title: Rotating CGPoint around a center point
body: <p>I have been trying to find an example of using the 2D transform matrix to rotate a CGPoint around the center of another CGPoint but I've had no luck finding anything recent. </p>
  
  <p>Has anyone managed to achieve this? Using CGAffineTransform isn't an option in this use case as I need the points. </p>
  
  <p>Thanks in advance</p>