function TouchPanner() {
  window.addEventListener('touchstart', this.onTouchStart_.bind(this));
  window.addEventListener('touchmove', this.onTouchMove_.bind(this));
  window.addEventListener('touchend', this.onTouchEnd_.bind(this));

  this.isTouching = false;
  this.rotateStart = new MathUtil.Vector2();
  this.rotateEnd = new MathUtil.Vector2();
  this.rotateDelta = new MathUtil.Vector2();

  this.theta = 0;
  this.orientation = new MathUtil.Quaternion();
}
Provides a quaternion responsible for pre-panning the scene before further
transformations due to device sensors.