Tracking accessories in volumetric windows

At a glance

Project structure

Source bundle/
└── TrackingAccessories/
    ├── TrackingAccessoriesApp.swift
    ├── Models/
    │   ├── SpatialController.swift
    │   ├── AccessoryTrackingModel.swift
    │   └── ThrowSpeedTracker.swift
    ├── Views/
    │   ├── AccessoryTrackingView.swift
    │   ├── AppStateView.swift
    │   └── GameStateView.swift
    └── Entities/
        ├── Arrow3D.swift
        ├── Ball.swift
        ├── Can.swift
        ├── CanStack.swift
        └── Crate.swift

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Swift.
• The verified tree contains 4 project/configuration file(s) and 18 source declaration(s).

Overall architecture

flowchart LR
    N1["TrackingAccessoriesApp"]
    N2["AccessoryTrackingView"]
    N3["AccessoryTrackingModel"]
    N4["ThrowSpeedTracker"]
    N5["ARKit APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4
    N4 --> N5

Reference code

TrackingAccessories/TrackingAccessoriesApp.swift:12 — architecture anchor

@main
struct TrackingAccessoriesApp: App {
    var body: some SwiftUI.Scene {
        WindowGroup {
            AccessoryTrackingView()
        }
        .windowStyle(.volumetric)
    }
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into ARKit.

Ownership and state

classDiagram
    SpatialController o-- AccessoryAnchor : anchor
    SpatialController *-- Throw : pendingThrow
    SpatialController o-- Throw : triggeredThrow
    SpatialController *-- Shake : pendingShake

Ownership evidence

TrackingAccessories/Models/SpatialController.swift:13 — stored dependency or nearest verified ownership anchor

    var anchor: AccessoryAnchor? = nil
    
    /// Returns `true` if the controller is connected and you're tracking both the position and the orientation.
    var isTracked: Bool {
        anchor?.trackingState == .positionOrientationTracked ? true : false
    }

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Class and protocol design

TrackingAccessories/TrackingAccessoriesApp.swift:13 — representative type boundary

struct TrackingAccessoriesApp: App {
    // ...
}

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

TrackingAccessories/Entities/CanStack.swift:10 — representative boundary

private let verticalSpacing: Float = 0.18

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: App: TrackingAccessoriesApp; Controller: SpatialController; Model: AccessoryTrackingModel; Tracker: ThrowSpeedTracker; View: AccessoryTrackingView, AppStateView, GameStateView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: ballThrown, setCanIsToppled, stopTracking, controller, actOnThrow, actOnShake, trackAllConnectedSpatialControllers, process.
• Files: TrackingAccessories/TrackingAccessoriesApp.swift, TrackingAccessories/Models/SpatialController.swift, TrackingAccessories/Models/AccessoryTrackingModel.swift, TrackingAccessories/Models/ThrowSpeedTracker.swift, TrackingAccessories/Views/AccessoryTrackingView.swift, TrackingAccessories/Views/AppStateView.swift.

Architecture takeaways

• TrackingAccessoriesApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches RealityKit, ARKit, SwiftUI, GameController through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation