code: function(evt) {
          evt.preventDefault();
          evt.stopPropagation();
          if (debug) { timedLog("secondFinger"); }
          if (evt.touches.length < 2) {
            return;
          }
          // we need to rebind finger 1, because it may have moved!
          transform.x1 = evt.touches[0].pageX;
          transform.y1 = evt.touches[0].pageY;
          transform.x2 = evt.touches[1].pageX;
          transform.y2 = evt.touches[1].pageY;
  
          var x1 = transform.x1,
            y1 = transform.y1,
            x2 = transform.x2,
            y2 = transform.y2,
            dx = x2 - x1,
            dy = y2 - y1,
            d = Math.sqrt(dx*dx + dy*dy),
            a = Math.atan2(dy,dx);
  
          transform.distance = d;
          transform.angle = a;
        }
docs: A second finger means we need to start tracking another
  event coordinate, which may lead to rotation and scaling
  updates for the element we're working for.