StackGenVis/frontend/node_modules/polybooljs/dist/polybool.js

(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
/*
 * @copyright 2016 Sean Connelly (@voidqk), http://syntheti.cc
 * @license MIT
 * @preserve Project Home: https://github.com/voidqk/polybooljs
 */

var BuildLog = require('./lib/build-log');
var Epsilon = require('./lib/epsilon');
var Intersecter = require('./lib/intersecter');
var SegmentChainer = require('./lib/segment-chainer');
var SegmentSelector = require('./lib/segment-selector');
var GeoJSON = require('./lib/geojson');

var buildLog = false;
var epsilon = Epsilon();

var PolyBool;
PolyBool = {
	// getter/setter for buildLog
	buildLog: function(bl){
		if (bl === true)
			buildLog = BuildLog();
		else if (bl === false)
			buildLog = false;
		return buildLog === false ? false : buildLog.list;
	},
	// getter/setter for epsilon
	epsilon: function(v){
		return epsilon.epsilon(v);
	},

	// core API
	segments: function(poly){
		var i = Intersecter(true, epsilon, buildLog);
		poly.regions.forEach(i.addRegion);
		return {
			segments: i.calculate(poly.inverted),
			inverted: poly.inverted
		};
	},
	combine: function(segments1, segments2){
		var i3 = Intersecter(false, epsilon, buildLog);
		return {
			combined: i3.calculate(
				segments1.segments, segments1.inverted,
				segments2.segments, segments2.inverted
			),
			inverted1: segments1.inverted,
			inverted2: segments2.inverted
		};
	},
	selectUnion: function(combined){
		return {
			segments: SegmentSelector.union(combined.combined, buildLog),
			inverted: combined.inverted1 || combined.inverted2
		}
	},
	selectIntersect: function(combined){
		return {
			segments: SegmentSelector.intersect(combined.combined, buildLog),
			inverted: combined.inverted1 && combined.inverted2
		}
	},
	selectDifference: function(combined){
		return {
			segments: SegmentSelector.difference(combined.combined, buildLog),
			inverted: combined.inverted1 && !combined.inverted2
		}
	},
	selectDifferenceRev: function(combined){
		return {
			segments: SegmentSelector.differenceRev(combined.combined, buildLog),
			inverted: !combined.inverted1 && combined.inverted2
		}
	},
	selectXor: function(combined){
		return {
			segments: SegmentSelector.xor(combined.combined, buildLog),
			inverted: combined.inverted1 !== combined.inverted2
		}
	},
	polygon: function(segments){
		return {
			regions: SegmentChainer(segments.segments, epsilon, buildLog),
			inverted: segments.inverted
		};
	},

	// GeoJSON converters
	polygonFromGeoJSON: function(geojson){
		return GeoJSON.toPolygon(PolyBool, geojson);
	},
	polygonToGeoJSON: function(poly){
		return GeoJSON.fromPolygon(PolyBool, epsilon, poly);
	},

	// helper functions for common operations
	union: function(poly1, poly2){
		return operate(poly1, poly2, PolyBool.selectUnion);
	},
	intersect: function(poly1, poly2){
		return operate(poly1, poly2, PolyBool.selectIntersect);
	},
	difference: function(poly1, poly2){
		return operate(poly1, poly2, PolyBool.selectDifference);
	},
	differenceRev: function(poly1, poly2){
		return operate(poly1, poly2, PolyBool.selectDifferenceRev);
	},
	xor: function(poly1, poly2){
		return operate(poly1, poly2, PolyBool.selectXor);
	}
};

function operate(poly1, poly2, selector){
	var seg1 = PolyBool.segments(poly1);
	var seg2 = PolyBool.segments(poly2);
	var comb = PolyBool.combine(seg1, seg2);
	var seg3 = selector(comb);
	return PolyBool.polygon(seg3);
}

if (typeof window === 'object')
	window.PolyBool = PolyBool;

module.exports = PolyBool;

},{"./lib/build-log":2,"./lib/epsilon":3,"./lib/geojson":4,"./lib/intersecter":5,"./lib/segment-chainer":7,"./lib/segment-selector":8}],2:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// used strictly for logging the processing of the algorithm... only useful if you intend on
// looking under the covers (for pretty UI's or debugging)
//

function BuildLog(){
	var my;
	var nextSegmentId = 0;
	var curVert = false;

	function push(type, data){
		my.list.push({
			type: type,
			data: data ? JSON.parse(JSON.stringify(data)) : void 0
		});
		return my;
	}

	my = {
		list: [],
		segmentId: function(){
			return nextSegmentId++;
		},
		checkIntersection: function(seg1, seg2){
			return push('check', { seg1: seg1, seg2: seg2 });
		},
		segmentChop: function(seg, end){
			push('div_seg', { seg: seg, pt: end });
			return push('chop', { seg: seg, pt: end });
		},
		statusRemove: function(seg){
			return push('pop_seg', { seg: seg });
		},
		segmentUpdate: function(seg){
			return push('seg_update', { seg: seg });
		},
		segmentNew: function(seg, primary){
			return push('new_seg', { seg: seg, primary: primary });
		},
		segmentRemove: function(seg){
			return push('rem_seg', { seg: seg });
		},
		tempStatus: function(seg, above, below){
			return push('temp_status', { seg: seg, above: above, below: below });
		},
		rewind: function(seg){
			return push('rewind', { seg: seg });
		},
		status: function(seg, above, below){
			return push('status', { seg: seg, above: above, below: below });
		},
		vert: function(x){
			if (x === curVert)
				return my;
			curVert = x;
			return push('vert', { x: x });
		},
		log: function(data){
			if (typeof data !== 'string')
				data = JSON.stringify(data, false, '  ');
			return push('log', { txt: data });
		},
		reset: function(){
			return push('reset');
		},
		selected: function(segs){
			return push('selected', { segs: segs });
		},
		chainStart: function(seg){
			return push('chain_start', { seg: seg });
		},
		chainRemoveHead: function(index, pt){
			return push('chain_rem_head', { index: index, pt: pt });
		},
		chainRemoveTail: function(index, pt){
			return push('chain_rem_tail', { index: index, pt: pt });
		},
		chainNew: function(pt1, pt2){
			return push('chain_new', { pt1: pt1, pt2: pt2 });
		},
		chainMatch: function(index){
			return push('chain_match', { index: index });
		},
		chainClose: function(index){
			return push('chain_close', { index: index });
		},
		chainAddHead: function(index, pt){
			return push('chain_add_head', { index: index, pt: pt });
		},
		chainAddTail: function(index, pt){
			return push('chain_add_tail', { index: index, pt: pt, });
		},
		chainConnect: function(index1, index2){
			return push('chain_con', { index1: index1, index2: index2 });
		},
		chainReverse: function(index){
			return push('chain_rev', { index: index });
		},
		chainJoin: function(index1, index2){
			return push('chain_join', { index1: index1, index2: index2 });
		},
		done: function(){
			return push('done');
		}
	};
	return my;
}

