code: function(x, y, evt) {
  
      // center is at half size
      center.set(x/2, y/2);
  
      var shift = x/10;
      line1.set(x/2 + shift, 0);
      line1.p1.set(x/2 - shift, y);
  
      line2.set(0, y/2 - shift);
      line2.p1.set(x, y/2 + shift);
  
      rect.size( x/2, y/2 );
      rect.setCenter( x/2, y/2 );
    }
docs: handler for Space resize