import SplayTree from 'splaytree';

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, descriptor.key, descriptor);
  }
}

function _createClass(Constructor, protoProps, staticProps) {
  if (protoProps) _defineProperties(Constructor.prototype, protoProps);
  if (staticProps) _defineProperties(Constructor, staticProps);
  return Constructor;
}

/**
 * A bounding box has the format:
 *
 *  { ll: { x: xmin, y: ymin }, ur: { x: xmax, y: ymax } }
 *
 */
var isInBbox = function isInBbox(bbox, point) {
  return bbox.ll.x <= point.x && point.x <= bbox.ur.x && bbox.ll.y <= point.y && point.y <= bbox.ur.y;
};
/* Returns either null, or a bbox (aka an ordered pair of points)
 * If there is only one point of overlap, a bbox with identical points
 * will be returned */

var getBboxOverlap = function getBboxOverlap(b1, b2) {
  // check if the bboxes overlap at all
  if (b2.ur.x < b1.ll.x || b1.ur.x < b2.ll.x || b2.ur.y < b1.ll.y || b1.ur.y < b2.ll.y) return null; // find the middle two X values

  var lowerX = b1.ll.x < b2.ll.x ? b2.ll.x : b1.ll.x;
  var upperX = b1.ur.x < b2.ur.x ? b1.ur.x : b2.ur.x; // find the middle two Y values

  var lowerY = b1.ll.y < b2.ll.y ? b2.ll.y : b1.ll.y;
  var upperY = b1.ur.y < b2.ur.y ? b1.ur.y : b2.ur.y; // put those middle values together to get the overlap

  return {
    ll: {
      x: lowerX,
      y: lowerY
    },
    ur: {
      x: upperX,
      y: upperY
    }
  };
};

/* Javascript doesn't do integer math. Everything is
 * floating point with percision Number.EPSILON.
 *
 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/EPSILON
 */
var epsilon = Number.EPSILON; // IE Polyfill

if (epsilon === undefined) epsilon = Math.pow(2, -52);
var EPSILON_SQ = epsilon * epsilon;
/* FLP comparator */

var cmp = function cmp(a, b) {
  // check if they're both 0
  if (-epsilon < a && a < epsilon) {
    if (-epsilon < b && b < epsilon) {
      return 0;
    }
  } // check if they're flp equal


  var ab = a - b;

  if (ab * ab < EPSILON_SQ * a * b) {
    return 0;
  } // normal comparison


  return a < b ? -1 : 1;
};

/**
 * This class rounds incoming values sufficiently so that
 * floating points problems are, for the most part, avoided.
 *
 * Incoming points are have their x & y values tested against
 * all previously seen x & y values. If either is 'too close'
 * to a previously seen value, it's value is 'snapped' to the
 * previously seen value.
 *
 * All points should be rounded by this class before being
 * stored in any data structures in the rest of this algorithm.
 */

var PtRounder = /*#__PURE__*/function () {
  function PtRounder() {
    _classCallCheck(this, PtRounder);

    this.reset();
  }

  _createClass(PtRounder, [{
    key: "reset",
    value: function reset() {
      this.xRounder = new CoordRounder();
      this.yRounder = new CoordRounder();
    }
  }, {
    key: "round",
    value: function round(x, y) {
      return {
        x: this.xRounder.round(x),
        y: this.yRounder.round(y)
      };
    }
  }]);

  return PtRounder;
}();

var CoordRounder = /*#__PURE__*/function () {
  function CoordRounder() {
    _classCallCheck(this, CoordRounder);

    this.tree = new SplayTree(); // preseed with 0 so we don't end up with values < Number.EPSILON

    this.round(0);
  } // Note: this can rounds input values backwards or forwards.
  //       You might ask, why not restrict this to just rounding
  //       forwards? Wouldn't that allow left endpoints to always
  //       remain left endpoints during splitting (never change to
  //       right). No - it wouldn't, because we snap intersections
  //       to endpoints (to establish independence from the segment
  //       angle for t-intersections).


  _createClass(CoordRounder, [{
    key: "round",
    value: function round(coord) {
      var node = this.tree.add(coord);
      var prevNode = this.tree.prev(node);

      if (prevNode !== null && cmp(node.key, prevNode.key) === 0) {
        this.tree.remove(coord);
        return prevNode.key;
      }

      var nextNode = this.tree.next(node);

      if (nextNode !== null && cmp(node.key, nextNode.key) === 0) {
        this.tree.remove(coord);
        return nextNode.key;
      }

      return coord;
    }
  }]);

  return CoordRounder;
}(); // singleton available by import


var rounder = new PtRounder();

/* Cross Product of two vectors with first point at origin */

var crossProduct = function crossProduct(a, b) {
  return a.x * b.y - a.y * b.x;
};
/* Dot Product of two vectors with first point at origin */

var dotProduct = function dotProduct(a, b) {
  return a.x * b.x + a.y * b.y;
};
/* Comparator for two vectors with same starting point */

var compareVectorAngles = function compareVectorAngles(basePt, endPt1, endPt2) {
  var v1 = {
    x: endPt1.x - basePt.x,
    y: endPt1.y - basePt.y
  };
  var v2 = {
    x: endPt2.x - basePt.x,
    y: endPt2.y - basePt.y
  };
  var kross = crossProduct(v1, v2);
  return cmp(kross, 0);
};
var length = function length(v) {
  return Math.sqrt(dotProduct(v, v));
};
/* Get the sine of the angle from pShared -> pAngle to pShaed -> pBase */

var sineOfAngle = function sineOfAngle(pShared, pBase, pAngle) {
  var vBase = {
    x: pBase.x - pShared.x,
    y: pBase.y - pShared.y
  };
  var vAngle = {
    x: pAngle.x - pShared.x,
    y: pAngle.y - pShared.y
  };
  return crossProduct(vAngle, vBase) / length(vAngle) / length(vBase);
};
/* Get the cosine of the angle from pShared -> pAngle to pShaed -> pBase */

var cosineOfAngle = function cosineOfAngle(pShared, pBase, pAngle) {
  var vBase = {
    x: pBase.x - pShared.x,
    y: pBase.y - pShared.y
  };
  var vAngle = {
    x: pAngle.x - pShared.x,
    y: pAngle.y - pShared.y
  };
  return dotProduct(vAngle, vBase) / length(vAngle) / length(vBase);
};
/* Get the x coordinate where the given line (defined by a point and vector)
 * crosses the horizontal line with the given y coordiante.
 * In the case of parrallel lines (including overlapping ones) returns null. */

var horizontalIntersection = function horizontalIntersection(pt, v, y) {
  if (v.y === 0) return null;
  return {
    x: pt.x + v.x / v.y * (y - pt.y),
    y: y
  };
};
/* Get the y coordinate where the given line (defined by a point and vector)
 * crosses the vertical line with the given x coordiante.
 * In the case of parrallel lines (including overlapping ones) returns null. */

var verticalIntersection = function verticalIntersection(pt, v, x) {
  if (v.x === 0) return null;
  return {
    x: x,
    y: pt.y + v.y / v.x * (x - pt.x)
  };
};
/* Get the intersection of two lines, each defined by a base point and a vector.
 * In the case of parrallel lines (including overlapping ones) returns null. */

var intersection = function intersection(pt1, v1, pt2, v2) {
  // take some shortcuts for vertical and horizontal lines
  // this also ensures we don't calculate an intersection and then discover
  // it's actually outside the bounding box of the line
  if (v1.x === 0) return verticalIntersection(pt2, v2, pt1.x);
  if (v2.x === 0) return verticalIntersection(pt1, v1, pt2.x);
  if (v1.y === 0) return horizontalIntersection(pt2, v2, pt1.y);
  if (v2.y === 0) return horizontalIntersection(pt1, v1, pt2.y); // General case for non-overlapping segments.
  // This algorithm is based on Schneider and Eberly.
  // http://www.cimec.org.ar/~ncalvo/Schneider_Eberly.pdf - pg 244