module.exports = BuildLog;

},{}],3:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// provides the raw computation functions that takes epsilon into account
//
// zero is defined to be between (-epsilon, epsilon) exclusive
//

function Epsilon(eps){
	if (typeof eps !== 'number')
		eps = 0.0000000001; // sane default? sure why not
	var my = {
		epsilon: function(v){
			if (typeof v === 'number')
				eps = v;
			return eps;
		},
		pointAboveOrOnLine: function(pt, left, right){
			var Ax = left[0];
			var Ay = left[1];
			var Bx = right[0];
			var By = right[1];
			var Cx = pt[0];
			var Cy = pt[1];
			return (Bx - Ax) * (Cy - Ay) - (By - Ay) * (Cx - Ax) >= -eps;
		},
		pointBetween: function(p, left, right){
			// p must be collinear with left->right
			// returns false if p == left, p == right, or left == right
			var d_py_ly = p[1] - left[1];
			var d_rx_lx = right[0] - left[0];
			var d_px_lx = p[0] - left[0];
			var d_ry_ly = right[1] - left[1];

			var dot = d_px_lx * d_rx_lx + d_py_ly * d_ry_ly;
			// if `dot` is 0, then `p` == `left` or `left` == `right` (reject)
			// if `dot` is less than 0, then `p` is to the left of `left` (reject)
			if (dot < eps)
				return false;

			var sqlen = d_rx_lx * d_rx_lx + d_ry_ly * d_ry_ly;
			// if `dot` > `sqlen`, then `p` is to the right of `right` (reject)
			// therefore, if `dot - sqlen` is greater than 0, then `p` is to the right of `right` (reject)
			if (dot - sqlen > -eps)
				return false;

			return true;
		},
		pointsSameX: function(p1, p2){
			return Math.abs(p1[0] - p2[0]) < eps;
		},
		pointsSameY: function(p1, p2){
			return Math.abs(p1[1] - p2[1]) < eps;
		},
		pointsSame: function(p1, p2){
			return my.pointsSameX(p1, p2) && my.pointsSameY(p1, p2);
		},
		pointsCompare: function(p1, p2){
			// returns -1 if p1 is smaller, 1 if p2 is smaller, 0 if equal
			if (my.pointsSameX(p1, p2))
				return my.pointsSameY(p1, p2) ? 0 : (p1[1] < p2[1] ? -1 : 1);
			return p1[0] < p2[0] ? -1 : 1;
		},
		pointsCollinear: function(pt1, pt2, pt3){
			// does pt1->pt2->pt3 make a straight line?
			// essentially this is just checking to see if the slope(pt1->pt2) === slope(pt2->pt3)
			// if slopes are equal, then they must be collinear, because they share pt2
			var dx1 = pt1[0] - pt2[0];
			var dy1 = pt1[1] - pt2[1];
			var dx2 = pt2[0] - pt3[0];
			var dy2 = pt2[1] - pt3[1];
			return Math.abs(dx1 * dy2 - dx2 * dy1) < eps;
		},
		linesIntersect: function(a0, a1, b0, b1){
			// returns false if the lines are coincident (e.g., parallel or on top of each other)
			//
			// returns an object if the lines intersect:
			//   {
			//     pt: [x, y],    where the intersection point is at
			//     alongA: where intersection point is along A,
			//     alongB: where intersection point is along B
			//   }
			//
			//  alongA and alongB will each be one of: -2, -1, 0, 1, 2
			//
			//  with the following meaning:
			//
			//    -2   intersection point is before segment's first point
			//    -1   intersection point is directly on segment's first point
			//     0   intersection point is between segment's first and second points (exclusive)
			//     1   intersection point is directly on segment's second point
			//     2   intersection point is after segment's second point
			var adx = a1[0] - a0[0];
			var ady = a1[1] - a0[1];
			var bdx = b1[0] - b0[0];
			var bdy = b1[1] - b0[1];

			var axb = adx * bdy - ady * bdx;
			if (Math.abs(axb) < eps)
				return false; // lines are coincident

			var dx = a0[0] - b0[0];
			var dy = a0[1] - b0[1];

			var A = (bdx * dy - bdy * dx) / axb;
			var B = (adx * dy - ady * dx) / axb;

			var ret = {
				alongA: 0,
				alongB: 0,
				pt: [
					a0[0] + A * adx,
					a0[1] + A * ady
				]
			};

			// categorize where intersection point is along A and B

			if (A <= -eps)
				ret.alongA = -2;
			else if (A < eps)
				ret.alongA = -1;
			else if (A - 1 <= -eps)
				ret.alongA = 0;
			else if (A - 1 < eps)
				ret.alongA = 1;
			else
				ret.alongA = 2;

			if (B <= -eps)
				ret.alongB = -2;
			else if (B < eps)
				ret.alongB = -1;
			else if (B - 1 <= -eps)
				ret.alongB = 0;
			else if (B - 1 < eps)
				ret.alongB = 1;
			else
				ret.alongB = 2;

			return ret;
		},
		pointInsideRegion: function(pt, region){
			var x = pt[0];
			var y = pt[1];
			var last_x = region[region.length - 1][0];
			var last_y = region[region.length - 1][1];
			var inside = false;
			for (var i = 0; i < region.length; i++){
				var curr_x = region[i][0];
				var curr_y = region[i][1];

