Creating a Spaceship game
At a glance
| Item | Summary |
|---|---|
| Purpose | Build an immersive game using RealityKit audio, simulation, and rendering features. |
| App architecture | A C/Objective-C header, Objective-C++, Swift sample with the source-visible chain SpaceshipApp → MenuView → HangarViewModel → ClosureSystem → RealityKit APIs. |
| Main patterns | Model-View-ViewModel |
| Project style | 57 scanned source file(s) across C/Objective-C header, Objective-C++, Swift, organized around ranked entry, type, and file boundaries. |
| Execution model | Source-visible boundaries: async declaration or closure, @MainActor, Task closure isolated to MainActor, Task; none alone proves a background thread. |
| State/event model | Source-visible mechanisms: @Observable, SwiftUI state property wrapper. |
| Key frameworks/packages | RealityKit, SwiftUI, QuartzCore, CoreAudio, Foundation; these are source dependencies, not architecture labels. |
Project structure
Source bundle/
└── Spaceship/
├── SpaceshipApp.swift
├── ECS/
│ ├── SpaceshipControl/
│ │ └── HandsShipControlProvider.swift
│ └── SpaceshipBehavior/
│ └── ShipFlight.swift
├── ViewModels/
│ ├── HangarViewModel.swift
│ └── ImmersiveViewModel.swift
├── Views/
│ ├── HangarView.swift
│ ├── ShipControlView.swift
│ ├── FlightSchoolView.swift
│ ├── MenuView.swift
│ ├── AudioMixerView.swift
│ └── ImmersiveView.swift
└── AppModel.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, Objective-C++, Swift.
- The verified tree contains 4 project/configuration file(s) and 72 source declaration(s).
Overall architecture
flowchart LR
N1["SpaceshipApp"]
N2["MenuView"]
N3["HangarViewModel"]
N4["ClosureSystem"]
N5["RealityKit APIs"]
N1 --> N2
N2 --> N3
N3 --> N4
N4 --> N5
Reference code
Spaceship/SpaceshipApp.swift:11 — architecture anchor
@main
struct SpaceshipApp: App {
// ...
@State 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 RealityKit.
Ownership and state
classDiagram
SpaceshipApp *-- AppModel : appModel
SpaceshipApp *-- Bool : isMenuExpanded
HandTrackingComponent o-- Location : location
HandsShipControlProviderSystem *-- Array : dependencies
Ownership evidence
Spaceship/SpaceshipApp.swift:14 — stored dependency or nearest verified ownership anchor
@main
struct SpaceshipApp: App {
// ...
@State var appModel = AppModel()
// ...
}| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
SpaceshipApp |
AppModel (appModel) |
owns wrapper-managed state | App/module collaborators |
SpaceshipApp |
Bool (isMenuExpanded) |
owns wrapper-managed state | App/module collaborators |
HandTrackingComponent |
Location (location) |
stores or receives | Initialized by the owner; the binding is immutable |
HandsShipControlProviderSystem |
Array (dependencies) |
owns value state | App/module collaborators |
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.
| Concern | Source mechanism | Verified placement or handoff | Evidence |
|---|---|---|---|
| Suspension boundary | async declaration or closure |
The source declares or crosses an asynchronous boundary; it does not by itself establish background execution. | Spaceship/ECS/Entity+Planet.swift:63 |
| Main isolation | @MainActor |
The cited annotation marks its attached declaration or closure as main-actor isolated. | Spaceship/ECS/SpaceshipControl/HandsShipControlProvider.swift:57 |
| Main isolation | Task closure isolated to MainActor |
The cited operation explicitly enters a main-actor-isolated region. | Spaceship/ECS/SpaceshipControl/HandsShipControlProvider.swift:57 |
| Task creation | Task |
The source creates an unstructured task; surrounding context determines inherited actor isolation. | Spaceship/ECS/SpaceshipControl/HandsShipControlProvider.swift:57 |
@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
Spaceship/ECS/Entity+Planet.swift:63 — representative execution boundary
static func makePlanet(radius: Float = 0.25) async throws -> Entity {
// ...
let planet = try await Entity(named: PlanetNames.resource, in: realityKitContentBundle)
// ...
