     
     /// used to keep track of all the strokes
     internal var stack: [Stroke]!
-    private var pointsArray: NSMutableArray!
+    private var pointsArray: [String]!
     
     private var lastPoint = CGPoint.zero
     

    public required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        initTouchDrawView(CGRect.zero)
    }

    /// adds the subviews and initializes stack

        if let touch = touches.first {
            lastPoint = touch.locationInView(self)
            pointsArray = []
            pointsArray.append(NSStringFromCGPoint(lastPoint))
        }
    }
    