				// if y is between curr_y and last_y, and
				// x is to the right of the boundary created by the line
				if ((curr_y - y > eps) != (last_y - y > eps) &&
					(last_x - curr_x) * (y - curr_y) / (last_y - curr_y) + curr_x - x > eps)
					inside = !inside

				last_x = curr_x;
				last_y = curr_y;
			}
			return inside;
		}
	};
	return my;
}

module.exports = Epsilon;

},{}],4:[function(require,module,exports){
// (c) Copyright 2017, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// convert between PolyBool polygon format and GeoJSON formats (Polygon and MultiPolygon)
//

var GeoJSON = {
	// convert a GeoJSON object to a PolyBool polygon
	toPolygon: function(PolyBool, geojson){

		// converts list of LineString's to segments
		function GeoPoly(coords){
			// check for empty coords
			if (coords.length <= 0)
				return PolyBool.segments({ inverted: false, regions: [] });

			// convert LineString to segments
			function LineString(ls){
				// remove tail which should be the same as head
				var reg = ls.slice(0, ls.length - 1);
				return PolyBool.segments({ inverted: false, regions: [reg] });
			}

			// the first LineString is considered the outside
			var out = LineString(coords[0]);

			// the rest of the LineStrings are considered interior holes, so subtract them from the
			// current result
			for (var i = 1; i < coords.length; i++)
				out = PolyBool.selectDifference(PolyBool.combine(out, LineString(coords[i])));

			return out;
		}

		if (geojson.type === 'Polygon'){
			// single polygon, so just convert it and we're done
			return PolyBool.polygon(GeoPoly(geojson.coordinates));
		}
		else if (geojson.type === 'MultiPolygon'){
			// multiple polygons, so union all the polygons together
			var out = PolyBool.segments({ inverted: false, regions: [] });
			for (var i = 0; i < geojson.coordinates.length; i++)
				out = PolyBool.selectUnion(PolyBool.combine(out, GeoPoly(geojson.coordinates[i])));
			return PolyBool.polygon(out);
		}
		throw new Error('PolyBool: Cannot convert GeoJSON object to PolyBool polygon');
	},

	// convert a PolyBool polygon to a GeoJSON object
	fromPolygon: function(PolyBool, eps, poly){
		// make sure out polygon is clean
		poly = PolyBool.polygon(PolyBool.segments(poly));

		// test if r1 is inside r2
		function regionInsideRegion(r1, r2){
			// we're guaranteed no lines intersect (because the polygon is clean), but a vertex
			// could be on the edge -- so we just average pt[0] and pt[1] to produce a point on the
			// edge of the first line, which cannot be on an edge
			return eps.pointInsideRegion([
				(r1[0][0] + r1[1][0]) * 0.5,
				(r1[0][1] + r1[1][1]) * 0.5
			], r2);
		}

		// calculate inside heirarchy
		//
		//  _____________________   _______    roots -> A       -> F
		// |          A          | |   F   |            |          |
		// |  _______   _______  | |  ___  |            +-- B      +-- G
		// | |   B   | |   C   | | | |   | |            |   |
		// | |  ___  | |  ___  | | | |   | |            |   +-- D
		// | | | D | | | | E | | | | | G | |            |
		// | | |___| | | |___| | | | |   | |            +-- C
		// | |_______| |_______| | | |___| |                |
		// |_____________________| |_______|                +-- E

		function newNode(region){
			return {
				region: region,
				children: []
			};
		}

		var roots = newNode(null);

		function addChild(root, region){
			// first check if we're inside any children
			for (var i = 0; i < root.children.length; i++){
				var child = root.children[i];
				if (regionInsideRegion(region, child.region)){
					// we are, so insert inside them instead
					addChild(child, region);
					return;
				}
			}

			// not inside any children, so check to see if any children are inside us
			var node = newNode(region);
			for (var i = 0; i < root.children.length; i++){
				var child = root.children[i];
				if (regionInsideRegion(child.region, region)){
					// oops... move the child beneath us, and remove them from root
					node.children.push(child);
					root.children.splice(i, 1);
					i--;
				}
			}

			// now we can add ourselves
			root.children.push(node);
		}

		// add all regions to the root
		for (var i = 0; i < poly.regions.length; i++){
			var region = poly.regions[i];
			if (region.length < 3) // regions must have at least 3 points (sanity check)
				continue;
			addChild(roots, region);
		}

		// with our heirarchy, we can distinguish between exterior borders, and interior holes
		// the root nodes are exterior, children are interior, children's children are exterior,
		// children's children's children are interior, etc

		// while we're at it, exteriors are counter-clockwise, and interiors are clockwise

		function forceWinding(region, clockwise){
			// first, see if we're clockwise or counter-clockwise
			// https://en.wikipedia.org/wiki/Shoelace_formula
			var winding = 0;
			var last_x = region[region.length - 1][0];
			var last_y = region[region.length - 1][1];
			var copy = [];
			for (var i = 0; i < region.length; i++){
				var curr_x = region[i][0];
				var curr_y = region[i][1];
				copy.push([curr_x, curr_y]); // create a copy while we're at it
				winding += curr_y * last_x - curr_x * last_y;
				last_x = curr_x;
				last_y = curr_y;
			}
			// this assumes Cartesian coordinates (Y is positive going up)
			var isclockwise = winding < 0;
			if (isclockwise !== clockwise)
				copy.reverse();
			// while we're here, the last point must be the first point...
			copy.push([copy[0][0], copy[0][1]]);
			return copy;
		}

		var geopolys = [];

		function addExterior(node){
			var poly = [forceWinding(node.region, false)];
			geopolys.push(poly);
			// children of exteriors are interior
			for (var i = 0; i < node.children.length; i++)
				poly.push(getInterior(node.children[i]));
		}

		function getInterior(node){
			// children of interiors are exterior
			for (var i = 0; i < node.children.length; i++)
				addExterior(node.children[i]);
			// return the clockwise interior
			return forceWinding(node.region, true);
		}

