handleTouchStartRotate method

dynamic handleTouchStartRotate()

Implementation

handleTouchStartRotate() {
  if (pointers.length == 1) {
    rotateStart.set(pointers[0].pageX, pointers[0].pageY);
  } else {
    var x = 0.5 * (pointers[0].pageX + pointers[1].pageX);
    var y = 0.5 * (pointers[0].pageY + pointers[1].pageY);

    rotateStart.set(x, y);
  }
}