How do you add an outline to text programmatically? - ios

Question

I have two apps, one with a UILabel and one using SpriteKit with a SKLabelNode. I'd like to add a black outline around the white text.
I can't find any outline or border properties or anything like that within swift. I've tried just creating new labels with slightly bigger, black font behind them but that didn't look right at all.
Here is my game with SpriteKit
title.position = CGPoint(x: self.frame.width / 2, y: self.frame.height / 2)
title.text = "Tap to start!"
title.fontName = "Arial"
title.zPosition = 10
title.fontSize = 50
self.addChild(title)
And here is my other one that uses UILables (It's within a red rectangle so it's easier to see)
let rectangle = UIView(frame:CGRect(x: self.view.frame.size.width / 2 - 150, y: self.view.frame.size.height / 2 - 75, width: 300, height: 150))
rectangle.backgroundColor = UIColor.red
self.view.addSubview(rectangle)
let label = UILabel(frame: CGRect(x: rectangle.frame.size.width / 2 - 75, y: rectangle.frame.size.height / 2 - 10, width: 150, height: 20))
label.textAlignment = .center
label.text = "Tap to Start!"
label.textColor = UIColor.white
label.font = UIFont(name: "Arial", size: 20)
rectangle.addSubview(label)
How do I outline these labels?

Answer 1

For SKLabelNode's, there is no 'easy' way of outlining text. There is however a 'hack'. It involves adding 8 additional duplicate nodes around the label that are coloured black (or whatever colour you want the outline to be), have a zPosition less than the original and otherwise, be identical.
It's important that each label has the same font size as the original.
Your attempt at doing this involved increasing the font size of your one outline copy label. As you said in the question, it doesn't work. You have to use multiple labels so the effect appears seamlessly.
You would place one copy directly above the original, one directly below, one to the left, one to the right, then one on each corner (top right, top left, bottom right, and bottom left). This gives the effect of an outline, however is not efficient and should be taken with a grain of salt.
Note: Keep the amount shifted from the original consistent for all the copies, so the 'outline' is evenly sized.
This should work for UILabels too, however I think there might be an easier way to do this with UILabels.