		// root nodes are exterior
		for (var i = 0; i < roots.children.length; i++)
			addExterior(roots.children[i]);

		// lastly, construct the approrpriate GeoJSON object

		if (geopolys.length <= 0) // empty GeoJSON Polygon
			return { type: 'Polygon', coordinates: [] };
		if (geopolys.length == 1) // use a GeoJSON Polygon
			return { type: 'Polygon', coordinates: geopolys[0] };
		return { // otherwise, use a GeoJSON MultiPolygon
			type: 'MultiPolygon',
			coordinates: geopolys
		};
	}
};

module.exports = GeoJSON;

},{}],5:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// this is the core work-horse
//

var LinkedList = require('./linked-list');

function Intersecter(selfIntersection, eps, buildLog){
	// selfIntersection is true/false depending on the phase of the overall algorithm

	//
	// segment creation
	//

	function segmentNew(start, end){
		return {
			id: buildLog ? buildLog.segmentId() : -1,
			start: start,
			end: end,
			myFill: {
				above: null, // is there fill above us?
				below: null  // is there fill below us?
			},
			otherFill: null
		};
	}

	function segmentCopy(start, end, seg){
		return {
			id: buildLog ? buildLog.segmentId() : -1,
			start: start,
			end: end,
			myFill: {
				above: seg.myFill.above,
				below: seg.myFill.below
			},
			otherFill: null
		};
	}

	//
	// event logic
	//

	var event_root = LinkedList.create();

	function eventCompare(p1_isStart, p1_1, p1_2, p2_isStart, p2_1, p2_2){
		// compare the selected points first
		var comp = eps.pointsCompare(p1_1, p2_1);
		if (comp !== 0)
			return comp;
		// the selected points are the same

		if (eps.pointsSame(p1_2, p2_2)) // if the non-selected points are the same too...
			return 0; // then the segments are equal

		if (p1_isStart !== p2_isStart) // if one is a start and the other isn't...
			return p1_isStart ? 1 : -1; // favor the one that isn't the start

		// otherwise, we'll have to calculate which one is below the other manually
		return eps.pointAboveOrOnLine(p1_2,
			p2_isStart ? p2_1 : p2_2, // order matters
			p2_isStart ? p2_2 : p2_1
		) ? 1 : -1;
	}

	function eventAdd(ev, other_pt){
		event_root.insertBefore(ev, function(here){
			// should ev be inserted before here?
			var comp = eventCompare(
				ev  .isStart, ev  .pt,      other_pt,
				here.isStart, here.pt, here.other.pt
			);
			return comp < 0;
		});
	}

	function eventAddSegmentStart(seg, primary){
		var ev_start = LinkedList.node({
			isStart: true,
			pt: seg.start,
			seg: seg,
			primary: primary,
			other: null,
			status: null
		});
		eventAdd(ev_start, seg.end);
		return ev_start;
	}

	function eventAddSegmentEnd(ev_start, seg, primary){
		var ev_end = LinkedList.node({
			isStart: false,
			pt: seg.end,
			seg: seg,
			primary: primary,
			other: ev_start,
			status: null
		});
		ev_start.other = ev_end;
		eventAdd(ev_end, ev_start.pt);
	}

	function eventAddSegment(seg, primary){
		var ev_start = eventAddSegmentStart(seg, primary);
		eventAddSegmentEnd(ev_start, seg, primary);
		return ev_start;
	}

	function eventUpdateEnd(ev, end){
		// slides an end backwards
		//   (start)------------(end)    to:
		//   (start)---(end)

		if (buildLog)
			buildLog.segmentChop(ev.seg, end);

		ev.other.remove();
		ev.seg.end = end;
		ev.other.pt = end;
		eventAdd(ev.other, ev.pt);
	}

	function eventDivide(ev, pt){
		var ns = segmentCopy(pt, ev.seg.end, ev.seg);
		eventUpdateEnd(ev, pt);
		return eventAddSegment(ns, ev.primary);
	}

	function calculate(primaryPolyInverted, secondaryPolyInverted){
		// if selfIntersection is true then there is no secondary polygon, so that isn't used

		//
		// status logic
		//

		var status_root = LinkedList.create();

		function statusCompare(ev1, ev2){
			var a1 = ev1.seg.start;
			var a2 = ev1.seg.end;
			var b1 = ev2.seg.start;
			var b2 = ev2.seg.end;

			if (eps.pointsCollinear(a1, b1, b2)){
				if (eps.pointsCollinear(a2, b1, b2))
					return 1;//eventCompare(true, a1, a2, true, b1, b2);
				return eps.pointAboveOrOnLine(a2, b1, b2) ? 1 : -1;
			}
			return eps.pointAboveOrOnLine(a1, b1, b2) ? 1 : -1;
		}

		function statusFindSurrounding(ev){
			return status_root.findTransition(function(here){
				var comp = statusCompare(ev, here.ev);
				return comp > 0;
			});
		}

		function checkIntersection(ev1, ev2){
			// returns the segment equal to ev1, or false if nothing equal

			var seg1 = ev1.seg;
			var seg2 = ev2.seg;
			var a1 = seg1.start;
			var a2 = seg1.end;
			var b1 = seg2.start;
			var b2 = seg2.end;

			if (buildLog)
				buildLog.checkIntersection(seg1, seg2);

			var i = eps.linesIntersect(a1, a2, b1, b2);

			if (i === false){
				// segments are parallel or coincident

				// if points aren't collinear, then the segments are parallel, so no intersections
				if (!eps.pointsCollinear(a1, a2, b1))
					return false;
				// otherwise, segments are on top of each other somehow (aka coincident)

				if (eps.pointsSame(a1, b2) || eps.pointsSame(a2, b1))
					return false; // segments touch at endpoints... no intersection

				var a1_equ_b1 = eps.pointsSame(a1, b1);
				var a2_equ_b2 = eps.pointsSame(a2, b2);

				if (a1_equ_b1 && a2_equ_b2)
					return ev2; // segments are exactly equal

				var a1_between = !a1_equ_b1 && eps.pointBetween(a1, b1, b2);
				var a2_between = !a2_equ_b2 && eps.pointBetween(a2, b1, b2);

