
    tetrad: function tetrad() {
      return this._applyCombination(polyad, [4]);
    }
  };

  // If input is an object, force 1 into "1.0" to handle ratios properly
  // String input requires "1.0" as input, so 1 will be treated as 1
  tinycolor.fromRatio = function (color, opts) {
    if (_typeof(color) == "object") {
      var newColor = {};
      for (var i in color) {
        if (color.hasOwnProperty(i)) {
          if (i === "a") {
            newColor[i] = color[i];
          } else {
            newColor[i] = convertToPercentage(color[i]);
          }
        }
      }
      color = newColor;
    }
    return tinycolor(color, opts);
  };

  // Given a string or object, convert that input to RGB
  // Possible string inputs:
  //
  //     "red"
  //     "#f00" or "f00"
  //     "#ff0000" or "ff0000"
  //     "#ff000000" or "ff000000"
  //     "rgb 255 0 0" or "rgb (255, 0, 0)"
  //     "rgb 1.0 0 0" or "rgb (1, 0, 0)"
  //     "rgba (255, 0, 0, 1)" or "rgba 255, 0, 0, 1"
  //     "rgba (1.0, 0, 0, 1)" or "rgba 1.0, 0, 0, 1"
  //     "hsl(0, 100%, 50%)" or "hsl 0 100% 50%"
  //     "hsla(0, 100%, 50%, 1)" or "hsla 0 100% 50%, 1"
  //     "hsv(0, 100%, 100%)" or "hsv 0 100% 100%"
  //
  function inputToRGB(color) {
    var rgb = {
      r: 0,
      g: 0,
      b: 0
    };
    var a = 1;
    var s = null;
    var v = null;
    var l = null;
    var ok = false;
    var format = false;
    if (typeof color == "string") {
      color = stringInputToObject(color);
    }
    if (_typeof(color) == "object") {
      if (isValidCSSUnit(color.r) && isValidCSSUnit(color.g) && isValidCSSUnit(color.b)) {
        rgb = rgbToRgb(color.r, color.g, color.b);
        ok = true;
        format = String(color.r).substr(-1) === "%" ? "prgb" : "rgb";
      } else if (isValidCSSUnit(color.h) && isValidCSSUnit(color.s) && isValidCSSUnit(color.v)) {
        s = convertToPercentage(color.s);
        v = convertToPercentage(color.v);
        rgb = hsvToRgb(color.h, s, v);
        ok = true;
        format = "hsv";
      } else if (isValidCSSUnit(color.h) && isValidCSSUnit(color.s) && isValidCSSUnit(color.l)) {
        s = convertToPercentage(color.s);
        l = convertToPercentage(color.l);
        rgb = hslToRgb(color.h, s, l);
        ok = true;
        format = "hsl";
      }
      if (color.hasOwnProperty("a")) {
        a = color.a;
      }
    }
    a = boundAlpha(a);
    return {
      ok: ok,
      format: color.format || format,
      r: Math.min(255, Math.max(rgb.r, 0)),
      g: Math.min(255, Math.max(rgb.g, 0)),
      b: Math.min(255, Math.max(rgb.b, 0)),
      a: a
    };
  }

  // Conversion Functions
  // --------------------

  // `rgbToHsl`, `rgbToHsv`, `hslToRgb`, `hsvToRgb` modified from:
  // <http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript>

  // `rgbToRgb`
  // Handle bounds / percentage checking to conform to CSS color spec
  // <http://www.w3.org/TR/css3-color/>
  // *Assumes:* r, g, b in [0, 255] or [0, 1]
  // *Returns:* { r, g, b } in [0, 255]
  function rgbToRgb(r, g, b) {
    return {
      r: bound01(r, 255) * 255,
      g: bound01(g, 255) * 255,
      b: bound01(b, 255) * 255
    };
  }

  // `rgbToHsl`
  // Converts an RGB color value to HSL.
  // *Assumes:* r, g, and b are contained in [0, 255] or [0, 1]
  // *Returns:* { h, s, l } in [0,1]
  function rgbToHsl(r, g, b) {
    r = bound01(r, 255);
    g = bound01(g, 255);
    b = bound01(b, 255);
    var max = Math.max(r, g, b),
      min = Math.min(r, g, b);
    var h,
      s,
      l = (max + min) / 2;
    if (max == min) {
      h = s = 0; // achromatic
    } else {
      var d = max - min;
      s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
      switch (max) {
        case r:
          h = (g - b) / d + (g < b ? 6 : 0);
          break;
        case g:
          h = (b - r) / d + 2;
          break;
        case b:
          h = (r - g) / d + 4;
          break;
      }
      h /= 6;
    }
    return {
      h: h,
      s: s,
      l: l
    };
  }

  // `hslToRgb`
  // Converts an HSL color value to RGB.
  // *Assumes:* h is contained in [0, 1] or [0, 360] and s and l are contained [0, 1] or [0, 100]
  // *Returns:* { r, g, b } in the set [0, 255]
  function hslToRgb(h, s, l) {
    var r, g, b;
    h = bound01(h, 360);
    s = bound01(s, 100);
    l = bound01(l, 100);
    function hue2rgb(p, q, t) {
      if (t < 0) t += 1;
      if (t > 1) t -= 1;
      if (t < 1 / 6) return p + (q - p) * 6 * t;
      if (t < 1 / 2) return q;
      if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
      return p;
    }
    if (s === 0) {
      r = g = b = l; // achromatic
    } else {
      var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
      var p = 2 * l - q;
      r = hue2rgb(p, q, h + 1 / 3);
      g = hue2rgb(p, q, h);
      b = hue2rgb(p, q, h - 1 / 3);
    }
    return {
      r: r * 255,
      g: g * 255,
      b: b * 255
    };
  }

  // `rgbToHsv`
  // Converts an RGB color value to HSV
  // *Assumes:* r, g, and b are contained in the set [0, 255] or [0, 1]
  // *Returns:* { h, s, v } in [0,1]
  function rgbToHsv(r, g, b) {
    r = bound01(r, 255);
    g = bound01(g, 255);
    b = bound01(b, 255);
    var max = Math.max(r, g, b),
      min = Math.min(r, g, b);
    var h,
      s,
      v = max;
    var d = max - min;
    s = max === 0 ? 0 : d / max;
    if (max == min) {
      h = 0; // achromatic
    } else {
      switch (max) {
        case r:
          h = (g - b) / d + (g < b ? 6 : 0);
          break;
        case g:
          h = (b - r) / d + 2;
          break;
        case b:
          h = (r - g) / d + 4;
          break;
      }
      h /= 6;
    }
    return {
      h: h,
      s: s,
      v: v
    };
  }

  // `hsvToRgb`
  // Converts an HSV color value to RGB.
  // *Assumes:* h is contained in [0, 1] or [0, 360] and s and v are contained in [0, 1] or [0, 100]
  // *Returns:* { r, g, b } in the set [0, 255]
  function hsvToRgb(h, s, v) {
    h = bound01(h, 360) * 6;
    s = bound01(s, 100);
    v = bound01(v, 100);
    var i = Math.floor(h),
      f = h - i,
      p = v * (1 - s),
      q = v * (1 - f * s),
      t = v * (1 - (1 - f) * s),
      mod = i % 6,
      r = [v, q, p, p, t, v][mod],
      g = [t, v, v, q, p, p][mod],
      b = [p, p, t, v, v, q][mod];
    return {
      r: r * 255,
      g: g * 255,
      b: b * 255
    };
  }

  // `rgbToHex`
  // Converts an RGB color to hex
  // Assumes r, g, and b are contained in the set [0, 255]
  // Returns a 3 or 6 character hex
  function rgbToHex(r, g, b, allow3Char) {
    var hex = [pad2(Math.round(r).toString(16)), pad2(Math.round(g).toString(16)), pad2(Math.round(b).toString(16))];

    // Return a 3 character hex if possible
    if (allow3Char && hex[0].charAt(0) == hex[0].charAt(1) && hex[1].charAt(0) == hex[1].charAt(1) && hex[2].charAt(0) == hex[2].charAt(1)) {
      return hex[0].charAt(0) + hex[1].charAt(0) + hex[2].charAt(0);
    }
    return hex.join("");
  }

  // `rgbaToHex`
  // Converts an RGBA color plus alpha transparency to hex
  // Assumes r, g, b are contained in the set [0, 255] and
  // a in [0, 1]. Returns a 4 or 8 character rgba hex
  function rgbaToHex(r, g, b, a, allow4Char) {
    var hex = [pad2(Math.round(r).toString(16)), pad2(Math.round(g).toString(16)), pad2(Math.round(b).toString(16)), pad2(convertDecimalToHex(a))];

    // Return a 4 character hex if possible
    if (allow4Char && hex[0].charAt(0) == hex[0].charAt(1) && hex[1].charAt(0) == hex[1].charAt(1) && hex[2].charAt(0) == hex[2].charAt(1) && hex[3].charAt(0) == hex[3].charAt(1)) {
      return hex[0].charAt(0) + hex[1].charAt(0) + hex[2].charAt(0) + hex[3].charAt(0);
    }
    return hex.join("");
  }

  // `rgbaToArgbHex`
  // Converts an RGBA color to an ARGB Hex8 string
  // Rarely used, but required for "toFilter()"
  function rgbaToArgbHex(r, g, b, a) {
    var hex = [pad2(convertDecimalToHex(a)), pad2(Math.round(r).toString(16)), pad2(Math.round(g).toString(16)), pad2(Math.round(b).toString(16))];
    return hex.join("");
  }

  // `equals`
  // Can be called with any tinycolor input
  tinycolor.equals = function (color1, color2) {
    if (!color1 || !color2) return false;
    return tinycolor(color1).toRgbString() == tinycolor(color2).toRgbString();
  };
  tinycolor.random = function () {
    return tinycolor.fromRatio({
      r: Math.random(),
      g: Math.random(),
      b: Math.random()
    });
  };

  // Modification Functions
  // ----------------------
  // Thanks to less.js for some of the basics here
  // <https://github.com/cloudhead/less.js/blob/master/lib/less/functions.js>

  function _desaturate(color, amount) {
    amount = amount === 0 ? 0 : amount || 10;
    var hsl = tinycolor(color).toHsl();
    hsl.s -= amount / 100;
    hsl.s = clamp01(hsl.s);
    return tinycolor(hsl);
  }
  function _saturate(color, amount) {
    amount = amount === 0 ? 0 : amount || 10;
    var hsl = tinycolor(color).toHsl();
    hsl.s += amount / 100;
    hsl.s = clamp01(hsl.s);
    return tinycolor(hsl);
  }
  function _greyscale(color) {
    return tinycolor(color).desaturate(100);
  }
  function _lighten(color, amount) {
    amount = amount === 0 ? 0 : amount || 10;
    var hsl = tinycolor(color).toHsl();
    hsl.l += amount / 100;
    hsl.l = clamp01(hsl.l);
    return tinycolor(hsl);
  }
  function _brighten(color, amount) {
    amount = amount === 0 ? 0 : amount || 10;
    var rgb = tinycolor(color).toRgb();
    rgb.r = Math.max(0, Math.min(255, rgb.r - Math.round(255 * -(amount / 100))));
    rgb.g = Math.max(0, Math.min(255, rgb.g - Math.round(255 * -(amount / 100))));
    rgb.b = Math.max(0, Math.min(255, rgb.b - Math.round(255 * -(amount / 100))));
    return tinycolor(rgb);
  }
  function _darken(color, amount) {
    amount = amount === 0 ? 0 : amount || 10;
    var hsl = tinycolor(color).toHsl();
    hsl.l -= amount / 100;
    hsl.l = clamp01(hsl.l);
    return tinycolor(hsl);
  }

  // Spin takes a positive or negative amount within [-360, 360] indicating the change of hue.
  // Values outside of this range will be wrapped into this range.
  function _spin(color, amount) {
    var hsl = tinycolor(color).toHsl();
    var hue = (hsl.h + amount) % 360;
    hsl.h = hue < 0 ? 360 + hue : hue;
    return tinycolor(hsl);
  }

  // Combination Functions
  // ---------------------
  // Thanks to jQuery xColor for some of the ideas behind these
  // <https://github.com/infusion/jQuery-xcolor/blob/master/jquery.xcolor.js>

  function _complement(color) {
    var hsl = tinycolor(color).toHsl();
    hsl.h = (hsl.h + 180) % 360;
    return tinycolor(hsl);
  }
  function polyad(color, number) {
    if (isNaN(number) || number <= 0) {
      throw new Error("Argument to polyad must be a positive number");
    }
    var hsl = tinycolor(color).toHsl();
    var result = [tinycolor(color)];
    var step = 360 / number;
    for (var i = 1; i < number; i++) {
      result.push(tinycolor({
        h: (hsl.h + i * step) % 360,
        s: hsl.s,
        l: hsl.l
      }));
    }
    return result;
  }
  function _splitcomplement(color) {
    var hsl = tinycolor(color).toHsl();
    var h = hsl.h;
    return [tinycolor(color), tinycolor({
      h: (h + 72) % 360,
      s: hsl.s,
      l: hsl.l
    }), tinycolor({
      h: (h + 216) % 360,
      s: hsl.s,
      l: hsl.l
    })];
  }
  function _analogous(color, results, slices) {
    results = results || 6;
    slices = slices || 30;
    var hsl = tinycolor(color).toHsl();
    var part = 360 / slices;
    var ret = [tinycolor(color)];
    for (hsl.h = (hsl.h - (part * results >> 1) + 720) % 360; --results;) {
      hsl.h = (hsl.h + part) % 360;
      ret.push(tinycolor(hsl));
    }
    return ret;
  }
  function _monochromatic(color, results) {
    results = results || 6;
    var hsv = tinycolor(color).toHsv();
    var h = hsv.h,
      s = hsv.s,
      v = hsv.v;
    var ret = [];
    var modification = 1 / results;
    while (results--) {
      ret.push(tinycolor({
        h: h,
        s: s,
        v: v
      }));
      v = (v + modification) % 1;
    }
    return ret;
  }

  // Utility Functions
  // ---------------------

  tinycolor.mix = function (color1, color2, amount) {
    amount = amount === 0 ? 0 : amount || 50;
    var rgb1 = tinycolor(color1).toRgb();
    var rgb2 = tinycolor(color2).toRgb();
    var p = amount / 100;
    var rgba = {
      r: (rgb2.r - rgb1.r) * p + rgb1.r,
      g: (rgb2.g - rgb1.g) * p + rgb1.g,
      b: (rgb2.b - rgb1.b) * p + rgb1.b,
      a: (rgb2.a - rgb1.a) * p + rgb1.a
    };
    return tinycolor(rgba);
  };

  // Readability Functions
  // ---------------------
  // <http://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef (WCAG Version 2)

  // `contrast`
  // Analyze the 2 colors and returns the color contrast defined by (WCAG Version 2)
  tinycolor.readability = function (color1, color2) {
    var c1 = tinycolor(color1);
    var c2 = tinycolor(color2);
    return (Math.max(c1.getLuminance(), c2.getLuminance()) + 0.05) / (Math.min(c1.getLuminance(), c2.getLuminance()) + 0.05);
  };

  // `isReadable`
  // Ensure that foreground and background color combinations meet WCAG2 guidelines.
  // The third argument is an optional Object.
  //      the 'level' property states 'AA' or 'AAA' - if missing or invalid, it defaults to 'AA';
  //      the 'size' property states 'large' or 'small' - if missing or invalid, it defaults to 'small'.
  // If the entire object is absent, isReadable defaults to {level:"AA",size:"small"}.

  // *Example*
  //    tinycolor.isReadable("#000", "#111") => false
  //    tinycolor.isReadable("#000", "#111",{level:"AA",size:"large"}) => false
  tinycolor.isReadable = function (color1, color2, wcag2) {
    var readability = tinycolor.readability(color1, color2);
    var wcag2Parms, out;
    out = false;
    wcag2Parms = validateWCAG2Parms(wcag2);
    switch (wcag2Parms.level + wcag2Parms.size) {
      case "AAsmall":
      case "AAAlarge":
        out = readability >= 4.5;
        break;
      case "AAlarge":
        out = readability >= 3;
        break;
      case "AAAsmall":
        out = readability >= 7;
        break;
    }
    return out;
  };

  // `mostReadable`
  // Given a base color and a list of possible foreground or background
  // colors for that base, returns the most readable color.
  // Optionally returns Black or White if the most readable color is unreadable.
  // *Example*
  //    tinycolor.mostReadable(tinycolor.mostReadable("#123", ["#124", "#125"],{includeFallbackColors:false}).toHexString(); // "#112255"
  //    tinycolor.mostReadable(tinycolor.mostReadable("#123", ["#124", "#125"],{includeFallbackColors:true}).toHexString();  // "#ffffff"
  //    tinycolor.mostReadable("#a8015a", ["#faf3f3"],{includeFallbackColors:true,level:"AAA",size:"large"}).toHexString(); // "#faf3f3"
  //    tinycolor.mostReadable("#a8015a", ["#faf3f3"],{includeFallbackColors:true,level:"AAA",size:"small"}).toHexString(); // "#ffffff"
  tinycolor.mostReadable = function (baseColor, colorList, args) {
    var bestColor = null;
    var bestScore = 0;
    var readability;
    var includeFallbackColors, level, size;
    args = args || {};
    includeFallbackColors = args.includeFallbackColors;
    level = args.level;
    size = args.size;
    for (var i = 0; i < colorList.length; i++) {
      readability = tinycolor.readability(baseColor, colorList[i]);
      if (readability > bestScore) {
        bestScore = readability;
        bestColor = tinycolor(colorList[i]);
      }
    }
    if (tinycolor.isReadable(baseColor, bestColor, {
      level: level,
      size: size
    }) || !includeFallbackColors) {
      return bestColor;
    } else {
      args.includeFallbackColors = false;
      return tinycolor.mostReadable(baseColor, ["#fff", "#000"], args);
    }
  };

  // Big List of Colors
  // ------------------
  // <https://www.w3.org/TR/css-color-4/#named-colors>
  var names = tinycolor.names = {
    aliceblue: "f0f8ff",
    antiquewhite: "faebd7",
    aqua: "0ff",
    aquamarine: "7fffd4",
    azure: "f0ffff",
    beige: "f5f5dc",
    bisque: "ffe4c4",
    black: "000",
    blanchedalmond: "ffebcd",
    blue: "00f",
    blueviolet: "8a2be2",
    brown: "a52a2a",
    burlywood: "deb887",
    burntsienna: "ea7e5d",
    cadetblue: "5f9ea0",
    chartreuse: "7fff00",
    chocolate: "d2691e",
    coral: "ff7f50",
    cornflowerblue: "6495ed",
    cornsilk: "fff8dc",
    crimson: "dc143c",
    cyan: "0ff",
    darkblue: "00008b",
    darkcyan: "008b8b",
    darkgoldenrod: "b8860b",
    darkgray: "a9a9a9",
    darkgreen: "006400",
    darkgrey: "a9a9a9",
    darkkhaki: "bdb76b",
    darkmagenta: "8b008b",
    darkolivegreen: "556b2f",
    darkorange: "ff8c00",
    darkorchid: "9932cc",
    darkred: "8b0000",
    darksalmon: "e9967a",
    darkseagreen: "8fbc8f",
    darkslateblue: "483d8b",
    darkslategray: "2f4f4f",
    darkslategrey: "2f4f4f",
    darkturquoise: "00ced1",
    darkviolet: "9400d3",
    deeppink: "ff1493",
    deepskyblue: "00bfff",
    dimgray: "696969",
    dimgrey: "696969",
    dodgerblue: "1e90ff",
    firebrick: "b22222",
    floralwhite: "fffaf0",
    forestgreen: "228b22",
    fuchsia: "f0f",
    gainsboro: "dcdcdc",
    ghostwhite: "f8f8ff",
    gold: "ffd700",
    goldenrod: "daa520",
    gray: "808080",
    green: "008000",
    greenyellow: "adff2f",
    grey: "808080",
    honeydew: "f0fff0",
    hotpink: "ff69b4",
    indianred: "cd5c5c",
    indigo: "4b0082",
    ivory: "fffff0",
    khaki: "f0e68c",
    lavender: "e6e6fa",
    lavenderblush: "fff0f5",
    lawngreen: "7cfc00",
    lemonchiffon: "fffacd",
    lightblue: "add8e6",
    lightcoral: "f08080",
    lightcyan: "e0ffff",
    lightgoldenrodyellow: "fafad2",
    lightgray: "d3d3d3",
    lightgreen: "90ee90",
    lightgrey: "d3d3d3",
    lightpink: "ffb6c1",
    lightsalmon: "ffa07a",
    lightseagreen: "20b2aa",
    lightskyblue: "87cefa",
    lightslategray: "789",
    lightslategrey: "789",
    lightsteelblue: "b0c4de",
    lightyellow: "ffffe0",
    lime: "0f0",
    limegreen: "32cd32",
    linen: "faf0e6",
    magenta: "f0f",
    maroon: "800000",
    mediumaquamarine: "66cdaa",
    mediumblue: "0000cd",
    mediumorchid: "ba55d3",
    mediumpurple: "9370db",
    mediumseagreen: "3cb371",
    mediumslateblue: "7b68ee",
    mediumspringgreen: "00fa9a",
    mediumturquoise: "48d1cc",
    mediumvioletred: "c71585",
    midnightblue: "191970",
    mintcream: "f5fffa",
    mistyrose: "ffe4e1",
    moccasin: "ffe4b5",
    navajowhite: "ffdead",
    navy: "000080",
    oldlace: "fdf5e6",
    olive: "808000",
    olivedrab: "6b8e23",
    orange: "ffa500",
    orangered: "ff4500",
    orchid: "da70d6",
    palegoldenrod: "eee8aa",
    palegreen: "98fb98",
    paleturquoise: "afeeee",
    palevioletred: "db7093",
    papayawhip: "ffefd5",
    peachpuff: "ffdab9",
    peru: "cd853f",
    pink: "ffc0cb",
    plum: "dda0dd",
    powderblue: "b0e0e6",
    purple: "800080",
    rebeccapurple: "663399",
    red: "f00",
    rosybrown: "bc8f8f",
    royalblue: "4169e1",
    saddlebrown: "8b4513",
    salmon: "fa8072",
    sandybrown: "f4a460",
    seagreen: "2e8b57",
    seashell: "fff5ee",
    sienna: "a0522d",
    silver: "c0c0c0",
    skyblue: "87ceeb",
    slateblue: "6a5acd",
    slategray: "708090",
    slategrey: "708090",
    snow: "fffafa",
    springgreen: "00ff7f",
    steelblue: "4682b4",
    tan: "d2b48c",
    teal: "008080",
    thistle: "d8bfd8",
    tomato: "ff6347",
    turquoise: "40e0d0",
    violet: "ee82ee",
    wheat: "f5deb3",
    white: "fff",
    whitesmoke: "f5f5f5",
    yellow: "ff0",
    yellowgreen: "9acd32"
  };

  // Make it easy to access colors via `hexNames[hex]`
  var hexNames = tinycolor.hexNames = flip(names);

  // Utilities
  // ---------

  // `{ 'name1': 'val1' }` becomes `{ 'val1': 'name1' }`
  function flip(o) {
    var flipped = {};
    for (var i in o) {
      if (o.hasOwnProperty(i)) {
        flipped[o[i]] = i;
      }
    }
    return flipped;
  }

  // Return a valid alpha value [0,1] with all invalid values being set to 1
  function boundAlpha(a) {
    a = parseFloat(a);
    if (isNaN(a) || a < 0 || a > 1) {
      a = 1;
    }
    return a;
  }

  // Take input from [0, n] and return it as [0, 1]
  function bound01(n, max) {
    if (isOnePointZero(n)) n = "100%";
    var processPercent = isPercentage(n);
    n = Math.min(max, Math.max(0, parseFloat(n)));

    // Automatically convert percentage into number
    if (processPercent) {
      n = parseInt(n * max, 10) / 100;
    }

    // Handle floating point rounding errors
    if (Math.abs(n - max) < 0.000001) {
      return 1;
    }

    // Convert into [0, 1] range if it isn't already
    return n % max / parseFloat(max);
  }

  // Force a number between 0 and 1
  function clamp01(val) {
    return Math.min(1, Math.max(0, val));
  }

  // Parse a base-16 hex value into a base-10 integer
  function parseIntFromHex(val) {
    return parseInt(val, 16);
  }

  // Need to handle 1.0 as 100%, since once it is a number, there is no difference between it and 1
  // <http://stackoverflow.com/questions/7422072/javascript-how-to-detect-number-as-a-decimal-including-1-0>
  function isOnePointZero(n) {
    return typeof n == "string" && n.indexOf(".") != -1 && parseFloat(n) === 1;
  }

  // Check to see if string passed in is a percentage
  function isPercentage(n) {
    return typeof n === "string" && n.indexOf("%") != -1;
  }

  // Force a hex value to have 2 characters
  function pad2(c) {
    return c.length == 1 ? "0" + c : "" + c;
  }

  // Replace a decimal with it's percentage value
  function convertToPercentage(n) {
    if (n <= 1) {
      n = n * 100 + "%";
    }
    return n;
  }

  // Converts a decimal to a hex value
  function convertDecimalToHex(d) {
    return Math.round(parseFloat(d) * 255).toString(16);
  }
  // Converts a hex value to a decimal
  function convertHexToDecimal(h) {
    return parseIntFromHex(h) / 255;
  }
  var matchers = function () {
    // <http://www.w3.org/TR/css3-values/#integers>
    var CSS_INTEGER = "[-\\+]?\\d+%?";

