Implement layer masking with bazier path

selected-rounded-corner-ASImageNode.swift

    image.imageModificationBlock = { image in
        // try to set rounded corner only to top left and bottom left
        var modifiedImage: UIImage?
        var rect = CGRect(origin: CGPoint.zero, size: image.size)

        UIGraphicsBeginImageContextWithOptions(image.size, false, UIScreen.main.scale)
        let maskPath = UIBezierPath(roundedRect: rect, byRoundingCorners: [UIRectCorner.topLeft, UIRectCorner.bottomLeft], cornerRadii: CGSize(width: 10, height: 10))
        maskPath.addClip()
        image.draw(in: rect)
        modifiedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return modifiedImage
    }