This is a simple control which maps touches within its bounds to a 0.0 - 1.0 range on the horizontal and vertical axes, returned as a CIVector.

TouchCaptureControl.swift

class TouchCaptureControl: UIControl {
    var value: CIVector = CIVector(x: 0.0, y: 0.0)
    
    @IBInspectable var horizontalMinimumValue: CGFloat = 0.0
    @IBInspectable var horizontalMaximumValue: CGFloat = 1.0
    @IBInspectable var verticalMinimumValue: CGFloat = 0.0
    @IBInspectable var verticalMaximumValue: CGFloat = 1.0
    
    @IBInspectable var flipHorizontalAxis: Bool = false
    @IBInspectable var flipVerticalAxis: Bool = false
    
    //MARK: - Value Translation
    
    func setValueForPoint(point: CGPoint) {
        var normalizedX = point.x / bounds.width
        if flipHorizontalAxis { normalizedX = 1.0 - normalizedX }
        
        var normalizedY = point.y / bounds.height
        if flipVerticalAxis { normalizedY = 1.0 - normalizedY }
        
        let mappedX = (horizontalMaximumValue - horizontalMinimumValue) * normalizedX + horizontalMinimumValue
        let mappedY = (verticalMaximumValue - verticalMinimumValue) * normalizedY + verticalMinimumValue
        
        let newValue = CIVector(x: mappedX, y: mappedY)
        if newValue != value {
            value = newValue
            sendActionsForControlEvents(.ValueChanged)
        }
    }
    
    //MARK: - Touches
    
    override func beginTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool {
        setValueForPoint(touch.locationInView(self))
        return super.beginTrackingWithTouch(touch, withEvent: event)
    }
    
    override func continueTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool {
        setValueForPoint(touch.locationInView(self))
        return super.continueTrackingWithTouch(touch, withEvent: event)
    }
    
}