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

Based on the accepted answer, here's another mashup in Swift. I've made it into a function and made the invert optional

class func mask(viewToMask: UIView, maskRect: CGRect, invert: Bool = false) {
    let maskLayer = CAShapeLayer()
    let path = CGPathCreateMutable()
    if (invert) {
        CGPathAddRect(path, nil, viewToMask.bounds)
    }
    CGPathAddRect(path, nil, maskRect)

    maskLayer.path = path
    if (invert) {
        maskLayer.fillRule = kCAFillRuleEvenOdd
    }

    // Set the mask of the view.
    viewToMask.layer.mask = maskLayer;
}