 		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
 		}
 

			UIRectFill(vp)
		}

		UIColor.redColor().colorWithAlphaComponent(0.5).set()
		UIRectFrameUsingBlendMode(rect, kCGBlendModeNormal)

		controller!.draw(ctx)
	}


class DrawingTestView : UIView {

	private var drawing:Drawing?
	private var controller:DrawingInputController?
	private var tracking:Bool = false

	override init(frame:CGRect) {
		super.init( frame: frame )