}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.
| Category | Mechanism or module | Verified role | Evidence |
|---|---|---|---|
| State propagation | @Observable |
Observation macro publishes source-visible changes. | Spaceship/AppModel.swift:11 |
| State propagation | SwiftUI state property wrapper |
A SwiftUI property wrapper supplies or observes UI state. | Spaceship/SpaceshipApp.swift:14 |
| Source import | RealityKit |
The cited file imports this module; runtime use and architectural role are not inferred. | Spaceship/AppModel.swift:9 |
| Source import | SwiftUI |
The cited file imports this module; runtime use and architectural role are not inferred. | Spaceship/AppModel.swift:8 |
| Source import | QuartzCore |
The cited file imports this module; runtime use and architectural role are not inferred. | Spaceship/ECS/Entity+Planet.swift:9 |
| Source import | CoreAudio |
The cited file imports this module; runtime use and architectural role are not inferred. | Spaceship/ECS/SpaceshipBehavior/ShipAudio.swift:8 |
| Source import | Foundation |
The cited file imports this module; runtime use and architectural role are not inferred. | Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:8 |
| Source import | RealityKitContent |
The cited file imports this module; runtime use and architectural role are not inferred. | Spaceship/ECS/Entity+Planet.swift:11 |
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
Spaceship/SpaceshipApp.swift:12 — representative type boundary
@main
struct SpaceshipApp: App {
// ...
@State var appModel = AppModel()
// ...
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
SpaceshipApp |
Application entry and top-level composition | App |
HandTrackingComponent |
Stores entity-component data or behavior | Component |
ThrottleLabelPlacementComponent |
Stores entity-component data or behavior | Component |
PitchRollLabelPlacementComponent |
Stores entity-component data or behavior | Component |
HandsShipControlProviderSystem |
Runs entity-component-system update logic | System |
HangarViewModel |
UI-facing state and feature coordination | Concrete collaborators/imported frameworks |
ImmersiveViewModel |
UI-facing state and feature coordination | Concrete collaborators/imported frameworks |
HangarView |
User-interface presentation and input forwarding | View |
SpaceshipView |
User-interface presentation and input forwarding | View, Animatable |
ThrottleControlView |
User-interface presentation and input forwarding | View |
No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.
Access control
| Symbol | Access | Verified effect | Likely rationale |
|---|---|---|---|
realityKitContentBundle (Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:11) |
public |
The symbol is visible to importing modules. | Inference: make the declaration available across a module or target boundary. |
studioBundle (Packages/Studio/Sources/Studio/Studio.swift:11) |
public |
The symbol is visible to importing modules. | Inference: make the declaration available across a module or target boundary. |
throttle (Spaceship/AudioUnitTurbine/AudioUnitTurbine.h:26) |
header-visible |
The declaration is exposed to translation units that import the header. | Inference: declare a contract needed by other Objective-C/C translation units. |
carrierFrequencyMin (Spaceship/AudioUnitTurbine/AudioUnitTurbine.h:27) |
header-visible |
The declaration is exposed to translation units that import the header. | Inference: declare a contract needed by other Objective-C/C translation units. |
Reference code
Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:11 — representative boundary
public let realityKitContentBundle = Bundle.moduleSwift 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
| Logic | Owning type or file | Placement rationale |
|---|---|---|
| Application entry and top-level composition | SpaceshipApp |
The source’s App suffix makes this role explicit. |
| Stores entity-component data or behavior | AsteroidComponent, AudioMaterialComponent, AudioMaterialLookupComponent, CargoComponent |
The source’s Component suffix makes this role explicit. |
| Feature data or observable state | AppModel |
The source’s Model suffix makes this role explicit. |
| Runs entity-component-system update logic | ClosureSystem, EnvironmentLightingFadeSystem, HandsShipControlProviderSystem, PlanetVisualsSystem |
The source’s System suffix makes this role explicit. |
| User-interface presentation and input forwarding | AudioMixerView, FlightSchoolView, HangarView, ImmersiveView |
The source’s View suffix makes this role explicit. |
| UI-facing state and feature coordination | HangarViewModel, ImmersiveViewModel |
The source’s ViewModel suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| Model-View-ViewModel | Spaceship/ViewModels/HangarViewModel.swift:14 |