    // <http://www.w3.org/TR/css3-values/#number-value>
    var CSS_NUMBER = "[-\\+]?\\d*\\.\\d+%?";

    // Allow positive/negative integer/number.  Don't capture the either/or, just the entire outcome.
    var CSS_UNIT = "(?:" + CSS_NUMBER + ")|(?:" + CSS_INTEGER + ")";

    // Actual matching.
    // Parentheses and commas are optional, but not required.
    // Whitespace can take the place of commas or opening paren
    var PERMISSIVE_MATCH3 = "[\\s|\\(]+(" + CSS_UNIT + ")[,|\\s]+(" + CSS_UNIT + ")[,|\\s]+(" + CSS_UNIT + ")\\s*\\)?";
    var PERMISSIVE_MATCH4 = "[\\s|\\(]+(" + CSS_UNIT + ")[,|\\s]+(" + CSS_UNIT + ")[,|\\s]+(" + CSS_UNIT + ")[,|\\s]+(" + CSS_UNIT + ")\\s*\\)?";
    return {
      CSS_UNIT: new RegExp(CSS_UNIT),
      rgb: new RegExp("rgb" + PERMISSIVE_MATCH3),
      rgba: new RegExp("rgba" + PERMISSIVE_MATCH4),
      hsl: new RegExp("hsl" + PERMISSIVE_MATCH3),
      hsla: new RegExp("hsla" + PERMISSIVE_MATCH4),
      hsv: new RegExp("hsv" + PERMISSIVE_MATCH3),
      hsva: new RegExp("hsva" + PERMISSIVE_MATCH4),
      hex3: /^#?([0-9a-fA-F]{1})([0-9a-fA-F]{1})([0-9a-fA-F]{1})$/,
      hex6: /^#?([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})$/,
      hex4: /^#?([0-9a-fA-F]{1})([0-9a-fA-F]{1})([0-9a-fA-F]{1})([0-9a-fA-F]{1})$/,
      hex8: /^#?([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})$/
    };
  }();

  // `isValidCSSUnit`
  // Take in a single string / number and check to see if it looks like a CSS unit
  // (see `matchers` above for definition).
  function isValidCSSUnit(color) {
    return !!matchers.CSS_UNIT.exec(color);
  }

  // `stringInputToObject`
  // Permissive string parsing.  Take in a number of formats, and output an object
  // based on detected format.  Returns `{ r, g, b }` or `{ h, s, l }` or `{ h, s, v}`
  function stringInputToObject(color) {
    color = color.replace(trimLeft, "").replace(trimRight, "").toLowerCase();
    var named = false;
    if (names[color]) {
      color = names[color];
      named = true;
    } else if (color == "transparent") {
      return {
        r: 0,
        g: 0,
        b: 0,
        a: 0,
        format: "name"
      };
    }

    // Try to match string input using regular expressions.
    // Keep most of the number bounding out of this function - don't worry about [0,1] or [0,100] or [0,360]
    // Just return an object and let the conversion functions handle that.
    // This way the result will be the same whether the tinycolor is initialized with string or object.
    var match;
    if (match = matchers.rgb.exec(color)) {
      return {
        r: match[1],
        g: match[2],
        b: match[3]
      };
    }
    if (match = matchers.rgba.exec(color)) {
      return {
        r: match[1],
        g: match[2],
        b: match[3],
        a: match[4]
      };
    }
    if (match = matchers.hsl.exec(color)) {
      return {
        h: match[1],
        s: match[2],
        l: match[3]
      };
    }
    if (match = matchers.hsla.exec(color)) {
      return {
        h: match[1],
        s: match[2],
        l: match[3],
        a: match[4]
      };
    }
    if (match = matchers.hsv.exec(color)) {
      return {
        h: match[1],
        s: match[2],
        v: match[3]
      };
    }
    if (match = matchers.hsva.exec(color)) {
      return {
        h: match[1],
        s: match[2],
        v: match[3],
        a: match[4]
      };
    }
    if (match = matchers.hex8.exec(color)) {
      return {
        r: parseIntFromHex(match[1]),
        g: parseIntFromHex(match[2]),
        b: parseIntFromHex(match[3]),
        a: convertHexToDecimal(match[4]),
        format: named ? "name" : "hex8"
      };
    }
    if (match = matchers.hex6.exec(color)) {
      return {
        r: parseIntFromHex(match[1]),
        g: parseIntFromHex(match[2]),
        b: parseIntFromHex(match[3]),
        format: named ? "name" : "hex"
      };
    }
    if (match = matchers.hex4.exec(color)) {
      return {
        r: parseIntFromHex(match[1] + "" + match[1]),
        g: parseIntFromHex(match[2] + "" + match[2]),
        b: parseIntFromHex(match[3] + "" + match[3]),
        a: convertHexToDecimal(match[4] + "" + match[4]),
        format: named ? "name" : "hex8"
      };
    }
    if (match = matchers.hex3.exec(color)) {
      return {
        r: parseIntFromHex(match[1] + "" + match[1]),
        g: parseIntFromHex(match[2] + "" + match[2]),
        b: parseIntFromHex(match[3] + "" + match[3]),
        format: named ? "name" : "hex"
      };
    }
    return false;
  }
  function validateWCAG2Parms(parms) {
    // return valid WCAG2 parms for isReadable.
    // If input parms are invalid, return {"level":"AA", "size":"small"}
    var level, size;
    parms = parms || {
      level: "AA",
      size: "small"
    };
    level = (parms.level || "AA").toUpperCase();
    size = (parms.size || "small").toLowerCase();
    if (level !== "AA" && level !== "AAA") {
      level = "AA";
    }
    if (size !== "small" && size !== "large") {
      size = "small";
    }
    return {
      level: level,
      size: size
    };
  }

  function _classCallCheck(instance, Constructor) {
    if (!(instance instanceof Constructor)) {
      throw new TypeError("Cannot call a class as a function");
    }
  }
  function _defineProperties(target, props) {
    for (var i = 0; i < props.length; i++) {
      var descriptor = props[i];
      descriptor.enumerable = descriptor.enumerable || false;
      descriptor.configurable = true;
      if ("value" in descriptor) descriptor.writable = true;
      Object.defineProperty(target, _toPropertyKey$1(descriptor.key), descriptor);
    }
  }
  function _createClass(Constructor, protoProps, staticProps) {
    if (protoProps) _defineProperties(Constructor.prototype, protoProps);
    if (staticProps) _defineProperties(Constructor, staticProps);
    Object.defineProperty(Constructor, "prototype", {
      writable: false
    });
    return Constructor;
  }
  function _toConsumableArray$1(arr) {
    return _arrayWithoutHoles$1(arr) || _iterableToArray$1(arr) || _unsupportedIterableToArray$1(arr) || _nonIterableSpread$1();
  }
  function _arrayWithoutHoles$1(arr) {
    if (Array.isArray(arr)) return _arrayLikeToArray$1(arr);
  }
  function _iterableToArray$1(iter) {
    if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter);
  }
  function _unsupportedIterableToArray$1(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _arrayLikeToArray$1(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(o);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray$1(o, minLen);
  }
  function _arrayLikeToArray$1(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i];
    return arr2;
  }
  function _nonIterableSpread$1() {
    throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }
  function _toPrimitive$1(input, hint) {
    if (typeof input !== "object" || input === null) return input;
    var prim = input[Symbol.toPrimitive];
    if (prim !== undefined) {
      var res = prim.call(input, hint || "default");
      if (typeof res !== "object") return res;
      throw new TypeError("@@toPrimitive must return a primitive value.");
    }
    return (hint === "string" ? String : Number)(input);
  }
  function _toPropertyKey$1(arg) {
    var key = _toPrimitive$1(arg, "string");
    return typeof key === "symbol" ? key : String(key);
  }

  var ENTROPY = 123; // Raise numbers to prevent collisions in lower indexes

  var int2HexColor = function int2HexColor(num) {
    return "#".concat(Math.min(num, Math.pow(2, 24)).toString(16).padStart(6, '0'));
  };
  var rgb2Int = function rgb2Int(r, g, b) {
    return (r << 16) + (g << 8) + b;
  };
  var colorStr2Int = function colorStr2Int(str) {
    var _tinyColor$toRgb = tinycolor(str).toRgb(),
      r = _tinyColor$toRgb.r,
      g = _tinyColor$toRgb.g,
      b = _tinyColor$toRgb.b;
    return rgb2Int(r, g, b);
  };
  var checksum = function checksum(n, csBits) {
    return n * ENTROPY % Math.pow(2, csBits);
  };
  var _default = /*#__PURE__*/function () {
    function _default() {
      var csBits = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 6;
      _classCallCheck(this, _default);
      this.csBits = csBits; // How many bits to reserve for checksum. Will eat away into the usable size of the registry.
      this.registry = ['__reserved for background__']; // indexed objects for rgb lookup;
    }
    _createClass(_default, [{
      key: "register",
      value: function register(obj) {
        if (this.registry.length >= Math.pow(2, 24 - this.csBits)) {
          // color has 24 bits (-checksum)
          return null; // Registry is full
        }

        var idx = this.registry.length;
        var cs = checksum(idx, this.csBits);
        var color = int2HexColor(idx + (cs << 24 - this.csBits));
        this.registry.push(obj);
        return color;
      }
    }, {
      key: "lookup",
      value: function lookup(color) {
        var n = typeof color === 'string' ? colorStr2Int(color) : rgb2Int.apply(void 0, _toConsumableArray$1(color));
        if (!n) return null; // 0 index is reserved for background

        var idx = n & Math.pow(2, 24 - this.csBits) - 1; // registry index
        var cs = n >> 24 - this.csBits & Math.pow(2, this.csBits) - 1; // extract bits reserved for checksum

        if (checksum(idx, this.csBits) !== cs || idx >= this.registry.length) return null; // failed checksum or registry out of bounds

        return this.registry[idx];
      }
    }]);
    return _default;
  }();

  function d3ForceCenter(x, y, z) {
    var nodes, strength = 1;

    if (x == null) x = 0;
    if (y == null) y = 0;
    if (z == null) z = 0;

    function force() {
      var i,
          n = nodes.length,
          node,
          sx = 0,
          sy = 0,
          sz = 0;

      for (i = 0; i < n; ++i) {
        node = nodes[i], sx += node.x || 0, sy += node.y || 0, sz += node.z || 0;
      }

      for (sx = (sx / n - x) * strength, sy = (sy / n - y) * strength, sz = (sz / n - z) * strength, i = 0; i < n; ++i) {
        node = nodes[i];
        if (sx) { node.x -= sx; }
        if (sy) { node.y -= sy; }
        if (sz) { node.z -= sz; }
      }
    }

    force.initialize = function(_) {
      nodes = _;
    };

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

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

    force.z = function(_) {
      return arguments.length ? (z = +_, force) : z;
    };

    force.strength = function(_) {
      return arguments.length ? (strength = +_, force) : strength;
    };

    return force;
  }

  function tree_add$2(d) {
    const x = +this._x.call(null, d);
    return add$2(this.cover(x), x, d);
  }

  function add$2(tree, x, d) {
    if (isNaN(x)) return tree; // ignore invalid points

    var parent,
        node = tree._root,
        leaf = {data: d},
        x0 = tree._x0,
        x1 = tree._x1,
        xm,
        xp,
        right,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return tree._root = leaf, tree;

    // Find the existing leaf for the new point, or add it.
    while (node.length) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (parent = node, !(node = node[i = +right])) return parent[i] = leaf, tree;
    }

    // Is the new point is exactly coincident with the existing point?
    xp = +tree._x.call(null, node.data);
    if (x === xp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;

    // Otherwise, split the leaf node until the old and new point are separated.
    do {
      parent = parent ? parent[i] = new Array(2) : tree._root = new Array(2);
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
    } while ((i = +right) === (j = +(xp >= xm)));
    return parent[j] = node, parent[i] = leaf, tree;
  }

  function addAll$2(data) {
    if (!Array.isArray(data)) data = Array.from(data);
    const n = data.length;
    const xz = new Float64Array(n);
    let x0 = Infinity,
        x1 = -Infinity;

    // Compute the points and their extent.
    for (let i = 0, x; i < n; ++i) {
      if (isNaN(x = +this._x.call(null, data[i]))) continue;
      xz[i] = x;
      if (x < x0) x0 = x;
      if (x > x1) x1 = x;
    }

    // If there were no (valid) points, abort.
    if (x0 > x1) return this;

    // Expand the tree to cover the new points.
    this.cover(x0).cover(x1);

    // Add the new points.
    for (let i = 0; i < n; ++i) {
      add$2(this, xz[i], data[i]);
    }

    return this;
  }

  function tree_cover$2(x) {
    if (isNaN(x = +x)) return this; // ignore invalid points

    var x0 = this._x0,
        x1 = this._x1;

    // If the binarytree has no extent, initialize them.
    // Integer extent are necessary so that if we later double the extent,
    // the existing half boundaries don’t change due to floating point error!
    if (isNaN(x0)) {
      x1 = (x0 = Math.floor(x)) + 1;
    }

    // Otherwise, double repeatedly to cover.
    else {
      var z = x1 - x0 || 1,
          node = this._root,
          parent,
          i;

      while (x0 > x || x >= x1) {
        i = +(x < x0);
        parent = new Array(2), parent[i] = node, node = parent, z *= 2;
        switch (i) {
          case 0: x1 = x0 + z; break;
          case 1: x0 = x1 - z; break;
        }
      }

      if (this._root && this._root.length) this._root = node;
    }

    this._x0 = x0;
    this._x1 = x1;
    return this;
  }

  function tree_data$2() {
    var data = [];
    this.visit(function(node) {
      if (!node.length) do data.push(node.data); while (node = node.next)
    });
    return data;
  }

  function tree_extent$2(_) {
    return arguments.length
        ? this.cover(+_[0][0]).cover(+_[1][0])
        : isNaN(this._x0) ? undefined : [[this._x0], [this._x1]];
  }

  function Half(node, x0, x1) {
    this.node = node;
    this.x0 = x0;
    this.x1 = x1;
  }

  function tree_find$2(x, radius) {
    var data,
        x0 = this._x0,
        x1,
        x2,
        x3 = this._x1,
        halves = [],
        node = this._root,
        q,
        i;

    if (node) halves.push(new Half(node, x0, x3));
    if (radius == null) radius = Infinity;
    else {
      x0 = x - radius;
      x3 = x + radius;
    }

    while (q = halves.pop()) {

      // Stop searching if this half can’t contain a closer node.
      if (!(node = q.node)
          || (x1 = q.x0) > x3
          || (x2 = q.x1) < x0) continue;

      // Bisect the current half.
      if (node.length) {
        var xm = (x1 + x2) / 2;

        halves.push(
          new Half(node[1], xm, x2),
          new Half(node[0], x1, xm)
        );

        // Visit the closest half first.
        if (i = +(x >= xm)) {
          q = halves[halves.length - 1];
          halves[halves.length - 1] = halves[halves.length - 1 - i];
          halves[halves.length - 1 - i] = q;
        }
      }

      // Visit this point. (Visiting coincident points isn’t necessary!)
      else {
        var d = Math.abs(x - +this._x.call(null, node.data));
        if (d < radius) {
          radius = d;
          x0 = x - d;
          x3 = x + d;
          data = node.data;
        }
      }
    }

    return data;
  }

  function tree_remove$2(d) {
    if (isNaN(x = +this._x.call(null, d))) return this; // ignore invalid points

    var parent,
        node = this._root,
        retainer,
        previous,
        next,
        x0 = this._x0,
        x1 = this._x1,
        x,
        xm,
        right,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return this;

    // Find the leaf node for the point.
    // While descending, also retain the deepest parent with a non-removed sibling.
    if (node.length) while (true) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (!(parent = node, node = node[i = +right])) return this;
      if (!node.length) break;
      if (parent[(i + 1) & 1]) retainer = parent, j = i;
    }

    // Find the point to remove.
    while (node.data !== d) if (!(previous = node, node = node.next)) return this;
    if (next = node.next) delete node.next;

    // If there are multiple coincident points, remove just the point.
    if (previous) return (next ? previous.next = next : delete previous.next), this;

    // If this is the root point, remove it.
    if (!parent) return this._root = next, this;

    // Remove this leaf.
    next ? parent[i] = next : delete parent[i];

    // If the parent now contains exactly one leaf, collapse superfluous parents.
    if ((node = parent[0] || parent[1])
        && node === (parent[1] || parent[0])
        && !node.length) {
      if (retainer) retainer[j] = node;
      else this._root = node;
    }

    return this;
  }

  function removeAll$2(data) {
    for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
    return this;
  }

  function tree_root$2() {
    return this._root;
  }

  function tree_size$2() {
    var size = 0;
    this.visit(function(node) {
      if (!node.length) do ++size; while (node = node.next)
    });
    return size;
  }

  function tree_visit$2(callback) {
    var halves = [], q, node = this._root, child, x0, x1;
    if (node) halves.push(new Half(node, this._x0, this._x1));
    while (q = halves.pop()) {
      if (!callback(node = q.node, x0 = q.x0, x1 = q.x1) && node.length) {
        var xm = (x0 + x1) / 2;
        if (child = node[1]) halves.push(new Half(child, xm, x1));
        if (child = node[0]) halves.push(new Half(child, x0, xm));
      }
    }
    return this;
  }

  function tree_visitAfter$2(callback) {
    var halves = [], next = [], q;
    if (this._root) halves.push(new Half(this._root, this._x0, this._x1));
    while (q = halves.pop()) {
      var node = q.node;
      if (node.length) {
        var child, x0 = q.x0, x1 = q.x1, xm = (x0 + x1) / 2;
        if (child = node[0]) halves.push(new Half(child, x0, xm));
        if (child = node[1]) halves.push(new Half(child, xm, x1));
      }
      next.push(q);
    }
    while (q = next.pop()) {
      callback(q.node, q.x0, q.x1);
    }
    return this;
  }

  function defaultX$2(d) {
    return d[0];
  }

  function tree_x$2(_) {
    return arguments.length ? (this._x = _, this) : this._x;
  }

  function binarytree(nodes, x) {
    var tree = new Binarytree(x == null ? defaultX$2 : x, NaN, NaN);
    return nodes == null ? tree : tree.addAll(nodes);
  }

  function Binarytree(x, x0, x1) {
    this._x = x;
    this._x0 = x0;
    this._x1 = x1;
    this._root = undefined;
  }

  function leaf_copy$2(leaf) {
    var copy = {data: leaf.data}, next = copy;
    while (leaf = leaf.next) next = next.next = {data: leaf.data};
    return copy;
  }

  var treeProto$2 = binarytree.prototype = Binarytree.prototype;

  treeProto$2.copy = function() {
    var copy = new Binarytree(this._x, this._x0, this._x1),
        node = this._root,
        nodes,
        child;

    if (!node) return copy;

    if (!node.length) return copy._root = leaf_copy$2(node), copy;

    nodes = [{source: node, target: copy._root = new Array(2)}];
    while (node = nodes.pop()) {
      for (var i = 0; i < 2; ++i) {
        if (child = node.source[i]) {
          if (child.length) nodes.push({source: child, target: node.target[i] = new Array(2)});
          else node.target[i] = leaf_copy$2(child);
        }
      }
    }

    return copy;
  };

  treeProto$2.add = tree_add$2;
  treeProto$2.addAll = addAll$2;
  treeProto$2.cover = tree_cover$2;
  treeProto$2.data = tree_data$2;
  treeProto$2.extent = tree_extent$2;
  treeProto$2.find = tree_find$2;
  treeProto$2.remove = tree_remove$2;
  treeProto$2.removeAll = removeAll$2;
  treeProto$2.root = tree_root$2;
  treeProto$2.size = tree_size$2;
  treeProto$2.visit = tree_visit$2;
  treeProto$2.visitAfter = tree_visitAfter$2;
  treeProto$2.x = tree_x$2;

  function tree_add$1(d) {
    const x = +this._x.call(null, d),
        y = +this._y.call(null, d);
    return add$1(this.cover(x, y), x, y, d);
  }

  function add$1(tree, x, y, d) {
    if (isNaN(x) || isNaN(y)) return tree; // ignore invalid points

    var parent,
        node = tree._root,
        leaf = {data: d},
        x0 = tree._x0,
        y0 = tree._y0,
        x1 = tree._x1,
        y1 = tree._y1,
        xm,
        ym,
        xp,
        yp,
        right,
        bottom,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return tree._root = leaf, tree;

    // Find the existing leaf for the new point, or add it.
    while (node.length) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
      if (parent = node, !(node = node[i = bottom << 1 | right])) return parent[i] = leaf, tree;
    }

    // Is the new point is exactly coincident with the existing point?
    xp = +tree._x.call(null, node.data);
    yp = +tree._y.call(null, node.data);
    if (x === xp && y === yp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;

    // Otherwise, split the leaf node until the old and new point are separated.
    do {
      parent = parent ? parent[i] = new Array(4) : tree._root = new Array(4);
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
    } while ((i = bottom << 1 | right) === (j = (yp >= ym) << 1 | (xp >= xm)));
    return parent[j] = node, parent[i] = leaf, tree;
  }

  function addAll$1(data) {
    var d, i, n = data.length,
        x,
        y,
        xz = new Array(n),
        yz = new Array(n),
        x0 = Infinity,
        y0 = Infinity,
        x1 = -Infinity,
        y1 = -Infinity;

    // Compute the points and their extent.
    for (i = 0; i < n; ++i) {
      if (isNaN(x = +this._x.call(null, d = data[i])) || isNaN(y = +this._y.call(null, d))) continue;
      xz[i] = x;
      yz[i] = y;
      if (x < x0) x0 = x;
      if (x > x1) x1 = x;
      if (y < y0) y0 = y;
      if (y > y1) y1 = y;
    }

    // If there were no (valid) points, abort.
    if (x0 > x1 || y0 > y1) return this;

    // Expand the tree to cover the new points.
    this.cover(x0, y0).cover(x1, y1);

    // Add the new points.
    for (i = 0; i < n; ++i) {
      add$1(this, xz[i], yz[i], data[i]);
    }

    return this;
  }

  function tree_cover$1(x, y) {
    if (isNaN(x = +x) || isNaN(y = +y)) return this; // ignore invalid points

    var x0 = this._x0,
        y0 = this._y0,
        x1 = this._x1,
        y1 = this._y1;

    // If the quadtree has no extent, initialize them.
    // Integer extent are necessary so that if we later double the extent,
    // the existing quadrant boundaries don’t change due to floating point error!
    if (isNaN(x0)) {
      x1 = (x0 = Math.floor(x)) + 1;
      y1 = (y0 = Math.floor(y)) + 1;
    }

    // Otherwise, double repeatedly to cover.
    else {
      var z = x1 - x0 || 1,
          node = this._root,
          parent,
          i;

      while (x0 > x || x >= x1 || y0 > y || y >= y1) {
        i = (y < y0) << 1 | (x < x0);
        parent = new Array(4), parent[i] = node, node = parent, z *= 2;
        switch (i) {
          case 0: x1 = x0 + z, y1 = y0 + z; break;
          case 1: x0 = x1 - z, y1 = y0 + z; break;
          case 2: x1 = x0 + z, y0 = y1 - z; break;
          case 3: x0 = x1 - z, y0 = y1 - z; break;
        }
      }

      if (this._root && this._root.length) this._root = node;
    }

    this._x0 = x0;
    this._y0 = y0;
    this._x1 = x1;
    this._y1 = y1;
    return this;
  }

  function tree_data$1() {
    var data = [];
    this.visit(function(node) {
      if (!node.length) do data.push(node.data); while (node = node.next)
    });
    return data;
  }

  function tree_extent$1(_) {
    return arguments.length
        ? this.cover(+_[0][0], +_[0][1]).cover(+_[1][0], +_[1][1])
        : isNaN(this._x0) ? undefined : [[this._x0, this._y0], [this._x1, this._y1]];
  }

  function Quad(node, x0, y0, x1, y1) {
    this.node = node;
    this.x0 = x0;
    this.y0 = y0;
    this.x1 = x1;
    this.y1 = y1;
  }

  function tree_find$1(x, y, radius) {
    var data,
        x0 = this._x0,
        y0 = this._y0,
        x1,
        y1,
        x2,
        y2,
        x3 = this._x1,
        y3 = this._y1,
        quads = [],
        node = this._root,
        q,
        i;

    if (node) quads.push(new Quad(node, x0, y0, x3, y3));
    if (radius == null) radius = Infinity;
    else {
      x0 = x - radius, y0 = y - radius;
      x3 = x + radius, y3 = y + radius;
      radius *= radius;
    }

    while (q = quads.pop()) {

      // Stop searching if this quadrant can’t contain a closer node.
      if (!(node = q.node)
          || (x1 = q.x0) > x3
          || (y1 = q.y0) > y3
          || (x2 = q.x1) < x0
          || (y2 = q.y1) < y0) continue;

      // Bisect the current quadrant.
      if (node.length) {
        var xm = (x1 + x2) / 2,
            ym = (y1 + y2) / 2;

        quads.push(
          new Quad(node[3], xm, ym, x2, y2),
          new Quad(node[2], x1, ym, xm, y2),
          new Quad(node[1], xm, y1, x2, ym),
          new Quad(node[0], x1, y1, xm, ym)
        );

        // Visit the closest quadrant first.
        if (i = (y >= ym) << 1 | (x >= xm)) {
          q = quads[quads.length - 1];
          quads[quads.length - 1] = quads[quads.length - 1 - i];
          quads[quads.length - 1 - i] = q;
        }
      }

