@flatten-js/core

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width,initial-scale=1"> <title>classes/polygon.js - Documentation</title> <script src="scripts/prettify/prettify.js"></script> <script src="scripts/prettify/lang-css.js"></script>  <link type="text/css" rel="stylesheet" href="https://code.ionicframework.com/ionicons/2.0.1/css/ionicons.min.css"> <link type="text/css" rel="stylesheet" href="styles/prettify-tomorrow.css"> <link type="text/css" rel="stylesheet" href="styles/jsdoc-default.css"> </head> <body> <input type="checkbox" id="nav-trigger" class="nav-trigger" /> <label for="nav-trigger" class="navicon-button x"> <div class="navicon"></div> </label> <label for="nav-trigger" class="overlay"></label> <nav> <li class="nav-link nav-home-link"><a href="index.html">Home</a></li><li class="nav-heading">Classes</li><li class="nav-heading">C<a href="Arc.html">Arc</a></li><li class="nav-item">F<a href="Arc.html#clone">clone</a></li><li 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href="Face.html#remove">remove</a></li><li class="nav-item">F<a href="Face.html#reverse">reverse</a></li><li class="nav-item">F<a href="Face.html#setArcLength">setArcLength</a></li><li class="nav-item">F<a href="Face.html#area">area</a></li><li class="nav-item">F<a href="Face.html#signedArea">signedArea</a></li><li class="nav-item">F<a href="Face.html#orientation">orientation</a></li><li class="nav-item">F<a href="Face.html#isSimple">isSimple</a></li><li class="nav-item">F<a href="Face.html#findEdgeByPoint">findEdgeByPoint</a></li><li class="nav-item">F<a href="Face.html#toPolygon">toPolygon</a></li><li class="nav-item">F<a href="Face.html#svg">svg</a></li><li class="nav-heading">C<a href="Line.html">Line</a></li><li class="nav-item">F<a href="Line.html#clone">clone</a></li><li class="nav-item">F<a href="Line.html#parallelTo">parallelTo</a></li><li class="nav-item">F<a href="Line.html#incidentTo">incidentTo</a></li><li class="nav-item">F<a href="Line.html#contains">contains</a></li><li class="nav-item">F<a href="Line.html#coord">coord</a></li><li class="nav-item">F<a href="Line.html#intersect">intersect</a></li><li class="nav-item">F<a href="Line.html#distanceTo">distanceTo</a></li><li class="nav-item">F<a href="Line.html#split">split</a></li><li class="nav-item">F<a href="Line.html#sortPoints">sortPoints</a></li><li class="nav-item">F<a href="Line.html#toJSON">toJSON</a></li><li class="nav-item">F<a href="Line.html#svg">svg</a></li><li class="nav-heading">C<a href="Matrix.html">Matrix</a></li><li class="nav-item">F<a href="Matrix.html#clone">clone</a></li><li class="nav-item">F<a href="Matrix.html#transform">transform</a></li><li class="nav-item">F<a href="Matrix.html#multiply">multiply</a></li><li class="nav-item">F<a href="Matrix.html#translate">translate</a></li><li class="nav-item">F<a href="Matrix.html#rotate">rotate</a></li><li class="nav-item">F<a href="Matrix.html#scale">scale</a></li><li class="nav-item">F<a href="Matrix.html#equalTo">equalTo</a></li><li class="nav-heading">C<a href="Multiline.html">Multiline</a></li><li class="nav-item">F<a href="Multiline.html#clone">clone</a></li><li class="nav-item">F<a href="Multiline.html#addVertex">addVertex</a></li><li class="nav-item">F<a href="Multiline.html#split">split</a></li><li class="nav-item">F<a href="Multiline.html#findEdgeByPoint">findEdgeByPoint</a></li><li class="nav-item">F<a href="Multiline.html#translate">translate</a></li><li class="nav-item">F<a href="Multiline.html#rotate">rotate</a></li><li class="nav-item">F<a href="Multiline.html#transform">transform</a></li><li class="nav-item">F<a href="Multiline.html#toShapes">toShapes</a></li><li class="nav-item">F<a href="Multiline.html#toJSON">toJSON</a></li><li class="nav-item">F<a href="Multiline.html#svg">svg</a></li><li class="nav-heading">C<a href="Point.html">Point</a></li><li class="nav-item">F<a href="Point.html#clone">clone</a></li><li class="nav-item">F<a href="Point.html#equalTo">equalTo</a></li><li class="nav-item">F<a href="Point.html#lessThan">lessThan</a></li><li class="nav-item">F<a