问SpriteKit -为SKShapeNode形状路径设置动画

EN

class ViewController: UIViewController {


@IBOutlet weak var skview: SKView!
var  path1: CGPath!
var  path2: CGPath!

override func viewDidLoad() {
    super.viewDidLoad()

  path1  = CGPath.init(rect: CGRect.init(x: 0, y: 0, width: 100, height: 100), transform: nil)

    path2 = CGPath.init(rect: CGRect.init(x: 0, y: 0, width: 250, height: 400), transform: nil)

}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    let shapeLayer = CAShapeLayer()
    self.view.layer.addSublayer(shapeLayer)
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.path = path1

    let anim = CABasicAnimation.init(keyPath: "path")
    anim.duration = 1.0
    anim.fromValue  = path1
    anim.toValue = path2
    anim.isRemovedOnCompletion  = false


    let shapeNode = SKShapeNode.init(path: path1)
    shapeNode.fillColor = UIColor.green

    skview.scene?.addChild(shapeNode)


    shapeLayer.add(anim, forKey:
    "prepanimation")
    shapeNode.run(SKAction.customAction(withDuration: anim.duration, actionBlock: { (node, timeDuration) in
        (node as! SKShapeNode).path =
        shapeLayer.presentation()?.path
    }))

}
}