				// handy for debugging:
				// buildLog.log({
				//	a1_equ_b1: a1_equ_b1,
				//	a2_equ_b2: a2_equ_b2,
				//	a1_between: a1_between,
				//	a2_between: a2_between
				// });

				if (a1_equ_b1){
					if (a2_between){
						//  (a1)---(a2)
						//  (b1)----------(b2)
						eventDivide(ev2, a2);
					}
					else{
						//  (a1)----------(a2)
						//  (b1)---(b2)
						eventDivide(ev1, b2);
					}
					return ev2;
				}
				else if (a1_between){
					if (!a2_equ_b2){
						// make a2 equal to b2
						if (a2_between){
							//         (a1)---(a2)
							//  (b1)-----------------(b2)
							eventDivide(ev2, a2);
						}
						else{
							//         (a1)----------(a2)
							//  (b1)----------(b2)
							eventDivide(ev1, b2);
						}
					}

					//         (a1)---(a2)
					//  (b1)----------(b2)
					eventDivide(ev2, a1);
				}
			}
			else{
				// otherwise, lines intersect at i.pt, which may or may not be between the endpoints

				// is A divided between its endpoints? (exclusive)
				if (i.alongA === 0){
					if (i.alongB === -1) // yes, at exactly b1
						eventDivide(ev1, b1);
					else if (i.alongB === 0) // yes, somewhere between B's endpoints
						eventDivide(ev1, i.pt);
					else if (i.alongB === 1) // yes, at exactly b2
						eventDivide(ev1, b2);
				}

				// is B divided between its endpoints? (exclusive)
				if (i.alongB === 0){
					if (i.alongA === -1) // yes, at exactly a1
						eventDivide(ev2, a1);
					else if (i.alongA === 0) // yes, somewhere between A's endpoints (exclusive)
						eventDivide(ev2, i.pt);
					else if (i.alongA === 1) // yes, at exactly a2
						eventDivide(ev2, a2);
				}
			}
			return false;
		}

		//
		// main event loop
		//
		var segments = [];
		while (!event_root.isEmpty()){
			var ev = event_root.getHead();

			if (buildLog)
				buildLog.vert(ev.pt[0]);

			if (ev.isStart){

				if (buildLog)
					buildLog.segmentNew(ev.seg, ev.primary);

				var surrounding = statusFindSurrounding(ev);
				var above = surrounding.before ? surrounding.before.ev : null;
				var below = surrounding.after ? surrounding.after.ev : null;

				if (buildLog){
					buildLog.tempStatus(
						ev.seg,
						above ? above.seg : false,
						below ? below.seg : false
					);
				}

				function checkBothIntersections(){
					if (above){
						var eve = checkIntersection(ev, above);
						if (eve)
							return eve;
					}
					if (below)
						return checkIntersection(ev, below);
					return false;
				}

				var eve = checkBothIntersections();
				if (eve){
					// ev and eve are equal
					// we'll keep eve and throw away ev

					// merge ev.seg's fill information into eve.seg

					if (selfIntersection){
						var toggle; // are we a toggling edge?
						if (ev.seg.myFill.below === null)
							toggle = true;
						else
							toggle = ev.seg.myFill.above !== ev.seg.myFill.below;

						// merge two segments that belong to the same polygon
						// think of this as sandwiching two segments together, where `eve.seg` is
						// the bottom -- this will cause the above fill flag to toggle
						if (toggle)
							eve.seg.myFill.above = !eve.seg.myFill.above;
					}
					else{
						// merge two segments that belong to different polygons
						// each segment has distinct knowledge, so no special logic is needed
						// note that this can only happen once per segment in this phase, because we
						// are guaranteed that all self-intersections are gone
						eve.seg.otherFill = ev.seg.myFill;
					}

					if (buildLog)
						buildLog.segmentUpdate(eve.seg);

					ev.other.remove();
					ev.remove();
				}

				if (event_root.getHead() !== ev){
					// something was inserted before us in the event queue, so loop back around and
					// process it before continuing
					if (buildLog)
						buildLog.rewind(ev.seg);
					continue;
				}

				//
				// calculate fill flags
				//
				if (selfIntersection){
					var toggle; // are we a toggling edge?
					if (ev.seg.myFill.below === null) // if we are a new segment...
						toggle = true; // then we toggle
					else // we are a segment that has previous knowledge from a division
						toggle = ev.seg.myFill.above !== ev.seg.myFill.below; // calculate toggle

					// next, calculate whether we are filled below us
					if (!below){ // if nothing is below us...
						// we are filled below us if the polygon is inverted
						ev.seg.myFill.below = primaryPolyInverted;
					}
					else{
						// otherwise, we know the answer -- it's the same if whatever is below
						// us is filled above it
						ev.seg.myFill.below = below.seg.myFill.above;
					}

					// since now we know if we're filled below us, we can calculate whether
					// we're filled above us by applying toggle to whatever is below us
					if (toggle)
						ev.seg.myFill.above = !ev.seg.myFill.below;
					else
						ev.seg.myFill.above = ev.seg.myFill.below;
				}
				else{
					// now we fill in any missing transition information, since we are all-knowing
					// at this point

					if (ev.seg.otherFill === null){
						// if we don't have other information, then we need to figure out if we're
						// inside the other polygon
						var inside;
						if (!below){
							// if nothing is below us, then we're inside if the other polygon is
							// inverted
							inside =
								ev.primary ? secondaryPolyInverted : primaryPolyInverted;
						}
						else{ // otherwise, something is below us
							// so copy the below segment's other polygon's above
							if (ev.primary === below.primary)
								inside = below.seg.otherFill.above;
							else
								inside = below.seg.myFill.above;
						}
						ev.seg.otherFill = {
							above: inside,
							below: inside
						};
					}
				}

				if (buildLog){
					buildLog.status(
						ev.seg,
						above ? above.seg : false,
						below ? below.seg : false
					);
				}

