1.GameViewController
let scene = GameScene(size: CGSize(width: 1080, height: 1920))
let skView = self.view as! SKView
scene.scaleMode = .aspectFill
skView.presentScene(scene)
2.GameScene
let background = SKSpriteNode(imageNamed: "background.jpg")
background.position = CGPoint(x: size.width / 2, y: size.height / 2)
addChild(background)
