Source: AABB.js

  1. import { Vector } from "./Vector.js";
  2. import { Line } from "./Line.js";
  4. /** Class representing an Axis-Aligned Bounding Box. */
  5. export class AABB {
  6.   /**
  7.    * Create an AABB using centre position, width, and height.
  8.    * @param {number} x - The x value of the centre.
  9.    * @param {number} y - The y value of the centre.
  10.    * @param {number} width - The width measured from the centre.
  11.    * @param {number} height - The height measured from the centre.
  12.    */
  13.   constructor(x, y, width, height) {
  14.     this.x = x;
  15.     this.y = y;
  16.     this.width = width;
  17.     this.height = height;
  18.   }
  20.   /**
  21.    * Create an AABB from four corner [Vectors]{@link Vector}.
  22.    * @param {Vector} topLeft
  23.    * @param {Vector} topRight
  24.    * @param {Vector} bottomRight
  25.    * @param {Vector} bottomLeft
  26.    * @returns {AABB} - A new AABB object.
  27.    */
  28.   static fromCorners(topLeft, topRight, bottomRight, bottomLeft) {
  29.     const centre = new Vector(topRight.x - topLeft.x, bottomLeft.y - topLeft.y);
  31.     const width = topRight.x - centre.x;
  32.     const height = bottomRight.y - centre.y;
  34.     return new AABB(centre.x, centre.y, width, height);
  35.   }
  37.   /**
  38.    * Check if this AABB contains a {@link Vector}.
  39.    * @param {Vector} point - The vector to check.
  40.    * @returns {boolean}
  41.    */
  42.   contains(point) {
  43.     return (
  44.       point.x > this.x - this.width &&
  45.       point.x < this.x + this.width &&
  46.       point.y > this.y - this.height &&
  47.       point.y < this.y + this.height
  48.     );
  49.   }
  51.   /**
  52.    * Check if this AABB intersects another AABB.
  53.    * @param {AABB} range - The target AABB to check.
  54.    * @returns {boolean}
  55.    */
  56.   intersects(range) {
  57.     return !(
  58.       range.x - range.width > this.x + this.width ||
  59.       range.x + range.width < this.x - this.width ||
  60.       range.y - range.height > this.y + this.height ||
  61.       range.y + range.height < this.y - this.height
  62.     );
  63.   }
  65.   /**
  66.    * Create an array of [Lines]{@link Line} containing one line for each side of the AABB.
  67. 	 * @param {string} [options.stroke]
  68. 	 * @param {number} [options.strokeWidth]
  69.    * @returns {Line[]} - An array of Lines that can be added
  70.    * to a {@link Plot} using {@link Plot#add}.
  71.    */
  72.   lines(options = {}) {
  73.     const topLeft = new Vector(this.x - this.width, this.y - this.height);
  74.     const topRight = new Vector(this.x + this.width, this.y - this.height);
  75.     const bottomLeft = new Vector(this.x - this.width, this.y + this.height);
  76.     const bottomRight = new Vector(this.x + this.width, this.y + this.height);
  78.     let lines = [];
  80.     lines.push(
  81.       new Line(topLeft, topRight, options),
  82.       new Line(topRight, bottomRight, options),
  83.       new Line(bottomRight, bottomLeft, options),
  84.       new Line(bottomLeft, topLeft, options),
  85.     );
  87.     return lines;
  88.   }
  89. }