      // Visit this point. (Visiting coincident points isn’t necessary!)
      else {
        var dx = x - +this._x.call(null, node.data),
            dy = y - +this._y.call(null, node.data),
            d2 = dx * dx + dy * dy;
        if (d2 < radius) {
          var d = Math.sqrt(radius = d2);
          x0 = x - d, y0 = y - d;
          x3 = x + d, y3 = y + d;
          data = node.data;
        }
      }
    }

    return data;
  }

  function tree_remove$1(d) {
    if (isNaN(x = +this._x.call(null, d)) || isNaN(y = +this._y.call(null, d))) return this; // ignore invalid points

    var parent,
        node = this._root,
        retainer,
        previous,
        next,
        x0 = this._x0,
        y0 = this._y0,
        x1 = this._x1,
        y1 = this._y1,
        x,
        y,
        xm,
        ym,
        right,
        bottom,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return this;

    // Find the leaf node for the point.
    // While descending, also retain the deepest parent with a non-removed sibling.
    if (node.length) while (true) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
      if (!(parent = node, node = node[i = bottom << 1 | right])) return this;
      if (!node.length) break;
      if (parent[(i + 1) & 3] || parent[(i + 2) & 3] || parent[(i + 3) & 3]) retainer = parent, j = i;
    }

    // Find the point to remove.
    while (node.data !== d) if (!(previous = node, node = node.next)) return this;
    if (next = node.next) delete node.next;

    // If there are multiple coincident points, remove just the point.
    if (previous) return (next ? previous.next = next : delete previous.next), this;

    // If this is the root point, remove it.
    if (!parent) return this._root = next, this;

    // Remove this leaf.
    next ? parent[i] = next : delete parent[i];

    // If the parent now contains exactly one leaf, collapse superfluous parents.
    if ((node = parent[0] || parent[1] || parent[2] || parent[3])
        && node === (parent[3] || parent[2] || parent[1] || parent[0])
        && !node.length) {
      if (retainer) retainer[j] = node;
      else this._root = node;
    }

    return this;
  }

  function removeAll$1(data) {
    for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
    return this;
  }

  function tree_root$1() {
    return this._root;
  }

  function tree_size$1() {
    var size = 0;
    this.visit(function(node) {
      if (!node.length) do ++size; while (node = node.next)
    });
    return size;
  }

  function tree_visit$1(callback) {
    var quads = [], q, node = this._root, child, x0, y0, x1, y1;
    if (node) quads.push(new Quad(node, this._x0, this._y0, this._x1, this._y1));
    while (q = quads.pop()) {
      if (!callback(node = q.node, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1) && node.length) {
        var xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
        if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
        if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
        if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
        if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
      }
    }
    return this;
  }

  function tree_visitAfter$1(callback) {
    var quads = [], next = [], q;
    if (this._root) quads.push(new Quad(this._root, this._x0, this._y0, this._x1, this._y1));
    while (q = quads.pop()) {
      var node = q.node;
      if (node.length) {
        var child, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1, xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
        if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
        if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
        if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
        if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
      }
      next.push(q);
    }
    while (q = next.pop()) {
      callback(q.node, q.x0, q.y0, q.x1, q.y1);
    }
    return this;
  }

  function defaultX$1(d) {
    return d[0];
  }

  function tree_x$1(_) {
    return arguments.length ? (this._x = _, this) : this._x;
  }

  function defaultY$1(d) {
    return d[1];
  }

  function tree_y$1(_) {
    return arguments.length ? (this._y = _, this) : this._y;
  }

  function quadtree(nodes, x, y) {
    var tree = new Quadtree(x == null ? defaultX$1 : x, y == null ? defaultY$1 : y, NaN, NaN, NaN, NaN);
    return nodes == null ? tree : tree.addAll(nodes);
  }

  function Quadtree(x, y, x0, y0, x1, y1) {
    this._x = x;
    this._y = y;
    this._x0 = x0;
    this._y0 = y0;
    this._x1 = x1;
    this._y1 = y1;
    this._root = undefined;
  }

  function leaf_copy$1(leaf) {
    var copy = {data: leaf.data}, next = copy;
    while (leaf = leaf.next) next = next.next = {data: leaf.data};
    return copy;
  }

  var treeProto$1 = quadtree.prototype = Quadtree.prototype;

  treeProto$1.copy = function() {
    var copy = new Quadtree(this._x, this._y, this._x0, this._y0, this._x1, this._y1),
        node = this._root,
        nodes,
        child;

    if (!node) return copy;

    if (!node.length) return copy._root = leaf_copy$1(node), copy;

    nodes = [{source: node, target: copy._root = new Array(4)}];
    while (node = nodes.pop()) {
      for (var i = 0; i < 4; ++i) {
        if (child = node.source[i]) {
          if (child.length) nodes.push({source: child, target: node.target[i] = new Array(4)});
          else node.target[i] = leaf_copy$1(child);
        }
      }
    }

    return copy;
  };

  treeProto$1.add = tree_add$1;
  treeProto$1.addAll = addAll$1;
  treeProto$1.cover = tree_cover$1;
  treeProto$1.data = tree_data$1;
  treeProto$1.extent = tree_extent$1;
  treeProto$1.find = tree_find$1;
  treeProto$1.remove = tree_remove$1;
  treeProto$1.removeAll = removeAll$1;
  treeProto$1.root = tree_root$1;
  treeProto$1.size = tree_size$1;
  treeProto$1.visit = tree_visit$1;
  treeProto$1.visitAfter = tree_visitAfter$1;
  treeProto$1.x = tree_x$1;
  treeProto$1.y = tree_y$1;

  function tree_add(d) {
    const x = +this._x.call(null, d),
        y = +this._y.call(null, d),
        z = +this._z.call(null, d);
    return add(this.cover(x, y, z), x, y, z, d);
  }

  function add(tree, x, y, z, d) {
    if (isNaN(x) || isNaN(y) || isNaN(z)) return tree; // ignore invalid points

    var parent,
        node = tree._root,
        leaf = {data: d},
        x0 = tree._x0,
        y0 = tree._y0,
        z0 = tree._z0,
        x1 = tree._x1,
        y1 = tree._y1,
        z1 = tree._z1,
        xm,
        ym,
        zm,
        xp,
        yp,
        zp,
        right,
        bottom,
        deep,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return tree._root = leaf, tree;

    // Find the existing leaf for the new point, or add it.
    while (node.length) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
      if (deep = z >= (zm = (z0 + z1) / 2)) z0 = zm; else z1 = zm;
      if (parent = node, !(node = node[i = deep << 2 | bottom << 1 | right])) return parent[i] = leaf, tree;
    }

    // Is the new point is exactly coincident with the existing point?
    xp = +tree._x.call(null, node.data);
    yp = +tree._y.call(null, node.data);
    zp = +tree._z.call(null, node.data);
    if (x === xp && y === yp && z === zp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;

    // Otherwise, split the leaf node until the old and new point are separated.
    do {
      parent = parent ? parent[i] = new Array(8) : tree._root = new Array(8);
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
      if (deep = z >= (zm = (z0 + z1) / 2)) z0 = zm; else z1 = zm;
    } while ((i = deep << 2 | bottom << 1 | right) === (j = (zp >= zm) << 2 | (yp >= ym) << 1 | (xp >= xm)));
    return parent[j] = node, parent[i] = leaf, tree;
  }

  function addAll(data) {
    if (!Array.isArray(data)) data = Array.from(data);
    const n = data.length;
    const xz = new Float64Array(n);
    const yz = new Float64Array(n);
    const zz = new Float64Array(n);
    let x0 = Infinity,
        y0 = Infinity,
        z0 = Infinity,
        x1 = -Infinity,
        y1 = -Infinity,
        z1 = -Infinity;

    // Compute the points and their extent.
    for (let i = 0, d, x, y, z; i < n; ++i) {
      if (isNaN(x = +this._x.call(null, d = data[i])) || isNaN(y = +this._y.call(null, d)) || isNaN(z = +this._z.call(null, d))) continue;
      xz[i] = x;
      yz[i] = y;
      zz[i] = z;
      if (x < x0) x0 = x;
      if (x > x1) x1 = x;
      if (y < y0) y0 = y;
      if (y > y1) y1 = y;
      if (z < z0) z0 = z;
      if (z > z1) z1 = z;
    }

    // If there were no (valid) points, abort.
    if (x0 > x1 || y0 > y1 || z0 > z1) return this;

    // Expand the tree to cover the new points.
    this.cover(x0, y0, z0).cover(x1, y1, z1);

    // Add the new points.
    for (let i = 0; i < n; ++i) {
      add(this, xz[i], yz[i], zz[i], data[i]);
    }

    return this;
  }

  function tree_cover(x, y, z) {
    if (isNaN(x = +x) || isNaN(y = +y) || isNaN(z = +z)) return this; // ignore invalid points

    var x0 = this._x0,
        y0 = this._y0,
        z0 = this._z0,
        x1 = this._x1,
        y1 = this._y1,
        z1 = this._z1;

    // If the octree has no extent, initialize them.
    // Integer extent are necessary so that if we later double the extent,
    // the existing octant boundaries don’t change due to floating point error!
    if (isNaN(x0)) {
      x1 = (x0 = Math.floor(x)) + 1;
      y1 = (y0 = Math.floor(y)) + 1;
      z1 = (z0 = Math.floor(z)) + 1;
    }

    // Otherwise, double repeatedly to cover.
    else {
      var t = x1 - x0 || 1,
          node = this._root,
          parent,
          i;

      while (x0 > x || x >= x1 || y0 > y || y >= y1 || z0 > z || z >= z1) {
        i = (z < z0) << 2 | (y < y0) << 1 | (x < x0);
        parent = new Array(8), parent[i] = node, node = parent, t *= 2;
        switch (i) {
          case 0: x1 = x0 + t, y1 = y0 + t, z1 = z0 + t; break;
          case 1: x0 = x1 - t, y1 = y0 + t, z1 = z0 + t; break;
          case 2: x1 = x0 + t, y0 = y1 - t, z1 = z0 + t; break;
          case 3: x0 = x1 - t, y0 = y1 - t, z1 = z0 + t; break;
          case 4: x1 = x0 + t, y1 = y0 + t, z0 = z1 - t; break;
          case 5: x0 = x1 - t, y1 = y0 + t, z0 = z1 - t; break;
          case 6: x1 = x0 + t, y0 = y1 - t, z0 = z1 - t; break;
          case 7: x0 = x1 - t, y0 = y1 - t, z0 = z1 - t; break;
        }
      }

      if (this._root && this._root.length) this._root = node;
    }

    this._x0 = x0;
    this._y0 = y0;
    this._z0 = z0;
    this._x1 = x1;
    this._y1 = y1;
    this._z1 = z1;
    return this;
  }

  function tree_data() {
    var data = [];
    this.visit(function(node) {
      if (!node.length) do data.push(node.data); while (node = node.next)
    });
    return data;
  }

  function tree_extent(_) {
    return arguments.length
        ? this.cover(+_[0][0], +_[0][1], +_[0][2]).cover(+_[1][0], +_[1][1], +_[1][2])
        : isNaN(this._x0) ? undefined : [[this._x0, this._y0, this._z0], [this._x1, this._y1, this._z1]];
  }

  function Octant(node, x0, y0, z0, x1, y1, z1) {
    this.node = node;
    this.x0 = x0;
    this.y0 = y0;
    this.z0 = z0;
    this.x1 = x1;
    this.y1 = y1;
    this.z1 = z1;
  }

  function tree_find(x, y, z, radius) {
    var data,
        x0 = this._x0,
        y0 = this._y0,
        z0 = this._z0,
        x1,
        y1,
        z1,
        x2,
        y2,
        z2,
        x3 = this._x1,
        y3 = this._y1,
        z3 = this._z1,
        octs = [],
        node = this._root,
        q,
        i;

    if (node) octs.push(new Octant(node, x0, y0, z0, x3, y3, z3));
    if (radius == null) radius = Infinity;
    else {
      x0 = x - radius, y0 = y - radius, z0 = z - radius;
      x3 = x + radius, y3 = y + radius, z3 = z + radius;
      radius *= radius;
    }

    while (q = octs.pop()) {

      // Stop searching if this octant can’t contain a closer node.
      if (!(node = q.node)
          || (x1 = q.x0) > x3
          || (y1 = q.y0) > y3
          || (z1 = q.z0) > z3
          || (x2 = q.x1) < x0
          || (y2 = q.y1) < y0
          || (z2 = q.z1) < z0) continue;

      // Bisect the current octant.
      if (node.length) {
        var xm = (x1 + x2) / 2,
            ym = (y1 + y2) / 2,
            zm = (z1 + z2) / 2;

        octs.push(
          new Octant(node[7], xm, ym, zm, x2, y2, z2),
          new Octant(node[6], x1, ym, zm, xm, y2, z2),
          new Octant(node[5], xm, y1, zm, x2, ym, z2),
          new Octant(node[4], x1, y1, zm, xm, ym, z2),
          new Octant(node[3], xm, ym, z1, x2, y2, zm),
          new Octant(node[2], x1, ym, z1, xm, y2, zm),
          new Octant(node[1], xm, y1, z1, x2, ym, zm),
          new Octant(node[0], x1, y1, z1, xm, ym, zm)
        );

        // Visit the closest octant first.
        if (i = (z >= zm) << 2 | (y >= ym) << 1 | (x >= xm)) {
          q = octs[octs.length - 1];
          octs[octs.length - 1] = octs[octs.length - 1 - i];
          octs[octs.length - 1 - i] = q;
        }
      }

      // Visit this point. (Visiting coincident points isn’t necessary!)
      else {
        var dx = x - +this._x.call(null, node.data),
            dy = y - +this._y.call(null, node.data),
            dz = z - +this._z.call(null, node.data),
            d2 = dx * dx + dy * dy + dz * dz;
        if (d2 < radius) {
          var d = Math.sqrt(radius = d2);
          x0 = x - d, y0 = y - d, z0 = z - d;
          x3 = x + d, y3 = y + d, z3 = z + d;
          data = node.data;
        }
      }
    }

    return data;
  }

  function tree_remove(d) {
    if (isNaN(x = +this._x.call(null, d)) || isNaN(y = +this._y.call(null, d)) || isNaN(z = +this._z.call(null, d))) return this; // ignore invalid points

    var parent,
        node = this._root,
        retainer,
        previous,
        next,
        x0 = this._x0,
        y0 = this._y0,
        z0 = this._z0,
        x1 = this._x1,
        y1 = this._y1,
        z1 = this._z1,
        x,
        y,
        z,
        xm,
        ym,
        zm,
        right,
        bottom,
        deep,
        i,
        j;

    // If the tree is empty, initialize the root as a leaf.
    if (!node) return this;

    // Find the leaf node for the point.
    // While descending, also retain the deepest parent with a non-removed sibling.
    if (node.length) while (true) {
      if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
      if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
      if (deep = z >= (zm = (z0 + z1) / 2)) z0 = zm; else z1 = zm;
      if (!(parent = node, node = node[i = deep << 2 | bottom << 1 | right])) return this;
      if (!node.length) break;
      if (parent[(i + 1) & 7] || parent[(i + 2) & 7] || parent[(i + 3) & 7] || parent[(i + 4) & 7] || parent[(i + 5) & 7] || parent[(i + 6) & 7] || parent[(i + 7) & 7]) retainer = parent, j = i;
    }

    // Find the point to remove.
    while (node.data !== d) if (!(previous = node, node = node.next)) return this;
    if (next = node.next) delete node.next;

    // If there are multiple coincident points, remove just the point.
    if (previous) return (next ? previous.next = next : delete previous.next), this;

    // If this is the root point, remove it.
    if (!parent) return this._root = next, this;

    // Remove this leaf.
    next ? parent[i] = next : delete parent[i];

    // If the parent now contains exactly one leaf, collapse superfluous parents.
    if ((node = parent[0] || parent[1] || parent[2] || parent[3] || parent[4] || parent[5] || parent[6] || parent[7])
        && node === (parent[7] || parent[6] || parent[5] || parent[4] || parent[3] || parent[2] || parent[1] || parent[0])
        && !node.length) {
      if (retainer) retainer[j] = node;
      else this._root = node;
    }

    return this;
  }

  function removeAll(data) {
    for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
    return this;
  }

  function tree_root() {
    return this._root;
  }

  function tree_size() {
    var size = 0;
    this.visit(function(node) {
      if (!node.length) do ++size; while (node = node.next)
    });
    return size;
  }

  function tree_visit(callback) {
    var octs = [], q, node = this._root, child, x0, y0, z0, x1, y1, z1;
    if (node) octs.push(new Octant(node, this._x0, this._y0, this._z0, this._x1, this._y1, this._z1));
    while (q = octs.pop()) {
      if (!callback(node = q.node, x0 = q.x0, y0 = q.y0, z0 = q.z0, x1 = q.x1, y1 = q.y1, z1 = q.z1) && node.length) {
        var xm = (x0 + x1) / 2, ym = (y0 + y1) / 2, zm = (z0 + z1) / 2;
        if (child = node[7]) octs.push(new Octant(child, xm, ym, zm, x1, y1, z1));
        if (child = node[6]) octs.push(new Octant(child, x0, ym, zm, xm, y1, z1));
        if (child = node[5]) octs.push(new Octant(child, xm, y0, zm, x1, ym, z1));
        if (child = node[4]) octs.push(new Octant(child, x0, y0, zm, xm, ym, z1));
        if (child = node[3]) octs.push(new Octant(child, xm, ym, z0, x1, y1, zm));
        if (child = node[2]) octs.push(new Octant(child, x0, ym, z0, xm, y1, zm));
        if (child = node[1]) octs.push(new Octant(child, xm, y0, z0, x1, ym, zm));
        if (child = node[0]) octs.push(new Octant(child, x0, y0, z0, xm, ym, zm));
      }
    }
    return this;
  }

  function tree_visitAfter(callback) {
    var octs = [], next = [], q;
    if (this._root) octs.push(new Octant(this._root, this._x0, this._y0, this._z0, this._x1, this._y1, this._z1));
    while (q = octs.pop()) {
      var node = q.node;
      if (node.length) {
        var child, x0 = q.x0, y0 = q.y0, z0 = q.z0, x1 = q.x1, y1 = q.y1, z1 = q.z1, xm = (x0 + x1) / 2, ym = (y0 + y1) / 2, zm = (z0 + z1) / 2;
        if (child = node[0]) octs.push(new Octant(child, x0, y0, z0, xm, ym, zm));
        if (child = node[1]) octs.push(new Octant(child, xm, y0, z0, x1, ym, zm));
        if (child = node[2]) octs.push(new Octant(child, x0, ym, z0, xm, y1, zm));
        if (child = node[3]) octs.push(new Octant(child, xm, ym, z0, x1, y1, zm));
        if (child = node[4]) octs.push(new Octant(child, x0, y0, zm, xm, ym, z1));
        if (child = node[5]) octs.push(new Octant(child, xm, y0, zm, x1, ym, z1));
        if (child = node[6]) octs.push(new Octant(child, x0, ym, zm, xm, y1, z1));
        if (child = node[7]) octs.push(new Octant(child, xm, ym, zm, x1, y1, z1));
      }
      next.push(q);
    }
    while (q = next.pop()) {
      callback(q.node, q.x0, q.y0, q.z0, q.x1, q.y1, q.z1);
    }
    return this;
  }

  function defaultX(d) {
    return d[0];
  }

  function tree_x(_) {
    return arguments.length ? (this._x = _, this) : this._x;
  }

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

  function tree_y(_) {
    return arguments.length ? (this._y = _, this) : this._y;
  }

  function defaultZ(d) {
    return d[2];
  }

  function tree_z(_) {
    return arguments.length ? (this._z = _, this) : this._z;
  }

  function octree(nodes, x, y, z) {
    var tree = new Octree(x == null ? defaultX : x, y == null ? defaultY : y, z == null ? defaultZ : z, NaN, NaN, NaN, NaN, NaN, NaN);
    return nodes == null ? tree : tree.addAll(nodes);
  }

  function Octree(x, y, z, x0, y0, z0, x1, y1, z1) {
    this._x = x;
    this._y = y;
    this._z = z;
    this._x0 = x0;
    this._y0 = y0;
    this._z0 = z0;
    this._x1 = x1;
    this._y1 = y1;
    this._z1 = z1;
    this._root = undefined;
  }

  function leaf_copy(leaf) {
    var copy = {data: leaf.data}, next = copy;
    while (leaf = leaf.next) next = next.next = {data: leaf.data};
    return copy;
  }

  var treeProto = octree.prototype = Octree.prototype;

  treeProto.copy = function() {
    var copy = new Octree(this._x, this._y, this._z, this._x0, this._y0, this._z0, this._x1, this._y1, this._z1),
        node = this._root,
        nodes,
        child;

    if (!node) return copy;

    if (!node.length) return copy._root = leaf_copy(node), copy;

    nodes = [{source: node, target: copy._root = new Array(8)}];
    while (node = nodes.pop()) {
      for (var i = 0; i < 8; ++i) {
        if (child = node.source[i]) {
          if (child.length) nodes.push({source: child, target: node.target[i] = new Array(8)});
          else node.target[i] = leaf_copy(child);
        }
      }
    }

    return copy;
  };

  treeProto.add = tree_add;
  treeProto.addAll = addAll;
  treeProto.cover = tree_cover;
  treeProto.data = tree_data;
  treeProto.extent = tree_extent;
  treeProto.find = tree_find;
  treeProto.remove = tree_remove;
  treeProto.removeAll = removeAll;
  treeProto.root = tree_root;
  treeProto.size = tree_size;
  treeProto.visit = tree_visit;
  treeProto.visitAfter = tree_visitAfter;
  treeProto.x = tree_x;
  treeProto.y = tree_y;
  treeProto.z = tree_z;

