arkit_session_tracking

arkit_session_tracking.swift

//1
class ViewController: UIViewController, ARSCNViewDelegate {
    lazy var sceneView: ARSCNView = {
        let view = ARSCNView(frame: CGRect.zero)
        view.delegate = self
        return view
    }()
    //2
    lazy var infoLabel: UILabel = {
        let label = UILabel(frame: CGRect.zero)
        label.font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.title1)
        label.textAlignment = .center
        label.backgroundColor = .white
        return label
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(sceneView)
        //3
        view.addSubview(infoLabel)
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        sceneView.frame = view.bounds
        //4
        infoLabel.frame = CGRect(x: 0, y: 16, width: view.bounds.width, height: 64)
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        let configuration = ARWorldTrackingConfiguration()
        sceneView.session.run(configuration, options: [.resetTracking, .removeExistingAnchors])
    }
    
    // MARK: ARSCNViewDelegate
    func session(_ session: ARSession, cameraDidChangeTrackingState camera: ARCamera) {
        //5
        var status = "Loading..."
        switch camera.trackingState {
        case ARCamera.TrackingState.notAvailable:
            status = "Not available"
        case ARCamera.TrackingState.limited(_):
            status = "Analyzing..."
        case ARCamera.TrackingState.normal:
            status = "Ready"
        }
        infoLabel.text = status
    }
}