Tracking specific points in world space

At a glance

Project structure

Source bundle/
└── ObjectPlacement/
    ├── ObjectPlacementApp.swift
    ├── Views/
    │   ├── ObjectPlacementRealityView.swift
    │   ├── HomeView.swift
    │   ├── ObjectPlacementMenuView.swift
    │   ├── ObjectSelectionView.swift
    │   └── TooltipView.swift
    ├── App/
    │   ├── PlaceableObject.swift
    │   ├── PlacementManager.swift
    │   └── AppState.swift
    └── Utilities/
        ├── ModelLoader.swift
        ├── PersistenceManager.swift
        └── PlaneAnchorHandler.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 23 source declaration(s).

Overall architecture

flowchart LR
    N1["ObjectPlacementApp"]
    N2["HomeView"]
    N3["PersistenceManager"]
    N4["ModelLoader"]
    N5["RealityKit / SwiftUI APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4
    N4 --> N5

Reference code

ObjectPlacement/ObjectPlacementApp.swift:14 — architecture anchor

@main
@MainActor
struct ObjectPlacementApp: App {
    @State private var appState = AppState()
    // ...
}

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 visionOS.

Ownership and state

classDiagram
    ObjectPlacementApp *-- AppState : appState
    ObjectPlacementApp *-- ModelLoader : modelLoader
    ObjectPlacementRealityView o-- AppState : appState
    ObjectPlacementRealityView *-- PlacementManager : placementManager

Ownership evidence

ObjectPlacement/ObjectPlacementApp.swift:17 — stored dependency or nearest verified ownership anchor

@main
@MainActor
struct ObjectPlacementApp: App {
    @State private var appState = AppState()
    // ...
}

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.

Concurrency, scheduling, and thread safety

Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.

@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.

Reference code

ObjectPlacement/App/AppState.swift:13 — representative execution boundary

@Observable
@MainActor
class AppState {
    var immersiveSpaceOpened: Bool { placementManager != nil }
    // ...
}

State propagation, frameworks, and dependencies

Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.

receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.

Class and protocol design

ObjectPlacement/ObjectPlacementApp.swift:16 — representative type boundary

@main
@MainActor
struct ObjectPlacementApp: App {
    @State private var appState = AppState()
    // ...
}

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

Access control

Reference code

ObjectPlacement/App/AppState.swift:16 — representative boundary

@Observable
@MainActor
class AppState {
    // ...
    private(set) weak var placementManager: PlacementManager? = nil
    // ...
}

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: ObjectPlacementApp; Handler: PlaneAnchorHandler; Loader: ModelLoader; Manager: PersistenceManager, PlacementManager; View: HomeView, ObjectPlacementMenuView, ObjectPlacementRealityView, ObjectSelectionView, TooltipView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: materialize, matchesCollisionEvent, attachPreviewEntity, applyMaterial, look, saveWorldAnchorsObjectsMapToDisk, addPlacementTooltip, removeHighlightedObject.
• Files: ObjectPlacement/ObjectPlacementApp.swift, ObjectPlacement/Views/ObjectPlacementRealityView.swift, ObjectPlacement/App/PlaceableObject.swift, ObjectPlacement/App/PlacementManager.swift, ObjectPlacement/Utilities/ModelLoader.swift, ObjectPlacement/Utilities/PersistenceManager.swift.

Architecture takeaways

• ObjectPlacementApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches RealityKit, SwiftUI, ARKit, UIKit 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