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

  function jiggle(random) {
    return (random() - 0.5) * 1e-6;
  }

  function index$1(d) {
    return d.index;
  }

  function find(nodeById, nodeId) {
    var node = nodeById.get(nodeId);
    if (!node) throw new Error("node not found: " + nodeId);
    return node;
  }

  function d3ForceLink(links) {
    var id = index$1,
        strength = defaultStrength,
        strengths,
        distance = constant(30),
        distances,
        nodes,
        nDim,
        count,
        bias,
        random,
        iterations = 1;

    if (links == null) links = [];

    function defaultStrength(link) {
      return 1 / Math.min(count[link.source.index], count[link.target.index]);
    }

    function force(alpha) {
      for (var k = 0, n = links.length; k < iterations; ++k) {
        for (var i = 0, link, source, target, x = 0, y = 0, z = 0, l, b; i < n; ++i) {
          link = links[i], source = link.source, target = link.target;
          x = target.x + target.vx - source.x - source.vx || jiggle(random);
          if (nDim > 1) { y = target.y + target.vy - source.y - source.vy || jiggle(random); }
          if (nDim > 2) { z = target.z + target.vz - source.z - source.vz || jiggle(random); }
          l = Math.sqrt(x * x + y * y + z * z);
          l = (l - distances[i]) / l * alpha * strengths[i];
          x *= l, y *= l, z *= l;

          target.vx -= x * (b = bias[i]);
          if (nDim > 1) { target.vy -= y * b; }
          if (nDim > 2) { target.vz -= z * b; }

          source.vx += x * (b = 1 - b);
          if (nDim > 1) { source.vy += y * b; }
          if (nDim > 2) { source.vz += z * b; }
        }
      }
    }

    function initialize() {
      if (!nodes) return;

      var i,
          n = nodes.length,
          m = links.length,
          nodeById = new Map(nodes.map((d, i) => [id(d, i, nodes), d])),
          link;

      for (i = 0, count = new Array(n); i < m; ++i) {
        link = links[i], link.index = i;
        if (typeof link.source !== "object") link.source = find(nodeById, link.source);
        if (typeof link.target !== "object") link.target = find(nodeById, link.target);
        count[link.source.index] = (count[link.source.index] || 0) + 1;
        count[link.target.index] = (count[link.target.index] || 0) + 1;
      }

      for (i = 0, bias = new Array(m); i < m; ++i) {
        link = links[i], bias[i] = count[link.source.index] / (count[link.source.index] + count[link.target.index]);
      }

      strengths = new Array(m), initializeStrength();
      distances = new Array(m), initializeDistance();
    }

    function initializeStrength() {
      if (!nodes) return;

      for (var i = 0, n = links.length; i < n; ++i) {
        strengths[i] = +strength(links[i], i, links);
      }
    }

    function initializeDistance() {
      if (!nodes) return;

      for (var i = 0, n = links.length; i < n; ++i) {
        distances[i] = +distance(links[i], i, links);
      }
    }

    force.initialize = function(_nodes, ...args) {
      nodes = _nodes;
      random = args.find(arg => typeof arg === 'function') || Math.random;
      nDim = args.find(arg => [1, 2, 3].includes(arg)) || 2;
      initialize();
    };

    force.links = function(_) {
      return arguments.length ? (links = _, initialize(), force) : links;
    };

    force.id = function(_) {
      return arguments.length ? (id = _, force) : id;
    };

    force.iterations = function(_) {
      return arguments.length ? (iterations = +_, force) : iterations;
    };

    force.strength = function(_) {
      return arguments.length ? (strength = typeof _ === "function" ? _ : constant(+_), initializeStrength(), force) : strength;
    };

    force.distance = function(_) {
      return arguments.length ? (distance = typeof _ === "function" ? _ : constant(+_), initializeDistance(), force) : distance;
    };

    return force;
  }

  // https://en.wikipedia.org/wiki/Linear_congruential_generator#Parameters_in_common_use
  const a = 1664525;
  const c = 1013904223;
  const m = 4294967296; // 2^32

  function lcg() {
    let s = 1;
    return () => (s = (a * s + c) % m) / m;
  }

  var MAX_DIMENSIONS = 3;

  function x(d) {
    return d.x;
  }

  function y(d) {
    return d.y;
  }

  function z(d) {
    return d.z;
  }

  var initialRadius = 10,
      initialAngleRoll = Math.PI * (3 - Math.sqrt(5)), // Golden ratio angle
      initialAngleYaw = Math.PI * 20 / (9 + Math.sqrt(221)); // Markov irrational number

  function d3ForceSimulation(nodes, numDimensions) {
    numDimensions = numDimensions || 2;

    var nDim = Math.min(MAX_DIMENSIONS, Math.max(1, Math.round(numDimensions))),
        simulation,
        alpha = 1,
        alphaMin = 0.001,
        alphaDecay = 1 - Math.pow(alphaMin, 1 / 300),
        alphaTarget = 0,
        velocityDecay = 0.6,
        forces = new Map(),
        stepper = timer(step),
        event = dispatch("tick", "end"),
        random = lcg();

    if (nodes == null) nodes = [];

    function step() {
      tick();
      event.call("tick", simulation);
      if (alpha < alphaMin) {
        stepper.stop();
        event.call("end", simulation);
      }
    }

    function tick(iterations) {
      var i, n = nodes.length, node;

      if (iterations === undefined) iterations = 1;

      for (var k = 0; k < iterations; ++k) {
        alpha += (alphaTarget - alpha) * alphaDecay;

        forces.forEach(function (force) {
          force(alpha);
        });

        for (i = 0; i < n; ++i) {
          node = nodes[i];
          if (node.fx == null) node.x += node.vx *= velocityDecay;
          else node.x = node.fx, node.vx = 0;
          if (nDim > 1) {
            if (node.fy == null) node.y += node.vy *= velocityDecay;
            else node.y = node.fy, node.vy = 0;
          }
          if (nDim > 2) {
            if (node.fz == null) node.z += node.vz *= velocityDecay;
            else node.z = node.fz, node.vz = 0;
          }
        }
      }

      return simulation;
    }

    function initializeNodes() {
      for (var i = 0, n = nodes.length, node; i < n; ++i) {
        node = nodes[i], node.index = i;
        if (node.fx != null) node.x = node.fx;
        if (node.fy != null) node.y = node.fy;
        if (node.fz != null) node.z = node.fz;
        if (isNaN(node.x) || (nDim > 1 && isNaN(node.y)) || (nDim > 2 && isNaN(node.z))) {
          var radius = initialRadius * (nDim > 2 ? Math.cbrt(0.5 + i) : (nDim > 1 ? Math.sqrt(0.5 + i) : i)),
            rollAngle = i * initialAngleRoll,
            yawAngle = i * initialAngleYaw;

          if (nDim === 1) {
            node.x = radius;
          } else if (nDim === 2) {
            node.x = radius * Math.cos(rollAngle);
            node.y = radius * Math.sin(rollAngle);
          } else { // 3 dimensions: use spherical distribution along 2 irrational number angles
            node.x = radius * Math.sin(rollAngle) * Math.cos(yawAngle);
            node.y = radius * Math.cos(rollAngle);
            node.z = radius * Math.sin(rollAngle) * Math.sin(yawAngle);
          }
        }
        if (isNaN(node.vx) || (nDim > 1 && isNaN(node.vy)) || (nDim > 2 && isNaN(node.vz))) {
          node.vx = 0;
          if (nDim > 1) { node.vy = 0; }
          if (nDim > 2) { node.vz = 0; }
        }
      }
    }

    function initializeForce(force) {
      if (force.initialize) force.initialize(nodes, random, nDim);
      return force;
    }

    initializeNodes();

    return simulation = {
      tick: tick,

      restart: function() {
        return stepper.restart(step), simulation;
      },

      stop: function() {
        return stepper.stop(), simulation;
      },

      numDimensions: function(_) {
        return arguments.length
            ? (nDim = Math.min(MAX_DIMENSIONS, Math.max(1, Math.round(_))), forces.forEach(initializeForce), simulation)
            : nDim;
      },

      nodes: function(_) {
        return arguments.length ? (nodes = _, initializeNodes(), forces.forEach(initializeForce), simulation) : nodes;
      },

      alpha: function(_) {
        return arguments.length ? (alpha = +_, simulation) : alpha;
      },

      alphaMin: function(_) {
        return arguments.length ? (alphaMin = +_, simulation) : alphaMin;
      },

      alphaDecay: function(_) {
        return arguments.length ? (alphaDecay = +_, simulation) : +alphaDecay;
      },

      alphaTarget: function(_) {
        return arguments.length ? (alphaTarget = +_, simulation) : alphaTarget;
      },

      velocityDecay: function(_) {
        return arguments.length ? (velocityDecay = 1 - _, simulation) : 1 - velocityDecay;
      },

      randomSource: function(_) {
        return arguments.length ? (random = _, forces.forEach(initializeForce), simulation) : random;
      },

      force: function(name, _) {
        return arguments.length > 1 ? ((_ == null ? forces.delete(name) : forces.set(name, initializeForce(_))), simulation) : forces.get(name);
      },

      find: function() {
        var args = Array.prototype.slice.call(arguments);
        var x = args.shift() || 0,
            y = (nDim > 1 ? args.shift() : null) || 0,
            z = (nDim > 2 ? args.shift() : null) || 0,
            radius = args.shift() || Infinity;

        var i = 0,
            n = nodes.length,
            dx,
            dy,
            dz,
            d2,
            node,
            closest;

        radius *= radius;

        for (i = 0; i < n; ++i) {
          node = nodes[i];
          dx = x - node.x;
          dy = y - (node.y || 0);
          dz = z - (node.z ||0);
          d2 = dx * dx + dy * dy + dz * dz;
          if (d2 < radius) closest = node, radius = d2;
        }

        return closest;
      },

      on: function(name, _) {
        return arguments.length > 1 ? (event.on(name, _), simulation) : event.on(name);
      }
    };
  }

  function d3ForceManyBody() {
    var nodes,
        nDim,
        node,
        random,
        alpha,
        strength = constant(-30),
        strengths,
        distanceMin2 = 1,
        distanceMax2 = Infinity,
        theta2 = 0.81;

    function force(_) {
      var i,
          n = nodes.length,
          tree =
              (nDim === 1 ? binarytree(nodes, x)
              :(nDim === 2 ? quadtree(nodes, x, y)
              :(nDim === 3 ? octree(nodes, x, y, z)
              :null
          ))).visitAfter(accumulate);

      for (alpha = _, i = 0; i < n; ++i) node = nodes[i], tree.visit(apply);
    }

    function initialize() {
      if (!nodes) return;
      var i, n = nodes.length, node;
      strengths = new Array(n);
      for (i = 0; i < n; ++i) node = nodes[i], strengths[node.index] = +strength(node, i, nodes);
    }

    function accumulate(treeNode) {
      var strength = 0, q, c, weight = 0, x, y, z, i;
      var numChildren = treeNode.length;

      // For internal nodes, accumulate forces from children.
      if (numChildren) {
        for (x = y = z = i = 0; i < numChildren; ++i) {
          if ((q = treeNode[i]) && (c = Math.abs(q.value))) {
            strength += q.value, weight += c, x += c * (q.x || 0), y += c * (q.y || 0), z += c * (q.z || 0);
          }
        }
        strength *= Math.sqrt(4 / numChildren); // scale accumulated strength according to number of dimensions

        treeNode.x = x / weight;
        if (nDim > 1) { treeNode.y = y / weight; }
        if (nDim > 2) { treeNode.z = z / weight; }
      }

      // For leaf nodes, accumulate forces from coincident nodes.
      else {
        q = treeNode;
        q.x = q.data.x;
        if (nDim > 1) { q.y = q.data.y; }
        if (nDim > 2) { q.z = q.data.z; }
        do strength += strengths[q.data.index];
        while (q = q.next);
      }

      treeNode.value = strength;
    }

    function apply(treeNode, x1, arg1, arg2, arg3) {
      if (!treeNode.value) return true;
      var x2 = [arg1, arg2, arg3][nDim-1];

      var x = treeNode.x - node.x,
          y = (nDim > 1 ? treeNode.y - node.y : 0),
          z = (nDim > 2 ? treeNode.z - node.z : 0),
          w = x2 - x1,
          l = x * x + y * y + z * z;

      // Apply the Barnes-Hut approximation if possible.
      // Limit forces for very close nodes; randomize direction if coincident.
      if (w * w / theta2 < l) {
        if (l < distanceMax2) {
          if (x === 0) x = jiggle(random), l += x * x;
          if (nDim > 1 && y === 0) y = jiggle(random), l += y * y;
          if (nDim > 2 && z === 0) z = jiggle(random), l += z * z;
          if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
          node.vx += x * treeNode.value * alpha / l;
          if (nDim > 1) { node.vy += y * treeNode.value * alpha / l; }
          if (nDim > 2) { node.vz += z * treeNode.value * alpha / l; }
        }
        return true;
      }

      // Otherwise, process points directly.
      else if (treeNode.length || l >= distanceMax2) return;

      // Limit forces for very close nodes; randomize direction if coincident.
      if (treeNode.data !== node || treeNode.next) {
        if (x === 0) x = jiggle(random), l += x * x;
        if (nDim > 1 && y === 0) y = jiggle(random), l += y * y;
        if (nDim > 2 && z === 0) z = jiggle(random), l += z * z;
        if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
      }

      do if (treeNode.data !== node) {
        w = strengths[treeNode.data.index] * alpha / l;
        node.vx += x * w;
        if (nDim > 1) { node.vy += y * w; }
        if (nDim > 2) { node.vz += z * w; }
      } while (treeNode = treeNode.next);
    }

    force.initialize = function(_nodes, ...args) {
      nodes = _nodes;
      random = args.find(arg => typeof arg === 'function') || Math.random;
      nDim = args.find(arg => [1, 2, 3].includes(arg)) || 2;
      initialize();
    };

    force.strength = function(_) {
      return arguments.length ? (strength = typeof _ === "function" ? _ : constant(+_), initialize(), force) : strength;
    };

    force.distanceMin = function(_) {
      return arguments.length ? (distanceMin2 = _ * _, force) : Math.sqrt(distanceMin2);
    };

    force.distanceMax = function(_) {
      return arguments.length ? (distanceMax2 = _ * _, force) : Math.sqrt(distanceMax2);
    };

    force.theta = function(_) {
      return arguments.length ? (theta2 = _ * _, force) : Math.sqrt(theta2);
    };

    return force;
  }

  function d3ForceRadial(radius, x, y, z) {
    var nodes,
        nDim,
        strength = constant(0.1),
        strengths,
        radiuses;

    if (typeof radius !== "function") radius = constant(+radius);
    if (x == null) x = 0;
    if (y == null) y = 0;
    if (z == null) z = 0;

    function force(alpha) {
      for (var i = 0, n = nodes.length; i < n; ++i) {
        var node = nodes[i],
            dx = node.x - x || 1e-6,
            dy = (node.y || 0) - y || 1e-6,
            dz = (node.z || 0) - z || 1e-6,
            r = Math.sqrt(dx * dx + dy * dy + dz * dz),
            k = (radiuses[i] - r) * strengths[i] * alpha / r;
        node.vx += dx * k;
        if (nDim>1) { node.vy += dy * k; }
        if (nDim>2) { node.vz += dz * k; }
      }
    }

    function initialize() {
      if (!nodes) return;
      var i, n = nodes.length;
      strengths = new Array(n);
      radiuses = new Array(n);
      for (i = 0; i < n; ++i) {
        radiuses[i] = +radius(nodes[i], i, nodes);
        strengths[i] = isNaN(radiuses[i]) ? 0 : +strength(nodes[i], i, nodes);
      }
    }

    force.initialize = function(initNodes, ...args) {
      nodes = initNodes;
      nDim = args.find(arg => [1, 2, 3].includes(arg)) || 2;
      initialize();
    };

    force.strength = function(_) {
      return arguments.length ? (strength = typeof _ === "function" ? _ : constant(+_), initialize(), force) : strength;
    };

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

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

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

    force.z = function(_) {
      return arguments.length ? (z = +_, force) : z;
    };

    return force;
  }

  // math-inlining.
  const { abs: abs$1, cos: cos$1, sin: sin$1, acos: acos$1, atan2, sqrt: sqrt$1, pow } = Math;

  // cube root function yielding real roots
  function crt(v) {
    return v < 0 ? -pow(-v, 1 / 3) : pow(v, 1 / 3);
  }

  // trig constants
  const pi$1 = Math.PI,
    tau = 2 * pi$1,
    quart = pi$1 / 2,
    // float precision significant decimal
    epsilon = 0.000001,
    // extremas used in bbox calculation and similar algorithms
    nMax = Number.MAX_SAFE_INTEGER || 9007199254740991,
    nMin = Number.MIN_SAFE_INTEGER || -9007199254740991,
    // a zero coordinate, which is surprisingly useful
    ZERO = { x: 0, y: 0, z: 0 };

  // Bezier utility functions
  const utils = {
    // Legendre-Gauss abscissae with n=24 (x_i values, defined at i=n as the roots of the nth order Legendre polynomial Pn(x))
    Tvalues: [
      -0.0640568928626056260850430826247450385909,
      0.0640568928626056260850430826247450385909,
      -0.1911188674736163091586398207570696318404,
      0.1911188674736163091586398207570696318404,
      -0.3150426796961633743867932913198102407864,
      0.3150426796961633743867932913198102407864,
      -0.4337935076260451384870842319133497124524,
      0.4337935076260451384870842319133497124524,
      -0.5454214713888395356583756172183723700107,
      0.5454214713888395356583756172183723700107,
      -0.6480936519369755692524957869107476266696,
      0.6480936519369755692524957869107476266696,
      -0.7401241915785543642438281030999784255232,
      0.7401241915785543642438281030999784255232,
      -0.8200019859739029219539498726697452080761,
      0.8200019859739029219539498726697452080761,
      -0.8864155270044010342131543419821967550873,
      0.8864155270044010342131543419821967550873,
      -0.9382745520027327585236490017087214496548,
      0.9382745520027327585236490017087214496548,
      -0.9747285559713094981983919930081690617411,
      0.9747285559713094981983919930081690617411,
      -0.9951872199970213601799974097007368118745,
      0.9951872199970213601799974097007368118745,
    ],

    // Legendre-Gauss weights with n=24 (w_i values, defined by a function linked to in the Bezier primer article)
    Cvalues: [
      0.1279381953467521569740561652246953718517,
      0.1279381953467521569740561652246953718517,
      0.1258374563468282961213753825111836887264,
      0.1258374563468282961213753825111836887264,
      0.121670472927803391204463153476262425607,
      0.121670472927803391204463153476262425607,
      0.1155056680537256013533444839067835598622,
      0.1155056680537256013533444839067835598622,
      0.1074442701159656347825773424466062227946,
      0.1074442701159656347825773424466062227946,
      0.0976186521041138882698806644642471544279,
      0.0976186521041138882698806644642471544279,
      0.086190161531953275917185202983742667185,
      0.086190161531953275917185202983742667185,
      0.0733464814110803057340336152531165181193,
      0.0733464814110803057340336152531165181193,
      0.0592985849154367807463677585001085845412,
      0.0592985849154367807463677585001085845412,
      0.0442774388174198061686027482113382288593,
      0.0442774388174198061686027482113382288593,
      0.0285313886289336631813078159518782864491,
      0.0285313886289336631813078159518782864491,
      0.0123412297999871995468056670700372915759,
      0.0123412297999871995468056670700372915759,
    ],

    arcfn: function (t, derivativeFn) {
      const d = derivativeFn(t);
      let l = d.x * d.x + d.y * d.y;
      if (typeof d.z !== "undefined") {
        l += d.z * d.z;
      }
      return sqrt$1(l);
    },

    compute: function (t, points, _3d) {
      // shortcuts
      if (t === 0) {
        points[0].t = 0;
        return points[0];
      }

      const order = points.length - 1;

      if (t === 1) {
        points[order].t = 1;
        return points[order];
      }

      const mt = 1 - t;
      let p = points;

      // constant?
      if (order === 0) {
        points[0].t = t;
        return points[0];
      }

      // linear?
      if (order === 1) {
        const ret = {
          x: mt * p[0].x + t * p[1].x,
          y: mt * p[0].y + t * p[1].y,
          t: t,
        };
        if (_3d) {
          ret.z = mt * p[0].z + t * p[1].z;
        }
        return ret;
      }

      // quadratic/cubic curve?
      if (order < 4) {
        let mt2 = mt * mt,
          t2 = t * t,
          a,
          b,
          c,
          d = 0;
        if (order === 2) {
          p = [p[0], p[1], p[2], ZERO];
          a = mt2;
          b = mt * t * 2;
          c = t2;
        } else if (order === 3) {
          a = mt2 * mt;
          b = mt2 * t * 3;
          c = mt * t2 * 3;
          d = t * t2;
        }
        const ret = {
          x: a * p[0].x + b * p[1].x + c * p[2].x + d * p[3].x,
          y: a * p[0].y + b * p[1].y + c * p[2].y + d * p[3].y,
          t: t,
        };
        if (_3d) {
          ret.z = a * p[0].z + b * p[1].z + c * p[2].z + d * p[3].z;
        }
        return ret;
      }

      // higher order curves: use de Casteljau's computation
      const dCpts = JSON.parse(JSON.stringify(points));
      while (dCpts.length > 1) {
        for (let i = 0; i < dCpts.length - 1; i++) {
          dCpts[i] = {
            x: dCpts[i].x + (dCpts[i + 1].x - dCpts[i].x) * t,
            y: dCpts[i].y + (dCpts[i + 1].y - dCpts[i].y) * t,
          };
          if (typeof dCpts[i].z !== "undefined") {
            dCpts[i].z = dCpts[i].z + (dCpts[i + 1].z - dCpts[i].z) * t;
          }
        }
        dCpts.splice(dCpts.length - 1, 1);
      }
      dCpts[0].t = t;
      return dCpts[0];
    },

    computeWithRatios: function (t, points, ratios, _3d) {
      const mt = 1 - t,
        r = ratios,
        p = points;

      let f1 = r[0],
        f2 = r[1],
        f3 = r[2],
        f4 = r[3],
        d;

      // spec for linear
      f1 *= mt;
      f2 *= t;

      if (p.length === 2) {
        d = f1 + f2;
        return {
          x: (f1 * p[0].x + f2 * p[1].x) / d,
          y: (f1 * p[0].y + f2 * p[1].y) / d,
          z: !_3d ? false : (f1 * p[0].z + f2 * p[1].z) / d,
          t: t,
        };
      }

      // upgrade to quadratic
      f1 *= mt;
      f2 *= 2 * mt;
      f3 *= t * t;

      if (p.length === 3) {
        d = f1 + f2 + f3;
        return {
          x: (f1 * p[0].x + f2 * p[1].x + f3 * p[2].x) / d,
          y: (f1 * p[0].y + f2 * p[1].y + f3 * p[2].y) / d,
          z: !_3d ? false : (f1 * p[0].z + f2 * p[1].z + f3 * p[2].z) / d,
          t: t,
        };
      }

      // upgrade to cubic
      f1 *= mt;
      f2 *= 1.5 * mt;
      f3 *= 3 * mt;
      f4 *= t * t * t;

      if (p.length === 4) {
        d = f1 + f2 + f3 + f4;
        return {
          x: (f1 * p[0].x + f2 * p[1].x + f3 * p[2].x + f4 * p[3].x) / d,
          y: (f1 * p[0].y + f2 * p[1].y + f3 * p[2].y + f4 * p[3].y) / d,
          z: !_3d
            ? false
            : (f1 * p[0].z + f2 * p[1].z + f3 * p[2].z + f4 * p[3].z) / d,
          t: t,
        };
      }
    },

    derive: function (points, _3d) {
      const dpoints = [];
      for (let p = points, d = p.length, c = d - 1; d > 1; d--, c--) {
        const list = [];
        for (let j = 0, dpt; j < c; j++) {
          dpt = {
            x: c * (p[j + 1].x - p[j].x),
            y: c * (p[j + 1].y - p[j].y),
          };
          if (_3d) {
            dpt.z = c * (p[j + 1].z - p[j].z);
          }
          list.push(dpt);
        }
        dpoints.push(list);
        p = list;
      }
      return dpoints;
    },

    between: function (v, m, M) {
      return (
        (m <= v && v <= M) ||
        utils.approximately(v, m) ||
        utils.approximately(v, M)
      );
    },

    approximately: function (a, b, precision) {
      return abs$1(a - b) <= (precision || epsilon);
    },

    length: function (derivativeFn) {
      const z = 0.5,
        len = utils.Tvalues.length;

      let sum = 0;

      for (let i = 0, t; i < len; i++) {
        t = z * utils.Tvalues[i] + z;
        sum += utils.Cvalues[i] * utils.arcfn(t, derivativeFn);
      }
      return z * sum;
    },

    map: function (v, ds, de, ts, te) {
      const d1 = de - ds,
        d2 = te - ts,
        v2 = v - ds,
        r = v2 / d1;
      return ts + d2 * r;
    },

    lerp: function (r, v1, v2) {
      const ret = {
        x: v1.x + r * (v2.x - v1.x),
        y: v1.y + r * (v2.y - v1.y),
      };
      if (v1.z !== undefined && v2.z !== undefined) {
        ret.z = v1.z + r * (v2.z - v1.z);
      }
      return ret;
    },

    pointToString: function (p) {
      let s = p.x + "/" + p.y;
      if (typeof p.z !== "undefined") {
        s += "/" + p.z;
      }
      return s;
    },

    pointsToString: function (points) {
      return "[" + points.map(utils.pointToString).join(", ") + "]";
    },

    copy: function (obj) {
      return JSON.parse(JSON.stringify(obj));
    },

    angle: function (o, v1, v2) {
      const dx1 = v1.x - o.x,
        dy1 = v1.y - o.y,
        dx2 = v2.x - o.x,
        dy2 = v2.y - o.y,
        cross = dx1 * dy2 - dy1 * dx2,
        dot = dx1 * dx2 + dy1 * dy2;
      return atan2(cross, dot);
    },

