source/modules/Body.js

const Result = require('./Result')
const SAT = require('./SAT')

/**
 * The base class for bodies used to detect collisions
 * @class
 * @protected
 */
class Body {
  /**
   * @constructor
   * @param {Number} [x = 0] The starting X coordinate
   * @param {Number} [y = 0] The starting Y coordinate
   * @param {Number} [padding = 0] The amount to pad the bounding volume when testing for potential collisions
   */
  constructor (x = 0, y = 0, padding = 0) {
    /**
     * @desc The X coordinate of the body
     * @type {Number}
     */
    this.x = x

    /**
     * @desc The Y coordinate of the body
     * @type {Number}
     */
    this.y = y

    /**
     * @desc The amount to pad the bounding volume when testing for potential collisions
     * @type {Number}
     */
    this.padding = padding

    /** @private */
    this._circle = false

    /** @private */
    this._polygon = false

    /** @private */
    this._point = false

    /** @private */
    this._bvh = null

    /** @private */
    this._bvh_parent = null

    /** @private */
    this._bvh_branch = false

    /** @private */
    this._bvh_padding = padding

    /** @private */
    this._bvh_min_x = 0

    /** @private */
    this._bvh_min_y = 0

    /** @private */
    this._bvh_max_x = 0

    /** @private */
    this._bvh_max_y = 0
  }

  /**
   * Determines if the body is colliding with another body
   * @param {Circle|Polygon|Point} target The target body to test against
   * @param {Result} [result = null] A Result object on which to store information about the collision
   * @param {Boolean} [aabb = true] Set to false to skip the AABB test (useful if you use your own potential collision heuristic)
   * @returns {Boolean}
   */
  collides (target, result = null, aabb = true) {
    return SAT(this, target, result, aabb)
  }

  /**
   * Returns a list of potential collisions
   * @returns {Array<Body>}
   */
  potentials () {
    const bvh = this._bvh

    if (bvh === null) {
      throw new Error('Body does not belong to a collision system')
    }

    return bvh.potentials(this)
  }

  /**
   * Removes the body from its current collision system
   */
  remove () {
    const bvh = this._bvh

    if (bvh) {
      bvh.remove(this, false)
    }
  }

  /**
   * Creates a {@link Result} used to collect the detailed results of a collision test
   */
  createResult () {
    return new Result()
  }

  /**
   * Creates a Result used to collect the detailed results of a collision test
   */
  static createResult () {
    return new Result()
  }
};

module.exports = Body

module.exports.default = module.exports