Swift: Producing a circle UIView is giving a diamond like shape - ios

Question

I created an extension on UIView so that I can create circle views easily without writing the code in each custom component. My code looks as:
extension UIView {
func createCircleView(targetView: UIView) {
let square = CGSize(width: min(targetView.frame.width, targetView.frame.height), height: min(targetView.frame.width, targetView.frame.height))
targetView.frame = CGRect(origin: CGPoint(x: 0, y: 0), size: square)
targetView.layer.cornerRadius = square.width / 2.0
}
}
the purpose of the property square is to always compute a perfect square based on the smallest property of width or height from the target view, this stops rectangles from trying to become squares, as that could obviously never produce a circle.
Inside my custom component I call this method with:
// machineCircle is a child view of my cell
#IBOutlet weak var machineCircle: UIView!
// Whenever data is set, update the cell with an observer
var machineData: MachineData? {
didSet {
createCircleView(machineCircle)
}
}
The problem I am having is that my circles are rendering to the screen like this:
When debugging, I inspected the square variable, it consistently prints width: 95, height: 95, which would lead me to believe that a perfect circle should be rendered each time.
Why am I seeing these strange shapes?
UPDATE I have found why perfect circles aren't being formed but I am not sure how to go about it.
In my storyboard I set the default size of my machineCircle view to be 95x95, however when my view loads, the collection cells width and height are computed dynamically with this method:
override func viewDidLoad() {
super.viewDidLoad()
let width = CGRectGetWidth(collectionView!.frame) / 3
let layout = collectionViewLayout as! UICollectionViewFlowLayout
layout.itemSize = CGSize(width: width, height: width + width / 2)
}
This resizes the collection view cells so that they can fit in cols of 3 accross the screen, but it does not seem to change the base scale of the inner machineCircle view. The machineCircle view still retains its size of 95x95 but seems to scale down inside the view causing the effect to be caused (thats what I have observed thus far). Any ideas?

Answer 1

Taking Matt's advice, I created a method to draw a circle within a UIView using CALayers.
For any who are interested, here is my implementation:
func drawCircleInView(parentView: UIView, targetView: UIView, color: UIColor, diameter: CGFloat)
{
let square = CGSize(width: min(parentView.bounds.width, parentView.bounds.height), height: min(parentView.bounds.width, parentView.bounds.height))
let center = CGPointMake(square.width / 2 - diameter, square.height / 2 - diameter)
let circlePath = UIBezierPath(arcCenter: center, radius: CGFloat(diameter), startAngle: CGFloat(0), endAngle: CGFloat(M_PI * 2), clockwise: true)
let shapeLayer = CAShapeLayer()
print(targetView.center)
shapeLayer.path = circlePath.CGPath
shapeLayer.fillColor = color.CGColor
shapeLayer.strokeColor = color.CGColor
shapeLayer.lineWidth = 1.0
targetView.backgroundColor = UIColor.clearColor()
targetView.layer.addSublayer(shapeLayer)
}
And it is called with:
drawCircleInView(self, machineCircle, color: UIColor.redColor(), radius: 30)
Here is the result:
The white box behind is for demonstration purposes only, it shows the parent view that the circle is drawn into, this will be set to transparent in production.