Create a rounded UIBezierPath with a different corner radius per corner

UIBezierPathExtensions.swift

extension UIBezierPath {
    
    /// Defines a corner of a rounded rectangle path.
    public enum RoundedRectCorner {
        case topLeft
        case topRight
        case bottomLeft
        case bottomRight
        case all
    }
    
    /// Creates a rounded rectangle with the given corners.
    /// This allows the creation of a rectangle with a different corner radius for one of more corners.
    ///
    /// Be warned that this method does not clamp the corner radius for specific corners. It is possible to end up with an invalid or incorrect path while doing this.
    ///
    ///  **Example**
    ///
    /// In order to change 1 corner from the rest, simply supply `.all` and the corner you want to change to `corners:`.
    ///  `[.all: 26, .bottomRight: 9]`
    ///
    /// - Parameters:
    ///   - rect: The rectangle that defines the basic shape of the path
    ///   - corners: The corners to adjust the corner radius for. The specific corner will always take priority over the `all` option.
    convenience init(roundedRect rect: CGRect, corners: [RoundedRectCorner: CGFloat]) {
        self.init()
        
        let allCorners = min(corners[.all] ?? 0, rect.width / 2, rect.height / 2)
        let topLeft = corners[.topLeft] ?? allCorners
        let topRight = corners[.topRight] ?? allCorners
        let bottomLeft = corners[.bottomLeft] ?? allCorners
        let bottomRight = corners[.bottomRight] ?? allCorners
        
        let path = self
        path.move(to: CGPoint(x: 0 + topLeft, y: 0)); // Move to top left but inset with radius
        path.addLine(to: CGPoint(x: rect.width - topRight, y: 0)) // Add line at the top from left to right
        path.addArc(withCenter: CGPoint(x: rect.width - topRight, y: topRight), radius: topRight, startAngle: 3 * .pi / 2, endAngle: 0, clockwise: true) // Add top right rounded corner
        path.addLine(to: CGPoint(x: rect.width, y: rect.height - bottomRight)) // Add line from top to bottom on right side
        path.addArc(withCenter: CGPoint(x: rect.height - bottomRight, y: rect.width - bottomRight), radius: bottomRight, startAngle: 0, endAngle: .pi / 2, clockwise: true) // Add bottom right rounded corner
        path.addLine(to: CGPoint(x: bottomLeft, y: rect.height)) // Add line from bottom right to bottom left
        path.addArc(withCenter: CGPoint(x: bottomLeft, y: rect.height - bottomLeft), radius: bottomLeft, startAngle: .pi / 2, endAngle: .pi, clockwise: true) // Add bottom left rounded corner
        path.addLine(to: CGPoint(x: 0, y: topLeft)) // Add line from bottom to top on left side
        path.addArc(withCenter: CGPoint(x: topLeft, y: topLeft), radius: topLeft, startAngle: .pi, endAngle: 3 * .pi / 2, clockwise: true) // Add top left rounded corner
        path.close() // Complete the path
    }
    
 }