href="Point.html#rotate">rotate</a></li><li class="nav-item">F<a href="Point.html#translate">translate</a></li><li class="nav-item">F<a href="Point.html#transform">transform</a></li><li class="nav-item">F<a href="Point.html#projectionOn">projectionOn</a></li><li class="nav-item">F<a href="Point.html#leftTo">leftTo</a></li><li class="nav-item">F<a href="Point.html#distanceTo">distanceTo</a></li><li class="nav-item">F<a href="Point.html#on">on</a></li><li class="nav-item">F<a href="Point.html#toJSON">toJSON</a></li><li class="nav-item">F<a href="Point.html#svg">svg</a></li><li class="nav-heading">C<a href="Polygon.html">Polygon</a></li><li class="nav-item">F<a href="Polygon.html#clone">clone</a></li><li class="nav-item">F<a href="Polygon.html#isEmpty">isEmpty</a></li><li class="nav-item">F<a href="Polygon.html#isValid">isValid</a></li><li class="nav-item">F<a href="Polygon.html#area">area</a></li><li class="nav-item">F<a href="Polygon.html#addFace">addFace</a></li><li class="nav-item">F<a href="Polygon.html#deleteFace">deleteFace</a></li><li class="nav-item">F<a href="Polygon.html#removeChain">removeChain</a></li><li class="nav-item">F<a href="Polygon.html#addVertex">addVertex</a></li><li class="nav-item">F<a href="Polygon.html#cut">cut</a></li><li class="nav-item">F<a href="Polygon.html#cutFace">cutFace</a></li><li class="nav-item">F<a href="Polygon.html#findEdgeByPoint">findEdgeByPoint</a></li><li class="nav-item">F<a href="Polygon.html#splitToIslands">splitToIslands</a></li><li class="nav-item">F<a href="Polygon.html#reverse">reverse</a></li><li class="nav-item">F<a href="Polygon.html#contains">contains</a></li><li class="nav-item">F<a href="Polygon.html#distanceTo">distanceTo</a></li><li class="nav-item">F<a href="Polygon.html#intersect">intersect</a></li><li class="nav-item">F<a href="Polygon.html#translate">translate</a></li><li class="nav-item">F<a href="Polygon.html#rotate">rotate</a></li><li class="nav-item">F<a href="Polygon.html#transform">transform</a></li><li class="nav-item">F<a href="Polygon.html#toJSON">toJSON</a></li><li class="nav-item">F<a href="Polygon.html#toArray">toArray</a></li><li class="nav-item">F<a href="Polygon.html#svg">svg</a></li><li class="nav-heading">C<a href="Ray.html">Ray</a></li><li class="nav-item">F<a href="Ray.html#clone">clone</a></li><li class="nav-item">F<a href="Ray.html#contains">contains</a></li><li class="nav-item">F<a href="Ray.html#split">split</a></li><li class="nav-item">F<a href="Ray.html#intersect">intersect</a></li><li class="nav-item">F<a href="Ray.html#svg">svg</a></li><li class="nav-heading">C<a href="Segment.html">Segment</a></li><li class="nav-item">F<a href="Segment.html#clone">clone</a></li><li class="nav-item">F<a href="Segment.html#equalTo">equalTo</a></li><li class="nav-item">F<a href="Segment.html#contains">contains</a></li><li class="nav-item">F<a href="Segment.html#intersect">intersect</a></li><li class="nav-item">F<a href="Segment.html#distanceTo">distanceTo</a></li><li class="nav-item">F<a href="Segment.html#tangentInStart">tangentInStart</a></li><li class="nav-item">F<a href="Segment.html#tangentInEnd">tangentInEnd</a></li><li class="nav-item">F<a href="Segment.html#reverse">reverse</a></li><li class="nav-item">F<a href="Segment.html#split">split</a></li><li class="nav-item">F<a href="Segment.html#middle">middle</a></li><li class="nav-item">F<a href="Segment.html#translate">translate</a></li><li class="nav-item">F<a href="Segment.html#rotate">rotate</a></li><li class="nav-item">F<a href="Segment.html#transform">transform</a></li><li class="nav-item">F<a href="Segment.html#isZeroLength">isZeroLength</a></li><li class="nav-item">F<a href="Segment.html#sortPoints">sortPoints</a></li><li class="nav-item">F<a href="Segment.html#toJSON">toJSON</a></li><li class="nav-item">F<a href="Segment.html#svg">svg</a></li><li class="nav-heading">C<a href="Vector.html">Vector</a></li><li class="nav-item">F<a href="Vector.html#clone">clone</a></li><li class="nav-item">F<a href="Vector.html#equalTo">equalTo</a></li><li class="nav-item">F<a