function setPointerKey(key) {
  if (key !== 1 && key !== 2 && key !== 3) {
    key = 1;
  }
  Pointer.key = key - 1;
  Pointer.right = key === 2;
}
*************************************************************************
  UtilsPointer - pointer utility methods
 - x,y are in GL coordinates, i.e. from BOTTOM LEFT
 - top,left are in ui coordinates, i.e. from TOP LEFT
**************************************************************************