  var kross = crossProduct(v1, v2);
  if (kross == 0) return null;
  var ve = {
    x: pt2.x - pt1.x,
    y: pt2.y - pt1.y
  };
  var d1 = crossProduct(ve, v1) / kross;
  var d2 = crossProduct(ve, v2) / kross; // take the average of the two calculations to minimize rounding error

  var x1 = pt1.x + d2 * v1.x,
      x2 = pt2.x + d1 * v2.x;
  var y1 = pt1.y + d2 * v1.y,
      y2 = pt2.y + d1 * v2.y;
  var x = (x1 + x2) / 2;
  var y = (y1 + y2) / 2;
  return {
    x: x,
    y: y
  };
};

var SweepEvent = /*#__PURE__*/function () {
  _createClass(SweepEvent, null, [{
    key: "compare",
    // for ordering sweep events in the sweep event queue
    value: function compare(a, b) {
      // favor event with a point that the sweep line hits first
      var ptCmp = SweepEvent.comparePoints(a.point, b.point);
      if (ptCmp !== 0) return ptCmp; // the points are the same, so link them if needed

      if (a.point !== b.point) a.link(b); // favor right events over left

      if (a.isLeft !== b.isLeft) return a.isLeft ? 1 : -1; // we have two matching left or right endpoints
      // ordering of this case is the same as for their segments

      return Segment.compare(a.segment, b.segment);
    } // for ordering points in sweep line order

  }, {
    key: "comparePoints",
    value: function comparePoints(aPt, bPt) {
      if (aPt.x < bPt.x) return -1;
      if (aPt.x > bPt.x) return 1;
      if (aPt.y < bPt.y) return -1;
      if (aPt.y > bPt.y) return 1;
      return 0;
    } // Warning: 'point' input will be modified and re-used (for performance)

  }]);

  function SweepEvent(point, isLeft) {
    _classCallCheck(this, SweepEvent);

    if (point.events === undefined) point.events = [this];else point.events.push(this);
    this.point = point;
    this.isLeft = isLeft; // this.segment, this.otherSE set by factory
  }

  _createClass(SweepEvent, [{
    key: "link",
    value: function link(other) {
      if (other.point === this.point) {
        throw new Error('Tried to link already linked events');
      }

      var otherEvents = other.point.events;

      for (var i = 0, iMax = otherEvents.length; i < iMax; i++) {
        var evt = otherEvents[i];
        this.point.events.push(evt);
        evt.point = this.point;
      }

      this.checkForConsuming();
    }
    /* Do a pass over our linked events and check to see if any pair
     * of segments match, and should be consumed. */

  }, {
    key: "checkForConsuming",
    value: function checkForConsuming() {
      // FIXME: The loops in this method run O(n^2) => no good.
      //        Maintain little ordered sweep event trees?
      //        Can we maintaining an ordering that avoids the need
      //        for the re-sorting with getLeftmostComparator in geom-out?
      // Compare each pair of events to see if other events also match
      var numEvents = this.point.events.length;

      for (var i = 0; i < numEvents; i++) {
        var evt1 = this.point.events[i];
        if (evt1.segment.consumedBy !== undefined) continue;

        for (var j = i + 1; j < numEvents; j++) {
          var evt2 = this.point.events[j];
          if (evt2.consumedBy !== undefined) continue;
          if (evt1.otherSE.point.events !== evt2.otherSE.point.events) continue;
          evt1.segment.consume(evt2.segment);
        }
      }
    }
  }, {
    key: "getAvailableLinkedEvents",
    value: function getAvailableLinkedEvents() {
      // point.events is always of length 2 or greater
      var events = [];

      for (var i = 0, iMax = this.point.events.length; i < iMax; i++) {
        var evt = this.point.events[i];

        if (evt !== this && !evt.segment.ringOut && evt.segment.isInResult()) {
          events.push(evt);
        }
      }

      return events;
    }
    /**
     * Returns a comparator function for sorting linked events that will
     * favor the event that will give us the smallest left-side angle.
     * All ring construction starts as low as possible heading to the right,
     * so by always turning left as sharp as possible we'll get polygons
     * without uncessary loops & holes.
     *
     * The comparator function has a compute cache such that it avoids
     * re-computing already-computed values.
     */

  }, {
    key: "getLeftmostComparator",
    value: function getLeftmostComparator(baseEvent) {
      var _this = this;

      var cache = new Map();

      var fillCache = function fillCache(linkedEvent) {
        var nextEvent = linkedEvent.otherSE;
        cache.set(linkedEvent, {
          sine: sineOfAngle(_this.point, baseEvent.point, nextEvent.point),
          cosine: cosineOfAngle(_this.point, baseEvent.point, nextEvent.point)
        });
      };

      return function (a, b) {
        if (!cache.has(a)) fillCache(a);
        if (!cache.has(b)) fillCache(b);

        var _cache$get = cache.get(a),
            asine = _cache$get.sine,
            acosine = _cache$get.cosine;

        var _cache$get2 = cache.get(b),
            bsine = _cache$get2.sine,
            bcosine = _cache$get2.cosine; // both on or above x-axis


        if (asine >= 0 && bsine >= 0) {
          if (acosine < bcosine) return 1;
          if (acosine > bcosine) return -1;
          return 0;
        } // both below x-axis


        if (asine < 0 && bsine < 0) {
          if (acosine < bcosine) return -1;
          if (acosine > bcosine) return 1;
          return 0;
        } // one above x-axis, one below


        if (bsine < asine) return -1;
        if (bsine > asine) return 1;
        return 0;
      };
    }
  }]);

  return SweepEvent;
}();

// segments and sweep events when all else is identical

var segmentId = 0;

var Segment = /*#__PURE__*/function () {
  _createClass(Segment, null, [{
    key: "compare",

    /* This compare() function is for ordering segments in the sweep
     * line tree, and does so according to the following criteria:
     *
     * Consider the vertical line that lies an infinestimal step to the
     * right of the right-more of the two left endpoints of the input
     * segments. Imagine slowly moving a point up from negative infinity
     * in the increasing y direction. Which of the two segments will that
     * point intersect first? That segment comes 'before' the other one.
     *
     * If neither segment would be intersected by such a line, (if one
     * or more of the segments are vertical) then the line to be considered
     * is directly on the right-more of the two left inputs.
     */
    value: function compare(a, b) {
      var alx = a.leftSE.point.x;
      var blx = b.leftSE.point.x;
      var arx = a.rightSE.point.x;
      var brx = b.rightSE.point.x; // check if they're even in the same vertical plane

      if (brx < alx) return 1;
      if (arx < blx) return -1;
      var aly = a.leftSE.point.y;
      var bly = b.leftSE.point.y;
      var ary = a.rightSE.point.y;
      var bry = b.rightSE.point.y; // is left endpoint of segment B the right-more?

      if (alx < blx) {
        // are the two segments in the same horizontal plane?
        if (bly < aly && bly < ary) return 1;
        if (bly > aly && bly > ary) return -1; // is the B left endpoint colinear to segment A?

        var aCmpBLeft = a.comparePoint(b.leftSE.point);
        if (aCmpBLeft < 0) return 1;
        if (aCmpBLeft > 0) return -1; // is the A right endpoint colinear to segment B ?