href="Vector.html#multiply">multiply</a></li><li class="nav-item">F<a href="Vector.html#dot">dot</a></li><li class="nav-item">F<a href="Vector.html#cross">cross</a></li><li class="nav-item">F<a href="Vector.html#normalize">normalize</a></li><li class="nav-item">F<a href="Vector.html#rotate">rotate</a></li><li class="nav-item">F<a href="Vector.html#rotate90CCW">rotate90CCW</a></li><li class="nav-item">F<a href="Vector.html#rotate90CW">rotate90CW</a></li><li class="nav-item">F<a href="Vector.html#invert">invert</a></li><li class="nav-item">F<a href="Vector.html#add">add</a></li><li class="nav-item">F<a href="Vector.html#subtract">subtract</a></li><li class="nav-item">F<a href="Vector.html#angleTo">angleTo</a></li><li class="nav-item">F<a href="Vector.html#projectionOn">projectionOn</a></li><li class="nav-item">F<a href="Vector.html#toJSON">toJSON</a></li><li class="nav-heading">C<a href="CircularLinkedList.html">CircularLinkedList</a></li><li class="nav-item">F<a href="CircularLinkedList.html#append">append</a></li><li class="nav-item">F<a href="CircularLinkedList.html#insert">insert</a></li><li class="nav-item">F<a href="CircularLinkedList.html#remove">remove</a></li><li class="nav-heading">C<a href="DE9IM.html">DE9IM</a></li><li class="nav-item">F<a href="DE9IM.html#toString">toString</a></li><li class="nav-heading">C<a href="LinkedList.html">LinkedList</a></li><li class="nav-item">F<a href="LinkedList.html#toArray">toArray</a></li><li class="nav-item">F<a href="LinkedList.html#append">append</a></li><li class="nav-item">F<a href="LinkedList.html#insert">insert</a></li><li class="nav-item">F<a href="LinkedList.html#remove">remove</a></li><li class="nav-item">F<a href="LinkedList.html#isEmpty">isEmpty</a></li><li class="nav-item">F<a href="LinkedList.html#.testInfiniteLoop">testInfiniteLoop</a></li><li class="nav-heading">C<a href="PlanarSet.html">PlanarSet</a></li><li class="nav-item">F<a href="PlanarSet.html#add">add</a></li><li class="nav-item">F<a href="PlanarSet.html#delete">delete</a></li><li class="nav-item">F<a href="PlanarSet.html#clear">clear</a></li><li class="nav-item">F<a href="PlanarSet.html#search">search</a></li><li class="nav-item">F<a href="PlanarSet.html#hit">hit</a></li><li class="nav-item">F<a href="PlanarSet.html#svg">svg</a></li><li class="nav-heading">C<a href="Errors.html">Errors</a></li><li class="nav-heading">Modules</li><li class="nav-heading">M<a href="module-BooleanOperations.html">BooleanOperations</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.unify">unify</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.subtract">subtract</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.intersect">intersect</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.innerClip">innerClip</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.outerClip">outerClip</a></li><li class="nav-item">F<a href="module-BooleanOperations.html#.calculateIntersections">calculateIntersections</a></li><li class="nav-heading">M<a href="module-RayShoot.html">RayShoot</a></li><li class="nav-item">F<a href="module-RayShoot.html#.ray_shoot">ray_shoot</a></li><li class="nav-heading">M<a href="module-Relation.html">Relation</a></li><li class="nav-item">F<a href="module-Relation.html#.equal">equal</a></li><li class="nav-item">F<a href="module-Relation.html#.intersect">intersect</a></li><li class="nav-item">F<a href="module-Relation.html#.touch">touch</a></li><li class="nav-item">F<a href="module-Relation.html#.disjoint">disjoint</a></li><li class="nav-item">F<a href="module-Relation.html#.inside">inside</a></li><li class="nav-item">F<a href="module-Relation.html#.covered">covered</a></li><li class="nav-item">F<a href="module-Relation.html#.contain">contain</a></li><li class="nav-item">F<a href="module-Relation.html#.cover">cover</a></li><li class="nav-item">F<a href="module-Relation.html#.relate">relate</a></li><li class="nav-heading"><a href="global.html">Globals</a></li><li class="nav-item">F<a href="global.html#inverse">inverse</a></li><li class="nav-item">M<a href="global.html#arc">arc</a></li><li