title: Is there a way to capture Metal output as a bitmap or other format suitable for printing?
body: <p>I'm converting an app from OpenGL to Metal, using MTKit. The original app allowed the user to print the OpenGL-generated screen being viewed (I've also done this with Core Graphics). I'd like to do the same in Metal. I thought it would be easy to find a solution or at least an approach to the problem, but I'm stuck. Has anyone solved this, or does anyone have any inklings about what I should be looking for?</p>
  
  <p>I'm a seasoned Mac programmer (would prefer an Objective-C solution but I do a bit of work with everything else) and am an advanced novice at Metal.</p>
  
  <ul>
  <li>MacOS 10.15.3, all MacBooks.</li>
  <li>Swift 5.</li>
  <li>Xcode 11.2.1.</li>
  </ul>