        var bCmpARight = b.comparePoint(a.rightSE.point);
        if (bCmpARight !== 0) return bCmpARight; // colinear segments, consider the one with left-more
        // left endpoint to be first (arbitrary?)

        return -1;
      } // is left endpoint of segment A the right-more?


      if (alx > blx) {
        if (aly < bly && aly < bry) return -1;
        if (aly > bly && aly > bry) return 1; // is the A left endpoint colinear to segment B?

        var bCmpALeft = b.comparePoint(a.leftSE.point);
        if (bCmpALeft !== 0) return bCmpALeft; // is the B right endpoint colinear to segment A?

        var aCmpBRight = a.comparePoint(b.rightSE.point);
        if (aCmpBRight < 0) return 1;
        if (aCmpBRight > 0) return -1; // colinear segments, consider the one with left-more
        // left endpoint to be first (arbitrary?)

        return 1;
      } // if we get here, the two left endpoints are in the same
      // vertical plane, ie alx === blx
      // consider the lower left-endpoint to come first


      if (aly < bly) return -1;
      if (aly > bly) return 1; // left endpoints are identical
      // check for colinearity by using the left-more right endpoint
      // is the A right endpoint more left-more?

      if (arx < brx) {
        var _bCmpARight = b.comparePoint(a.rightSE.point);

        if (_bCmpARight !== 0) return _bCmpARight;
      } // is the B right endpoint more left-more?


      if (arx > brx) {
        var _aCmpBRight = a.comparePoint(b.rightSE.point);

        if (_aCmpBRight < 0) return 1;
        if (_aCmpBRight > 0) return -1;
      }

      if (arx !== brx) {
        // are these two [almost] vertical segments with opposite orientation?
        // if so, the one with the lower right endpoint comes first
        var ay = ary - aly;
        var ax = arx - alx;
        var by = bry - bly;
        var bx = brx - blx;
        if (ay > ax && by < bx) return 1;
        if (ay < ax && by > bx) return -1;
      } // we have colinear segments with matching orientation
      // consider the one with more left-more right endpoint to be first


      if (arx > brx) return 1;
      if (arx < brx) return -1; // if we get here, two two right endpoints are in the same
      // vertical plane, ie arx === brx
      // consider the lower right-endpoint to come first

      if (ary < bry) return -1;
      if (ary > bry) return 1; // right endpoints identical as well, so the segments are idential
      // fall back on creation order as consistent tie-breaker

      if (a.id < b.id) return -1;
      if (a.id > b.id) return 1; // identical segment, ie a === b

      return 0;
    }
    /* Warning: a reference to ringWindings input will be stored,
     *  and possibly will be later modified */

  }]);

  function Segment(leftSE, rightSE, rings, windings) {
    _classCallCheck(this, Segment);

    this.id = ++segmentId;
    this.leftSE = leftSE;
    leftSE.segment = this;
    leftSE.otherSE = rightSE;
    this.rightSE = rightSE;
    rightSE.segment = this;
    rightSE.otherSE = leftSE;
    this.rings = rings;
    this.windings = windings; // left unset for performance, set later in algorithm
    // this.ringOut, this.consumedBy, this.prev
  }

  _createClass(Segment, [{
    key: "replaceRightSE",

    /* When a segment is split, the rightSE is replaced with a new sweep event */
    value: function replaceRightSE(newRightSE) {
      this.rightSE = newRightSE;
      this.rightSE.segment = this;
      this.rightSE.otherSE = this.leftSE;
      this.leftSE.otherSE = this.rightSE;
    }
  }, {
    key: "bbox",
    value: function bbox() {
      var y1 = this.leftSE.point.y;
      var y2 = this.rightSE.point.y;
      return {
        ll: {
          x: this.leftSE.point.x,
          y: y1 < y2 ? y1 : y2
        },
        ur: {
          x: this.rightSE.point.x,
          y: y1 > y2 ? y1 : y2
        }
      };
    }
    /* A vector from the left point to the right */

  }, {
    key: "vector",
    value: function vector() {
      return {
        x: this.rightSE.point.x - this.leftSE.point.x,
        y: this.rightSE.point.y - this.leftSE.point.y
      };
    }
  }, {
    key: "isAnEndpoint",
    value: function isAnEndpoint(pt) {
      return pt.x === this.leftSE.point.x && pt.y === this.leftSE.point.y || pt.x === this.rightSE.point.x && pt.y === this.rightSE.point.y;
    }
    /* Compare this segment with a point.
     *
     * A point P is considered to be colinear to a segment if there
     * exists a distance D such that if we travel along the segment
     * from one * endpoint towards the other a distance D, we find
     * ourselves at point P.
     *
     * Return value indicates:
     *
     *   1: point lies above the segment (to the left of vertical)
     *   0: point is colinear to segment
     *  -1: point lies below the segment (to the right of vertical)
     */

  }, {
    key: "comparePoint",
    value: function comparePoint(point) {
      if (this.isAnEndpoint(point)) return 0;
      var lPt = this.leftSE.point;
      var rPt = this.rightSE.point;
      var v = this.vector(); // Exactly vertical segments.

      if (lPt.x === rPt.x) {
        if (point.x === lPt.x) return 0;
        return point.x < lPt.x ? 1 : -1;
      } // Nearly vertical segments with an intersection.
      // Check to see where a point on the line with matching Y coordinate is.


      var yDist = (point.y - lPt.y) / v.y;
      var xFromYDist = lPt.x + yDist * v.x;
      if (point.x === xFromYDist) return 0; // General case.
      // Check to see where a point on the line with matching X coordinate is.

      var xDist = (point.x - lPt.x) / v.x;
      var yFromXDist = lPt.y + xDist * v.y;
      if (point.y === yFromXDist) return 0;
      return point.y < yFromXDist ? -1 : 1;
    }
    /**
     * Given another segment, returns the first non-trivial intersection
     * between the two segments (in terms of sweep line ordering), if it exists.
     *
     * A 'non-trivial' intersection is one that will cause one or both of the
     * segments to be split(). As such, 'trivial' vs. 'non-trivial' intersection:
     *
     *   * endpoint of segA with endpoint of segB --> trivial
     *   * endpoint of segA with point along segB --> non-trivial
     *   * endpoint of segB with point along segA --> non-trivial
     *   * point along segA with point along segB --> non-trivial
     *
     * If no non-trivial intersection exists, return null
     * Else, return null.
     */

  }, {
    key: "getIntersection",
    value: function getIntersection(other) {
      // If bboxes don't overlap, there can't be any intersections
      var tBbox = this.bbox();
      var oBbox = other.bbox();
      var bboxOverlap = getBboxOverlap(tBbox, oBbox);
      if (bboxOverlap === null) return null; // We first check to see if the endpoints can be considered intersections.
      // This will 'snap' intersections to endpoints if possible, and will
      // handle cases of colinearity.

      var tlp = this.leftSE.point;
      var trp = this.rightSE.point;
      var olp = other.leftSE.point;
      var orp = other.rightSE.point; // does each endpoint touch the other segment?
      // note that we restrict the 'touching' definition to only allow segments
      // to touch endpoints that lie forward from where we are in the sweep line pass

      var touchesOtherLSE = isInBbox(tBbox, olp) && this.comparePoint(olp) === 0;
      var touchesThisLSE = isInBbox(oBbox, tlp) && other.comparePoint(tlp) === 0;
      var touchesOtherRSE = isInBbox(tBbox, orp) && this.comparePoint(orp) === 0;
      var touchesThisRSE = isInBbox(oBbox, trp) && other.comparePoint(trp) === 0; // do left endpoints match?

