Source: ui/gl_matrix/matrix_quaternion.js

  1. /*! @license
  2.  * glMatrix: https://github.com/toji/gl-matrix/
  3.  * Copyright 2015-2021, Brandon Jones, Colin MacKenzie IV
  4.  * SPDX-License-Identifier: MIT
  5.  */
  8. goog.provide('shaka.ui.MatrixQuaternion');
  10. /**
  11.  * Quaternion in the format XYZW
  12.  */
  13. shaka.ui.MatrixQuaternion = class {
  14.   /**
  15.    * Creates a new identity quaternion
  16.    *
  17.    * @return {!Float32Array} a new quaternion
  18.    */
  19.   static create() {
  20.     const out = new Float32Array(4);
  21.     out[3] = 1;
  22.     return out;
  23.   }
  25.   /**
  26.    * Normalize a quaternion
  27.    *
  28.    * @param {!Float32Array} out the receiving quaternion
  29.    * @param {!Float32Array} a quaternion to normalize
  30.    */
  31.   static normalize(out, a) {
  32.     const x = a[0];
  33.     const y = a[1];
  34.     const z = a[2];
  35.     const w = a[3];
  36.     let len = x * x + y * y + z * z + w * w;
  37.     if (len > 0) {
  38.       len = 1 / Math.sqrt(len);
  39.     }
  40.     out[0] = x * len;
  41.     out[1] = y * len;
  42.     out[2] = z * len;
  43.     out[3] = w * len;
  44.   }
  45. };