iOS make part of an UIImage transparent

Question

I have an UIImage where part of it has been selected by the user to clear out (make transparent). To make the selection I used NSBezierPath.

How can I clear/make tra

Answer 1

Swift4 solution from landweber's above answer:

UIGraphicsBeginImageContext(image!.size)
image!.draw(at: CGPoint.zero)
let context:CGContext = UIGraphicsGetCurrentContext()!;
let bez = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 10, height: 10))
context.addPath(bez.cgPath)
context.clip();
context.clear(CGRect(x: 0,y: 0,width: image!.size.width,height: image!.size.height));
let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!;
UIGraphicsEndImageContext();