Sample CodeiOS, iPadOS, Mac Catalyst, macOSReviewed 2026-07-21View on Apple Developer

Applying temporal antialiasing and upscaling using MetalFX

At a glance

Item Summary
Purpose Reduce render workloads while increasing image detail with MetalFX.
App architecture A C/Objective-C header, Metal, Swift sample with the source-visible chain AAPLAppDelegateAAPLViewControllerAAPLRendererMetal APIs.
Main patterns View-controller organization, Delegate or data-source callbacks
Project style 10 scanned source file(s) across C/Objective-C header, Metal, Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── Application/
│   ├── iOS/
│   │   ├── AAPLAppDelegate.swift
│   │   ├── AAPLViewController.swift
│   │   └── Base.lproj/
│   │       ├── LaunchScreen.storyboard
│   │       └── Main.storyboard
│   └── macOS/
│       ├── AAPLAppDelegate.swift
│       └── AAPLViewController.swift
└── Renderer/
    ├── AAPLRenderer.swift
    ├── AAPLRenderTarget.swift
    ├── AAPLRendererHelper.swift
    ├── Shaders.metal
    ├── AAPLMathUtilities.swift
    └── ShaderTypes.h

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 8 project/configuration file(s) and 9 source declaration(s).

Overall architecture

Reference code

Application/iOS/AAPLAppDelegate.swift:10 — architecture anchor

@main
class AAPLAppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}

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 MetalFX.

Ownership and state

Ownership evidence

Application/iOS/AAPLAppDelegate.swift:13 — stored dependency or nearest verified ownership anchor

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        /// The override point for customization after app launch.
        return true
    }
Owner Object or state Relationship Mutation authority
AAPLAppDelegate UIWindow (window) stores or receives App/module collaborators
AAPLRenderer Bool (animationEnabled) owns value state App/module collaborators
AAPLRenderer Bool (resetHistoryEnabled) owns value state App/module collaborators
AAPLRenderer Bool (firstFrameTemporal) 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.

Class and protocol design

Application/iOS/AAPLAppDelegate.swift:11 — representative type boundary

class AAPLAppDelegate: UIResponder, UIApplicationDelegate {
    // ...
}
Type Responsibility Depends on or conforms to
AAPLAppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
AAPLAppDelegate Receives callback-driven events NSObject, NSApplicationDelegate
AAPLRenderer Owns drawing, GPU, or presentation processing NSObject, MTKViewDelegate
AAPLViewController View lifecycle, callbacks, and feature coordination UIViewController
AAPLViewController View lifecycle, callbacks, and feature coordination NSViewController
AAPLScalingMode Defines a closed set of feature states or choices Int
AAPLRenderTarget Owns feature behavior and collaborator lifecycle Concrete collaborators/imported frameworks
AAPLRendererHelper Owns feature behavior and collaborator lifecycle Concrete collaborators/imported frameworks
AAPLVertexV4T2 Represents a feature value or composable behavior Concrete collaborators/imported frameworks

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
renderScale (Renderer/AAPLRenderTarget.swift:22) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
animationEnabled (Renderer/AAPLRenderer.swift:21) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
resetHistoryEnabled (Renderer/AAPLRenderer.swift:22) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
firstFrameTemporal (Renderer/AAPLRenderer.swift:23) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.

Reference code

Renderer/AAPLRenderTarget.swift:22 — representative boundary

    public var renderScale: Float = 0.5

    init(mtlDevice: MTLDevice) {
        device = mtlDevice
    }

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

Logic Owning type or file Placement rationale
View lifecycle, callbacks, and feature coordination AAPLViewController The source’s Controller suffix makes this role explicit.
Receives callback-driven events AAPLAppDelegate The source’s Delegate suffix makes this role explicit.
Owns drawing, GPU, or presentation processing AAPLRenderer The source’s Renderer suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
View-controller organization Application/iOS/AAPLViewController.swift:12 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Delegate or data-source callbacks Application/iOS/AAPLAppDelegate.swift:11 Callback protocols invert event delivery back into the sample’s owner.

Naming conventions

  • Types: Controller: AAPLViewController; Delegate: AAPLAppDelegate; Renderer: AAPLRenderer.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: application, applicationWillResignActive, applicationDidEnterBackground, applicationWillEnterForeground, applicationDidBecomeActive, applicationDidFinishLaunching, applicationWillTerminate, applicationShouldTerminateAfterLastWindowClosed.
  • Files: Application/iOS/AAPLAppDelegate.swift, Application/macOS/AAPLAppDelegate.swift, Renderer/AAPLRenderer.swift, Application/iOS/AAPLViewController.swift, Application/macOS/AAPLViewController.swift, Renderer/AAPLRenderTarget.swift.

Architecture takeaways

  • AAPLAppDelegate is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches MetalKit, simd, Cocoa, Metal 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
Application/iOS/AAPLAppDelegate.swift AAPLAppDelegate
Application/macOS/AAPLAppDelegate.swift AAPLAppDelegate
Renderer/AAPLRenderer.swift AAPLScalingMode, AAPLRenderer
Application/iOS/AAPLViewController.swift AAPLViewController
Application/macOS/AAPLViewController.swift AAPLViewController
Renderer/AAPLRenderTarget.swift AAPLRenderTarget
Renderer/AAPLRendererHelper.swift AAPLRendererHelper
Renderer/Shaders.metal AAPLVertexV4T2
Renderer/AAPLMathUtilities.swift Feature implementation
Renderer/ShaderTypes.h Feature implementation