      if (touchesThisLSE && touchesOtherLSE) {
        // these two cases are for colinear segments with matching left
        // endpoints, and one segment being longer than the other
        if (touchesThisRSE && !touchesOtherRSE) return trp;
        if (!touchesThisRSE && touchesOtherRSE) return orp; // either the two segments match exactly (two trival intersections)
        // or just on their left endpoint (one trivial intersection

        return null;
      } // does this left endpoint matches (other doesn't)


      if (touchesThisLSE) {
        // check for segments that just intersect on opposing endpoints
        if (touchesOtherRSE) {
          if (tlp.x === orp.x && tlp.y === orp.y) return null;
        } // t-intersection on left endpoint


        return tlp;
      } // does other left endpoint matches (this doesn't)


      if (touchesOtherLSE) {
        // check for segments that just intersect on opposing endpoints
        if (touchesThisRSE) {
          if (trp.x === olp.x && trp.y === olp.y) return null;
        } // t-intersection on left endpoint


        return olp;
      } // trivial intersection on right endpoints


      if (touchesThisRSE && touchesOtherRSE) return null; // t-intersections on just one right endpoint

      if (touchesThisRSE) return trp;
      if (touchesOtherRSE) return orp; // None of our endpoints intersect. Look for a general intersection between
      // infinite lines laid over the segments

      var pt = intersection(tlp, this.vector(), olp, other.vector()); // are the segments parrallel? Note that if they were colinear with overlap,
      // they would have an endpoint intersection and that case was already handled above

      if (pt === null) return null; // is the intersection found between the lines not on the segments?

      if (!isInBbox(bboxOverlap, pt)) return null; // round the the computed point if needed

      return rounder.round(pt.x, pt.y);
    }
    /**
     * Split the given segment into multiple segments on the given points.
     *  * Each existing segment will retain its leftSE and a new rightSE will be
     *    generated for it.
     *  * A new segment will be generated which will adopt the original segment's
     *    rightSE, and a new leftSE will be generated for it.
     *  * If there are more than two points given to split on, new segments
     *    in the middle will be generated with new leftSE and rightSE's.
     *  * An array of the newly generated SweepEvents will be returned.
     *
     * Warning: input array of points is modified
     */

  }, {
    key: "split",
    value: function split(point) {
      var newEvents = [];
      var alreadyLinked = point.events !== undefined;
      var newLeftSE = new SweepEvent(point, true);
      var newRightSE = new SweepEvent(point, false);
      var oldRightSE = this.rightSE;
      this.replaceRightSE(newRightSE);
      newEvents.push(newRightSE);
      newEvents.push(newLeftSE);
      var newSeg = new Segment(newLeftSE, oldRightSE, this.rings.slice(), this.windings.slice()); // when splitting a nearly vertical downward-facing segment,
      // sometimes one of the resulting new segments is vertical, in which
      // case its left and right events may need to be swapped

      if (SweepEvent.comparePoints(newSeg.leftSE.point, newSeg.rightSE.point) > 0) {
        newSeg.swapEvents();
      }

      if (SweepEvent.comparePoints(this.leftSE.point, this.rightSE.point) > 0) {
        this.swapEvents();
      } // in the point we just used to create new sweep events with was already
      // linked to other events, we need to check if either of the affected
      // segments should be consumed


      if (alreadyLinked) {
        newLeftSE.checkForConsuming();
        newRightSE.checkForConsuming();
      }

      return newEvents;
    }
    /* Swap which event is left and right */

  }, {
    key: "swapEvents",
    value: function swapEvents() {
      var tmpEvt = this.rightSE;
      this.rightSE = this.leftSE;
      this.leftSE = tmpEvt;
      this.leftSE.isLeft = true;
      this.rightSE.isLeft = false;

      for (var i = 0, iMax = this.windings.length; i < iMax; i++) {
        this.windings[i] *= -1;
      }
    }
    /* Consume another segment. We take their rings under our wing
     * and mark them as consumed. Use for perfectly overlapping segments */

  }, {
    key: "consume",
    value: function consume(other) {
      var consumer = this;
      var consumee = other;

      while (consumer.consumedBy) {
        consumer = consumer.consumedBy;
      }

      while (consumee.consumedBy) {
        consumee = consumee.consumedBy;
      }

      var cmp = Segment.compare(consumer, consumee);
      if (cmp === 0) return; // already consumed
      // the winner of the consumption is the earlier segment
      // according to sweep line ordering

      if (cmp > 0) {
        var tmp = consumer;
        consumer = consumee;
        consumee = tmp;
      } // make sure a segment doesn't consume it's prev


      if (consumer.prev === consumee) {
        var _tmp = consumer;
        consumer = consumee;
        consumee = _tmp;
      }

      for (var i = 0, iMax = consumee.rings.length; i < iMax; i++) {
        var ring = consumee.rings[i];
        var winding = consumee.windings[i];
        var index = consumer.rings.indexOf(ring);

        if (index === -1) {
          consumer.rings.push(ring);
          consumer.windings.push(winding);
        } else consumer.windings[index] += winding;
      }

      consumee.rings = null;
      consumee.windings = null;
      consumee.consumedBy = consumer; // mark sweep events consumed as to maintain ordering in sweep event queue

      consumee.leftSE.consumedBy = consumer.leftSE;
      consumee.rightSE.consumedBy = consumer.rightSE;
    }
    /* The first segment previous segment chain that is in the result */

  }, {
    key: "prevInResult",
    value: function prevInResult() {
      if (this._prevInResult !== undefined) return this._prevInResult;
      if (!this.prev) this._prevInResult = null;else if (this.prev.isInResult()) this._prevInResult = this.prev;else this._prevInResult = this.prev.prevInResult();
      return this._prevInResult;
    }
  }, {
    key: "beforeState",
    value: function beforeState() {
      if (this._beforeState !== undefined) return this._beforeState;
      if (!this.prev) this._beforeState = {
        rings: [],
        windings: [],
        multiPolys: []
      };else {
        var seg = this.prev.consumedBy || this.prev;
        this._beforeState = seg.afterState();
      }
      return this._beforeState;
    }
  }, {
    key: "afterState",
    value: function afterState() {
      if (this._afterState !== undefined) return this._afterState;
      var beforeState = this.beforeState();
      this._afterState = {
        rings: beforeState.rings.slice(0),
        windings: beforeState.windings.slice(0),
        multiPolys: []
      };
      var ringsAfter = this._afterState.rings;
      var windingsAfter = this._afterState.windings;
      var mpsAfter = this._afterState.multiPolys; // calculate ringsAfter, windingsAfter

      for (var i = 0, iMax = this.rings.length; i < iMax; i++) {
        var ring = this.rings[i];
        var winding = this.windings[i];
        var index = ringsAfter.indexOf(ring);

        if (index === -1) {
          ringsAfter.push(ring);
          windingsAfter.push(winding);
        } else windingsAfter[index] += winding;
      } // calcualte polysAfter


      var polysAfter = [];
      var polysExclude = [];

      for (var _i = 0, _iMax = ringsAfter.length; _i < _iMax; _i++) {
        if (windingsAfter[_i] === 0) continue; // non-zero rule

        var _ring = ringsAfter[_i];
        var poly = _ring.poly;
        if (polysExclude.indexOf(poly) !== -1) continue;
        if (_ring.isExterior) polysAfter.push(poly);else {
          if (polysExclude.indexOf(poly) === -1) polysExclude.push(poly);

          var _index = polysAfter.indexOf(_ring.poly);

          if (_index !== -1) polysAfter.splice(_index, 1);
        }
      } // calculate multiPolysAfter


      for (var _i2 = 0, _iMax2 = polysAfter.length; _i2 < _iMax2; _i2++) {
        var mp = polysAfter[_i2].multiPoly;
        if (mpsAfter.indexOf(mp) === -1) mpsAfter.push(mp);
      }

      return this._afterState;
    }
    /* Is this segment part of the final result? */