				// insert the status and remember it for later removal
				ev.other.status = surrounding.insert(LinkedList.node({ ev: ev }));
			}
			else{
				var st = ev.status;

				if (st === null){
					throw new Error('PolyBool: Zero-length segment detected; your epsilon is ' +
						'probably too small or too large');
				}

				// removing the status will create two new adjacent edges, so we'll need to check
				// for those
				if (status_root.exists(st.prev) && status_root.exists(st.next))
					checkIntersection(st.prev.ev, st.next.ev);

				if (buildLog)
					buildLog.statusRemove(st.ev.seg);

				// remove the status
				st.remove();

				// if we've reached this point, we've calculated everything there is to know, so
				// save the segment for reporting
				if (!ev.primary){
					// make sure `seg.myFill` actually points to the primary polygon though
					var s = ev.seg.myFill;
					ev.seg.myFill = ev.seg.otherFill;
					ev.seg.otherFill = s;
				}
				segments.push(ev.seg);
			}

			// remove the event and continue
			event_root.getHead().remove();
		}

		if (buildLog)
			buildLog.done();

		return segments;
	}

	// return the appropriate API depending on what we're doing
	if (!selfIntersection){
		// performing combination of polygons, so only deal with already-processed segments
		return {
			calculate: function(segments1, inverted1, segments2, inverted2){
				// segmentsX come from the self-intersection API, or this API
				// invertedX is whether we treat that list of segments as an inverted polygon or not
				// returns segments that can be used for further operations
				segments1.forEach(function(seg){
					eventAddSegment(segmentCopy(seg.start, seg.end, seg), true);
				});
				segments2.forEach(function(seg){
					eventAddSegment(segmentCopy(seg.start, seg.end, seg), false);
				});
				return calculate(inverted1, inverted2);
			}
		};
	}

	// otherwise, performing self-intersection, so deal with regions
	return {
		addRegion: function(region){
			// regions are a list of points:
			//  [ [0, 0], [100, 0], [50, 100] ]
			// you can add multiple regions before running calculate
			var pt1;
			var pt2 = region[region.length - 1];
			for (var i = 0; i < region.length; i++){
				pt1 = pt2;
				pt2 = region[i];

				var forward = eps.pointsCompare(pt1, pt2);
				if (forward === 0) // points are equal, so we have a zero-length segment
					continue; // just skip it

				eventAddSegment(
					segmentNew(
						forward < 0 ? pt1 : pt2,
						forward < 0 ? pt2 : pt1
					),
					true
				);
			}
		},
		calculate: function(inverted){
			// is the polygon inverted?
			// returns segments
			return calculate(inverted, false);
		}
	};
}

module.exports = Intersecter;

},{"./linked-list":6}],6:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// simple linked list implementation that allows you to traverse down nodes and save positions
//

var LinkedList = {
	create: function(){
		var my = {
			root: { root: true, next: null },
			exists: function(node){
				if (node === null || node === my.root)
					return false;
				return true;
			},
			isEmpty: function(){
				return my.root.next === null;
			},
			getHead: function(){
				return my.root.next;
			},
			insertBefore: function(node, check){
				var last = my.root;
				var here = my.root.next;
				while (here !== null){
					if (check(here)){
						node.prev = here.prev;
						node.next = here;
						here.prev.next = node;
						here.prev = node;
						return;
					}
					last = here;
					here = here.next;
				}
				last.next = node;
				node.prev = last;
				node.next = null;
			},
			findTransition: function(check){
				var prev = my.root;
				var here = my.root.next;
				while (here !== null){
					if (check(here))
						break;
					prev = here;
					here = here.next;
				}
				return {
					before: prev === my.root ? null : prev,
					after: here,
					insert: function(node){
						node.prev = prev;
						node.next = here;
						prev.next = node;
						if (here !== null)
							here.prev = node;
						return node;
					}
				};
			}
		};
		return my;
	},
	node: function(data){
		data.prev = null;
		data.next = null;
		data.remove = function(){
			data.prev.next = data.next;
			if (data.next)
				data.next.prev = data.prev;
			data.prev = null;
			data.next = null;
		};
		return data;
	}
};

module.exports = LinkedList;

},{}],7:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// converts a list of segments into a list of regions, while also removing unnecessary verticies
//

function SegmentChainer(segments, eps, buildLog){
	var chains = [];
	var regions = [];

	segments.forEach(function(seg){
		var pt1 = seg.start;
		var pt2 = seg.end;
		if (eps.pointsSame(pt1, pt2)){
			console.warn('PolyBool: Warning: Zero-length segment detected; your epsilon is ' +
				'probably too small or too large');
			return;
		}

		if (buildLog)
			buildLog.chainStart(seg);

		// search for two chains that this segment matches
		var first_match = {
			index: 0,
			matches_head: false,
			matches_pt1: false
		};
		var second_match = {
			index: 0,
			matches_head: false,
			matches_pt1: false
		};
		var next_match = first_match;
		function setMatch(index, matches_head, matches_pt1){
			// return true if we've matched twice
			next_match.index = index;
			next_match.matches_head = matches_head;
			next_match.matches_pt1 = matches_pt1;
			if (next_match === first_match){
				next_match = second_match;
				return false;
			}
			next_match = null;
			return true; // we've matched twice, we're done here
		}
		for (var i = 0; i < chains.length; i++){
			var chain = chains[i];
			var head  = chain[0];
			var head2 = chain[1];
			var tail  = chain[chain.length - 1];
			var tail2 = chain[chain.length - 2];
			if (eps.pointsSame(head, pt1)){
				if (setMatch(i, true, true))
					break;
			}
			else if (eps.pointsSame(head, pt2)){
				if (setMatch(i, true, false))
					break;
			}
			else if (eps.pointsSame(tail, pt1)){
				if (setMatch(i, false, true))
					break;
			}
			else if (eps.pointsSame(tail, pt2)){
				if (setMatch(i, false, false))
					break;
			}
		}

		if (next_match === first_match){
			// we didn't match anything, so create a new chain
			chains.push([ pt1, pt2 ]);
			if (buildLog)
				buildLog.chainNew(pt1, pt2);
			return;
		}

		if (next_match === second_match){
			// we matched a single chain

			if (buildLog)
				buildLog.chainMatch(first_match.index);

