Pass the device around

Terrain/Renderer.swift

@@ -12,6 +12,12 @@ import MetalKit
 
 class Renderer: NSObject, MTKViewDelegate {
 
+    let device: MTLDevice
+
+    init(device: MTLDevice) {
+        self.device = device
+    }
+
     func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {
         print("Size of \(view.debugDescription) will change to \(size)")
     }

Terrain/TerrainViewController.swift

@@ -11,7 +11,7 @@ import MetalKit
 
 class TerrainViewController: NSViewController {
 
-    let renderer = Renderer()
+    var renderer: Renderer!
 
     private var metalView: MTKView! {
         return view as? MTKView
@@ -19,14 +19,21 @@ class TerrainViewController: NSViewController {
 
     override func loadView() {
         guard let device = MTLCreateSystemDefaultDevice() else {
-            return
+            fatalError("Couldn't create system default Metal device")
         }
         let v = MTKView(frame: CGRect(), device: device)
         v.translatesAutoresizingMaskIntoConstraints = false
         v.widthAnchor.constraint(greaterThanOrEqualToConstant: 640).isActive = true
         v.heightAnchor.constraint(greaterThanOrEqualToConstant: 480).isActive = true
-        v.delegate = renderer
         view = v
     }
+
+    override func viewDidLoad() {
+        guard let device = metalView.device else {
+            fatalError("Couldn't get device from Metal view")
+        }
+        renderer = Renderer(device: device)
+        metalView.delegate = renderer
+    }
     
 }