rounded_rect

        let path = UIBezierPath()
        let radius : CGFloat = 4
        
        let topRightStartAngle = -CGFloat(M_PI_2)
        let topRightEndAngle : CGFloat = 0.0
        
        let bottomRightStartAngle : CGFloat = 0.0
        let bottomRightEndAngle : CGFloat = -(CGFloat(M_PI) * 3) / 2
        let bottomRightCenterPoint = CGPoint(x: CGRectGetWidth(self.bounds) - radius, y: CGRectGetHeight(self.bounds) - radius)

        let bottomLeftStartAngle : CGFloat = -((CGFloat(M_PI)*3)/2)
        let bottomLeftEndAngle : CGFloat = -CGFloat(M_PI)

        let topLeftStartAngle: CGFloat = -CGFloat(M_PI)
        let topLeftEndAngle : CGFloat = -(CGFloat(M_PI)/2)

        path.moveToPoint(CGPoint(x: radius, y: 0))

        path.addLineToPoint(CGPoint(x: CGRectGetWidth(self.bounds) - radius, y: 0))
        path.addArcWithCenter(CGPoint(x: CGRectGetWidth(self.bounds) - radius, y: radius), radius: radius, startAngle: topRightEndAngle, endAngle: topRightEndAngle, clockwise: true)
        
        path.addLineToPoint(CGPoint(x: CGRectGetWidth(self.bounds), y: CGRectGetHeight(self.bounds) - radius))
        path.addArcWithCenter(bottomRightCenterPoint, radius: radius, startAngle: bottomRightStartAngle, endAngle: bottomRightEndAngle, clockwise: true)
        
        path.addLineToPoint(CGPoint(x: radius, y: CGRectGetHeight(self.bounds)))
        path.addArcWithCenter(CGPoint(x: radius, y: CGRectGetHeight(self.bounds) - radius), radius: radius, startAngle: bottomLeftStartAngle, endAngle: bottomLeftEndAngle, clockwise: true)
        
        path.addLineToPoint(CGPoint(x: 0, y: radius))
        path.addArcWithCenter(CGPoint(x: radius, y: radius), radius: radius, startAngle: topLeftStartAngle, endAngle: topLeftEndAngle, clockwise: true)