    // round as string, to avoid rounding errors
    round: function (v, d) {
      const s = "" + v;
      const pos = s.indexOf(".");
      return parseFloat(s.substring(0, pos + 1 + d));
    },

    dist: function (p1, p2) {
      const dx = p1.x - p2.x,
        dy = p1.y - p2.y;
      return sqrt$1(dx * dx + dy * dy);
    },

    closest: function (LUT, point) {
      let mdist = pow(2, 63),
        mpos,
        d;
      LUT.forEach(function (p, idx) {
        d = utils.dist(point, p);
        if (d < mdist) {
          mdist = d;
          mpos = idx;
        }
      });
      return { mdist: mdist, mpos: mpos };
    },

    abcratio: function (t, n) {
      // see ratio(t) note on http://pomax.github.io/bezierinfo/#abc
      if (n !== 2 && n !== 3) {
        return false;
      }
      if (typeof t === "undefined") {
        t = 0.5;
      } else if (t === 0 || t === 1) {
        return t;
      }
      const bottom = pow(t, n) + pow(1 - t, n),
        top = bottom - 1;
      return abs$1(top / bottom);
    },

    projectionratio: function (t, n) {
      // see u(t) note on http://pomax.github.io/bezierinfo/#abc
      if (n !== 2 && n !== 3) {
        return false;
      }
      if (typeof t === "undefined") {
        t = 0.5;
      } else if (t === 0 || t === 1) {
        return t;
      }
      const top = pow(1 - t, n),
        bottom = pow(t, n) + top;
      return top / bottom;
    },

    lli8: function (x1, y1, x2, y2, x3, y3, x4, y4) {
      const nx =
          (x1 * y2 - y1 * x2) * (x3 - x4) - (x1 - x2) * (x3 * y4 - y3 * x4),
        ny = (x1 * y2 - y1 * x2) * (y3 - y4) - (y1 - y2) * (x3 * y4 - y3 * x4),
        d = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4);
      if (d == 0) {
        return false;
      }
      return { x: nx / d, y: ny / d };
    },

    lli4: function (p1, p2, p3, p4) {
      const x1 = p1.x,
        y1 = p1.y,
        x2 = p2.x,
        y2 = p2.y,
        x3 = p3.x,
        y3 = p3.y,
        x4 = p4.x,
        y4 = p4.y;
      return utils.lli8(x1, y1, x2, y2, x3, y3, x4, y4);
    },

    lli: function (v1, v2) {
      return utils.lli4(v1, v1.c, v2, v2.c);
    },

    makeline: function (p1, p2) {
      return new Bezier(
        p1.x,
        p1.y,
        (p1.x + p2.x) / 2,
        (p1.y + p2.y) / 2,
        p2.x,
        p2.y
      );
    },

    findbbox: function (sections) {
      let mx = nMax,
        my = nMax,
        MX = nMin,
        MY = nMin;
      sections.forEach(function (s) {
        const bbox = s.bbox();
        if (mx > bbox.x.min) mx = bbox.x.min;
        if (my > bbox.y.min) my = bbox.y.min;
        if (MX < bbox.x.max) MX = bbox.x.max;
        if (MY < bbox.y.max) MY = bbox.y.max;
      });
      return {
        x: { min: mx, mid: (mx + MX) / 2, max: MX, size: MX - mx },
        y: { min: my, mid: (my + MY) / 2, max: MY, size: MY - my },
      };
    },

    shapeintersections: function (
      s1,
      bbox1,
      s2,
      bbox2,
      curveIntersectionThreshold
    ) {
      if (!utils.bboxoverlap(bbox1, bbox2)) return [];
      const intersections = [];
      const a1 = [s1.startcap, s1.forward, s1.back, s1.endcap];
      const a2 = [s2.startcap, s2.forward, s2.back, s2.endcap];
      a1.forEach(function (l1) {
        if (l1.virtual) return;
        a2.forEach(function (l2) {
          if (l2.virtual) return;
          const iss = l1.intersects(l2, curveIntersectionThreshold);
          if (iss.length > 0) {
            iss.c1 = l1;
            iss.c2 = l2;
            iss.s1 = s1;
            iss.s2 = s2;
            intersections.push(iss);
          }
        });
      });
      return intersections;
    },

    makeshape: function (forward, back, curveIntersectionThreshold) {
      const bpl = back.points.length;
      const fpl = forward.points.length;
      const start = utils.makeline(back.points[bpl - 1], forward.points[0]);
      const end = utils.makeline(forward.points[fpl - 1], back.points[0]);
      const shape = {
        startcap: start,
        forward: forward,
        back: back,
        endcap: end,
        bbox: utils.findbbox([start, forward, back, end]),
      };
      shape.intersections = function (s2) {
        return utils.shapeintersections(
          shape,
          shape.bbox,
          s2,
          s2.bbox,
          curveIntersectionThreshold
        );
      };
      return shape;
    },

    getminmax: function (curve, d, list) {
      if (!list) return { min: 0, max: 0 };
      let min = nMax,
        max = nMin,
        t,
        c;
      if (list.indexOf(0) === -1) {
        list = [0].concat(list);
      }
      if (list.indexOf(1) === -1) {
        list.push(1);
      }
      for (let i = 0, len = list.length; i < len; i++) {
        t = list[i];
        c = curve.get(t);
        if (c[d] < min) {
          min = c[d];
        }
        if (c[d] > max) {
          max = c[d];
        }
      }
      return { min: min, mid: (min + max) / 2, max: max, size: max - min };
    },

    align: function (points, line) {
      const tx = line.p1.x,
        ty = line.p1.y,
        a = -atan2(line.p2.y - ty, line.p2.x - tx),
        d = function (v) {
          return {
            x: (v.x - tx) * cos$1(a) - (v.y - ty) * sin$1(a),
            y: (v.x - tx) * sin$1(a) + (v.y - ty) * cos$1(a),
          };
        };
      return points.map(d);
    },

    roots: function (points, line) {
      line = line || { p1: { x: 0, y: 0 }, p2: { x: 1, y: 0 } };

      const order = points.length - 1;
      const aligned = utils.align(points, line);
      const reduce = function (t) {
        return 0 <= t && t <= 1;
      };

      if (order === 2) {
        const a = aligned[0].y,
          b = aligned[1].y,
          c = aligned[2].y,
          d = a - 2 * b + c;
        if (d !== 0) {
          const m1 = -sqrt$1(b * b - a * c),
            m2 = -a + b,
            v1 = -(m1 + m2) / d,
            v2 = -(-m1 + m2) / d;
          return [v1, v2].filter(reduce);
        } else if (b !== c && d === 0) {
          return [(2 * b - c) / (2 * b - 2 * c)].filter(reduce);
        }
        return [];
      }

      // see http://www.trans4mind.com/personal_development/mathematics/polynomials/cubicAlgebra.htm
      const pa = aligned[0].y,
        pb = aligned[1].y,
        pc = aligned[2].y,
        pd = aligned[3].y;

      let d = -pa + 3 * pb - 3 * pc + pd,
        a = 3 * pa - 6 * pb + 3 * pc,
        b = -3 * pa + 3 * pb,
        c = pa;

      if (utils.approximately(d, 0)) {
        // this is not a cubic curve.
        if (utils.approximately(a, 0)) {
          // in fact, this is not a quadratic curve either.
          if (utils.approximately(b, 0)) {
            // in fact in fact, there are no solutions.
            return [];
          }
          // linear solution:
          return [-c / b].filter(reduce);
        }
        // quadratic solution:
        const q = sqrt$1(b * b - 4 * a * c),
          a2 = 2 * a;
        return [(q - b) / a2, (-b - q) / a2].filter(reduce);
      }

      // at this point, we know we need a cubic solution:

      a /= d;
      b /= d;
      c /= d;

      const p = (3 * b - a * a) / 3,
        p3 = p / 3,
        q = (2 * a * a * a - 9 * a * b + 27 * c) / 27,
        q2 = q / 2,
        discriminant = q2 * q2 + p3 * p3 * p3;

      let u1, v1, x1, x2, x3;
      if (discriminant < 0) {
        const mp3 = -p / 3,
          mp33 = mp3 * mp3 * mp3,
          r = sqrt$1(mp33),
          t = -q / (2 * r),
          cosphi = t < -1 ? -1 : t > 1 ? 1 : t,
          phi = acos$1(cosphi),
          crtr = crt(r),
          t1 = 2 * crtr;
        x1 = t1 * cos$1(phi / 3) - a / 3;
        x2 = t1 * cos$1((phi + tau) / 3) - a / 3;
        x3 = t1 * cos$1((phi + 2 * tau) / 3) - a / 3;
        return [x1, x2, x3].filter(reduce);
      } else if (discriminant === 0) {
        u1 = q2 < 0 ? crt(-q2) : -crt(q2);
        x1 = 2 * u1 - a / 3;
        x2 = -u1 - a / 3;
        return [x1, x2].filter(reduce);
      } else {
        const sd = sqrt$1(discriminant);
        u1 = crt(-q2 + sd);
        v1 = crt(q2 + sd);
        return [u1 - v1 - a / 3].filter(reduce);
      }
    },

    droots: function (p) {
      // quadratic roots are easy
      if (p.length === 3) {
        const a = p[0],
          b = p[1],
          c = p[2],
          d = a - 2 * b + c;
        if (d !== 0) {
          const m1 = -sqrt$1(b * b - a * c),
            m2 = -a + b,
            v1 = -(m1 + m2) / d,
            v2 = -(-m1 + m2) / d;
          return [v1, v2];
        } else if (b !== c && d === 0) {
          return [(2 * b - c) / (2 * (b - c))];
        }
        return [];
      }

      // linear roots are even easier
      if (p.length === 2) {
        const a = p[0],
          b = p[1];
        if (a !== b) {
          return [a / (a - b)];
        }
        return [];
      }

      return [];
    },

    curvature: function (t, d1, d2, _3d, kOnly) {
      let num,
        dnm,
        adk,
        dk,
        k = 0,
        r = 0;

      //
      // We're using the following formula for curvature:
      //
      //              x'y" - y'x"
      //   k(t) = ------------------
      //           (x'² + y'²)^(3/2)
      //
      // from https://en.wikipedia.org/wiki/Radius_of_curvature#Definition
      //
      // With it corresponding 3D counterpart:
      //
      //          sqrt( (y'z" - y"z')² + (z'x" - z"x')² + (x'y" - x"y')²)
      //   k(t) = -------------------------------------------------------
      //                     (x'² + y'² + z'²)^(3/2)
      //

      const d = utils.compute(t, d1);
      const dd = utils.compute(t, d2);
      const qdsum = d.x * d.x + d.y * d.y;

      if (_3d) {
        num = sqrt$1(
          pow(d.y * dd.z - dd.y * d.z, 2) +
            pow(d.z * dd.x - dd.z * d.x, 2) +
            pow(d.x * dd.y - dd.x * d.y, 2)
        );
        dnm = pow(qdsum + d.z * d.z, 3 / 2);
      } else {
        num = d.x * dd.y - d.y * dd.x;
        dnm = pow(qdsum, 3 / 2);
      }

      if (num === 0 || dnm === 0) {
        return { k: 0, r: 0 };
      }

      k = num / dnm;
      r = dnm / num;

      // We're also computing the derivative of kappa, because
      // there is value in knowing the rate of change for the
      // curvature along the curve. And we're just going to
      // ballpark it based on an epsilon.
      if (!kOnly) {
        // compute k'(t) based on the interval before, and after it,
        // to at least try to not introduce forward/backward pass bias.
        const pk = utils.curvature(t - 0.001, d1, d2, _3d, true).k;
        const nk = utils.curvature(t + 0.001, d1, d2, _3d, true).k;
        dk = (nk - k + (k - pk)) / 2;
        adk = (abs$1(nk - k) + abs$1(k - pk)) / 2;
      }

      return { k: k, r: r, dk: dk, adk: adk };
    },

    inflections: function (points) {
      if (points.length < 4) return [];

      // FIXME: TODO: add in inflection abstraction for quartic+ curves?

      const p = utils.align(points, { p1: points[0], p2: points.slice(-1)[0] }),
        a = p[2].x * p[1].y,
        b = p[3].x * p[1].y,
        c = p[1].x * p[2].y,
        d = p[3].x * p[2].y,
        v1 = 18 * (-3 * a + 2 * b + 3 * c - d),
        v2 = 18 * (3 * a - b - 3 * c),
        v3 = 18 * (c - a);

      if (utils.approximately(v1, 0)) {
        if (!utils.approximately(v2, 0)) {
          let t = -v3 / v2;
          if (0 <= t && t <= 1) return [t];
        }
        return [];
      }

      const d2 = 2 * v1;

      if (utils.approximately(d2, 0)) return [];

      const trm = v2 * v2 - 4 * v1 * v3;

      if (trm < 0) return [];

      const sq = Math.sqrt(trm);

      return [(sq - v2) / d2, -(v2 + sq) / d2].filter(function (r) {
        return 0 <= r && r <= 1;
      });
    },

    bboxoverlap: function (b1, b2) {
      const dims = ["x", "y"],
        len = dims.length;

      for (let i = 0, dim, l, t, d; i < len; i++) {
        dim = dims[i];
        l = b1[dim].mid;
        t = b2[dim].mid;
        d = (b1[dim].size + b2[dim].size) / 2;
        if (abs$1(l - t) >= d) return false;
      }
      return true;
    },

    expandbox: function (bbox, _bbox) {
      if (_bbox.x.min < bbox.x.min) {
        bbox.x.min = _bbox.x.min;
      }
      if (_bbox.y.min < bbox.y.min) {
        bbox.y.min = _bbox.y.min;
      }
      if (_bbox.z && _bbox.z.min < bbox.z.min) {
        bbox.z.min = _bbox.z.min;
      }
      if (_bbox.x.max > bbox.x.max) {
        bbox.x.max = _bbox.x.max;
      }
      if (_bbox.y.max > bbox.y.max) {
        bbox.y.max = _bbox.y.max;
      }
      if (_bbox.z && _bbox.z.max > bbox.z.max) {
        bbox.z.max = _bbox.z.max;
      }
      bbox.x.mid = (bbox.x.min + bbox.x.max) / 2;
      bbox.y.mid = (bbox.y.min + bbox.y.max) / 2;
      if (bbox.z) {
        bbox.z.mid = (bbox.z.min + bbox.z.max) / 2;
      }
      bbox.x.size = bbox.x.max - bbox.x.min;
      bbox.y.size = bbox.y.max - bbox.y.min;
      if (bbox.z) {
        bbox.z.size = bbox.z.max - bbox.z.min;
      }
    },

    pairiteration: function (c1, c2, curveIntersectionThreshold) {
      const c1b = c1.bbox(),
        c2b = c2.bbox(),
        r = 100000,
        threshold = curveIntersectionThreshold || 0.5;

      if (
        c1b.x.size + c1b.y.size < threshold &&
        c2b.x.size + c2b.y.size < threshold
      ) {
        return [
          (((r * (c1._t1 + c1._t2)) / 2) | 0) / r +
            "/" +
            (((r * (c2._t1 + c2._t2)) / 2) | 0) / r,
        ];
      }

      let cc1 = c1.split(0.5),
        cc2 = c2.split(0.5),
        pairs = [
          { left: cc1.left, right: cc2.left },
          { left: cc1.left, right: cc2.right },
          { left: cc1.right, right: cc2.right },
          { left: cc1.right, right: cc2.left },
        ];

      pairs = pairs.filter(function (pair) {
        return utils.bboxoverlap(pair.left.bbox(), pair.right.bbox());
      });

      let results = [];

      if (pairs.length === 0) return results;

      pairs.forEach(function (pair) {
        results = results.concat(
          utils.pairiteration(pair.left, pair.right, threshold)
        );
      });

      results = results.filter(function (v, i) {
        return results.indexOf(v) === i;
      });

      return results;
    },

    getccenter: function (p1, p2, p3) {
      const dx1 = p2.x - p1.x,
        dy1 = p2.y - p1.y,
        dx2 = p3.x - p2.x,
        dy2 = p3.y - p2.y,
        dx1p = dx1 * cos$1(quart) - dy1 * sin$1(quart),
        dy1p = dx1 * sin$1(quart) + dy1 * cos$1(quart),
        dx2p = dx2 * cos$1(quart) - dy2 * sin$1(quart),
        dy2p = dx2 * sin$1(quart) + dy2 * cos$1(quart),
        // chord midpoints
        mx1 = (p1.x + p2.x) / 2,
        my1 = (p1.y + p2.y) / 2,
        mx2 = (p2.x + p3.x) / 2,
        my2 = (p2.y + p3.y) / 2,
        // midpoint offsets
        mx1n = mx1 + dx1p,
        my1n = my1 + dy1p,
        mx2n = mx2 + dx2p,
        my2n = my2 + dy2p,
        // intersection of these lines:
        arc = utils.lli8(mx1, my1, mx1n, my1n, mx2, my2, mx2n, my2n),
        r = utils.dist(arc, p1);

      // arc start/end values, over mid point:
      let s = atan2(p1.y - arc.y, p1.x - arc.x),
        m = atan2(p2.y - arc.y, p2.x - arc.x),
        e = atan2(p3.y - arc.y, p3.x - arc.x),
        _;

      // determine arc direction (cw/ccw correction)
      if (s < e) {
        // if s<m<e, arc(s, e)
        // if m<s<e, arc(e, s + tau)
        // if s<e<m, arc(e, s + tau)
        if (s > m || m > e) {
          s += tau;
        }
        if (s > e) {
          _ = e;
          e = s;
          s = _;
        }
      } else {
        // if e<m<s, arc(e, s)
        // if m<e<s, arc(s, e + tau)
        // if e<s<m, arc(s, e + tau)
        if (e < m && m < s) {
          _ = e;
          e = s;
          s = _;
        } else {
          e += tau;
        }
      }
      // assign and done.
      arc.s = s;
      arc.e = e;
      arc.r = r;
      return arc;
    },

    numberSort: function (a, b) {
      return a - b;
    },
  };

  /**
   * Poly Bezier
   * @param {[type]} curves [description]
   */
  class PolyBezier {
    constructor(curves) {
      this.curves = [];
      this._3d = false;
      if (!!curves) {
        this.curves = curves;
        this._3d = this.curves[0]._3d;
      }
    }

    valueOf() {
      return this.toString();
    }

    toString() {
      return (
        "[" +
        this.curves
          .map(function (curve) {
            return utils.pointsToString(curve.points);
          })
          .join(", ") +
        "]"
      );
    }

    addCurve(curve) {
      this.curves.push(curve);
      this._3d = this._3d || curve._3d;
    }

    length() {
      return this.curves
        .map(function (v) {
          return v.length();
        })
        .reduce(function (a, b) {
          return a + b;
        });
    }

    curve(idx) {
      return this.curves[idx];
    }

    bbox() {
      const c = this.curves;
      var bbox = c[0].bbox();
      for (var i = 1; i < c.length; i++) {
        utils.expandbox(bbox, c[i].bbox());
      }
      return bbox;
    }

    offset(d) {
      const offset = [];
      this.curves.forEach(function (v) {
        offset.push(...v.offset(d));
      });
      return new PolyBezier(offset);
    }
  }

  /**
    A javascript Bezier curve library by Pomax.

    Based on http://pomax.github.io/bezierinfo

    This code is MIT licensed.
  **/


  // math-inlining.
  const { abs, min, max, cos, sin, acos, sqrt } = Math;
  const pi = Math.PI;

  /**
   * Bezier curve constructor.
   *
   * ...docs pending...
   */
  class Bezier {
    constructor(coords) {
      let args =
        coords && coords.forEach ? coords : Array.from(arguments).slice();
      let coordlen = false;

      if (typeof args[0] === "object") {
        coordlen = args.length;
        const newargs = [];
        args.forEach(function (point) {
          ["x", "y", "z"].forEach(function (d) {
            if (typeof point[d] !== "undefined") {
              newargs.push(point[d]);
            }
          });
        });
        args = newargs;
      }

      let higher = false;
      const len = args.length;

      if (coordlen) {
        if (coordlen > 4) {
          if (arguments.length !== 1) {
            throw new Error(
              "Only new Bezier(point[]) is accepted for 4th and higher order curves"
            );
          }
          higher = true;
        }
      } else {
        if (len !== 6 && len !== 8 && len !== 9 && len !== 12) {
          if (arguments.length !== 1) {
            throw new Error(
              "Only new Bezier(point[]) is accepted for 4th and higher order curves"
            );
          }
        }
      }

      const _3d = (this._3d =
        (!higher && (len === 9 || len === 12)) ||
        (coords && coords[0] && typeof coords[0].z !== "undefined"));

      const points = (this.points = []);
      for (let idx = 0, step = _3d ? 3 : 2; idx < len; idx += step) {
        var point = {
          x: args[idx],
          y: args[idx + 1],
        };
        if (_3d) {
          point.z = args[idx + 2];
        }
        points.push(point);
      }
      const order = (this.order = points.length - 1);

      const dims = (this.dims = ["x", "y"]);
      if (_3d) dims.push("z");
      this.dimlen = dims.length;

      // is this curve, practically speaking, a straight line?
      const aligned = utils.align(points, { p1: points[0], p2: points[order] });
      const baselength = utils.dist(points[0], points[order]);
      this._linear = aligned.reduce((t, p) => t + abs(p.y), 0) < baselength / 50;

      this._lut = [];
      this._t1 = 0;
      this._t2 = 1;
      this.update();
    }

    static quadraticFromPoints(p1, p2, p3, t) {
      if (typeof t === "undefined") {
        t = 0.5;
      }
      // shortcuts, although they're really dumb
      if (t === 0) {
        return new Bezier(p2, p2, p3);
      }
      if (t === 1) {
        return new Bezier(p1, p2, p2);
      }
      // real fitting.
      const abc = Bezier.getABC(2, p1, p2, p3, t);
      return new Bezier(p1, abc.A, p3);
    }

    static cubicFromPoints(S, B, E, t, d1) {
      if (typeof t === "undefined") {
        t = 0.5;
      }
      const abc = Bezier.getABC(3, S, B, E, t);
      if (typeof d1 === "undefined") {
        d1 = utils.dist(B, abc.C);
      }
      const d2 = (d1 * (1 - t)) / t;

      const selen = utils.dist(S, E),
        lx = (E.x - S.x) / selen,
        ly = (E.y - S.y) / selen,
        bx1 = d1 * lx,
        by1 = d1 * ly,
        bx2 = d2 * lx,
        by2 = d2 * ly;
      // derivation of new hull coordinates
      const e1 = { x: B.x - bx1, y: B.y - by1 },
        e2 = { x: B.x + bx2, y: B.y + by2 },
        A = abc.A,
        v1 = { x: A.x + (e1.x - A.x) / (1 - t), y: A.y + (e1.y - A.y) / (1 - t) },
        v2 = { x: A.x + (e2.x - A.x) / t, y: A.y + (e2.y - A.y) / t },
        nc1 = { x: S.x + (v1.x - S.x) / t, y: S.y + (v1.y - S.y) / t },
        nc2 = {
          x: E.x + (v2.x - E.x) / (1 - t),
          y: E.y + (v2.y - E.y) / (1 - t),
        };
      // ...done
      return new Bezier(S, nc1, nc2, E);
    }

    static getUtils() {
      return utils;
    }

    getUtils() {
      return Bezier.getUtils();
    }

    static get PolyBezier() {
      return PolyBezier;
    }

    valueOf() {
      return this.toString();
    }

    toString() {
      return utils.pointsToString(this.points);
    }

    toSVG() {
      if (this._3d) return false;
      const p = this.points,
        x = p[0].x,
        y = p[0].y,
        s = ["M", x, y, this.order === 2 ? "Q" : "C"];
      for (let i = 1, last = p.length; i < last; i++) {
        s.push(p[i].x);
        s.push(p[i].y);
      }
      return s.join(" ");
    }

    setRatios(ratios) {
      if (ratios.length !== this.points.length) {
        throw new Error("incorrect number of ratio values");
      }
      this.ratios = ratios;
      this._lut = []; //  invalidate any precomputed LUT
    }

    verify() {
      const print = this.coordDigest();
      if (print !== this._print) {
        this._print = print;
        this.update();
      }
    }

    coordDigest() {
      return this.points
        .map(function (c, pos) {
          return "" + pos + c.x + c.y + (c.z ? c.z : 0);
        })
        .join("");
    }

    update() {
      // invalidate any precomputed LUT
      this._lut = [];
      this.dpoints = utils.derive(this.points, this._3d);
      this.computedirection();
    }

    computedirection() {
      const points = this.points;
      const angle = utils.angle(points[0], points[this.order], points[1]);
      this.clockwise = angle > 0;
    }

    length() {
      return utils.length(this.derivative.bind(this));
    }

    static getABC(order = 2, S, B, E, t = 0.5) {
      const u = utils.projectionratio(t, order),
        um = 1 - u,
        C = {
          x: u * S.x + um * E.x,
          y: u * S.y + um * E.y,
        },
        s = utils.abcratio(t, order),
        A = {
          x: B.x + (B.x - C.x) / s,
          y: B.y + (B.y - C.y) / s,
        };
      return { A, B, C, S, E };
    }

    getABC(t, B) {
      B = B || this.get(t);
      let S = this.points[0];
      let E = this.points[this.order];
      return Bezier.getABC(this.order, S, B, E, t);
    }

    getLUT(steps) {
      this.verify();
      steps = steps || 100;
      if (this._lut.length === steps + 1) {
        return this._lut;
      }
      this._lut = [];
      // n steps means n+1 points
      steps++;
      this._lut = [];
      for (let i = 0, p, t; i < steps; i++) {
        t = i / (steps - 1);
        p = this.compute(t);
        p.t = t;
        this._lut.push(p);
      }
      return this._lut;
    }

    on(point, error) {
      error = error || 5;
      const lut = this.getLUT(),
        hits = [];
      for (let i = 0, c, t = 0; i < lut.length; i++) {
        c = lut[i];
        if (utils.dist(c, point) < error) {
          hits.push(c);
          t += i / lut.length;
        }
      }
      if (!hits.length) return false;
      return (t /= hits.length);
    }

    project(point) {
      // step 1: coarse check
      const LUT = this.getLUT(),
        l = LUT.length - 1,
        closest = utils.closest(LUT, point),
        mpos = closest.mpos,
        t1 = (mpos - 1) / l,
        t2 = (mpos + 1) / l,
        step = 0.1 / l;

      // step 2: fine check
      let mdist = closest.mdist,
        t = t1,
        ft = t,
        p;
      mdist += 1;
      for (let d; t < t2 + step; t += step) {
        p = this.compute(t);
        d = utils.dist(point, p);
        if (d < mdist) {
          mdist = d;
          ft = t;
        }
      }
      ft = ft < 0 ? 0 : ft > 1 ? 1 : ft;
      p = this.compute(ft);
      p.t = ft;
      p.d = mdist;
      return p;
    }

    get(t) {
      return this.compute(t);
    }

    point(idx) {
      return this.points[idx];
    }

    compute(t) {
      if (this.ratios) {
        return utils.computeWithRatios(t, this.points, this.ratios, this._3d);
      }
      return utils.compute(t, this.points, this._3d, this.ratios);
    }

    raise() {
      const p = this.points,
        np = [p[0]],
        k = p.length;
      for (let i = 1, pi, pim; i < k; i++) {
        pi = p[i];
        pim = p[i - 1];
        np[i] = {
          x: ((k - i) / k) * pi.x + (i / k) * pim.x,
          y: ((k - i) / k) * pi.y + (i / k) * pim.y,
        };
      }
      np[k] = p[k - 1];
      return new Bezier(np);
    }

    derivative(t) {
      return utils.compute(t, this.dpoints[0], this._3d);
    }

    dderivative(t) {
      return utils.compute(t, this.dpoints[1], this._3d);
    }

    align() {
      let p = this.points;
      return new Bezier(utils.align(p, { p1: p[0], p2: p[p.length - 1] }));
    }

    curvature(t) {
      return utils.curvature(t, this.dpoints[0], this.dpoints[1], this._3d);
    }

    inflections() {
      return utils.inflections(this.points);
    }

    normal(t) {
      return this._3d ? this.__normal3(t) : this.__normal2(t);
    }

    __normal2(t) {
      const d = this.derivative(t);
      const q = sqrt(d.x * d.x + d.y * d.y);
      return { t, x: -d.y / q, y: d.x / q };
    }