			// add the other point to the apporpriate end, and check to see if we've closed the
			// chain into a loop

			var index = first_match.index;
			var pt = first_match.matches_pt1 ? pt2 : pt1; // if we matched pt1, then we add pt2, etc
			var addToHead = first_match.matches_head; // if we matched at head, then add to the head

			var chain = chains[index];
			var grow  = addToHead ? chain[0] : chain[chain.length - 1];
			var grow2 = addToHead ? chain[1] : chain[chain.length - 2];
			var oppo  = addToHead ? chain[chain.length - 1] : chain[0];
			var oppo2 = addToHead ? chain[chain.length - 2] : chain[1];

			if (eps.pointsCollinear(grow2, grow, pt)){
				// grow isn't needed because it's directly between grow2 and pt:
				// grow2 ---grow---> pt
				if (addToHead){
					if (buildLog)
						buildLog.chainRemoveHead(first_match.index, pt);
					chain.shift();
				}
				else{
					if (buildLog)
						buildLog.chainRemoveTail(first_match.index, pt);
					chain.pop();
				}
				grow = grow2; // old grow is gone... new grow is what grow2 was
			}

			if (eps.pointsSame(oppo, pt)){
				// we're closing the loop, so remove chain from chains
				chains.splice(index, 1);

				if (eps.pointsCollinear(oppo2, oppo, grow)){
					// oppo isn't needed because it's directly between oppo2 and grow:
					// oppo2 ---oppo--->grow
					if (addToHead){
						if (buildLog)
							buildLog.chainRemoveTail(first_match.index, grow);
						chain.pop();
					}
					else{
						if (buildLog)
							buildLog.chainRemoveHead(first_match.index, grow);
						chain.shift();
					}
				}

				if (buildLog)
					buildLog.chainClose(first_match.index);

				// we have a closed chain!
				regions.push(chain);
				return;
			}

			// not closing a loop, so just add it to the apporpriate side
			if (addToHead){
				if (buildLog)
					buildLog.chainAddHead(first_match.index, pt);
				chain.unshift(pt);
			}
			else{
				if (buildLog)
					buildLog.chainAddTail(first_match.index, pt);
				chain.push(pt);
			}
			return;
		}

		// otherwise, we matched two chains, so we need to combine those chains together

		function reverseChain(index){
			if (buildLog)
				buildLog.chainReverse(index);
			chains[index].reverse(); // gee, that's easy
		}

		function appendChain(index1, index2){
			// index1 gets index2 appended to it, and index2 is removed
			var chain1 = chains[index1];
			var chain2 = chains[index2];
			var tail  = chain1[chain1.length - 1];
			var tail2 = chain1[chain1.length - 2];
			var head  = chain2[0];
			var head2 = chain2[1];

			if (eps.pointsCollinear(tail2, tail, head)){
				// tail isn't needed because it's directly between tail2 and head
				// tail2 ---tail---> head
				if (buildLog)
					buildLog.chainRemoveTail(index1, tail);
				chain1.pop();
				tail = tail2; // old tail is gone... new tail is what tail2 was
			}

			if (eps.pointsCollinear(tail, head, head2)){
				// head isn't needed because it's directly between tail and head2
				// tail ---head---> head2
				if (buildLog)
					buildLog.chainRemoveHead(index2, head);
				chain2.shift();
			}

			if (buildLog)
				buildLog.chainJoin(index1, index2);
			chains[index1] = chain1.concat(chain2);
			chains.splice(index2, 1);
		}

		var F = first_match.index;
		var S = second_match.index;

		if (buildLog)
			buildLog.chainConnect(F, S);

		var reverseF = chains[F].length < chains[S].length; // reverse the shorter chain, if needed
		if (first_match.matches_head){
			if (second_match.matches_head){
				if (reverseF){
					// <<<< F <<<< --- >>>> S >>>>
					reverseChain(F);
					// >>>> F >>>> --- >>>> S >>>>
					appendChain(F, S);
				}
				else{
					// <<<< F <<<< --- >>>> S >>>>
					reverseChain(S);
					// <<<< F <<<< --- <<<< S <<<<   logically same as:
					// >>>> S >>>> --- >>>> F >>>>
					appendChain(S, F);
				}
			}
			else{
				// <<<< F <<<< --- <<<< S <<<<   logically same as:
				// >>>> S >>>> --- >>>> F >>>>
				appendChain(S, F);
			}
		}
		else{
			if (second_match.matches_head){
				// >>>> F >>>> --- >>>> S >>>>
				appendChain(F, S);
			}
			else{
				if (reverseF){
					// >>>> F >>>> --- <<<< S <<<<
					reverseChain(F);
					// <<<< F <<<< --- <<<< S <<<<   logically same as:
					// >>>> S >>>> --- >>>> F >>>>
					appendChain(S, F);
				}
				else{
					// >>>> F >>>> --- <<<< S <<<<
					reverseChain(S);
					// >>>> F >>>> --- >>>> S >>>>
					appendChain(F, S);
				}
			}
		}
	});

	return regions;
}

module.exports = SegmentChainer;

},{}],8:[function(require,module,exports){
// (c) Copyright 2016, Sean Connelly (@voidqk), http://syntheti.cc
// MIT License
// Project Home: https://github.com/voidqk/polybooljs

