// MARK: - Lifecycle
extension ViewController {
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        setupAR()
        setupML()
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        sceneView.session.pause()
    }
}

// MARK: - Setup
extension ViewController {
    private func setupAR() {

        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(tapped))
        sceneView.addGestureRecognizer(tapGestureRecognizer)

        let configuration = ARWorldTrackingConfiguration()
        sceneView.session.run(configuration)
    }

    private func setupML() {
        guard let selectedModel = try? VNCoreMLModel(for: example_5s0_hand_model().model) else {
            fatalError("Could not load model.")
        }

        let classificationRequest = VNCoreMLRequest(model: selectedModel,
                                                    completionHandler: classificationCompleteHandler)
        classificationRequest.imageCropAndScaleOption = VNImageCropAndScaleOption.centerCrop
        visionRequests = [classificationRequest]

        loopCoreMLUpdate()
    }
}