  }, {
    key: "isInResult",
    value: function isInResult() {
      // if we've been consumed, we're not in the result
      if (this.consumedBy) return false;
      if (this._isInResult !== undefined) return this._isInResult;
      var mpsBefore = this.beforeState().multiPolys;
      var mpsAfter = this.afterState().multiPolys;

      switch (operation.type) {
        case 'union':
          {
            // UNION - included iff:
            //  * On one side of us there is 0 poly interiors AND
            //  * On the other side there is 1 or more.
            var noBefores = mpsBefore.length === 0;
            var noAfters = mpsAfter.length === 0;
            this._isInResult = noBefores !== noAfters;
            break;
          }

        case 'intersection':
          {
            // INTERSECTION - included iff:
            //  * on one side of us all multipolys are rep. with poly interiors AND
            //  * on the other side of us, not all multipolys are repsented
            //    with poly interiors
            var least;
            var most;

            if (mpsBefore.length < mpsAfter.length) {
              least = mpsBefore.length;
              most = mpsAfter.length;
            } else {
              least = mpsAfter.length;
              most = mpsBefore.length;
            }

            this._isInResult = most === operation.numMultiPolys && least < most;
            break;
          }

        case 'xor':
          {
            // XOR - included iff:
            //  * the difference between the number of multipolys represented
            //    with poly interiors on our two sides is an odd number
            var diff = Math.abs(mpsBefore.length - mpsAfter.length);
            this._isInResult = diff % 2 === 1;
            break;
          }

        case 'difference':
          {
            // DIFFERENCE included iff:
            //  * on exactly one side, we have just the subject
            var isJustSubject = function isJustSubject(mps) {
              return mps.length === 1 && mps[0].isSubject;
            };

            this._isInResult = isJustSubject(mpsBefore) !== isJustSubject(mpsAfter);
            break;
          }

        default:
          throw new Error("Unrecognized operation type found ".concat(operation.type));
      }

      return this._isInResult;
    }
  }], [{
    key: "fromRing",
    value: function fromRing(pt1, pt2, ring) {
      var leftPt, rightPt, winding; // ordering the two points according to sweep line ordering

      var cmpPts = SweepEvent.comparePoints(pt1, pt2);

      if (cmpPts < 0) {
        leftPt = pt1;
        rightPt = pt2;
        winding = 1;
      } else if (cmpPts > 0) {
        leftPt = pt2;
        rightPt = pt1;
        winding = -1;
      } else throw new Error("Tried to create degenerate segment at [".concat(pt1.x, ", ").concat(pt1.y, "]"));

      var leftSE = new SweepEvent(leftPt, true);
      var rightSE = new SweepEvent(rightPt, false);
      return new Segment(leftSE, rightSE, [ring], [winding]);
    }
  }]);

  return Segment;
}();

var RingIn = /*#__PURE__*/function () {
  function RingIn(geomRing, poly, isExterior) {
    _classCallCheck(this, RingIn);

    if (!Array.isArray(geomRing) || geomRing.length === 0) {
      throw new Error('Input geometry is not a valid Polygon or MultiPolygon');
    }

    this.poly = poly;
    this.isExterior = isExterior;
    this.segments = [];

    if (typeof geomRing[0][0] !== 'number' || typeof geomRing[0][1] !== 'number') {
      throw new Error('Input geometry is not a valid Polygon or MultiPolygon');
    }

    var firstPoint = rounder.round(geomRing[0][0], geomRing[0][1]);
    this.bbox = {
      ll: {
        x: firstPoint.x,
        y: firstPoint.y
      },
      ur: {
        x: firstPoint.x,
        y: firstPoint.y
      }
    };
    var prevPoint = firstPoint;

    for (var i = 1, iMax = geomRing.length; i < iMax; i++) {
      if (typeof geomRing[i][0] !== 'number' || typeof geomRing[i][1] !== 'number') {
        throw new Error('Input geometry is not a valid Polygon or MultiPolygon');
      }

      var point = rounder.round(geomRing[i][0], geomRing[i][1]); // skip repeated points

      if (point.x === prevPoint.x && point.y === prevPoint.y) continue;
      this.segments.push(Segment.fromRing(prevPoint, point, this));
      if (point.x < this.bbox.ll.x) this.bbox.ll.x = point.x;
      if (point.y < this.bbox.ll.y) this.bbox.ll.y = point.y;
      if (point.x > this.bbox.ur.x) this.bbox.ur.x = point.x;
      if (point.y > this.bbox.ur.y) this.bbox.ur.y = point.y;
      prevPoint = point;
    } // add segment from last to first if last is not the same as first


    if (firstPoint.x !== prevPoint.x || firstPoint.y !== prevPoint.y) {
      this.segments.push(Segment.fromRing(prevPoint, firstPoint, this));
    }
  }

  _createClass(RingIn, [{
    key: "getSweepEvents",
    value: function getSweepEvents() {
      var sweepEvents = [];

      for (var i = 0, iMax = this.segments.length; i < iMax; i++) {
        var segment = this.segments[i];
        sweepEvents.push(segment.leftSE);
        sweepEvents.push(segment.rightSE);
      }

      return sweepEvents;
    }
  }]);

  return RingIn;
}();
var PolyIn = /*#__PURE__*/function () {
  function PolyIn(geomPoly, multiPoly) {
    _classCallCheck(this, PolyIn);

    if (!Array.isArray(geomPoly)) {
      throw new Error('Input geometry is not a valid Polygon or MultiPolygon');
    }

    this.exteriorRing = new RingIn(geomPoly[0], this, true); // copy by value

    this.bbox = {
      ll: {
        x: this.exteriorRing.bbox.ll.x,
        y: this.exteriorRing.bbox.ll.y
      },
      ur: {
        x: this.exteriorRing.bbox.ur.x,
        y: this.exteriorRing.bbox.ur.y
      }
    };
    this.interiorRings = [];

    for (var i = 1, iMax = geomPoly.length; i < iMax; i++) {
      var ring = new RingIn(geomPoly[i], this, false);
      if (ring.bbox.ll.x < this.bbox.ll.x) this.bbox.ll.x = ring.bbox.ll.x;
      if (ring.bbox.ll.y < this.bbox.ll.y) this.bbox.ll.y = ring.bbox.ll.y;
      if (ring.bbox.ur.x > this.bbox.ur.x) this.bbox.ur.x = ring.bbox.ur.x;
      if (ring.bbox.ur.y > this.bbox.ur.y) this.bbox.ur.y = ring.bbox.ur.y;
      this.interiorRings.push(ring);
    }

    this.multiPoly = multiPoly;
  }

  _createClass(PolyIn, [{
    key: "getSweepEvents",
    value: function getSweepEvents() {
      var sweepEvents = this.exteriorRing.getSweepEvents();

      for (var i = 0, iMax = this.interiorRings.length; i < iMax; i++) {
        var ringSweepEvents = this.interiorRings[i].getSweepEvents();

        for (var j = 0, jMax = ringSweepEvents.length; j < jMax; j++) {
          sweepEvents.push(ringSweepEvents[j]);
        }
      }

      return sweepEvents;
    }
  }]);

  return PolyIn;
}();
var MultiPolyIn = /*#__PURE__*/function () {
  function MultiPolyIn(geom, isSubject) {
    _classCallCheck(this, MultiPolyIn);

    if (!Array.isArray(geom)) {
      throw new Error('Input geometry is not a valid Polygon or MultiPolygon');
    }