    __normal3(t) {
      // see http://stackoverflow.com/questions/25453159
      const r1 = this.derivative(t),
        r2 = this.derivative(t + 0.01),
        q1 = sqrt(r1.x * r1.x + r1.y * r1.y + r1.z * r1.z),
        q2 = sqrt(r2.x * r2.x + r2.y * r2.y + r2.z * r2.z);
      r1.x /= q1;
      r1.y /= q1;
      r1.z /= q1;
      r2.x /= q2;
      r2.y /= q2;
      r2.z /= q2;
      // cross product
      const c = {
        x: r2.y * r1.z - r2.z * r1.y,
        y: r2.z * r1.x - r2.x * r1.z,
        z: r2.x * r1.y - r2.y * r1.x,
      };
      const m = sqrt(c.x * c.x + c.y * c.y + c.z * c.z);
      c.x /= m;
      c.y /= m;
      c.z /= m;
      // rotation matrix
      const R = [
        c.x * c.x,
        c.x * c.y - c.z,
        c.x * c.z + c.y,
        c.x * c.y + c.z,
        c.y * c.y,
        c.y * c.z - c.x,
        c.x * c.z - c.y,
        c.y * c.z + c.x,
        c.z * c.z,
      ];
      // normal vector:
      const n = {
        t,
        x: R[0] * r1.x + R[1] * r1.y + R[2] * r1.z,
        y: R[3] * r1.x + R[4] * r1.y + R[5] * r1.z,
        z: R[6] * r1.x + R[7] * r1.y + R[8] * r1.z,
      };
      return n;
    }

    hull(t) {
      let p = this.points,
        _p = [],
        q = [],
        idx = 0;
      q[idx++] = p[0];
      q[idx++] = p[1];
      q[idx++] = p[2];
      if (this.order === 3) {
        q[idx++] = p[3];
      }
      // we lerp between all points at each iteration, until we have 1 point left.
      while (p.length > 1) {
        _p = [];
        for (let i = 0, pt, l = p.length - 1; i < l; i++) {
          pt = utils.lerp(t, p[i], p[i + 1]);
          q[idx++] = pt;
          _p.push(pt);
        }
        p = _p;
      }
      return q;
    }

    split(t1, t2) {
      // shortcuts
      if (t1 === 0 && !!t2) {
        return this.split(t2).left;
      }
      if (t2 === 1) {
        return this.split(t1).right;
      }

      // no shortcut: use "de Casteljau" iteration.
      const q = this.hull(t1);
      const result = {
        left:
          this.order === 2
            ? new Bezier([q[0], q[3], q[5]])
            : new Bezier([q[0], q[4], q[7], q[9]]),
        right:
          this.order === 2
            ? new Bezier([q[5], q[4], q[2]])
            : new Bezier([q[9], q[8], q[6], q[3]]),
        span: q,
      };

      // make sure we bind _t1/_t2 information!
      result.left._t1 = utils.map(0, 0, 1, this._t1, this._t2);
      result.left._t2 = utils.map(t1, 0, 1, this._t1, this._t2);
      result.right._t1 = utils.map(t1, 0, 1, this._t1, this._t2);
      result.right._t2 = utils.map(1, 0, 1, this._t1, this._t2);

      // if we have no t2, we're done
      if (!t2) {
        return result;
      }

      // if we have a t2, split again:
      t2 = utils.map(t2, t1, 1, 0, 1);
      return result.right.split(t2).left;
    }

    extrema() {
      const result = {};
      let roots = [];

      this.dims.forEach(
        function (dim) {
          let mfn = function (v) {
            return v[dim];
          };
          let p = this.dpoints[0].map(mfn);
          result[dim] = utils.droots(p);
          if (this.order === 3) {
            p = this.dpoints[1].map(mfn);
            result[dim] = result[dim].concat(utils.droots(p));
          }
          result[dim] = result[dim].filter(function (t) {
            return t >= 0 && t <= 1;
          });
          roots = roots.concat(result[dim].sort(utils.numberSort));
        }.bind(this)
      );

      result.values = roots.sort(utils.numberSort).filter(function (v, idx) {
        return roots.indexOf(v) === idx;
      });

      return result;
    }

    bbox() {
      const extrema = this.extrema(),
        result = {};
      this.dims.forEach(
        function (d) {
          result[d] = utils.getminmax(this, d, extrema[d]);
        }.bind(this)
      );
      return result;
    }

    overlaps(curve) {
      const lbbox = this.bbox(),
        tbbox = curve.bbox();
      return utils.bboxoverlap(lbbox, tbbox);
    }

    offset(t, d) {
      if (typeof d !== "undefined") {
        const c = this.get(t),
          n = this.normal(t);
        const ret = {
          c: c,
          n: n,
          x: c.x + n.x * d,
          y: c.y + n.y * d,
        };
        if (this._3d) {
          ret.z = c.z + n.z * d;
        }
        return ret;
      }
      if (this._linear) {
        const nv = this.normal(0),
          coords = this.points.map(function (p) {
            const ret = {
              x: p.x + t * nv.x,
              y: p.y + t * nv.y,
            };
            if (p.z && nv.z) {
              ret.z = p.z + t * nv.z;
            }
            return ret;
          });
        return [new Bezier(coords)];
      }
      return this.reduce().map(function (s) {
        if (s._linear) {
          return s.offset(t)[0];
        }
        return s.scale(t);
      });
    }

    simple() {
      if (this.order === 3) {
        const a1 = utils.angle(this.points[0], this.points[3], this.points[1]);
        const a2 = utils.angle(this.points[0], this.points[3], this.points[2]);
        if ((a1 > 0 && a2 < 0) || (a1 < 0 && a2 > 0)) return false;
      }
      const n1 = this.normal(0);
      const n2 = this.normal(1);
      let s = n1.x * n2.x + n1.y * n2.y;
      if (this._3d) {
        s += n1.z * n2.z;
      }
      return abs(acos(s)) < pi / 3;
    }

    reduce() {
      // TODO: examine these var types in more detail...
      let i,
        t1 = 0,
        t2 = 0,
        step = 0.01,
        segment,
        pass1 = [],
        pass2 = [];
      // first pass: split on extrema
      let extrema = this.extrema().values;
      if (extrema.indexOf(0) === -1) {
        extrema = [0].concat(extrema);
      }
      if (extrema.indexOf(1) === -1) {
        extrema.push(1);
      }

      for (t1 = extrema[0], i = 1; i < extrema.length; i++) {
        t2 = extrema[i];
        segment = this.split(t1, t2);
        segment._t1 = t1;
        segment._t2 = t2;
        pass1.push(segment);
        t1 = t2;
      }

      // second pass: further reduce these segments to simple segments
      pass1.forEach(function (p1) {
        t1 = 0;
        t2 = 0;
        while (t2 <= 1) {
          for (t2 = t1 + step; t2 <= 1 + step; t2 += step) {
            segment = p1.split(t1, t2);
            if (!segment.simple()) {
              t2 -= step;
              if (abs(t1 - t2) < step) {
                // we can never form a reduction
                return [];
              }
              segment = p1.split(t1, t2);
              segment._t1 = utils.map(t1, 0, 1, p1._t1, p1._t2);
              segment._t2 = utils.map(t2, 0, 1, p1._t1, p1._t2);
              pass2.push(segment);
              t1 = t2;
              break;
            }
          }
        }
        if (t1 < 1) {
          segment = p1.split(t1, 1);
          segment._t1 = utils.map(t1, 0, 1, p1._t1, p1._t2);
          segment._t2 = p1._t2;
          pass2.push(segment);
        }
      });
      return pass2;
    }

    translate(v, d1, d2) {
      d2 = typeof d2 === "number" ? d2 : d1;

      // TODO: make this take curves with control points outside
      //       of the start-end interval into account

      const o = this.order;
      let d = this.points.map((_, i) => (1 - i / o) * d1 + (i / o) * d2);
      return new Bezier(
        this.points.map((p, i) => ({
          x: p.x + v.x * d[i],
          y: p.y + v.y * d[i],
        }))
      );
    }

    scale(d) {
      const order = this.order;
      let distanceFn = false;
      if (typeof d === "function") {
        distanceFn = d;
      }
      if (distanceFn && order === 2) {
        return this.raise().scale(distanceFn);
      }

      // TODO: add special handling for non-linear degenerate curves.

      const clockwise = this.clockwise;
      const points = this.points;

      if (this._linear) {
        return this.translate(
          this.normal(0),
          distanceFn ? distanceFn(0) : d,
          distanceFn ? distanceFn(1) : d
        );
      }

      const r1 = distanceFn ? distanceFn(0) : d;
      const r2 = distanceFn ? distanceFn(1) : d;
      const v = [this.offset(0, 10), this.offset(1, 10)];
      const np = [];
      const o = utils.lli4(v[0], v[0].c, v[1], v[1].c);

      if (!o) {
        throw new Error("cannot scale this curve. Try reducing it first.");
      }

      // move all points by distance 'd' wrt the origin 'o',
      // and move end points by fixed distance along normal.
      [0, 1].forEach(function (t) {
        const p = (np[t * order] = utils.copy(points[t * order]));
        p.x += (t ? r2 : r1) * v[t].n.x;
        p.y += (t ? r2 : r1) * v[t].n.y;
      });

      if (!distanceFn) {
        // move control points to lie on the intersection of the offset
        // derivative vector, and the origin-through-control vector
        [0, 1].forEach((t) => {
          if (order === 2 && !!t) return;
          const p = np[t * order];
          const d = this.derivative(t);
          const p2 = { x: p.x + d.x, y: p.y + d.y };
          np[t + 1] = utils.lli4(p, p2, o, points[t + 1]);
        });
        return new Bezier(np);
      }

      // move control points by "however much necessary to
      // ensure the correct tangent to endpoint".
      [0, 1].forEach(function (t) {
        if (order === 2 && !!t) return;
        var p = points[t + 1];
        var ov = {
          x: p.x - o.x,
          y: p.y - o.y,
        };
        var rc = distanceFn ? distanceFn((t + 1) / order) : d;
        if (distanceFn && !clockwise) rc = -rc;
        var m = sqrt(ov.x * ov.x + ov.y * ov.y);
        ov.x /= m;
        ov.y /= m;
        np[t + 1] = {
          x: p.x + rc * ov.x,
          y: p.y + rc * ov.y,
        };
      });
      return new Bezier(np);
    }

    outline(d1, d2, d3, d4) {
      d2 = d2 === undefined ? d1 : d2;

      if (this._linear) {
        // TODO: find the actual extrema, because they might
        //       be before the start, or past the end.

        const n = this.normal(0);
        const start = this.points[0];
        const end = this.points[this.points.length - 1];
        let s, mid, e;

        if (d3 === undefined) {
          d3 = d1;
          d4 = d2;
        }

        s = { x: start.x + n.x * d1, y: start.y + n.y * d1 };
        e = { x: end.x + n.x * d3, y: end.y + n.y * d3 };
        mid = { x: (s.x + e.x) / 2, y: (s.y + e.y) / 2 };
        const fline = [s, mid, e];

        s = { x: start.x - n.x * d2, y: start.y - n.y * d2 };
        e = { x: end.x - n.x * d4, y: end.y - n.y * d4 };
        mid = { x: (s.x + e.x) / 2, y: (s.y + e.y) / 2 };
        const bline = [e, mid, s];

        const ls = utils.makeline(bline[2], fline[0]);
        const le = utils.makeline(fline[2], bline[0]);
        const segments = [ls, new Bezier(fline), le, new Bezier(bline)];
        return new PolyBezier(segments);
      }

      const reduced = this.reduce(),
        len = reduced.length,
        fcurves = [];

      let bcurves = [],
        p,
        alen = 0,
        tlen = this.length();

      const graduated = typeof d3 !== "undefined" && typeof d4 !== "undefined";

      function linearDistanceFunction(s, e, tlen, alen, slen) {
        return function (v) {
          const f1 = alen / tlen,
            f2 = (alen + slen) / tlen,
            d = e - s;
          return utils.map(v, 0, 1, s + f1 * d, s + f2 * d);
        };
      }

      // form curve oulines
      reduced.forEach(function (segment) {
        const slen = segment.length();
        if (graduated) {
          fcurves.push(
            segment.scale(linearDistanceFunction(d1, d3, tlen, alen, slen))
          );
          bcurves.push(
            segment.scale(linearDistanceFunction(-d2, -d4, tlen, alen, slen))
          );
        } else {
          fcurves.push(segment.scale(d1));
          bcurves.push(segment.scale(-d2));
        }
        alen += slen;
      });

      // reverse the "return" outline
      bcurves = bcurves
        .map(function (s) {
          p = s.points;
          if (p[3]) {
            s.points = [p[3], p[2], p[1], p[0]];
          } else {
            s.points = [p[2], p[1], p[0]];
          }
          return s;
        })
        .reverse();

      // form the endcaps as lines
      const fs = fcurves[0].points[0],
        fe = fcurves[len - 1].points[fcurves[len - 1].points.length - 1],
        bs = bcurves[len - 1].points[bcurves[len - 1].points.length - 1],
        be = bcurves[0].points[0],
        ls = utils.makeline(bs, fs),
        le = utils.makeline(fe, be),
        segments = [ls].concat(fcurves).concat([le]).concat(bcurves);

      return new PolyBezier(segments);
    }

    outlineshapes(d1, d2, curveIntersectionThreshold) {
      d2 = d2 || d1;
      const outline = this.outline(d1, d2).curves;
      const shapes = [];
      for (let i = 1, len = outline.length; i < len / 2; i++) {
        const shape = utils.makeshape(
          outline[i],
          outline[len - i],
          curveIntersectionThreshold
        );
        shape.startcap.virtual = i > 1;
        shape.endcap.virtual = i < len / 2 - 1;
        shapes.push(shape);
      }
      return shapes;
    }

    intersects(curve, curveIntersectionThreshold) {
      if (!curve) return this.selfintersects(curveIntersectionThreshold);
      if (curve.p1 && curve.p2) {
        return this.lineIntersects(curve);
      }
      if (curve instanceof Bezier) {
        curve = curve.reduce();
      }
      return this.curveintersects(
        this.reduce(),
        curve,
        curveIntersectionThreshold
      );
    }

    lineIntersects(line) {
      const mx = min(line.p1.x, line.p2.x),
        my = min(line.p1.y, line.p2.y),
        MX = max(line.p1.x, line.p2.x),
        MY = max(line.p1.y, line.p2.y);
      return utils.roots(this.points, line).filter((t) => {
        var p = this.get(t);
        return utils.between(p.x, mx, MX) && utils.between(p.y, my, MY);
      });
    }

    selfintersects(curveIntersectionThreshold) {
      // "simple" curves cannot intersect with their direct
      // neighbour, so for each segment X we check whether
      // it intersects [0:x-2][x+2:last].

      const reduced = this.reduce(),
        len = reduced.length - 2,
        results = [];

      for (let i = 0, result, left, right; i < len; i++) {
        left = reduced.slice(i, i + 1);
        right = reduced.slice(i + 2);
        result = this.curveintersects(left, right, curveIntersectionThreshold);
        results.push(...result);
      }
      return results;
    }

    curveintersects(c1, c2, curveIntersectionThreshold) {
      const pairs = [];
      // step 1: pair off any overlapping segments
      c1.forEach(function (l) {
        c2.forEach(function (r) {
          if (l.overlaps(r)) {
            pairs.push({ left: l, right: r });
          }
        });
      });
      // step 2: for each pairing, run through the convergence algorithm.
      let intersections = [];
      pairs.forEach(function (pair) {
        const result = utils.pairiteration(
          pair.left,
          pair.right,
          curveIntersectionThreshold
        );
        if (result.length > 0) {
          intersections = intersections.concat(result);
        }
      });
      return intersections;
    }

    arcs(errorThreshold) {
      errorThreshold = errorThreshold || 0.5;
      return this._iterate(errorThreshold, []);
    }

    _error(pc, np1, s, e) {
      const q = (e - s) / 4,
        c1 = this.get(s + q),
        c2 = this.get(e - q),
        ref = utils.dist(pc, np1),
        d1 = utils.dist(pc, c1),
        d2 = utils.dist(pc, c2);
      return abs(d1 - ref) + abs(d2 - ref);
    }

    _iterate(errorThreshold, circles) {
      let t_s = 0,
        t_e = 1,
        safety;
      // we do a binary search to find the "good `t` closest to no-longer-good"
      do {
        safety = 0;

        // step 1: start with the maximum possible arc
        t_e = 1;

        // points:
        let np1 = this.get(t_s),
          np2,
          np3,
          arc,
          prev_arc;

        // booleans:
        let curr_good = false,
          prev_good = false,
          done;

        // numbers:
        let t_m = t_e,
          prev_e = 1;

        // step 2: find the best possible arc
        do {
          prev_good = curr_good;
          prev_arc = arc;
          t_m = (t_s + t_e) / 2;

          np2 = this.get(t_m);
          np3 = this.get(t_e);

          arc = utils.getccenter(np1, np2, np3);

          //also save the t values
          arc.interval = {
            start: t_s,
            end: t_e,
          };

          let error = this._error(arc, np1, t_s, t_e);
          curr_good = error <= errorThreshold;

          done = prev_good && !curr_good;
          if (!done) prev_e = t_e;

          // this arc is fine: we can move 'e' up to see if we can find a wider arc
          if (curr_good) {
            // if e is already at max, then we're done for this arc.
            if (t_e >= 1) {
              // make sure we cap at t=1
              arc.interval.end = prev_e = 1;
              prev_arc = arc;
              // if we capped the arc segment to t=1 we also need to make sure that
              // the arc's end angle is correct with respect to the bezier end point.
              if (t_e > 1) {
                let d = {
                  x: arc.x + arc.r * cos(arc.e),
                  y: arc.y + arc.r * sin(arc.e),
                };
                arc.e += utils.angle({ x: arc.x, y: arc.y }, d, this.get(1));
              }
              break;
            }
            // if not, move it up by half the iteration distance
            t_e = t_e + (t_e - t_s) / 2;
          } else {
            // this is a bad arc: we need to move 'e' down to find a good arc
            t_e = t_m;
          }
        } while (!done && safety++ < 100);

        if (safety >= 100) {
          break;
        }

        // console.log("L835: [F] arc found", t_s, prev_e, prev_arc.x, prev_arc.y, prev_arc.s, prev_arc.e);

        prev_arc = prev_arc ? prev_arc : arc;
        circles.push(prev_arc);
        t_s = prev_e;
      } while (t_e < 1);
      return circles;
    }
  }

  function _iterableToArrayLimit(arr, i) {
    var _i = null == arr ? null : "undefined" != typeof Symbol && arr[Symbol.iterator] || arr["@@iterator"];
    if (null != _i) {
      var _s,
        _e,
        _x,
        _r,
        _arr = [],
        _n = !0,
        _d = !1;
      try {
        if (_x = (_i = _i.call(arr)).next, 0 === i) {
          if (Object(_i) !== _i) return;
          _n = !1;
        } else for (; !(_n = (_s = _x.call(_i)).done) && (_arr.push(_s.value), _arr.length !== i); _n = !0);
      } catch (err) {
        _d = !0, _e = err;
      } finally {
        try {
          if (!_n && null != _i.return && (_r = _i.return(), Object(_r) !== _r)) return;
        } finally {
          if (_d) throw _e;
        }
      }
      return _arr;
    }
  }
  function _objectWithoutPropertiesLoose(source, excluded) {
    if (source == null) return {};
    var target = {};
    var sourceKeys = Object.keys(source);
    var key, i;
    for (i = 0; i < sourceKeys.length; i++) {
      key = sourceKeys[i];
      if (excluded.indexOf(key) >= 0) continue;
      target[key] = source[key];
    }
    return target;
  }
  function _objectWithoutProperties(source, excluded) {
    if (source == null) return {};
    var target = _objectWithoutPropertiesLoose(source, excluded);
    var key, i;
    if (Object.getOwnPropertySymbols) {
      var sourceSymbolKeys = Object.getOwnPropertySymbols(source);
      for (i = 0; i < sourceSymbolKeys.length; i++) {
        key = sourceSymbolKeys[i];
        if (excluded.indexOf(key) >= 0) continue;
        if (!Object.prototype.propertyIsEnumerable.call(source, key)) continue;
        target[key] = source[key];
      }
    }
    return target;
  }
  function _slicedToArray(arr, i) {
    return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest();
  }
  function _toConsumableArray(arr) {
    return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _unsupportedIterableToArray(arr) || _nonIterableSpread();
  }
  function _arrayWithoutHoles(arr) {
    if (Array.isArray(arr)) return _arrayLikeToArray(arr);
  }
  function _arrayWithHoles(arr) {
    if (Array.isArray(arr)) return arr;
  }
  function _iterableToArray(iter) {
    if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter);
  }
  function _unsupportedIterableToArray(o, minLen) {
    if (!o) return;
    if (typeof o === "string") return _arrayLikeToArray(o, minLen);
    var n = Object.prototype.toString.call(o).slice(8, -1);
    if (n === "Object" && o.constructor) n = o.constructor.name;
    if (n === "Map" || n === "Set") return Array.from(o);
    if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen);
  }
  function _arrayLikeToArray(arr, len) {
    if (len == null || len > arr.length) len = arr.length;
    for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i];
    return arr2;
  }
  function _nonIterableSpread() {
    throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }
  function _nonIterableRest() {
    throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
  }
  function _toPrimitive(input, hint) {
    if (typeof input !== "object" || input === null) return input;
    var prim = input[Symbol.toPrimitive];
    if (prim !== undefined) {
      var res = prim.call(input, hint || "default");
      if (typeof res !== "object") return res;
      throw new TypeError("@@toPrimitive must return a primitive value.");
    }
    return (hint === "string" ? String : Number)(input);
  }
  function _toPropertyKey(arg) {
    var key = _toPrimitive(arg, "string");
    return typeof key === "symbol" ? key : String(key);
  }

  var index = (function () {
    var list = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
    var keyAccessors = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
    var multiItem = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : true;
    var flattenKeys = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : false;
    var keys = (keyAccessors instanceof Array ? keyAccessors.length ? keyAccessors : [undefined] : [keyAccessors]).map(function (key) {
      return {
        keyAccessor: key,
        isProp: !(key instanceof Function)
      };
    });
    var indexedResult = list.reduce(function (res, item) {
      var iterObj = res;
      var itemVal = item;
      keys.forEach(function (_ref, idx) {
        var keyAccessor = _ref.keyAccessor,
          isProp = _ref.isProp;
        var key;
        if (isProp) {
          var _itemVal = itemVal,
            propVal = _itemVal[keyAccessor],
            rest = _objectWithoutProperties(_itemVal, [keyAccessor].map(_toPropertyKey));
          key = propVal;
          itemVal = rest;
        } else {
          key = keyAccessor(itemVal, idx);
        }
        if (idx + 1 < keys.length) {
          if (!iterObj.hasOwnProperty(key)) {
            iterObj[key] = {};
          }
          iterObj = iterObj[key];
        } else {
          // Leaf key
          if (multiItem) {
            if (!iterObj.hasOwnProperty(key)) {
              iterObj[key] = [];
            }
            iterObj[key].push(itemVal);
          } else {
            iterObj[key] = itemVal;
          }
        }
      });
      return res;
    }, {});
    if (multiItem instanceof Function) {
      // Reduce leaf multiple values
      (function reduce(node) {
        var level = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;
        if (level === keys.length) {
          Object.keys(node).forEach(function (k) {
            return node[k] = multiItem(node[k]);
          });
        } else {
          Object.values(node).forEach(function (child) {
            return reduce(child, level + 1);
          });
        }
      })(indexedResult); // IIFE
    }

    var result = indexedResult;
    if (flattenKeys) {
      // flatten into array
      result = [];
      (function flatten(node) {
        var accKeys = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
        if (accKeys.length === keys.length) {
          result.push({
            keys: accKeys,
            vals: node
          });
        } else {
          Object.entries(node).forEach(function (_ref2) {
            var _ref3 = _slicedToArray(_ref2, 2),
              key = _ref3[0],
              val = _ref3[1];
            return flatten(val, [].concat(_toConsumableArray(accKeys), [key]));
          });
        }
      })(indexedResult); //IIFE

      if (keyAccessors instanceof Array && keyAccessors.length === 0 && result.length === 1) {
        // clear keys if there's no key accessors (single result)
        result[0].keys = [];
      }
    }
    return result;
  });

  function initRange(domain, range) {
    switch (arguments.length) {
      case 0: break;
      case 1: this.range(domain); break;
      default: this.range(range).domain(domain); break;
    }
    return this;
  }

  const implicit = Symbol("implicit");

  function ordinal() {
    var index = new InternMap(),
        domain = [],
        range = [],
        unknown = implicit;

    function scale(d) {
      let i = index.get(d);
      if (i === undefined) {
        if (unknown !== implicit) return unknown;
        index.set(d, i = domain.push(d) - 1);
      }
      return range[i % range.length];
    }

    scale.domain = function(_) {
      if (!arguments.length) return domain.slice();
      domain = [], index = new InternMap();
      for (const value of _) {
        if (index.has(value)) continue;
        index.set(value, domain.push(value) - 1);
      }
      return scale;
    };

    scale.range = function(_) {
      return arguments.length ? (range = Array.from(_), scale) : range.slice();
    };

    scale.unknown = function(_) {
      return arguments.length ? (unknown = _, scale) : unknown;
    };

    scale.copy = function() {
      return ordinal(domain, range).unknown(unknown);
    };

    initRange.apply(scale, arguments);

    return scale;
  }

  function colors(specifier) {
    var n = specifier.length / 6 | 0, colors = new Array(n), i = 0;
    while (i < n) colors[i] = "#" + specifier.slice(i * 6, ++i * 6);
    return colors;
  }

  var schemePaired = colors("a6cee31f78b4b2df8a33a02cfb9a99e31a1cfdbf6fff7f00cab2d66a3d9affff99b15928");

  var autoColorScale = ordinal(schemePaired);

