iOS invert mask in drawRect

Question

With the code below, I am successfully masking part of my drawing, but it\'s the inverse of what I want masked. This masks the inner portion of the drawing, where I would li

Answer 1

In order to invert mask you can to something like this

1. Here I have mask of crossed rectancles like

    let crossPath =  UIBezierPath(rect: cutout.insetBy(dx: 30, dy: -5))
             crossPath.append(UIBezierPath(rect: cutout.insetBy(dx: -5, dy: 30)))
               let crossMask = CAShapeLayer()
               crossMask.path = crossPath.cgPath
               crossMask.backgroundColor = UIColor.clear.cgColor
               crossMask.fillRule = .evenOdd
   

2. And here I add 3rd rectancle around my crossed rectancles so using .evenOdd it takes area that is equal to (New Rectancle - Old Crossed Rectangle) so in other words outside area of crossed rectancles

     let crossPath = UIBezierPath(rect: cutout.insetBy(dx: -5, dy: -5) )
       crossPath.append(UIBezierPath(rect: cutout.insetBy(dx: 30, dy: -5)))
       crossPath.append(UIBezierPath(rect: cutout.insetBy(dx: -5, dy: 30)))
       let crossMask = CAShapeLayer()
       crossMask.path = crossPath.cgPath
       crossMask.backgroundColor = UIColor.clear.cgColor
       crossMask.fillRule = .evenOdd