如何在椭圆形或圆形上裁剪UIImage？

import UIKit

extension UIImage {
    func circularImage() -> UIImage? {
        let squareSize = min(size.width, size.height)
        let imageSize = CGSize(width: squareSize, height: squareSize)
        
        UIGraphicsBeginImageContextWithOptions(imageSize, false, scale)
        defer { UIGraphicsEndImageContext() }
        
        guard let context = UIGraphicsGetCurrentContext() else { return nil }
        
        let rect = CGRect(origin: .zero, size: imageSize)
        let path = UIBezierPath(ovalIn: rect)
        path.addClip()
        
        draw(in: rect)
        
        guard let clippedImage = UIGraphicsGetImageFromCurrentImageContext() else { return nil }
        
        return clippedImage
    }
}

// 使用示例
let originalImage = UIImage(named: "example.jpg")
let clippedImage = originalImage?.circularImage()