Move all Metal setup to the Renderer

Terrain/TerrainViewController.swift

@@ -11,34 +11,24 @@ import MetalKit
 
 class TerrainViewController: NSViewController {
 
-    var renderer: Renderer!
+    let renderer = Renderer()
 
-    private var metalView: MTKView! {
-        return view as? MTKView
+    private var metalView: MTKView {
+        return view as! MTKView
     }
 
     override func loadView() {
-        guard let device = MTLCreateSystemDefaultDevice() else {
-            fatalError("Couldn't create system default Metal device")
-        }
-        let v = MTKView(frame: CGRect(), device: device)
+        let v = MTKView()
         v.translatesAutoresizingMaskIntoConstraints = false
         v.widthAnchor.constraint(greaterThanOrEqualToConstant: 640).isActive = true
         v.heightAnchor.constraint(greaterThanOrEqualToConstant: 480).isActive = true
         view = v
     }
 
-    override func viewDidLoad() {
-        renderer = Renderer()
-        metalView.delegate = renderer
-    }
-
     override func viewWillAppear() {
         super.viewWillAppear()
-        guard let device = metalView.device else {
-            return
-        }
-        renderer.setupMetal(withDevice: device, pixelFormat: metalView.colorPixelFormat)
+        metalView.delegate = renderer
+        renderer.setupMetal(withView: metalView)
         renderer.prepareToRender()
     }