function onWindowKeyPressed(event) {
      ctrlDown = event.ctrlKey;
      if (!ctrlDown) {
        drag.start.x = null;
        drag.start.y = null;
      }
    }
function onWindowKeyPressed(event) {
      ctrlDown = event.ctrlKey;
      if (!ctrlDown) {
        drag.start.x = null;
        drag.start.y = null;
      }
    }
function onWindowKeyPressed ( event ) { ctrlDown = event . ctrlKey ; if ( ! ctrlDown ) { drag . start . x = null ; drag . start . y = null ; } }
On key pressed callback
On key pressed callback