Clock Hour Numbers

I will try to reduce this to the minimum you need to get this to work. This code may differ significantly from what you need to write for Xcode 10 / Swift 4.2. Hopefully Xcode will suggest some good fixes.

This first section is going to try to figure out exactly how high your numbers are.

    
    func drawHourNumbers (rect : CGRect) {

        let fontSize = baseWidth * 14
        let attributes : NSDictionary = [
            NSForegroundColorAttributeName : color,
            NSParagraphStyleAttributeName : NSMutableParagraphStyle(),
            NSObliquenessAttributeName : 0,
            NSFontAttributeName : UIFont(
                name : "HoeflerText-Regular", size: 18)!        
        ];

        var maxHeight : CGFloat = 0
        for i in 1...12 {
            let s = "\(i)"
            let h = s.size(attributes: attributes as? [String : Any]).height
            if h > maxHeight {
                maxHeight = h
            }
        }

This next section will draw the numbers taking into account the width and height of the string (i.e. it is going to help you center them using an offset).

        
        let attributes2 : NSDictionary = [
            NSForegroundColorAttributeName : color,
            NSParagraphStyleAttributeName : NSMutableParagraphStyle(),
            NSObliquenessAttributeName : 0,
            NSFontAttributeName : UIFont(
                name : font, 
                size: fontSize * fontSize / maxHeight)!
        ];

        for i in 1...12 {
            let loc = angle(fromHour: i)
            let s = "\(i)"
            let w = s.size(attributes: attributes2 as? [String : Any]).width
            let h = s.size(attributes: attributes2 as? [String : Any]).height
            s.draw(with: CGRect(x: loc.x-w/2, 
                                y: loc.y-(fontSize*0.55),
                                width: w, 
                                height: h),
                   options: .usesLineFragmentOrigin,
                   attributes: attributes2 as? [String : Any], context: nil)
        }
    }