class="nav-item">M<a href="global.html#box">box</a></li><li class="nav-item">M<a href="global.html#circle">circle</a></li><li class="nav-item">M<a href="global.html#line">line</a></li><li class="nav-item">M<a href="global.html#matrix">matrix</a></li><li class="nav-item">M<a href="global.html#multiline">multiline</a></li><li class="nav-item">M<a href="global.html#point">point</a></li><li class="nav-item">M<a href="global.html#polygon">polygon</a></li><li class="nav-item">M<a href="global.html#segment">segment</a></li><li class="nav-item">M<a href="global.html#vector">vector</a></li><li class="nav-item">M<a href="global.html#CCW">CCW</a></li><li class="nav-item">M<a href="global.html#CW">CW</a></li><li class="nav-item">M<a href="global.html#ORIENTATION">ORIENTATION</a></li><li class="nav-item">M<a href="global.html#DP_TOL">DP_TOL</a></li><li class="nav-item">F<a href="global.html#setTolerance">setTolerance</a></li><li class="nav-item">F<a href="global.html#getTolerance">getTolerance</a></li><li class="nav-item">F<a href="global.html#EQ_0">EQ_0</a></li><li class="nav-item">F<a href="global.html#EQ">EQ</a></li><li class="nav-item">F<a href="global.html#GT">GT</a></li><li class="nav-item">F<a href="global.html#GE">GE</a></li><li class="nav-item">F<a href="global.html#LT">LT</a></li><li class="nav-item">F<a href="global.html#LE">LE</a></li> </nav> <div id="main"> <h1 class="page-title">classes/polygon.js</h1> <section> <article> <pre class="prettyprint source linenums"><code>/** * Created by Alex Bol on 3/15/2017. */ "use strict"; import Flatten from '../flatten'; import {ray_shoot} from "../algorithms/ray_shooting"; import * as Intersection from "../algorithms/intersection"; import * as Relations from "../algorithms/relation"; /** * Class representing a polygon. * Polygon in FlattenJS is a multipolygon comprised from a set of [faces]{@link Flatten.Face}. * Face, in turn, is a closed loop of [edges]{@link Flatten.Edge}, where edge may be segment or circular arc * @type {Polygon} */ export class Polygon { /** * Constructor creates new instance of polygon. With no arguments new polygon is empty. * Constructor accepts as argument array that define loop of shapes * or array of arrays in case of multi polygon * Loop may be defined in different ways: * - array of shapes of type Segment or Arc * - array of points (Flatten.Point) * - array of numeric pairs which represent points * - box or circle object * Alternatively, it is possible to use polygon.addFace method * @param {args} - array of shapes or array of arrays */ constructor() { /** * Container of faces (closed loops), may be empty * @type {PlanarSet} */ this.faces = new Flatten.PlanarSet(); /** * Container of edges * @type {PlanarSet} */ this.edges = new Flatten.PlanarSet(); /* It may be array of something that may represent one loop (face) or array of arrays that represent multiple loops */ let args = [...arguments]; if (args.length === 1 && ((args[0] instanceof Array && args[0].length > 0) || args[0] instanceof Flatten.Circle || args[0] instanceof Flatten.Box)) { let argsArray = args[0]; if (args[0] instanceof Array && args[0].every((loop) => {return loop instanceof Array})) { if (argsArray.every( el => {return el instanceof Array && el.length === 2 && typeof(el[0]) === "number" && typeof(el[1]) === "number"} )) { this.faces.add(new Flatten.Face(this, argsArray)); // one-loop polygon as array of pairs of numbers } else { for (let loop of argsArray) { // multi-loop polygon /* Check extra level of nesting for GeoJSON-style multi polygons */ if (loop instanceof Array && loop[0] instanceof Array && loop[0].every( el => {return el instanceof Array && el.length === 2 && typeof(el[0]) === "number" && typeof(el[1]) === "number"} )) { for (let loop1 of loop) { this.faces.add(new Flatten.Face(this, loop1)); } } else { this.faces.add(new Flatten.Face(this, loop)); } } } } else { this.faces.add(new Flatten.Face(this, argsArray)); // one-loop polygon } } } /** * (Getter) Returns bounding box of the polygon * @returns {Box} */ get box() { return [...this.faces].reduce((acc, face) => acc.merge(face.box), new