 		let touch = touches.first as! UITouch
 		let location = touch.locationInView(self)
 		controller!.touchBegan(location)
-		_tracking = true
+		tracking = true
 	}
 
 	override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) {
 
-		if !_tracking {
+		if !tracking {
 			return
 		}
 

		let controller = DrawingInputController()
		controller.drawing = drawingView.drawing!
		controller.view = drawingView
		controller.viewport = CGRect(x: 0, y: 0, width: 768, height: 1024).rectByInsetting(dx: 100, dy: 100)
		controller.fill = Fill.Brush
		drawingView.controller = controller

		view.addSubview(drawingView)

		var tgr = UITapGestureRecognizer(target: self, action: "eraseDrawing:")
		tgr.numberOfTapsRequired = 2
		tgr.numberOfTouchesRequired = 1
		drawingView.addGestureRecognizer(tgr)

		self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "DEBUG", style: UIBarButtonItemStyle.Plain, target: self, action: "toggleDebugRendering:")

		self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: "UNFO", style: UIBarButtonItemStyle.Plain, target: self, action: "undo:")
	}

	override func viewWillLayoutSubviews() {
		drawingView.frame = view.bounds
	}

	dynamic func undo( sender:AnyObject ) {
		drawingView.controller!.undo()
	}

	dynamic func eraseDrawing( sender:AnyObject ) {
		drawingView.drawing!.clear()
		drawingView.setNeedsDisplay()
	}

	dynamic func toggleDebugRendering( sender:AnyObject ) {
		drawingView.drawing!.debugRender = !drawingView.drawing!.debugRender
		drawingView.setNeedsDisplay()
	}

}
			UIRectFill(vp)
		}

		if drawing!.debugRender {
			UIColor.redColor().colorWithAlphaComponent(0.5).set()
			UIRectFrameUsingBlendMode(rect, kCGBlendModeNormal)
		}

		controller!.draw(ctx)
	}
