Interacting with virtual content blended with passthrough

At a glance

Project structure

Source bundle/
└── Compositor-Services-Interaction/
    ├── Compositor_Services_InteractionApp.swift
    ├── Renderer.swift
    ├── TintRenderer.swift
    ├── AppModel.swift
    ├── InteractionView.swift
    ├── PathCollection.swift
    ├── ImmersiveInteractionScene.swift
    ├── Bridging-Header.h
    ├── PathProperties.h
    ├── ShaderTypes.h
    ├── Shaders.metal
    └── Uniforms.swift

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: C/Objective-C header, Metal, Swift.
• The verified tree contains 4 project/configuration file(s) and 20 source declaration(s).

Overall architecture

flowchart LR
    N1["Compositor_Services_InteractionApp"]
    N2["InteractionView"]
    N3["AppModel"]
    N4["Renderer"]
    N5["CompositorServices APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4
    N4 --> N5

Reference code

Compositor-Services-Interaction/Compositor_Services_InteractionApp.swift:26 — architecture anchor

@main
struct InteractionApp: App {
    // ...
    @State private var appModel = AppModel()
    // ...
}

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 Compositor Services.

Ownership and state

classDiagram
    InteractionApp *-- AppModel : appModel
    RendererActor *-- RendererActor : shared
    Renderer o-- AppModel : appModel
    Renderer o-- PathCollection : pathCollection

Ownership evidence

Compositor-Services-Interaction/Compositor_Services_InteractionApp.swift:29 — stored dependency or nearest verified ownership anchor

@main
struct InteractionApp: App {
    // ...
    @State private var appModel = AppModel()
    // ...
}

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

Compositor-Services-Interaction/Compositor_Services_InteractionApp.swift:47 — representative execution boundary

                    Task { @MainActor in
                        // ...
                            case .opened:
                        // ...
                    }

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

Compositor-Services-Interaction/PathCollection.swift:16 — representative type boundary

@MainActor
private protocol Path {
    var id: PathID { get }
    var buffer: MTLBuffer { get }
    var vertexCount: Int { get }
    var parameters: PathProperties { get set }
}

The source explicitly defines local protocol relationships: CompletePath → Path, ActivePath → Path.

Access control

Reference code

Compositor-Services-Interaction/AppModel.swift:14 — representative boundary

@Observable
public class AppModel {
    // ...
    public var isFirstLaunch = true
    // ...
}

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: InteractionApp; Command: DrawCommand, PathCollectionDrawCommand, PathDrawCommand, TintDrawCommand; Model: AppModel; Renderer: Renderer, TintRenderer; Scene: ImmersiveInteractionScene; View: InteractionView.
• Protocols: Path.
• Methods: makeConfiguration, defaultRenderPipelineDescriptor, memorylessTexture, getMultisampleRenderTarget, renderLoop, renderPassDescriptor, renderFrame, buildMetalVertexDescriptor.
• Files: Compositor-Services-Interaction/Renderer.swift, Compositor-Services-Interaction/TintRenderer.swift, Compositor-Services-Interaction/AppModel.swift, Compositor-Services-Interaction/InteractionView.swift, Compositor-Services-Interaction/PathCollection.swift, Compositor-Services-Interaction/ImmersiveInteractionScene.swift.

Architecture takeaways

• Compositor_Services_InteractionApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches CompositorServices, SwiftUI, simd, MetalKit 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.
• Local protocol relationships provide an explicit substitution boundary.

Source map

• Official Apple documentation