  // Autoset attribute colorField by colorByAccessor property
  // If an object has already a color, don't set it
  // Objects can be nodes or links
  function autoColorObjects(objects, colorByAccessor, colorField) {
    if (!colorByAccessor || typeof colorField !== 'string') return;
    objects.filter(function (obj) {
      return !obj[colorField];
    }).forEach(function (obj) {
      obj[colorField] = autoColorScale(colorByAccessor(obj));
    });
  }

  function getDagDepths (_ref, idAccessor) {
    var nodes = _ref.nodes,
      links = _ref.links;
    var _ref2 = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {},
      _ref2$nodeFilter = _ref2.nodeFilter,
      nodeFilter = _ref2$nodeFilter === void 0 ? function () {
        return true;
      } : _ref2$nodeFilter,
      _ref2$onLoopError = _ref2.onLoopError,
      onLoopError = _ref2$onLoopError === void 0 ? function (loopIds) {
        throw "Invalid DAG structure! Found cycle in node path: ".concat(loopIds.join(' -> '), ".");
      } : _ref2$onLoopError;
    // linked graph
    var graph = {};
    nodes.forEach(function (node) {
      return graph[idAccessor(node)] = {
        data: node,
        out: [],
        depth: -1,
        skip: !nodeFilter(node)
      };
    });
    links.forEach(function (_ref3) {
      var source = _ref3.source,
        target = _ref3.target;
      var sourceId = getNodeId(source);
      var targetId = getNodeId(target);
      if (!graph.hasOwnProperty(sourceId)) throw "Missing source node with id: ".concat(sourceId);
      if (!graph.hasOwnProperty(targetId)) throw "Missing target node with id: ".concat(targetId);
      var sourceNode = graph[sourceId];
      var targetNode = graph[targetId];
      sourceNode.out.push(targetNode);
      function getNodeId(node) {
        return _typeof$1(node) === 'object' ? idAccessor(node) : node;
      }
    });
    var foundLoops = [];
    traverse(Object.values(graph));
    var nodeDepths = Object.assign.apply(Object, [{}].concat(_toConsumableArray$2(Object.entries(graph).filter(function (_ref4) {
      var _ref5 = _slicedToArray$2(_ref4, 2),
        node = _ref5[1];
      return !node.skip;
    }).map(function (_ref6) {
      var _ref7 = _slicedToArray$2(_ref6, 2),
        id = _ref7[0],
        node = _ref7[1];
      return _defineProperty({}, id, node.depth);
    }))));
    return nodeDepths;
    function traverse(nodes) {
      var nodeStack = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
      var currentDepth = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 0;
      var _loop = function _loop() {
        var node = nodes[i];
        if (nodeStack.indexOf(node) !== -1) {
          var loop = [].concat(_toConsumableArray$2(nodeStack.slice(nodeStack.indexOf(node))), [node]).map(function (d) {
            return idAccessor(d.data);
          });
          if (!foundLoops.some(function (foundLoop) {
            return foundLoop.length === loop.length && foundLoop.every(function (id, idx) {
              return id === loop[idx];
            });
          })) {
            foundLoops.push(loop);
            onLoopError(loop);
          }
          return 1; // continue
        }
        if (currentDepth > node.depth) {
          // Don't unnecessarily revisit chunks of the graph
          node.depth = currentDepth;
          traverse(node.out, [].concat(_toConsumableArray$2(nodeStack), [node]), currentDepth + (node.skip ? 0 : 1));
        }
      };
      for (var i = 0, l = nodes.length; i < l; i++) {
        if (_loop()) continue;
      }
    }
  }

  //

  var DAG_LEVEL_NODE_RATIO = 2;

  // whenever styling props are changed that require a canvas redraw
  var notifyRedraw = function notifyRedraw(_, state) {
    return state.onNeedsRedraw && state.onNeedsRedraw();
  };
  var updDataPhotons = function updDataPhotons(_, state) {
    if (!state.isShadow) {
      // Add photon particles
      var linkParticlesAccessor = index$2(state.linkDirectionalParticles);
      state.graphData.links.forEach(function (link) {
        var numPhotons = Math.round(Math.abs(linkParticlesAccessor(link)));
        if (numPhotons) {
          link.__photons = _toConsumableArray$2(Array(numPhotons)).map(function () {
            return {};
          });
        } else {
          delete link.__photons;
        }
      });
    }
  };
  var CanvasForceGraph = index$3({
    props: {
      graphData: {
        "default": {
          nodes: [],
          links: []
        },
        onChange: function onChange(_, state) {
          state.engineRunning = false; // Pause simulation
          updDataPhotons(_, state);
        }
      },
      dagMode: {
        onChange: function onChange(dagMode, state) {
          // td, bu, lr, rl, radialin, radialout
          !dagMode && (state.graphData.nodes || []).forEach(function (n) {
            return n.fx = n.fy = undefined;
          }); // unfix nodes when disabling dag mode
        }
      },
      dagLevelDistance: {},
      dagNodeFilter: {
        "default": function _default(node) {
          return true;
        }
      },
      onDagError: {
        triggerUpdate: false
      },
      nodeRelSize: {
        "default": 4,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      // area per val unit
      nodeId: {
        "default": 'id'
      },
      nodeVal: {
        "default": 'val',
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      nodeColor: {
        "default": 'color',
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      nodeAutoColorBy: {},
      nodeCanvasObject: {
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      nodeCanvasObjectMode: {
        "default": function _default() {
          return 'replace';
        },
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      nodeVisibility: {
        "default": true,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkSource: {
        "default": 'source'
      },
      linkTarget: {
        "default": 'target'
      },
      linkVisibility: {
        "default": true,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkColor: {
        "default": 'color',
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkAutoColorBy: {},
      linkLineDash: {
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkWidth: {
        "default": 1,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkCurvature: {
        "default": 0,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkCanvasObject: {
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkCanvasObjectMode: {
        "default": function _default() {
          return 'replace';
        },
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkDirectionalArrowLength: {
        "default": 0,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkDirectionalArrowColor: {
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      linkDirectionalArrowRelPos: {
        "default": 0.5,
        triggerUpdate: false,
        onChange: notifyRedraw
      },
      // value between 0<>1 indicating the relative pos along the (exposed) line
      linkDirectionalParticles: {
        "default": 0,
        triggerUpdate: false,
        onChange: updDataPhotons
      },
      // animate photons travelling in the link direction
      linkDirectionalParticleSpeed: {
        "default": 0.01,
        triggerUpdate: false
      },
      // in link length ratio per frame
      linkDirectionalParticleWidth: {
        "default": 4,
        triggerUpdate: false
      },
      linkDirectionalParticleColor: {
        triggerUpdate: false
      },
      globalScale: {
        "default": 1,
        triggerUpdate: false
      },
      d3AlphaMin: {
        "default": 0,
        triggerUpdate: false
      },
      d3AlphaDecay: {
        "default": 0.0228,
        triggerUpdate: false,
        onChange: function onChange(alphaDecay, state) {
          state.forceLayout.alphaDecay(alphaDecay);
        }
      },
      d3AlphaTarget: {
        "default": 0,
        triggerUpdate: false,
        onChange: function onChange(alphaTarget, state) {
          state.forceLayout.alphaTarget(alphaTarget);
        }
      },
      d3VelocityDecay: {
        "default": 0.4,
        triggerUpdate: false,
        onChange: function onChange(velocityDecay, state) {
          state.forceLayout.velocityDecay(velocityDecay);
        }
      },
      warmupTicks: {
        "default": 0,
        triggerUpdate: false
      },
      // how many times to tick the force engine at init before starting to render
      cooldownTicks: {
        "default": Infinity,
        triggerUpdate: false
      },
      cooldownTime: {
        "default": 15000,
        triggerUpdate: false
      },
      // ms
      onUpdate: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onFinishUpdate: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onEngineTick: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onEngineStop: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onNeedsRedraw: {
        triggerUpdate: false
      },
      isShadow: {
        "default": false,
        triggerUpdate: false
      }
    },
    methods: {
      // Expose d3 forces for external manipulation
      d3Force: function d3Force(state, forceName, forceFn) {
        if (forceFn === undefined) {
          return state.forceLayout.force(forceName); // Force getter
        }
        state.forceLayout.force(forceName, forceFn); // Force setter
        return this;
      },
      d3ReheatSimulation: function d3ReheatSimulation(state) {
        state.forceLayout.alpha(1);
        this.resetCountdown();
        return this;
      },
      // reset cooldown state
      resetCountdown: function resetCountdown(state) {
        state.cntTicks = 0;
        state.startTickTime = new Date();
        state.engineRunning = true;
        return this;
      },
      isEngineRunning: function isEngineRunning(state) {
        return !!state.engineRunning;
      },
      tickFrame: function tickFrame(state) {
        !state.isShadow && layoutTick();
        paintLinks();
        !state.isShadow && paintArrows();
        !state.isShadow && paintPhotons();
        paintNodes();
        return this;

        //

        function layoutTick() {
          if (state.engineRunning) {
            if (++state.cntTicks > state.cooldownTicks || new Date() - state.startTickTime > state.cooldownTime || state.d3AlphaMin > 0 && state.forceLayout.alpha() < state.d3AlphaMin) {
              state.engineRunning = false; // Stop ticking graph
              state.onEngineStop();
            } else {
              state.forceLayout.tick(); // Tick it
              state.onEngineTick();
            }
          }
        }
        function paintNodes() {
          var getVisibility = index$2(state.nodeVisibility);
          var getVal = index$2(state.nodeVal);
          var getColor = index$2(state.nodeColor);
          var getNodeCanvasObjectMode = index$2(state.nodeCanvasObjectMode);
          var ctx = state.ctx;

          // Draw wider nodes by 1px on shadow canvas for more precise hovering (due to boundary anti-aliasing)
          var padAmount = state.isShadow / state.globalScale;
          var visibleNodes = state.graphData.nodes.filter(getVisibility);
          ctx.save();
          visibleNodes.forEach(function (node) {
            var nodeCanvasObjectMode = getNodeCanvasObjectMode(node);
            if (state.nodeCanvasObject && (nodeCanvasObjectMode === 'before' || nodeCanvasObjectMode === 'replace')) {
              // Custom node before/replace paint
              state.nodeCanvasObject(node, ctx, state.globalScale);
              if (nodeCanvasObjectMode === 'replace') {
                ctx.restore();
                return;
              }
            }

            // Draw wider nodes by 1px on shadow canvas for more precise hovering (due to boundary anti-aliasing)
            var r = Math.sqrt(Math.max(0, getVal(node) || 1)) * state.nodeRelSize + padAmount;
            ctx.beginPath();
            ctx.arc(node.x, node.y, r, 0, 2 * Math.PI, false);
            ctx.fillStyle = getColor(node) || 'rgba(31, 120, 180, 0.92)';
            ctx.fill();
            if (state.nodeCanvasObject && nodeCanvasObjectMode === 'after') {
              // Custom node after paint
              state.nodeCanvasObject(node, state.ctx, state.globalScale);
            }
          });
          ctx.restore();
        }
        function paintLinks() {
          var getVisibility = index$2(state.linkVisibility);
          var getColor = index$2(state.linkColor);
          var getWidth = index$2(state.linkWidth);
          var getLineDash = index$2(state.linkLineDash);
          var getCurvature = index$2(state.linkCurvature);
          var getLinkCanvasObjectMode = index$2(state.linkCanvasObjectMode);
          var ctx = state.ctx;

          // Draw wider lines by 2px on shadow canvas for more precise hovering (due to boundary anti-aliasing)
          var padAmount = state.isShadow * 2;
          var visibleLinks = state.graphData.links.filter(getVisibility);
          visibleLinks.forEach(calcLinkControlPoints); // calculate curvature control points for all visible links

          var beforeCustomLinks = [],
            afterCustomLinks = [],
            defaultPaintLinks = visibleLinks;
          if (state.linkCanvasObject) {
            var replaceCustomLinks = [],
              otherCustomLinks = [];
            visibleLinks.forEach(function (d) {
              return ({
                before: beforeCustomLinks,
                after: afterCustomLinks,
                replace: replaceCustomLinks
              }[getLinkCanvasObjectMode(d)] || otherCustomLinks).push(d);
            });
            defaultPaintLinks = [].concat(_toConsumableArray$2(beforeCustomLinks), afterCustomLinks, otherCustomLinks);
            beforeCustomLinks = beforeCustomLinks.concat(replaceCustomLinks);
          }

          // Custom link before paints
          ctx.save();
          beforeCustomLinks.forEach(function (link) {
            return state.linkCanvasObject(link, ctx, state.globalScale);
          });
          ctx.restore();

          // Bundle strokes per unique color/width/dash for performance optimization
          var linksPerColor = index(defaultPaintLinks, [getColor, getWidth, getLineDash]);
          ctx.save();
          Object.entries(linksPerColor).forEach(function (_ref) {
            var _ref2 = _slicedToArray$2(_ref, 2),
              color = _ref2[0],
              linksPerWidth = _ref2[1];
            var lineColor = !color || color === 'undefined' ? 'rgba(0,0,0,0.15)' : color;
            Object.entries(linksPerWidth).forEach(function (_ref3) {
              var _ref4 = _slicedToArray$2(_ref3, 2),
                width = _ref4[0],
                linesPerLineDash = _ref4[1];
              var lineWidth = (width || 1) / state.globalScale + padAmount;
              Object.entries(linesPerLineDash).forEach(function (_ref5) {
                var _ref6 = _slicedToArray$2(_ref5, 2);
                  _ref6[0];
                  var links = _ref6[1];
                var lineDashSegments = getLineDash(links[0]);
                ctx.beginPath();
                links.forEach(function (link) {
                  var start = link.source;
                  var end = link.target;
                  if (!start || !end || !start.hasOwnProperty('x') || !end.hasOwnProperty('x')) return; // skip invalid link

                  ctx.moveTo(start.x, start.y);
                  var controlPoints = link.__controlPoints;
                  if (!controlPoints) {
                    // Straight line
                    ctx.lineTo(end.x, end.y);
                  } else {
                    // Use quadratic curves for regular lines and bezier for loops
                    ctx[controlPoints.length === 2 ? 'quadraticCurveTo' : 'bezierCurveTo'].apply(ctx, _toConsumableArray$2(controlPoints).concat([end.x, end.y]));
                  }
                });
                ctx.strokeStyle = lineColor;
                ctx.lineWidth = lineWidth;
                ctx.setLineDash(lineDashSegments || []);
                ctx.stroke();
              });
            });
          });
          ctx.restore();

          // Custom link after paints
          ctx.save();
          afterCustomLinks.forEach(function (link) {
            return state.linkCanvasObject(link, ctx, state.globalScale);
          });
          ctx.restore();

          //

          function calcLinkControlPoints(link) {
            var curvature = getCurvature(link);
            if (!curvature) {
              // straight line
              link.__controlPoints = null;
              return;
            }
            var start = link.source;
            var end = link.target;
            if (!start || !end || !start.hasOwnProperty('x') || !end.hasOwnProperty('x')) return; // skip invalid link

            var l = Math.sqrt(Math.pow(end.x - start.x, 2) + Math.pow(end.y - start.y, 2)); // line length

            if (l > 0) {
              var a = Math.atan2(end.y - start.y, end.x - start.x); // line angle
              var d = l * curvature; // control point distance

              var cp = {
                // control point
                x: (start.x + end.x) / 2 + d * Math.cos(a - Math.PI / 2),
                y: (start.y + end.y) / 2 + d * Math.sin(a - Math.PI / 2)
              };
              link.__controlPoints = [cp.x, cp.y];
            } else {
              // Same point, draw a loop
              var _d = curvature * 70;
              link.__controlPoints = [end.x, end.y - _d, end.x + _d, end.y];
            }
          }
        }
        function paintArrows() {
          var ARROW_WH_RATIO = 1.6;
          var ARROW_VLEN_RATIO = 0.2;
          var getLength = index$2(state.linkDirectionalArrowLength);
          var getRelPos = index$2(state.linkDirectionalArrowRelPos);
          var getVisibility = index$2(state.linkVisibility);
          var getColor = index$2(state.linkDirectionalArrowColor || state.linkColor);
          var getNodeVal = index$2(state.nodeVal);
          var ctx = state.ctx;
          ctx.save();
          state.graphData.links.filter(getVisibility).forEach(function (link) {
            var arrowLength = getLength(link);
            if (!arrowLength || arrowLength < 0) return;
            var start = link.source;
            var end = link.target;
            if (!start || !end || !start.hasOwnProperty('x') || !end.hasOwnProperty('x')) return; // skip invalid link

            var startR = Math.sqrt(Math.max(0, getNodeVal(start) || 1)) * state.nodeRelSize;
            var endR = Math.sqrt(Math.max(0, getNodeVal(end) || 1)) * state.nodeRelSize;
            var arrowRelPos = Math.min(1, Math.max(0, getRelPos(link)));
            var arrowColor = getColor(link) || 'rgba(0,0,0,0.28)';
            var arrowHalfWidth = arrowLength / ARROW_WH_RATIO / 2;

            // Construct bezier for curved lines
            var bzLine = link.__controlPoints && _construct(Bezier, [start.x, start.y].concat(_toConsumableArray$2(link.__controlPoints), [end.x, end.y]));
            var getCoordsAlongLine = bzLine ? function (t) {
              return bzLine.get(t);
            } // get position along bezier line
            : function (t) {
              return {
                // straight line: interpolate linearly
                x: start.x + (end.x - start.x) * t || 0,
                y: start.y + (end.y - start.y) * t || 0
              };
            };
            var lineLen = bzLine ? bzLine.length() : Math.sqrt(Math.pow(end.x - start.x, 2) + Math.pow(end.y - start.y, 2));
            var posAlongLine = startR + arrowLength + (lineLen - startR - endR - arrowLength) * arrowRelPos;
            var arrowHead = getCoordsAlongLine(posAlongLine / lineLen);
            var arrowTail = getCoordsAlongLine((posAlongLine - arrowLength) / lineLen);
            var arrowTailVertex = getCoordsAlongLine((posAlongLine - arrowLength * (1 - ARROW_VLEN_RATIO)) / lineLen);
            var arrowTailAngle = Math.atan2(arrowHead.y - arrowTail.y, arrowHead.x - arrowTail.x) - Math.PI / 2;
            ctx.beginPath();
            ctx.moveTo(arrowHead.x, arrowHead.y);
            ctx.lineTo(arrowTail.x + arrowHalfWidth * Math.cos(arrowTailAngle), arrowTail.y + arrowHalfWidth * Math.sin(arrowTailAngle));
            ctx.lineTo(arrowTailVertex.x, arrowTailVertex.y);
            ctx.lineTo(arrowTail.x - arrowHalfWidth * Math.cos(arrowTailAngle), arrowTail.y - arrowHalfWidth * Math.sin(arrowTailAngle));
            ctx.fillStyle = arrowColor;
            ctx.fill();
          });
          ctx.restore();
        }
        function paintPhotons() {
          var getNumPhotons = index$2(state.linkDirectionalParticles);
          var getSpeed = index$2(state.linkDirectionalParticleSpeed);
          var getDiameter = index$2(state.linkDirectionalParticleWidth);
          var getVisibility = index$2(state.linkVisibility);
          var getColor = index$2(state.linkDirectionalParticleColor || state.linkColor);
          var ctx = state.ctx;
          ctx.save();
          state.graphData.links.filter(getVisibility).forEach(function (link) {
            var numCyclePhotons = getNumPhotons(link);
            if (!link.hasOwnProperty('__photons') || !link.__photons.length) return;
            var start = link.source;
            var end = link.target;
            if (!start || !end || !start.hasOwnProperty('x') || !end.hasOwnProperty('x')) return; // skip invalid link

            var particleSpeed = getSpeed(link);
            var photons = link.__photons || [];
            var photonR = Math.max(0, getDiameter(link) / 2) / Math.sqrt(state.globalScale);
            var photonColor = getColor(link) || 'rgba(0,0,0,0.28)';
            ctx.fillStyle = photonColor;

            // Construct bezier for curved lines
            var bzLine = link.__controlPoints ? _construct(Bezier, [start.x, start.y].concat(_toConsumableArray$2(link.__controlPoints), [end.x, end.y])) : null;
            var cyclePhotonIdx = 0;
            var needsCleanup = false; // whether some photons need to be removed from list
            photons.forEach(function (photon) {
              var singleHop = !!photon.__singleHop;
              if (!photon.hasOwnProperty('__progressRatio')) {
                photon.__progressRatio = singleHop ? 0 : cyclePhotonIdx / numCyclePhotons;
              }
              !singleHop && cyclePhotonIdx++; // increase regular photon index

              photon.__progressRatio += particleSpeed;
              if (photon.__progressRatio >= 1) {
                if (!singleHop) {
                  photon.__progressRatio = photon.__progressRatio % 1;
                } else {
                  needsCleanup = true;
                  return;
                }
              }
              var photonPosRatio = photon.__progressRatio;
              var coords = bzLine ? bzLine.get(photonPosRatio) // get position along bezier line
              : {
                // straight line: interpolate linearly
                x: start.x + (end.x - start.x) * photonPosRatio || 0,
                y: start.y + (end.y - start.y) * photonPosRatio || 0
              };
              ctx.beginPath();
              ctx.arc(coords.x, coords.y, photonR, 0, 2 * Math.PI, false);
              ctx.fill();
            });
            if (needsCleanup) {
              // remove expired single hop photons
              link.__photons = link.__photons.filter(function (photon) {
                return !photon.__singleHop || photon.__progressRatio <= 1;
              });
            }
          });
          ctx.restore();
        }
      },
      emitParticle: function emitParticle(state, link) {
        if (link) {
          !link.__photons && (link.__photons = []);
          link.__photons.push({
            __singleHop: true
          }); // add a single hop particle
        }
        return this;
      }
    },
    stateInit: function stateInit() {
      return {
        forceLayout: d3ForceSimulation().force('link', d3ForceLink()).force('charge', d3ForceManyBody()).force('center', d3ForceCenter()).force('dagRadial', null).stop(),
        engineRunning: false
      };
    },
    init: function init(canvasCtx, state) {
      // Main canvas object to manipulate
      state.ctx = canvasCtx;
    },
    update: function update(state) {
      state.engineRunning = false; // Pause simulation
      state.onUpdate();
      if (state.nodeAutoColorBy !== null) {
        // Auto add color to uncolored nodes
        autoColorObjects(state.graphData.nodes, index$2(state.nodeAutoColorBy), state.nodeColor);
      }
      if (state.linkAutoColorBy !== null) {
        // Auto add color to uncolored links
        autoColorObjects(state.graphData.links, index$2(state.linkAutoColorBy), state.linkColor);
      }

      // parse links
      state.graphData.links.forEach(function (link) {
        link.source = link[state.linkSource];
        link.target = link[state.linkTarget];
      });

      // Feed data to force-directed layout
      state.forceLayout.stop().alpha(1) // re-heat the simulation
      .nodes(state.graphData.nodes);

      // add links (if link force is still active)
      var linkForce = state.forceLayout.force('link');
      if (linkForce) {
        linkForce.id(function (d) {
          return d[state.nodeId];
        }).links(state.graphData.links);
      }

      // setup dag force constraints
      var nodeDepths = state.dagMode && getDagDepths(state.graphData, function (node) {
        return node[state.nodeId];
      }, {
        nodeFilter: state.dagNodeFilter,
        onLoopError: state.onDagError || undefined
      });
      var maxDepth = Math.max.apply(Math, _toConsumableArray$2(Object.values(nodeDepths || [])));
      var dagLevelDistance = state.dagLevelDistance || state.graphData.nodes.length / (maxDepth || 1) * DAG_LEVEL_NODE_RATIO * (['radialin', 'radialout'].indexOf(state.dagMode) !== -1 ? 0.7 : 1);

      // Fix nodes to x,y for dag mode
      if (state.dagMode) {
        var getFFn = function getFFn(fix, invert) {
          return function (node) {
            return !fix ? undefined : (nodeDepths[node[state.nodeId]] - maxDepth / 2) * dagLevelDistance * (invert ? -1 : 1);
          };
        };
        var fxFn = getFFn(['lr', 'rl'].indexOf(state.dagMode) !== -1, state.dagMode === 'rl');
        var fyFn = getFFn(['td', 'bu'].indexOf(state.dagMode) !== -1, state.dagMode === 'bu');
        state.graphData.nodes.filter(state.dagNodeFilter).forEach(function (node) {
          node.fx = fxFn(node);
          node.fy = fyFn(node);
        });
      }