Role-named view models keep UI-facing state or coordination outside view declarations. |
Main application flow
sequenceDiagram
participant ImmersiveViewModel
participant sceneReconstruction
participant immersiveEnvironment
ImmersiveViewModel->>sceneReconstruction: start()
ImmersiveViewModel->>immersiveEnvironment: enterStudio()
ImmersiveViewModel->>immersiveEnvironment: enterOuterSpace()
ImmersiveViewModel->>immersiveEnvironment: exitStudio()
ImmersiveViewModel->>immersiveEnvironment: enterOuterSpace()
ImmersiveViewModel->>immersiveEnvironment: exitStudio()
ImmersiveViewModel->>immersiveEnvironment: exitOuterSpace()
ImmersiveViewModel->>immersiveEnvironment: exitOuterSpace()
Reference code
Spaceship/ViewModels/ImmersiveViewModel+Surroundings.swift:37 — transitionSurroundings()
func transitionSurroundings(from previous: Surroundings, to current: Surroundings) async throws {
#if os(visionOS)
if current == .passthrough {
try await sceneReconstruction.start()
rootEntity.addChild(sceneReconstruction.entity)
} else {
sceneReconstruction.entity.removeFromParent()
sceneReconstruction.stop()
}
#endif
switch (previous, current) {
case (.passthrough, .passthrough):
break
case (.passthrough, .studio), (.studio, .studio), (.deepSpace, .studio):
try await immersiveEnvironment.enterStudio()
case (.passthrough, .outerSpace), (.outerSpace, .outerSpace), (.deepSpace, .outerSpace):
try await immersiveEnvironment.enterOuterSpace()
case (.passthrough, .deepSpace):
break
case (.studio, .passthrough), (.studio, .deepSpace):
try await immersiveEnvironment.exitStudio()
case (.studio, .outerSpace):
try await immersiveEnvironment.enterOuterSpace()
try await immersiveEnvironment.exitStudio()
case (.outerSpace, .passthrough), (.outerSpace, .deepSpace):
try await immersiveEnvironment.exitOuterSpace()
case (.outerSpace, .studio):
try await immersiveEnvironment.enterStudio()
try await immersiveEnvironment.exitOuterSpace()
case (.deepSpace, .deepSpace), (.deepSpace, .passthrough):
break
}
}Naming conventions
- Types: App: SpaceshipApp; Component: AsteroidComponent, AudioMaterialComponent, AudioMaterialLookupComponent, CargoComponent, ClosureComponent; Model: AppModel; System: ClosureSystem, EnvironmentLightingFadeSystem, HandsShipControlProviderSystem, PlanetVisualsSystem, ShipAudioSystem; View: AudioMixerView, FlightSchoolView, HangarView, ImmersiveView, MenuView; ViewModel: HangarViewModel, ImmersiveViewModel.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
computeTransformWith,update,updateShipControlParameters,interpolateThrottle,computeTargetThrottle,computePitchAndRoll,interpolate,makeHandTrackingEntities. - Files:
Spaceship/SpaceshipApp.swift,Spaceship/ViewModels/HangarViewModel.swift,Spaceship/ViewModels/ImmersiveViewModel.swift,Spaceship/Views/HangarView.swift,Spaceship/Views/ShipControlView.swift,Spaceship/AppModel.swift.
Architecture takeaways
SpaceshipAppis the main source-visible entry or composition anchor for this sample.- Framework work reaches RealityKit, SwiftUI, QuartzCore, CoreAudio 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
| Source file | Relevant symbols |
|---|---|
Spaceship/SpaceshipApp.swift |
Cited implementation, SpaceshipApp, SwiftUI state property wrapper |
Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift |
Cited implementation, Foundation, Feature implementation |
Packages/Studio/Sources/Studio/Studio.swift |
Cited implementation, Feature implementation |
Spaceship/AudioUnitTurbine/AudioUnitTurbine.h |
throttle, carrierFrequencyMin, AudioUnitTurbine |
Spaceship/ViewModels/HangarViewModel.swift |
HangarViewModel |
Spaceship/ECS/Entity+Planet.swift |
async declaration or closure, QuartzCore, RealityKitContent, PlanetNames, PlanetVisualsComponent, PlanetVisualsSystem |
Spaceship/ECS/SpaceshipControl/HandsShipControlProvider.swift |
@MainActor, Task closure isolated to MainActor, Task, HandTrackingComponent, Location, ThrottleLabelPlacementComponent, PitchRollLabelPlacementComponent, HandsShipControlProviderSystem |
Spaceship/AppModel.swift |
@Observable, RealityKit, SwiftUI, AppModel, GamePhase |
Spaceship/ECS/SpaceshipBehavior/ShipAudio.swift |
CoreAudio, ShipAudioSystem, TurbineAudioComponent, ShipAudioComponent |
Spaceship/ViewModels/ImmersiveViewModel.swift |
ImmersiveViewModel |
Spaceship/Views/HangarView.swift |
HangarView, SpaceshipView, DragRotationModifier |
Spaceship/Views/ShipControlView.swift |
ThrottleControlView, PitchRollControlView, ShipControlView |
Spaceship/Views/FlightSchoolView.swift |
FlightSchoolView, FlightSchoolLabelModifier |
Spaceship/Views/MenuView.swift |
MenuView, FlyReturnToggleStyle |
Spaceship/ECS/SpaceshipBehavior/ShipFlight.swift |
ShipFlightComponent, ShipFlightSystem, ShipFlightStateComponent, PrimaryThrustComponent |
Spaceship/Views/AudioMixerView.swift |
AudioMixerView |
Spaceship/ViewModels/ImmersiveViewModel+Surroundings.swift |
transitionSurroundings |