lr-core/v2/index.js

Line Rider core library

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.len = len;
exports.lenSq = lenSq;
exports.angle = angle;
exports.angleTo = angleTo;
exports.dist = dist;
exports.distSq = distSq;
exports.dot = dot;
exports.cross = cross;
exports.equals = equals;
/**
 * @typedef Vec2
 *
 * @property {number} x - X component
 * @property {number} y - Y component
 */

function len(v) {
  return Math.sqrt(v.x * v.x + v.y * v.y);
}
function lenSq(v) {
  return v.x * v.x + v.y * v.y;
}
function angle(v) {
  return Math.atan2(v.y, v.x);
}
function angleTo(v, u) {
  return angle(u) - angle(v);
}
function dist(v, u) {
  const dx = u.x - v.x;
  const dy = u.y - v.y;
  return Math.sqrt(dx * dx + dy * dy);
}
function distSq(v, u) {
  const dx = u.x - v.x;
  const dy = u.y - v.y;
  return dx * dx + dy * dy;
}
function dot(v, u) {
  return v.x * u.x + v.y * u.y;
}
function cross(v, u) {
  return v.x * u.y - v.y * u.x;
}
function equals(v, u) {
  return v.x === u.x && v.y === u.y;
}
const V2Functions = { len, lenSq, angle, angleTo, dist, distSq, dot, cross, equals };

const V2Methods = {
  /* mutating methods */
  add(v) {
    this.x += v.x;
    this.y += v.y;
    return this;
  },
  sub(v) {
    this.x -= v.x;
    this.y -= v.y;
    return this;
  },
  mul(s) {
    this.x *= s;
    this.y *= s;
    return this;
  },
  div(s) {
    this.x /= s;
    this.y /= s;
    return this;
  },
  norm() {
    this.div(this.len());
    return this;
  },
  // X axis →
  // Y axis ↓
  // rotates clockwise
  rot(rads) {
    const cos = Math.cos(rads);
    const sin = Math.sin(rads);
    const x = this.x;
    const y = this.y;
    this.x = x * cos - y * sin;
    this.y = x * sin + y * cos;
    return this;
  },
  rotCW() {
    const x = this.x;
    const y = this.y;
    this.x = -y;
    this.y = x;
    return this;
  },
  rotCCW() {
    const x = this.x;
    const y = this.y;
    this.x = y;
    this.y = -x;
    return this;
  }
};

for (let key in V2Functions) {
  let fn = V2Functions[key];
  V2Methods[key] = function (v) {
    return fn(this, v);
  };
}

function V2(v) {
  let u = Object.create(V2Methods);
  u.x = v.x;
  u.y = v.y;
  return u;
}

Object.assign(V2, V2Functions);

exports.default = V2;