Flatten.Box()); } /** * (Getter) Returns array of vertices * @returns {Array} */ get vertices() { return [...this.edges].map(edge => edge.start); } /** * Create new cloned instance of the polygon * @returns {Polygon} */ clone() { let polygon = new Polygon(); for (let face of this.faces) { polygon.addFace(face.shapes); } return polygon; } /** * Return true is polygon has no edges * @returns {boolean} */ isEmpty() { return this.edges.size === 0; } /** * Return true if polygon is valid for boolean operations * Polygon is valid if * 1. All faces are simple polygons (there are no self-intersected polygons) * 2. All faces are orientable and there is no island inside island or hole inside hole - TODO * 3. There is no intersections between faces (excluding touching) - TODO * @returns {boolean} */ isValid() { let valid = true; // 1. Polygon is invalid if at least one face is not simple for (let face of this.faces) { if (!face.isSimple(this.edges)) { valid = false; break; } } // 2. TODO: check if no island inside island and no hole inside hole // 3. TODO: check the there is no intersection between faces return valid; } /** * Returns area of the polygon. Area of an island will be added, area of a hole will be subtracted * @returns {number} */ area() { let signedArea = [...this.faces].reduce((acc, face) => acc + face.signedArea(), 0); return Math.abs(signedArea); } /** * Add new face to polygon. Returns added face * @param {Points[]|Segments[]|Arcs[]|Circle|Box} args - new face may be create with one of the following ways: * 1) array of points that describe closed path (edges are segments) * 2) array of shapes (segments and arcs) which describe closed path * 3) circle - will be added as counterclockwise arc * 4) box - will be added as counterclockwise rectangle * You can chain method face.reverse() is you need to change direction of the creates face * @returns {Face} */ addFace(...args) { let face = new Flatten.Face(this, ...args); this.faces.add(face); return face; } /** * Delete existing face from polygon * @param {Face} face Face to be deleted * @returns {boolean} */ deleteFace(face) { for (let edge of face) { let deleted = this.edges.delete(edge); } let deleted = this.faces.delete(face); return deleted; } /** * Delete chain of edges from the face. * @param {Face} face Face to remove chain * @param {Edge} edgeFrom Start of the chain of edges to be removed * @param {Edge} edgeTo End of the chain of edges to be removed */ removeChain(face, edgeFrom, edgeTo) { // Special case: all edges removed if (edgeTo.next === edgeFrom) { this.deleteFace(face); return; } for (let edge = edgeFrom; edge !== edgeTo.next; edge = edge.next) { face.remove(edge); this.edges.delete(edge); // delete from PlanarSet of edges and update index if (face.isEmpty()) { this.deleteFace(face); // delete from PlanarSet of faces and update index break; } } } /** * Add point as a new vertex and split edge. Point supposed to belong to an edge. * When edge is split, new edge created from the start of the edge to the new vertex * and inserted before current edge. * Current edge is trimmed and updated. * Method returns new edge added. If no edge added, it returns edge before vertex * @param {Point} pt Point to be added as a new vertex * @param {Edge} edge Edge to be split with new vertex and then trimmed from start * @returns {Edge} */ addVertex(pt, edge) { let shapes = edge.shape.split(pt); // if (shapes.length < 2) return; if (shapes[0] === null) // point incident to edge start vertex, return previous edge return edge.prev; if (shapes[1] === null) // point incident to edge end vertex, return edge itself return edge; let newEdge = new Flatten.Edge(shapes[0]); let edgeBefore = edge.prev; /* Insert first split edge into linked list after edgeBefore */ edge.face.insert(newEdge, edgeBefore); // Remove old edge from edges container and 2d index this.edges.delete(edge); // Insert new edge to the edges container and 2d index this.edges.add(newEdge); // Update edge shape with second split edge keeping links edge.shape = shapes[1]; // Add updated edge to the edges container and 2d index this.edges.add(edge); return newEdge; } /** * Cut polygon with multiline and return array of new polygons * Multiline should be constructed from a line with intersection point, see notebook: * https://next.observablehq.com/@alexbol99/cut-polygon-with-line * @param {Multiline} multiline * @returns {Polygon[]} */ cut(multiline) { let cutPolygons = [this.clone()]; for (let edge of multiline) { if (edge.setInclusion(this) !