    try {
      // if the input looks like a polygon, convert it to a multipolygon
      if (typeof geom[0][0][0] === 'number') geom = [geom];
    } catch (ex) {// The input is either malformed or has empty arrays.
      // In either case, it will be handled later on.
    }

    this.polys = [];
    this.bbox = {
      ll: {
        x: Number.POSITIVE_INFINITY,
        y: Number.POSITIVE_INFINITY
      },
      ur: {
        x: Number.NEGATIVE_INFINITY,
        y: Number.NEGATIVE_INFINITY
      }
    };

    for (var i = 0, iMax = geom.length; i < iMax; i++) {
      var poly = new PolyIn(geom[i], this);
      if (poly.bbox.ll.x < this.bbox.ll.x) this.bbox.ll.x = poly.bbox.ll.x;
      if (poly.bbox.ll.y < this.bbox.ll.y) this.bbox.ll.y = poly.bbox.ll.y;
      if (poly.bbox.ur.x > this.bbox.ur.x) this.bbox.ur.x = poly.bbox.ur.x;
      if (poly.bbox.ur.y > this.bbox.ur.y) this.bbox.ur.y = poly.bbox.ur.y;
      this.polys.push(poly);
    }

    this.isSubject = isSubject;
  }

  _createClass(MultiPolyIn, [{
    key: "getSweepEvents",
    value: function getSweepEvents() {
      var sweepEvents = [];

      for (var i = 0, iMax = this.polys.length; i < iMax; i++) {
        var polySweepEvents = this.polys[i].getSweepEvents();

        for (var j = 0, jMax = polySweepEvents.length; j < jMax; j++) {
          sweepEvents.push(polySweepEvents[j]);
        }
      }

      return sweepEvents;
    }
  }]);

  return MultiPolyIn;
}();

var RingOut = /*#__PURE__*/function () {
  _createClass(RingOut, null, [{
    key: "factory",

    /* Given the segments from the sweep line pass, compute & return a series
     * of closed rings from all the segments marked to be part of the result */
    value: function factory(allSegments) {
      var ringsOut = [];

      for (var i = 0, iMax = allSegments.length; i < iMax; i++) {
        var segment = allSegments[i];
        if (!segment.isInResult() || segment.ringOut) continue;
        var prevEvent = null;
        var event = segment.leftSE;
        var nextEvent = segment.rightSE;
        var events = [event];
        var startingPoint = event.point;
        var intersectionLEs = [];
        /* Walk the chain of linked events to form a closed ring */

        while (true) {
          prevEvent = event;
          event = nextEvent;
          events.push(event);
          /* Is the ring complete? */

          if (event.point === startingPoint) break;

          while (true) {
            var availableLEs = event.getAvailableLinkedEvents();
            /* Did we hit a dead end? This shouldn't happen. Indicates some earlier
             * part of the algorithm malfunctioned... please file a bug report. */

            if (availableLEs.length === 0) {
              var firstPt = events[0].point;
              var lastPt = events[events.length - 1].point;
              throw new Error("Unable to complete output ring starting at [".concat(firstPt.x, ",") + " ".concat(firstPt.y, "]. Last matching segment found ends at") + " [".concat(lastPt.x, ", ").concat(lastPt.y, "]."));
            }
            /* Only one way to go, so cotinue on the path */


            if (availableLEs.length === 1) {
              nextEvent = availableLEs[0].otherSE;
              break;
            }
            /* We must have an intersection. Check for a completed loop */


            var indexLE = null;

            for (var j = 0, jMax = intersectionLEs.length; j < jMax; j++) {
              if (intersectionLEs[j].point === event.point) {
                indexLE = j;
                break;
              }
            }
            /* Found a completed loop. Cut that off and make a ring */


            if (indexLE !== null) {
              var intersectionLE = intersectionLEs.splice(indexLE)[0];
              var ringEvents = events.splice(intersectionLE.index);
              ringEvents.unshift(ringEvents[0].otherSE);
              ringsOut.push(new RingOut(ringEvents.reverse()));
              continue;
            }
            /* register the intersection */


            intersectionLEs.push({
              index: events.length,
              point: event.point
            });
            /* Choose the left-most option to continue the walk */

            var comparator = event.getLeftmostComparator(prevEvent);
            nextEvent = availableLEs.sort(comparator)[0].otherSE;
            break;
          }
        }

        ringsOut.push(new RingOut(events));
      }

      return ringsOut;
    }
  }]);

  function RingOut(events) {
    _classCallCheck(this, RingOut);

    this.events = events;

    for (var i = 0, iMax = events.length; i < iMax; i++) {
      events[i].segment.ringOut = this;
    }

    this.poly = null;
  }

  _createClass(RingOut, [{
    key: "getGeom",
    value: function getGeom() {
      // Remove superfluous points (ie extra points along a straight line),
      var prevPt = this.events[0].point;
      var points = [prevPt];

      for (var i = 1, iMax = this.events.length - 1; i < iMax; i++) {
        var _pt = this.events[i].point;
        var _nextPt = this.events[i + 1].point;
        if (compareVectorAngles(_pt, prevPt, _nextPt) === 0) continue;
        points.push(_pt);
        prevPt = _pt;
      } // ring was all (within rounding error of angle calc) colinear points


      if (points.length === 1) return null; // check if the starting point is necessary

      var pt = points[0];
      var nextPt = points[1];
      if (compareVectorAngles(pt, prevPt, nextPt) === 0) points.shift();
      points.push(points[0]);
      var step = this.isExteriorRing() ? 1 : -1;
      var iStart = this.isExteriorRing() ? 0 : points.length - 1;
      var iEnd = this.isExteriorRing() ? points.length : -1;
      var orderedPoints = [];

      for (var _i = iStart; _i != iEnd; _i += step) {
        orderedPoints.push([points[_i].x, points[_i].y]);
      }

      return orderedPoints;
    }
  }, {
    key: "isExteriorRing",
    value: function isExteriorRing() {
      if (this._isExteriorRing === undefined) {
        var enclosing = this.enclosingRing();
        this._isExteriorRing = enclosing ? !enclosing.isExteriorRing() : true;
      }

      return this._isExteriorRing;
    }
  }, {
    key: "enclosingRing",
    value: function enclosingRing() {
      if (this._enclosingRing === undefined) {
        this._enclosingRing = this._calcEnclosingRing();
      }

      return this._enclosingRing;
    }
    /* Returns the ring that encloses this one, if any */

  }, {
    key: "_calcEnclosingRing",
    value: function _calcEnclosingRing() {
      // start with the ealier sweep line event so that the prevSeg
      // chain doesn't lead us inside of a loop of ours
      var leftMostEvt = this.events[0];

      for (var i = 1, iMax = this.events.length; i < iMax; i++) {
        var evt = this.events[i];
        if (SweepEvent.compare(leftMostEvt, evt) > 0) leftMostEvt = evt;
      }

      var prevSeg = leftMostEvt.segment.prevInResult();
      var prevPrevSeg = prevSeg ? prevSeg.prevInResult() : null;

      while (true) {
        // no segment found, thus no ring can enclose us
        if (!prevSeg) return null; // no segments below prev segment found, thus the ring of the prev
        // segment must loop back around and enclose us

        if (!prevPrevSeg) return prevSeg.ringOut; // if the two segments are of different rings, the ring of the prev
        // segment must either loop around us or the ring of the prev prev
        // seg, which would make us and the ring of the prev peers

        if (prevPrevSeg.ringOut !== prevSeg.ringOut) {
          if (prevPrevSeg.ringOut.enclosingRing() !== prevSeg.ringOut) {
            return prevSeg.ringOut;
          } else return prevSeg.ringOut.enclosingRing();
        } // two segments are from the same ring, so this was a penisula
        // of that ring. iterate downward, keep searching


        prevSeg = prevPrevSeg.prevInResult();
        prevPrevSeg = prevSeg ? prevSeg.prevInResult() : null;
      }
    }
  }]);

  return RingOut;
}();
var PolyOut = /*#__PURE__*/function () {
  function PolyOut(exteriorRing) {
    _classCallCheck(this, PolyOut);

    this.exteriorRing = exteriorRing;
    exteriorRing.poly = this;
    this.interiorRings = [];
  }

