Cutting a UIImageView according to UIBezier?

Question

I have a UIImageView, with a certain image. I also have a UIBezierPath in some strange shape. I would like to cut the image to that shape and return a new image in that shape.

In the form of :

func getCut(bezier:UIBezierPath, image:UIImageView)->UIImageView

Answer 1

You can use mask to do so. Here's a quick example.

class ViewController: UIViewController {

    var path: UIBezierPath!
    var touchPoint: CGPoint!
    var startPoint: CGPoint!

    var imageView =  UIImageView(image: #imageLiteral(resourceName: "IMG_0715"))

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(imageView)
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            startPoint = touch.location(in: view)
            path = UIBezierPath()
            path.move(to: startPoint)
        }
    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            touchPoint = touch.location(in: view)
        }

        path.addLine(to: touchPoint)
        startPoint = touchPoint

    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        cut()
    }

    private func cut() {
        guard let path = path else { return }
        imageView = imageView.getCut(with: path)
    }

}

extension UIImageView {
    func getCut(with bezier: UIBezierPath) -> UIImageView {

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = bezier.cgPath

        self.layer.mask = shapeLayer

        return self
    }
}