      // Use radial force for radial dags
      state.forceLayout.force('dagRadial', ['radialin', 'radialout'].indexOf(state.dagMode) !== -1 ? d3ForceRadial(function (node) {
        var nodeDepth = nodeDepths[node[state.nodeId]] || -1;
        return (state.dagMode === 'radialin' ? maxDepth - nodeDepth : nodeDepth) * dagLevelDistance;
      }).strength(function (node) {
        return state.dagNodeFilter(node) ? 1 : 0;
      }) : null);
      for (var i = 0; i < state.warmupTicks && !(state.d3AlphaMin > 0 && state.forceLayout.alpha() < state.d3AlphaMin); i++) {
        state.forceLayout.tick();
      } // Initial ticks before starting to render

      this.resetCountdown();
      state.onFinishUpdate();
    }
  });

  function linkKapsule (kapsulePropNames, kapsuleType) {
    var propNames = kapsulePropNames instanceof Array ? kapsulePropNames : [kapsulePropNames];
    var dummyK = new kapsuleType(); // To extract defaults
    dummyK._destructor && dummyK._destructor();
    return {
      linkProp: function linkProp(prop) {
        // link property config
        return {
          "default": dummyK[prop](),
          onChange: function onChange(v, state) {
            propNames.forEach(function (propName) {
              return state[propName][prop](v);
            });
          },
          triggerUpdate: false
        };
      },
      linkMethod: function linkMethod(method) {
        // link method pass-through
        return function (state) {
          for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
            args[_key - 1] = arguments[_key];
          }
          var returnVals = [];
          propNames.forEach(function (propName) {
            var kapsuleInstance = state[propName];
            var returnVal = kapsuleInstance[method].apply(kapsuleInstance, args);
            if (returnVal !== kapsuleInstance) {
              returnVals.push(returnVal);
            }
          });
          return returnVals.length ? returnVals[0] : this; // chain based on the parent object, not the inner kapsule
        };
      }
    };
  }

  var HOVER_CANVAS_THROTTLE_DELAY = 800; // ms to throttle shadow canvas updates for perf improvement
  var ZOOM2NODES_FACTOR = 4;

  // Expose config from forceGraph
  var bindFG = linkKapsule('forceGraph', CanvasForceGraph);
  var bindBoth = linkKapsule(['forceGraph', 'shadowGraph'], CanvasForceGraph);
  var linkedProps = Object.assign.apply(Object, _toConsumableArray$2(['nodeColor', 'nodeAutoColorBy', 'nodeCanvasObject', 'nodeCanvasObjectMode', 'linkColor', 'linkAutoColorBy', 'linkLineDash', 'linkWidth', 'linkCanvasObject', 'linkCanvasObjectMode', 'linkDirectionalArrowLength', 'linkDirectionalArrowColor', 'linkDirectionalArrowRelPos', 'linkDirectionalParticles', 'linkDirectionalParticleSpeed', 'linkDirectionalParticleWidth', 'linkDirectionalParticleColor', 'dagMode', 'dagLevelDistance', 'dagNodeFilter', 'onDagError', 'd3AlphaMin', 'd3AlphaDecay', 'd3VelocityDecay', 'warmupTicks', 'cooldownTicks', 'cooldownTime', 'onEngineTick', 'onEngineStop'].map(function (p) {
    return _defineProperty({}, p, bindFG.linkProp(p));
  })).concat(_toConsumableArray$2(['nodeRelSize', 'nodeId', 'nodeVal', 'nodeVisibility', 'linkSource', 'linkTarget', 'linkVisibility', 'linkCurvature'].map(function (p) {
    return _defineProperty({}, p, bindBoth.linkProp(p));
  }))));
  var linkedMethods = Object.assign.apply(Object, _toConsumableArray$2(['d3Force', 'd3ReheatSimulation', 'emitParticle'].map(function (p) {
    return _defineProperty({}, p, bindFG.linkMethod(p));
  })));
  function adjustCanvasSize(state) {
    if (state.canvas) {
      var curWidth = state.canvas.width;
      var curHeight = state.canvas.height;
      if (curWidth === 300 && curHeight === 150) {
        // Default canvas dimensions
        curWidth = curHeight = 0;
      }
      var pxScale = window.devicePixelRatio; // 2 on retina displays
      curWidth /= pxScale;
      curHeight /= pxScale;

      // Resize canvases
      [state.canvas, state.shadowCanvas].forEach(function (canvas) {
        // Element size
        canvas.style.width = "".concat(state.width, "px");
        canvas.style.height = "".concat(state.height, "px");

        // Memory size (scaled to avoid blurriness)
        canvas.width = state.width * pxScale;
        canvas.height = state.height * pxScale;

        // Normalize coordinate system to use css pixels (on init only)
        if (!curWidth && !curHeight) {
          canvas.getContext('2d').scale(pxScale, pxScale);
        }
      });

      // Relative center panning based on 0,0
      var k = transform(state.canvas).k;
      state.zoom.translateBy(state.zoom.__baseElem, (state.width - curWidth) / 2 / k, (state.height - curHeight) / 2 / k);
      state.needsRedraw = true;
    }
  }
  function resetTransform(ctx) {
    var pxRatio = window.devicePixelRatio;
    ctx.setTransform(pxRatio, 0, 0, pxRatio, 0, 0);
  }
  function clearCanvas(ctx, width, height) {
    ctx.save();
    resetTransform(ctx); // reset transform
    ctx.clearRect(0, 0, width, height);
    ctx.restore(); //restore transforms
  }

  //

  var forceGraph = index$3({
    props: _objectSpread2({
      width: {
        "default": window.innerWidth,
        onChange: function onChange(_, state) {
          return adjustCanvasSize(state);
        },
        triggerUpdate: false
      },
      height: {
        "default": window.innerHeight,
        onChange: function onChange(_, state) {
          return adjustCanvasSize(state);
        },
        triggerUpdate: false
      },
      graphData: {
        "default": {
          nodes: [],
          links: []
        },
        onChange: function onChange(d, state) {
          [{
            type: 'Node',
            objs: d.nodes
          }, {
            type: 'Link',
            objs: d.links
          }].forEach(hexIndex);
          state.forceGraph.graphData(d);
          state.shadowGraph.graphData(d);
          function hexIndex(_ref4) {
            var type = _ref4.type,
              objs = _ref4.objs;
            objs.filter(function (d) {
              if (!d.hasOwnProperty('__indexColor')) return true;
              var cur = state.colorTracker.lookup(d.__indexColor);
              return !cur || !cur.hasOwnProperty('d') || cur.d !== d;
            }).forEach(function (d) {
              // store object lookup color
              d.__indexColor = state.colorTracker.register({
                type: type,
                d: d
              });
            });
          }
        },
        triggerUpdate: false
      },
      backgroundColor: {
        onChange: function onChange(color, state) {
          state.canvas && color && (state.canvas.style.background = color);
        },
        triggerUpdate: false
      },
      nodeLabel: {
        "default": 'name',
        triggerUpdate: false
      },
      nodePointerAreaPaint: {
        onChange: function onChange(paintFn, state) {
          state.shadowGraph.nodeCanvasObject(!paintFn ? null : function (node, ctx, globalScale) {
            return paintFn(node, node.__indexColor, ctx, globalScale);
          });
          state.flushShadowCanvas && state.flushShadowCanvas();
        },
        triggerUpdate: false
      },
      linkPointerAreaPaint: {
        onChange: function onChange(paintFn, state) {
          state.shadowGraph.linkCanvasObject(!paintFn ? null : function (link, ctx, globalScale) {
            return paintFn(link, link.__indexColor, ctx, globalScale);
          });
          state.flushShadowCanvas && state.flushShadowCanvas();
        },
        triggerUpdate: false
      },
      linkLabel: {
        "default": 'name',
        triggerUpdate: false
      },
      linkHoverPrecision: {
        "default": 4,
        triggerUpdate: false
      },
      minZoom: {
        "default": 0.01,
        onChange: function onChange(minZoom, state) {
          state.zoom.scaleExtent([minZoom, state.zoom.scaleExtent()[1]]);
        },
        triggerUpdate: false
      },
      maxZoom: {
        "default": 1000,
        onChange: function onChange(maxZoom, state) {
          state.zoom.scaleExtent([state.zoom.scaleExtent()[0], maxZoom]);
        },
        triggerUpdate: false
      },
      enableNodeDrag: {
        "default": true,
        triggerUpdate: false
      },
      enableZoomInteraction: {
        "default": true,
        triggerUpdate: false
      },
      enablePanInteraction: {
        "default": true,
        triggerUpdate: false
      },
      enableZoomPanInteraction: {
        "default": true,
        triggerUpdate: false
      },
      // to be deprecated
      enablePointerInteraction: {
        "default": true,
        onChange: function onChange(_, state) {
          state.hoverObj = null;
        },
        triggerUpdate: false
      },
      autoPauseRedraw: {
        "default": true,
        triggerUpdate: false
      },
      onNodeDrag: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onNodeDragEnd: {
        "default": function _default() {},
        triggerUpdate: false
      },
      onNodeClick: {
        triggerUpdate: false
      },
      onNodeRightClick: {
        triggerUpdate: false
      },
      onNodeHover: {
        triggerUpdate: false
      },
      onLinkClick: {
        triggerUpdate: false
      },
      onLinkRightClick: {
        triggerUpdate: false
      },
      onLinkHover: {
        triggerUpdate: false
      },
      onBackgroundClick: {
        triggerUpdate: false
      },
      onBackgroundRightClick: {
        triggerUpdate: false
      },
      onZoom: {
        triggerUpdate: false
      },
      onZoomEnd: {
        triggerUpdate: false
      },
      onRenderFramePre: {
        triggerUpdate: false
      },
      onRenderFramePost: {
        triggerUpdate: false
      }
    }, linkedProps),
    aliases: {
      // Prop names supported for backwards compatibility
      stopAnimation: 'pauseAnimation'
    },
    methods: _objectSpread2({
      graph2ScreenCoords: function graph2ScreenCoords(state, x, y) {
        var t = transform(state.canvas);
        return {
          x: x * t.k + t.x,
          y: y * t.k + t.y
        };
      },
      screen2GraphCoords: function screen2GraphCoords(state, x, y) {
        var t = transform(state.canvas);
        return {
          x: (x - t.x) / t.k,
          y: (y - t.y) / t.k
        };
      },
      centerAt: function centerAt(state, x, y, transitionDuration) {
        if (!state.canvas) return null; // no canvas yet

        // setter
        if (x !== undefined || y !== undefined) {
          var finalPos = Object.assign({}, x !== undefined ? {
            x: x
          } : {}, y !== undefined ? {
            y: y
          } : {});
          if (!transitionDuration) {
            // no animation
            setCenter(finalPos);
          } else {
            new Tween(getCenter()).to(finalPos, transitionDuration).easing(Easing.Quadratic.Out).onUpdate(setCenter).start();
          }
          return this;
        }

        // getter
        return getCenter();

        //

        function getCenter() {
          var t = transform(state.canvas);
          return {
            x: (state.width / 2 - t.x) / t.k,
            y: (state.height / 2 - t.y) / t.k
          };
        }
        function setCenter(_ref5) {
          var x = _ref5.x,
            y = _ref5.y;
          state.zoom.translateTo(state.zoom.__baseElem, x === undefined ? getCenter().x : x, y === undefined ? getCenter().y : y);
          state.needsRedraw = true;
        }
      },
      zoom: function zoom(state, k, transitionDuration) {
        if (!state.canvas) return null; // no canvas yet

        // setter
        if (k !== undefined) {
          if (!transitionDuration) {
            // no animation
            setZoom(k);
          } else {
            new Tween({
              k: getZoom()
            }).to({
              k: k
            }, transitionDuration).easing(Easing.Quadratic.Out).onUpdate(function (_ref6) {
              var k = _ref6.k;
              return setZoom(k);
            }).start();
          }
          return this;
        }

        // getter
        return getZoom();

        //

        function getZoom() {
          return transform(state.canvas).k;
        }
        function setZoom(k) {
          state.zoom.scaleTo(state.zoom.__baseElem, k);
          state.needsRedraw = true;
        }
      },
      zoomToFit: function zoomToFit(state) {
        var transitionDuration = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
        var padding = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 10;
        for (var _len = arguments.length, bboxArgs = new Array(_len > 3 ? _len - 3 : 0), _key = 3; _key < _len; _key++) {
          bboxArgs[_key - 3] = arguments[_key];
        }
        var bbox = this.getGraphBbox.apply(this, bboxArgs);
        if (bbox) {
          var center = {
            x: (bbox.x[0] + bbox.x[1]) / 2,
            y: (bbox.y[0] + bbox.y[1]) / 2
          };
          var zoomK = Math.max(1e-12, Math.min(1e12, (state.width - padding * 2) / (bbox.x[1] - bbox.x[0]), (state.height - padding * 2) / (bbox.y[1] - bbox.y[0])));
          this.centerAt(center.x, center.y, transitionDuration);
          this.zoom(zoomK, transitionDuration);
        }
        return this;
      },
      getGraphBbox: function getGraphBbox(state) {
        var nodeFilter = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function () {
          return true;
        };
        var getVal = index$2(state.nodeVal);
        var getR = function getR(node) {
          return Math.sqrt(Math.max(0, getVal(node) || 1)) * state.nodeRelSize;
        };
        var nodesPos = state.graphData.nodes.filter(nodeFilter).map(function (node) {
          return {
            x: node.x,
            y: node.y,
            r: getR(node)
          };
        });
        return !nodesPos.length ? null : {
          x: [min$1(nodesPos, function (node) {
            return node.x - node.r;
          }), max$1(nodesPos, function (node) {
            return node.x + node.r;
          })],
          y: [min$1(nodesPos, function (node) {
            return node.y - node.r;
          }), max$1(nodesPos, function (node) {
            return node.y + node.r;
          })]
        };
      },
      pauseAnimation: function pauseAnimation(state) {
        if (state.animationFrameRequestId) {
          cancelAnimationFrame(state.animationFrameRequestId);
          state.animationFrameRequestId = null;
        }
        return this;
      },
      resumeAnimation: function resumeAnimation(state) {
        if (!state.animationFrameRequestId) {
          this._animationCycle();
        }
        return this;
      },
      _destructor: function _destructor() {
        this.pauseAnimation();
        this.graphData({
          nodes: [],
          links: []
        });
      }
    }, linkedMethods),
    stateInit: function stateInit() {
      return {
        lastSetZoom: 1,
        zoom: d3Zoom(),
        forceGraph: new CanvasForceGraph(),
        shadowGraph: new CanvasForceGraph().cooldownTicks(0).nodeColor('__indexColor').linkColor('__indexColor').isShadow(true),
        colorTracker: new _default() // indexed objects for rgb lookup
      };
    },
    init: function init(domNode, state) {
      var _this = this;
      // Wipe DOM
      domNode.innerHTML = '';

      // Container anchor for canvas and tooltip
      var container = document.createElement('div');
      container.classList.add('force-graph-container');
      container.style.position = 'relative';
      domNode.appendChild(container);
      state.canvas = document.createElement('canvas');
      if (state.backgroundColor) state.canvas.style.background = state.backgroundColor;
      container.appendChild(state.canvas);
      state.shadowCanvas = document.createElement('canvas');

      // Show shadow canvas
      //state.shadowCanvas.style.position = 'absolute';
      //state.shadowCanvas.style.top = '0';
      //state.shadowCanvas.style.left = '0';
      //container.appendChild(state.shadowCanvas);

      var ctx = state.canvas.getContext('2d');
      var shadowCtx = state.shadowCanvas.getContext('2d', {
        willReadFrequently: true
      });
      var pointerPos = {
        x: -1e12,
        y: -1e12
      };
      var getObjUnderPointer = function getObjUnderPointer() {
        var obj = null;
        var pxScale = window.devicePixelRatio;
        var px = pointerPos.x > 0 && pointerPos.y > 0 ? shadowCtx.getImageData(pointerPos.x * pxScale, pointerPos.y * pxScale, 1, 1) : null;
        // Lookup object per pixel color
        px && (obj = state.colorTracker.lookup(px.data));
        return obj;
      };

      // Setup node drag interaction
      d3Select(state.canvas).call(d3Drag().subject(function () {
        if (!state.enableNodeDrag) {
          return null;
        }
        var obj = getObjUnderPointer();
        return obj && obj.type === 'Node' ? obj.d : null; // Only drag nodes
      }).on('start', function (ev) {
        var obj = ev.subject;
        obj.__initialDragPos = {
          x: obj.x,
          y: obj.y,
          fx: obj.fx,
          fy: obj.fy
        };

        // keep engine running at low intensity throughout drag
        if (!ev.active) {
          obj.fx = obj.x;
          obj.fy = obj.y; // Fix points
        }

        // drag cursor
        state.canvas.classList.add('grabbable');
      }).on('drag', function (ev) {
        var obj = ev.subject;
        var initPos = obj.__initialDragPos;
        var dragPos = ev;
        var k = transform(state.canvas).k;
        var translate = {
          x: initPos.x + (dragPos.x - initPos.x) / k - obj.x,
          y: initPos.y + (dragPos.y - initPos.y) / k - obj.y
        };

        // Move fx/fy (and x/y) of nodes based on the scaled drag distance since the drag start
        ['x', 'y'].forEach(function (c) {
          return obj["f".concat(c)] = obj[c] = initPos[c] + (dragPos[c] - initPos[c]) / k;
        });

        // prevent freeze while dragging
        state.forceGraph.d3AlphaTarget(0.3) // keep engine running at low intensity throughout drag
        .resetCountdown(); // prevent freeze while dragging

        state.isPointerDragging = true;
        obj.__dragged = true;
        state.onNodeDrag(obj, translate);
      }).on('end', function (ev) {
        var obj = ev.subject;
        var initPos = obj.__initialDragPos;
        var translate = {
          x: obj.x - initPos.x,
          y: obj.y - initPos.y
        };
        if (initPos.fx === undefined) {
          obj.fx = undefined;
        }
        if (initPos.fy === undefined) {
          obj.fy = undefined;
        }
        delete obj.__initialDragPos;
        if (state.forceGraph.d3AlphaTarget()) {
          state.forceGraph.d3AlphaTarget(0) // release engine low intensity
          .resetCountdown(); // let the engine readjust after releasing fixed nodes
        }

        // drag cursor
        state.canvas.classList.remove('grabbable');
        state.isPointerDragging = false;
        if (obj.__dragged) {
          delete obj.__dragged;
          state.onNodeDragEnd(obj, translate);
        }
      }));

      // Setup zoom / pan interaction
      state.zoom(state.zoom.__baseElem = d3Select(state.canvas)); // Attach controlling elem for easy access

      state.zoom.__baseElem.on('dblclick.zoom', null); // Disable double-click to zoom

      state.zoom.filter(function (ev) {
        return (
          // disable zoom interaction
          !ev.button && state.enableZoomPanInteraction && (state.enableZoomInteraction || ev.type !== 'wheel') && (state.enablePanInteraction || ev.type === 'wheel')
        );
      }).on('zoom', function (ev) {
        var t = ev.transform;
        [ctx, shadowCtx].forEach(function (c) {
          resetTransform(c);
          c.translate(t.x, t.y);
          c.scale(t.k, t.k);
        });
        state.onZoom && state.onZoom(_objectSpread2(_objectSpread2({}, t), _this.centerAt())); // report x,y coordinates relative to canvas center
        state.needsRedraw = true;
      }).on('end', function (ev) {
        return state.onZoomEnd && state.onZoomEnd(_objectSpread2(_objectSpread2({}, ev.transform), _this.centerAt()));
      });
      adjustCanvasSize(state);
      state.forceGraph.onNeedsRedraw(function () {
        return state.needsRedraw = true;
      }).onFinishUpdate(function () {
        // re-zoom, if still in default position (not user modified)
        if (transform(state.canvas).k === state.lastSetZoom && state.graphData.nodes.length) {
          state.zoom.scaleTo(state.zoom.__baseElem, state.lastSetZoom = ZOOM2NODES_FACTOR / Math.cbrt(state.graphData.nodes.length));
          state.needsRedraw = true;
        }
      });

      // Setup tooltip
      var toolTipElem = document.createElement('div');
      toolTipElem.classList.add('graph-tooltip');
      container.appendChild(toolTipElem);

      // Capture pointer coords on move or touchstart
      ['pointermove', 'pointerdown'].forEach(function (evType) {
        return container.addEventListener(evType, function (ev) {
          if (evType === 'pointerdown') {
            state.isPointerPressed = true; // track click state
            state.pointerDownEvent = ev;
          }

          // detect pointer drag on canvas pan
          !state.isPointerDragging && ev.type === 'pointermove' && state.onBackgroundClick // only bother detecting drags this way if background clicks are enabled (so they don't trigger accidentally on canvas panning)
          && (ev.pressure > 0 || state.isPointerPressed) // ev.pressure always 0 on Safari, so we use the isPointerPressed tracker
          && (ev.pointerType !== 'touch' || ev.movementX === undefined || [ev.movementX, ev.movementY].some(function (m) {
            return Math.abs(m) > 1;
          })) // relax drag trigger sensitivity on touch events
          && (state.isPointerDragging = true);

          // update the pointer pos
          var offset = getOffset(container);
          pointerPos.x = ev.pageX - offset.left;
          pointerPos.y = ev.pageY - offset.top;

          // Move tooltip
          toolTipElem.style.top = "".concat(pointerPos.y, "px");
          toolTipElem.style.left = "".concat(pointerPos.x, "px");

          // adjust horizontal position to not exceed canvas boundaries
          toolTipElem.style.transform = "translate(-".concat(pointerPos.x / state.width * 100, "%, ").concat(
          // flip to above if near bottom
          state.height - pointerPos.y < 100 ? 'calc(-100% - 8px)' : '21px', ")");

          //

          function getOffset(el) {
            var rect = el.getBoundingClientRect(),
              scrollLeft = window.pageXOffset || document.documentElement.scrollLeft,
              scrollTop = window.pageYOffset || document.documentElement.scrollTop;
            return {
              top: rect.top + scrollTop,
              left: rect.left + scrollLeft
            };
          }
        }, {
          passive: true
        });
      });

      // Handle click/touch events on nodes/links
      container.addEventListener('pointerup', function (ev) {
        state.isPointerPressed = false;
        if (state.isPointerDragging) {
          state.isPointerDragging = false;
          return; // don't trigger click events after pointer drag (pan / node drag functionality)
        }
        var cbEvents = [ev, state.pointerDownEvent];
        requestAnimationFrame(function () {
          // trigger click events asynchronously, to allow hoverObj to be set (on frame)
          if (ev.button === 0) {
            // mouse left-click or touch
            if (state.hoverObj) {
              var fn = state["on".concat(state.hoverObj.type, "Click")];
              fn && fn.apply(void 0, [state.hoverObj.d].concat(cbEvents));
            } else {
              state.onBackgroundClick && state.onBackgroundClick.apply(state, cbEvents);
            }
          }
          if (ev.button === 2) {
            // mouse right-click
            if (state.hoverObj) {
              var _fn = state["on".concat(state.hoverObj.type, "RightClick")];
              _fn && _fn.apply(void 0, [state.hoverObj.d].concat(cbEvents));
            } else {
              state.onBackgroundRightClick && state.onBackgroundRightClick.apply(state, cbEvents);
            }
          }
        });
      }, {
        passive: true
      });
      container.addEventListener('contextmenu', function (ev) {
        if (!state.onBackgroundRightClick && !state.onNodeRightClick && !state.onLinkRightClick) return true; // default contextmenu behavior
        ev.preventDefault();
        return false;
      });
      state.forceGraph(ctx);
      state.shadowGraph(shadowCtx);

      //

      var refreshShadowCanvas = throttle(function () {
        // wipe canvas
        clearCanvas(shadowCtx, state.width, state.height);

        // Adjust link hover area
        state.shadowGraph.linkWidth(function (l) {
          return index$2(state.linkWidth)(l) + state.linkHoverPrecision;
        });

        // redraw
        var t = transform(state.canvas);
        state.shadowGraph.globalScale(t.k).tickFrame();
      }, HOVER_CANVAS_THROTTLE_DELAY);
      state.flushShadowCanvas = refreshShadowCanvas.flush; // hook to immediately invoke shadow canvas paint

      // Kick-off renderer
      (this._animationCycle = function animate() {
        // IIFE
        var doRedraw = !state.autoPauseRedraw || !!state.needsRedraw || state.forceGraph.isEngineRunning() || state.graphData.links.some(function (d) {
          return d.__photons && d.__photons.length;
        });
        state.needsRedraw = false;
        if (state.enablePointerInteraction) {
          // Update tooltip and trigger onHover events
          var obj = !state.isPointerDragging ? getObjUnderPointer() : null; // don't hover during drag
          if (obj !== state.hoverObj) {
            var prevObj = state.hoverObj;
            var prevObjType = prevObj ? prevObj.type : null;
            var objType = obj ? obj.type : null;
            if (prevObjType && prevObjType !== objType) {
              // Hover out
              var fn = state["on".concat(prevObjType, "Hover")];
              fn && fn(null, prevObj.d);
            }
            if (objType) {
              // Hover in
              var _fn2 = state["on".concat(objType, "Hover")];
              _fn2 && _fn2(obj.d, prevObjType === objType ? prevObj.d : null);
            }
            var tooltipContent = obj ? index$2(state["".concat(obj.type.toLowerCase(), "Label")])(obj.d) || '' : '';
            toolTipElem.style.visibility = tooltipContent ? 'visible' : 'hidden';
            toolTipElem.innerHTML = tooltipContent;

            // set pointer if hovered object is clickable
            state.canvas.classList[obj && state["on".concat(objType, "Click")] || !obj && state.onBackgroundClick ? 'add' : 'remove']('clickable');
            state.hoverObj = obj;
          }
          doRedraw && refreshShadowCanvas();
        }
        if (doRedraw) {
          // Wipe canvas
          clearCanvas(ctx, state.width, state.height);

          // Frame cycle
          var globalScale = transform(state.canvas).k;
          state.onRenderFramePre && state.onRenderFramePre(ctx, globalScale);
          state.forceGraph.globalScale(globalScale).tickFrame();
          state.onRenderFramePost && state.onRenderFramePost(ctx, globalScale);
        }
        update(); // update canvas animation tweens

        state.animationFrameRequestId = requestAnimationFrame(animate);
      })();
    },
    update: function updateFn(state) {}
  });

  return forceGraph;

}));
//# sourceMappingURL=force-graph.js.map