  _createClass(PolyOut, [{
    key: "addInterior",
    value: function addInterior(ring) {
      this.interiorRings.push(ring);
      ring.poly = this;
    }
  }, {
    key: "getGeom",
    value: function getGeom() {
      var geom = [this.exteriorRing.getGeom()]; // exterior ring was all (within rounding error of angle calc) colinear points

      if (geom[0] === null) return null;

      for (var i = 0, iMax = this.interiorRings.length; i < iMax; i++) {
        var ringGeom = this.interiorRings[i].getGeom(); // interior ring was all (within rounding error of angle calc) colinear points

        if (ringGeom === null) continue;
        geom.push(ringGeom);
      }

      return geom;
    }
  }]);

  return PolyOut;
}();
var MultiPolyOut = /*#__PURE__*/function () {
  function MultiPolyOut(rings) {
    _classCallCheck(this, MultiPolyOut);

    this.rings = rings;
    this.polys = this._composePolys(rings);
  }

  _createClass(MultiPolyOut, [{
    key: "getGeom",
    value: function getGeom() {
      var geom = [];

      for (var i = 0, iMax = this.polys.length; i < iMax; i++) {
        var polyGeom = this.polys[i].getGeom(); // exterior ring was all (within rounding error of angle calc) colinear points

        if (polyGeom === null) continue;
        geom.push(polyGeom);
      }

      return geom;
    }
  }, {
    key: "_composePolys",
    value: function _composePolys(rings) {
      var polys = [];

      for (var i = 0, iMax = rings.length; i < iMax; i++) {
        var ring = rings[i];
        if (ring.poly) continue;
        if (ring.isExteriorRing()) polys.push(new PolyOut(ring));else {
          var enclosingRing = ring.enclosingRing();
          if (!enclosingRing.poly) polys.push(new PolyOut(enclosingRing));
          enclosingRing.poly.addInterior(ring);
        }
      }

      return polys;
    }
  }]);

  return MultiPolyOut;
}();

/**
 * NOTE:  We must be careful not to change any segments while
 *        they are in the SplayTree. AFAIK, there's no way to tell
 *        the tree to rebalance itself - thus before splitting
 *        a segment that's in the tree, we remove it from the tree,
 *        do the split, then re-insert it. (Even though splitting a
 *        segment *shouldn't* change its correct position in the
 *        sweep line tree, the reality is because of rounding errors,
 *        it sometimes does.)
 */

var SweepLine = /*#__PURE__*/function () {
  function SweepLine(queue) {
    var comparator = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : Segment.compare;

    _classCallCheck(this, SweepLine);

    this.queue = queue;
    this.tree = new SplayTree(comparator);
    this.segments = [];
  }

  _createClass(SweepLine, [{
    key: "process",
    value: function process(event) {
      var segment = event.segment;
      var newEvents = []; // if we've already been consumed by another segment,
      // clean up our body parts and get out

      if (event.consumedBy) {
        if (event.isLeft) this.queue.remove(event.otherSE);else this.tree.remove(segment);
        return newEvents;
      }

      var node = event.isLeft ? this.tree.insert(segment) : this.tree.find(segment);
      if (!node) throw new Error("Unable to find segment #".concat(segment.id, " ") + "[".concat(segment.leftSE.point.x, ", ").concat(segment.leftSE.point.y, "] -> ") + "[".concat(segment.rightSE.point.x, ", ").concat(segment.rightSE.point.y, "] ") + 'in SweepLine tree. Please submit a bug report.');
      var prevNode = node;
      var nextNode = node;
      var prevSeg = undefined;
      var nextSeg = undefined; // skip consumed segments still in tree

      while (prevSeg === undefined) {
        prevNode = this.tree.prev(prevNode);
        if (prevNode === null) prevSeg = null;else if (prevNode.key.consumedBy === undefined) prevSeg = prevNode.key;
      } // skip consumed segments still in tree


      while (nextSeg === undefined) {
        nextNode = this.tree.next(nextNode);
        if (nextNode === null) nextSeg = null;else if (nextNode.key.consumedBy === undefined) nextSeg = nextNode.key;
      }

      if (event.isLeft) {
        // Check for intersections against the previous segment in the sweep line
        var prevMySplitter = null;

        if (prevSeg) {
          var prevInter = prevSeg.getIntersection(segment);

          if (prevInter !== null) {
            if (!segment.isAnEndpoint(prevInter)) prevMySplitter = prevInter;

            if (!prevSeg.isAnEndpoint(prevInter)) {
              var newEventsFromSplit = this._splitSafely(prevSeg, prevInter);

              for (var i = 0, iMax = newEventsFromSplit.length; i < iMax; i++) {
                newEvents.push(newEventsFromSplit[i]);
              }
            }
          }
        } // Check for intersections against the next segment in the sweep line


        var nextMySplitter = null;

        if (nextSeg) {
          var nextInter = nextSeg.getIntersection(segment);

          if (nextInter !== null) {
            if (!segment.isAnEndpoint(nextInter)) nextMySplitter = nextInter;

            if (!nextSeg.isAnEndpoint(nextInter)) {
              var _newEventsFromSplit = this._splitSafely(nextSeg, nextInter);

              for (var _i = 0, _iMax = _newEventsFromSplit.length; _i < _iMax; _i++) {
                newEvents.push(_newEventsFromSplit[_i]);
              }
            }
          }
        } // For simplicity, even if we find more than one intersection we only
        // spilt on the 'earliest' (sweep-line style) of the intersections.
        // The other intersection will be handled in a future process().


        if (prevMySplitter !== null || nextMySplitter !== null) {
          var mySplitter = null;
          if (prevMySplitter === null) mySplitter = nextMySplitter;else if (nextMySplitter === null) mySplitter = prevMySplitter;else {
            var cmpSplitters = SweepEvent.comparePoints(prevMySplitter, nextMySplitter);
            mySplitter = cmpSplitters <= 0 ? prevMySplitter : nextMySplitter;
          } // Rounding errors can cause changes in ordering,
          // so remove afected segments and right sweep events before splitting

          this.queue.remove(segment.rightSE);
          newEvents.push(segment.rightSE);

          var _newEventsFromSplit2 = segment.split(mySplitter);

          for (var _i2 = 0, _iMax2 = _newEventsFromSplit2.length; _i2 < _iMax2; _i2++) {
            newEvents.push(_newEventsFromSplit2[_i2]);
          }
        }

        if (newEvents.length > 0) {
          // We found some intersections, so re-do the current event to
          // make sure sweep line ordering is totally consistent for later
          // use with the segment 'prev' pointers
          this.tree.remove(segment);
          newEvents.push(event);
        } else {
          // done with left event
          this.segments.push(segment);
          segment.prev = prevSeg;
        }
      } else {
        // event.isRight
        // since we're about to be removed from the sweep line, check for
        // intersections between our previous and next segments
        if (prevSeg && nextSeg) {
          var inter = prevSeg.getIntersection(nextSeg);

          if (inter !== null) {
            if (!prevSeg.isAnEndpoint(inter)) {
              var _newEventsFromSplit3 = this._splitSafely(prevSeg, inter);

              for (var _i3 = 0, _iMax3 = _newEventsFromSplit3.length; _i3 < _iMax3; _i3++) {
                newEvents.push(_newEventsFromSplit3[_i3]);
              }
            }

            if (!nextSeg.isAnEndpoint(inter)) {
              var _newEventsFromSplit4 = this._splitSafely(nextSeg, inter);

              for (var _i4 = 0, _iMax4 = _newEventsFromSplit4.length; _i4 < _iMax4; _i4++) {
                newEvents.push(_newEventsFromSplit4[_i4]);
              }
            }
          }
        }

        this.tree.remove(segment);
      }

      return newEvents;
    }
    /* Safely split a segment that is currently in the datastructures
     * IE - a segment other than the one that is currently being processed. */