//
// filter a list of segments based on boolean operations
//

function select(segments, selection, buildLog){
	var result = [];
	segments.forEach(function(seg){
		var index =
			(seg.myFill.above ? 8 : 0) +
			(seg.myFill.below ? 4 : 0) +
			((seg.otherFill && seg.otherFill.above) ? 2 : 0) +
			((seg.otherFill && seg.otherFill.below) ? 1 : 0);
		if (selection[index] !== 0){
			// copy the segment to the results, while also calculating the fill status
			result.push({
				id: buildLog ? buildLog.segmentId() : -1,
				start: seg.start,
				end: seg.end,
				myFill: {
					above: selection[index] === 1, // 1 if filled above
					below: selection[index] === 2  // 2 if filled below
				},
				otherFill: null
			});
		}
	});

	if (buildLog)
		buildLog.selected(result);

	return result;
}

var SegmentSelector = {
	union: function(segments, buildLog){ // primary | secondary
		// above1 below1 above2 below2    Keep?               Value
		//    0      0      0      0   =>   no                  0
		//    0      0      0      1   =>   yes filled below    2
		//    0      0      1      0   =>   yes filled above    1
		//    0      0      1      1   =>   no                  0
		//    0      1      0      0   =>   yes filled below    2
		//    0      1      0      1   =>   yes filled below    2
		//    0      1      1      0   =>   no                  0
		//    0      1      1      1   =>   no                  0
		//    1      0      0      0   =>   yes filled above    1
		//    1      0      0      1   =>   no                  0
		//    1      0      1      0   =>   yes filled above    1
		//    1      0      1      1   =>   no                  0
		//    1      1      0      0   =>   no                  0
		//    1      1      0      1   =>   no                  0
		//    1      1      1      0   =>   no                  0
		//    1      1      1      1   =>   no                  0
		return select(segments, [
			0, 2, 1, 0,
			2, 2, 0, 0,
			1, 0, 1, 0,
			0, 0, 0, 0
		], buildLog);
	},
	intersect: function(segments, buildLog){ // primary & secondary
		// above1 below1 above2 below2    Keep?               Value
		//    0      0      0      0   =>   no                  0
		//    0      0      0      1   =>   no                  0
		//    0      0      1      0   =>   no                  0
		//    0      0      1      1   =>   no                  0
		//    0      1      0      0   =>   no                  0
		//    0      1      0      1   =>   yes filled below    2
		//    0      1      1      0   =>   no                  0
		//    0      1      1      1   =>   yes filled below    2
		//    1      0      0      0   =>   no                  0
		//    1      0      0      1   =>   no                  0
		//    1      0      1      0   =>   yes filled above    1
		//    1      0      1      1   =>   yes filled above    1
		//    1      1      0      0   =>   no                  0
		//    1      1      0      1   =>   yes filled below    2
		//    1      1      1      0   =>   yes filled above    1
		//    1      1      1      1   =>   no                  0
		return select(segments, [
			0, 0, 0, 0,
			0, 2, 0, 2,
			0, 0, 1, 1,
			0, 2, 1, 0
		], buildLog);
	},
	difference: function(segments, buildLog){ // primary - secondary
		// above1 below1 above2 below2    Keep?               Value
		//    0      0      0      0   =>   no                  0
		//    0      0      0      1   =>   no                  0
		//    0      0      1      0   =>   no                  0
		//    0      0      1      1   =>   no                  0
		//    0      1      0      0   =>   yes filled below    2
		//    0      1      0      1   =>   no                  0
		//    0      1      1      0   =>   yes filled below    2
		//    0      1      1      1   =>   no                  0
		//    1      0      0      0   =>   yes filled above    1
		//    1      0      0      1   =>   yes filled above    1
		//    1      0      1      0   =>   no                  0
		//    1      0      1      1   =>   no                  0
		//    1      1      0      0   =>   no                  0
		//    1      1      0      1   =>   yes filled above    1
		//    1      1      1      0   =>   yes filled below    2
		//    1      1      1      1   =>   no                  0
		return select(segments, [
			0, 0, 0, 0,
			2, 0, 2, 0,
			1, 1, 0, 0,
			0, 1, 2, 0
		], buildLog);
	},
	differenceRev: function(segments, buildLog){ // secondary - primary
		// above1 below1 above2 below2    Keep?               Value
		//    0      0      0      0   =>   no                  0
		//    0      0      0      1   =>   yes filled below    2
		//    0      0      1      0   =>   yes filled above    1
		//    0      0      1      1   =>   no                  0
		//    0      1      0      0   =>   no                  0
		//    0      1      0      1   =>   no                  0
		//    0      1      1      0   =>   yes filled above    1
		//    0      1      1      1   =>   yes filled above    1
		//    1      0      0      0   =>   no                  0
		//    1      0      0      1   =>   yes filled below    2
		//    1      0      1      0   =>   no                  0
		//    1      0      1      1   =>   yes filled below    2
		//    1      1      0      0   =>   no                  0
		//    1      1      0      1   =>   no                  0
		//    1      1      1      0   =>   no                  0
		//    1      1      1      1   =>   no                  0
		return select(segments, [
			0, 2, 1, 0,
			0, 0, 1, 1,
			0, 2, 0, 2,
			0, 0, 0, 0
		], buildLog);
	},
	xor: function(segments, buildLog){ // primary ^ secondary
		// above1 below1 above2 below2    Keep?               Value
		//    0      0      0      0   =>   no                  0
		//    0      0      0      1   =>   yes filled below    2
		//    0      0      1      0   =>   yes filled above    1
		//    0      0      1      1   =>   no                  0
		//    0      1      0      0   =>   yes filled below    2
		//    0      1      0      1   =>   no                  0
		//    0      1      1      0   =>   no                  0
		//    0      1      1      1   =>   yes filled above    1
		//    1      0      0      0   =>   yes filled above    1
		//    1      0      0      1   =>   no                  0
		//    1      0      1      0   =>   no                  0
		//    1      0      1      1   =>   yes filled below    2
		//    1      1      0      0   =>   no                  0
		//    1      1      0      1   =>   yes filled above    1
		//    1      1      1      0   =>   yes filled below    2
		//    1      1      1      1   =>   no                  0
		return select(segments, [
			0, 2, 1, 0,
			2, 0, 0, 1,
			1, 0, 0, 2,
			0, 1, 2, 0
		], buildLog);
	}
};

module.exports = SegmentSelector;

},{}]},{},[1]);