Create CGContext from a CGSize

CGSize+Extension.swift

extension CGSize {
    
    typealias ContextClosure = (_ context: CGContext, _ frame: CGRect) -> ()
    func image(withContext context: ContextClosure) -> UIImage? {
        
        UIGraphicsBeginImageContext(self)
        let frame = CGRect(origin: .zero, size: self)
        context(UIGraphicsGetCurrentContext()!, frame)
        
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

example.swift

let face = UIImage(named: "face.jpg")

let image = CGSize(width: 100, height: 100).image { context, frame in
    
    // create a path to use both for clipping (masking) and the border
    let path = UIBezierPath(ovalIn: frame)
    path.addClip()
    
    // the color to use as background tint and border color
    let tint = UIColor.blue.cgColor
    
    // add a blue background
    context.setFillColor(tint)
    context.fill(frame)
    
    // add the profile image
    face?.draw(in: frame, blendMode: .luminosity, alpha: 1)
    
    // add the border
    context.addPath(path.cgPath)
    context.setStrokeColor(tint)
    context.setLineWidth(5)
    context.strokePath()
    
}

Using the UIGraphics functions don't feel very swifty to me so exploring with this little wrapper.

(Face from http://www.diverseui.com)