     
     private var previousTouchPoint = CGPoint.zero
     private var usableTrackingLength: CGFloat = 0
+    private var pointsPerValueScale: CGFloat = 1
     
     private let trackHeight: CGFloat = 4
     private let trackInset: CGFloat = 0

    public override func prepareForInterfaceBuilder() {
        trackLayer.frame = trackRectForBound(bounds)
        commonInit()
        updateLayersPosition()
        redrawLayers()
    }
    

    
    @IBInspectable public var minimum: Float = 0 {
        didSet {
            log("Minimum didSet")
            if (minimum > maximum) {
                maximum = minimum
            }
