         
         let pinch = UIPinchGestureRecognizer(target: self, action: #selector(pinchHandler))
         addGestureRecognizer(pinch)
+        
+        let pan = UIPanGestureRecognizer(target: self, action: #selector(panHandler))
+        addGestureRecognizer(pan)
         
         addSubview(segmentedControl)
         segmentedControl.addTarget(

        
        currentDrawable?.present()
        
        angle += 0.005
    }
    
    func rnd() -> Float

    private var frameStartTime: CFAbsoluteTime!
    private var frameNumber = 0
    
    private var panStartAngle: Float = 0
    private var panning: Bool = false
    
    private var width: CGFloat
    private let centerBuffer: MTLBuffer
    
