Bring keyboard and mouse gaming to iPad

4:42 - Keyboard event change handlers

if let keyboard = GCKeyboardDevice.coalesced?.keyboardInput {

  // bind to any key-up/-down
  keyboard.keyChangedHandler = {
    (keyboard, key, keyCode, pressed) in
    // compare buttons to GCKeyCode
  }
  
  // bind to a specific key-up/-down
  keyboard.button(forKeyCode: .spacebar)?.valueChangedHandler = {
    (key, value, pressed) in
    // spacebar was pressed or released
  }

}

5:18 - Polling keyboard state

func pollInput() {
  
  if let keyboard = GCKeyboardDevice.coalesced?.keyboardInput {
	  if (keyboard.button(forKeyCode: .keyW)?.isPressed ?? false) { /* move up    */ }
	  if (keyboard.button(forKeyCode: .keyA)?.isPressed ?? false) { /* move left  */ }
	  if (keyboard.button(forKeyCode: .keyS)?.isPressed ?? false) { /* move down  */ }
	  if (keyboard.button(forKeyCode: .keyD)?.isPressed ?? false) { /* move right */ }
  }
  
}

6:05 - Mouse event change handlers

if let mouse = GCMouse.currentMouse {

   mouse.mouseInput.mouseMovedHandler = {
     (mouse, deltaX, deltaY) in
     // use delta to calculate your game's cursor position or other motion
   }

}

7:27 - Pointer lock

class ViewController: UIViewController {
    
    override var prefersPointerLocked: Bool {
        return true
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()        
        self.setNeedsUpdateOfPrefersPointerLocked()
    }
}

8:07 - Discovery

class ViewController: UIViewController {
  var keyboard: GCKeyboard? = nil
  var mouse: GCMouse? = nil
  
  init() {
    let center = NotificationCenter.defaultCenter
    let main = OperationQueue.mainQueue
        
    center.addObserverForName(GCMouseDidConnectNotification, object: nil, queue: main) {
      (note) in
      self.mouse = note.object as? GCMouse
    }

    center.addObserverForName(GCKeyboardDidConnectNotification, object: nil, queue: main) {
      (note) in
      self.keyboard = note.object as? GCKeyboard // the same as GCKeyboard.coalesced
    }

  }
}

10:56 - Updating Fox 2

var delta: CGPoint = CGPoint.zero

func registerMouse(_ mouseDevice: GCMouse) {
  
  if #available(iOS 14.0, OSX 10.16, *) {
    guard let mouseInput = mouseDevice.mouseInput else {
      return
    }
          
    // set up our mouse value change handlers
    
  }
}

    weak var weakController = self

    mouseInput.mouseMovedHandler = {(mouse, deltaX, deltaY) in
      guard let strongController = weakController else {
        return
      }
                                    
      strongController.delta = CGPoint(x: CGFloat(deltaX), y: CGFloat(deltaY))
                                    
    }
            
    mouseInput.leftButton.valueChangedHandler = {(button, value, pressed) in
      guard let strongController = weakController else {
        return
      }
                                                 
      strongController.controllerAttack()
                                                 
    }
            
    mouseInput.scroll.valueChangedHandler = {(cursor, x, y) in
      guard let strongController = weakController else {
        return
      }          
      guard let camera = strongController.cameraNode.camera else {
        return
      }
                                             
      camera.fieldOfView = CGFloat.maximum(CGFloat.minimum(120,
                                           camera.fieldOfView + CGFloat(y)), 30)

      }
    }

func pollInput() {
  ...
  
  // Mouse
  let mouseSpeed: CGFloat = 0.02
  self.cameraDirection += simd_make_float2(-Float(self.delta.x * mouseSpeed), 
                                            Float(self.delta.y * mouseSpeed))
  self.delta = CGPoint.zero
        
  // Keyboard
  if let keyboard = GCKeyboard.coalesced?.keyboardInput {
    
      if (keyboard.button(forKeyCode: .keyA)?.isPressed ?? false) { self.characterDirection.x = -1.0 }
      if (keyboard.button(forKeyCode: .keyD)?.isPressed ?? false) { self.characterDirection.x = 1.0 }
      if (keyboard.button(forKeyCode: .keyW)?.isPressed ?? false) { self.characterDirection.y = -1.0 }
      if (keyboard.button(forKeyCode: .keyS)?.isPressed ?? false) { self.characterDirection.y = 1.0 }
            
      self.runModifier = (keyboard.button(forKeyCode: .leftShift)?.value ?? 0.0) + 1.0
    
  }
}