  }, {
    key: "_splitSafely",
    value: function _splitSafely(seg, pt) {
      // Rounding errors can cause changes in ordering,
      // so remove afected segments and right sweep events before splitting
      // removeNode() doesn't work, so have re-find the seg
      // https://github.com/w8r/splay-tree/pull/5
      this.tree.remove(seg);
      var rightSE = seg.rightSE;
      this.queue.remove(rightSE);
      var newEvents = seg.split(pt);
      newEvents.push(rightSE); // splitting can trigger consumption

      if (seg.consumedBy === undefined) this.tree.insert(seg);
      return newEvents;
    }
  }]);

  return SweepLine;
}();

var POLYGON_CLIPPING_MAX_QUEUE_SIZE = typeof process !== 'undefined' && process.env.POLYGON_CLIPPING_MAX_QUEUE_SIZE || 1000000;
var POLYGON_CLIPPING_MAX_SWEEPLINE_SEGMENTS = typeof process !== 'undefined' && process.env.POLYGON_CLIPPING_MAX_SWEEPLINE_SEGMENTS || 1000000;
var Operation = /*#__PURE__*/function () {
  function Operation() {
    _classCallCheck(this, Operation);
  }

  _createClass(Operation, [{
    key: "run",
    value: function run(type, geom, moreGeoms) {
      operation.type = type;
      rounder.reset();
      /* Convert inputs to MultiPoly objects */

      var multipolys = [new MultiPolyIn(geom, true)];

      for (var i = 0, iMax = moreGeoms.length; i < iMax; i++) {
        multipolys.push(new MultiPolyIn(moreGeoms[i], false));
      }

      operation.numMultiPolys = multipolys.length;
      /* BBox optimization for difference operation
       * If the bbox of a multipolygon that's part of the clipping doesn't
       * intersect the bbox of the subject at all, we can just drop that
       * multiploygon. */

      if (operation.type === 'difference') {
        // in place removal
        var subject = multipolys[0];
        var _i = 1;

        while (_i < multipolys.length) {
          if (getBboxOverlap(multipolys[_i].bbox, subject.bbox) !== null) _i++;else multipolys.splice(_i, 1);
        }
      }
      /* BBox optimization for intersection operation
       * If we can find any pair of multipolygons whose bbox does not overlap,
       * then the result will be empty. */


      if (operation.type === 'intersection') {
        // TODO: this is O(n^2) in number of polygons. By sorting the bboxes,
        //       it could be optimized to O(n * ln(n))
        for (var _i2 = 0, _iMax = multipolys.length; _i2 < _iMax; _i2++) {
          var mpA = multipolys[_i2];

          for (var j = _i2 + 1, jMax = multipolys.length; j < jMax; j++) {
            if (getBboxOverlap(mpA.bbox, multipolys[j].bbox) === null) return [];
          }
        }
      }
      /* Put segment endpoints in a priority queue */


      var queue = new SplayTree(SweepEvent.compare);

      for (var _i3 = 0, _iMax2 = multipolys.length; _i3 < _iMax2; _i3++) {
        var sweepEvents = multipolys[_i3].getSweepEvents();

        for (var _j = 0, _jMax = sweepEvents.length; _j < _jMax; _j++) {
          queue.insert(sweepEvents[_j]);

          if (queue.size > POLYGON_CLIPPING_MAX_QUEUE_SIZE) {
            // prevents an infinite loop, an otherwise common manifestation of bugs
            throw new Error('Infinite loop when putting segment endpoints in a priority queue ' + '(queue size too big). Please file a bug report.');
          }
        }
      }
      /* Pass the sweep line over those endpoints */


      var sweepLine = new SweepLine(queue);
      var prevQueueSize = queue.size;
      var node = queue.pop();

      while (node) {
        var evt = node.key;

        if (queue.size === prevQueueSize) {
          // prevents an infinite loop, an otherwise common manifestation of bugs
          var seg = evt.segment;
          throw new Error("Unable to pop() ".concat(evt.isLeft ? 'left' : 'right', " SweepEvent ") + "[".concat(evt.point.x, ", ").concat(evt.point.y, "] from segment #").concat(seg.id, " ") + "[".concat(seg.leftSE.point.x, ", ").concat(seg.leftSE.point.y, "] -> ") + "[".concat(seg.rightSE.point.x, ", ").concat(seg.rightSE.point.y, "] from queue. ") + 'Please file a bug report.');
        }

        if (queue.size > POLYGON_CLIPPING_MAX_QUEUE_SIZE) {
          // prevents an infinite loop, an otherwise common manifestation of bugs
          throw new Error('Infinite loop when passing sweep line over endpoints ' + '(queue size too big). Please file a bug report.');
        }

        if (sweepLine.segments.length > POLYGON_CLIPPING_MAX_SWEEPLINE_SEGMENTS) {
          // prevents an infinite loop, an otherwise common manifestation of bugs
          throw new Error('Infinite loop when passing sweep line over endpoints ' + '(too many sweep line segments). Please file a bug report.');
        }

        var newEvents = sweepLine.process(evt);

        for (var _i4 = 0, _iMax3 = newEvents.length; _i4 < _iMax3; _i4++) {
          var _evt = newEvents[_i4];
          if (_evt.consumedBy === undefined) queue.insert(_evt);
        }

        prevQueueSize = queue.size;
        node = queue.pop();
      } // free some memory we don't need anymore


      rounder.reset();
      /* Collect and compile segments we're keeping into a multipolygon */

      var ringsOut = RingOut.factory(sweepLine.segments);
      var result = new MultiPolyOut(ringsOut);
      return result.getGeom();
    }
  }]);

  return Operation;
}(); // singleton available by import

var operation = new Operation();

var union = function union(geom) {
  for (var _len = arguments.length, moreGeoms = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
    moreGeoms[_key - 1] = arguments[_key];
  }

  return operation.run('union', geom, moreGeoms);
};

var intersection$1 = function intersection(geom) {
  for (var _len2 = arguments.length, moreGeoms = new Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
    moreGeoms[_key2 - 1] = arguments[_key2];
  }

  return operation.run('intersection', geom, moreGeoms);
};

var xor = function xor(geom) {
  for (var _len3 = arguments.length, moreGeoms = new Array(_len3 > 1 ? _len3 - 1 : 0), _key3 = 1; _key3 < _len3; _key3++) {
    moreGeoms[_key3 - 1] = arguments[_key3];
  }

  return operation.run('xor', geom, moreGeoms);
};

var difference = function difference(subjectGeom) {
  for (var _len4 = arguments.length, clippingGeoms = new Array(_len4 > 1 ? _len4 - 1 : 0), _key4 = 1; _key4 < _len4; _key4++) {
    clippingGeoms[_key4 - 1] = arguments[_key4];
  }

  return operation.run('difference', subjectGeom, clippingGeoms);
};

var index = {
  union: union,
  intersection: intersection$1,
  xor: xor,
  difference: difference
};

export default index;