Cut a UIImage into a circle

Question

I want to cut a UIImage into a circle so that I can then use it as an annotation. Every answer on this site that I\'ve found describes creating an UIImage

Answer 1

Swift 5.3, Xcode 12.2, Handles all imageOrientations

Based on answer Leo Dabus

Thanks, works perfectly! BUT only for images with imageOrientation .up or .down. For images with .right or .left orientation there are distortions in result. And from iPhone/iPad camera for original photos initially we get .right orientation.

Code below takes into account imageOrientation property:

extension UIImage {

    func cropToCircle() -> UIImage? {
    
        let isLandscape = size.width > size.height
        let isUpOrDownImageOrientation = [0,1,4,5].contains(imageOrientation.rawValue)
    
        let breadth: CGFloat = min(size.width, size.height)
        let breadthSize = CGSize(width: breadth, height: breadth)
        let breadthRect = CGRect(origin: .zero, size: breadthSize)
    
        let xOriginPoint = CGFloat(isLandscape ?
                                (isUpOrDownImageOrientation ? ((size.width-size.height)/2).rounded(.down) : 0) :
                                (isUpOrDownImageOrientation ? 0 : ((size.height-size.width)/2).rounded(.down)))
        let yOriginPoint = CGFloat(isLandscape ?
                                (isUpOrDownImageOrientation ? 0 : ((size.width-size.height)/2).rounded(.down)) :
                                (isUpOrDownImageOrientation ? ((size.height-size.width)/2).rounded(.down) : 0))
    
        guard let cgImage = cgImage?.cropping(to: CGRect(origin: CGPoint(x: xOriginPoint, y: yOriginPoint),
                                                     size: breadthSize)) else { return nil }
        let format = imageRendererFormat
        format.opaque = false
    
        return UIGraphicsImageRenderer(size: breadthSize, format: format).image {_ in
            UIBezierPath(ovalIn: breadthRect).addClip()
            UIImage(cgImage: cgImage, scale: format.scale, orientation: imageOrientation).draw(in: CGRect(origin: .zero, size: breadthSize))
        }
    }
}