== Flatten.INSIDE) continue; let cut_edge_start = edge.shape.start; let cut_edge_end = edge.shape.end; let newCutPolygons = []; for (let polygon of cutPolygons) { if (polygon.findEdgeByPoint(cut_edge_start) === undefined) { newCutPolygons.push(polygon); } else { let [cutPoly1, cutPoly2] = polygon.cutFace(cut_edge_start, cut_edge_end); newCutPolygons.push(cutPoly1, cutPoly2); } } cutPolygons = newCutPolygons; } return cutPolygons; } /** * Cut face of polygon with a segment between two points and create two new polygons * Supposed that a segments between points does not intersect any other edge * @param {Point} pt1 * @param {Point} pt2 * @returns {Polygon[]} */ cutFace(pt1, pt2) { let edge1 = this.findEdgeByPoint(pt1); let edge2 = this.findEdgeByPoint(pt2); if (edge1.face != edge2.face) return; // Cut face into two and create new polygon with two faces let edgeBefore1 = this.addVertex(pt1, edge1); edge2 = this.findEdgeByPoint(pt2); let edgeBefore2 = this.addVertex(pt2, edge2); let face = edgeBefore1.face; let newEdge1 = new Flatten.Edge( new Flatten.Segment(edgeBefore1.end, edgeBefore2.end) ); let newEdge2 = new Flatten.Edge( new Flatten.Segment(edgeBefore2.end, edgeBefore1.end) ); // Swap links edgeBefore1.next.prev = newEdge2; newEdge2.next = edgeBefore1.next; edgeBefore1.next = newEdge1; newEdge1.prev = edgeBefore1; edgeBefore2.next.prev = newEdge1; newEdge1.next = edgeBefore2.next; edgeBefore2.next = newEdge2; newEdge2.prev = edgeBefore2; // Insert new edge to the edges container and 2d index this.edges.add(newEdge1); this.edges.add(newEdge2); // Add two new faces let face1 = this.addFace(newEdge1, edgeBefore1); let face2 = this.addFace(newEdge2, edgeBefore2); // Remove old face this.faces.delete(face); return [face1.toPolygon(), face2.toPolygon()]; } /** * Returns the first founded edge of polygon that contains given point * @param {Point} pt * @returns {Edge} */ findEdgeByPoint(pt) { let edge; for (let face of this.faces) { edge = face.findEdgeByPoint(pt); if (edge != undefined) break; } return edge; } /** * Split polygon into array of polygons, where each polygon is an island with all * hole that it contains * @returns {Flatten.Polygon[]} */ splitToIslands() { let polygons = this.toArray(); // split into array of one-loop polygons /* Sort polygons by area in descending order */ polygons.sort( (polygon1, polygon2) => polygon2.area() - polygon1.area() ); /* define orientation of the island by orientation of the first polygon in array */ let orientation = [...polygons[0].faces][0].orientation(); /* Create output array from polygons with same orientation as a first polygon (array of islands) */ let newPolygons = polygons.filter( polygon => [...polygon.faces][0].orientation() === orientation); for (let polygon of polygons) { let face = [...polygon.faces][0]; if (face.orientation() === orientation) continue; // skip same orientation /* Proceed with opposite orientation */ /* Look if any of island polygons contains tested polygon as a hole */ for (let islandPolygon of newPolygons) { if (face.shapes.every(shape => islandPolygon.contains(shape))) { islandPolygon.addFace(face.shapes); // add polygon as a hole in islandPolygon break; } } } // TODO: assert if not all polygons added into output return newPolygons; } /** * Reverse orientation of all faces to opposite * @returns {Polygon} */ reverse() { for (let face of this.faces) { face.reverse(); } return this; } /** * Returns true if polygon contains shape: no point of shape lay outside of the polygon, * false otherwise * @param {Shape} shape - test shape * @returns {boolean} */ contains(sha