Creating visual effects with SwiftUI

At a glance

Project structure

Source bundle/
├── CreateVisualEffectsDemo/
│   ├── CreateVisualEffectsDemo/
│   │   ├── CreateVisualEffectsDemoApp.swift
│   │   ├── Ripple.swift
│   │   ├── ScrollTransitions.swift
│   │   ├── TextTransition.swift
│   │   ├── CustomTransition.swift
│   │   ├── MeshGradient.swift
│   │   ├── Ripple.metal
│   │   ├── Stripes.metal
│   │   ├── Stripes.swift
│   │   └── VisualEffects.swift
│   └── CreateVisualEffectsDemo.xcodeproj/
│       └── .xcodesamplecode.plist
└── Configuration/
    └── SampleCode.xcconfig

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Metal, Swift.
• The verified tree contains 3 project/configuration file(s) and 15 source declaration(s).

Overall architecture

flowchart LR
    N1["CreateVisualEffectsDemoApp"]
    N2["AppearanceEffectRenderer"]
    N3["Coordinator"]
    N4["SwiftUI APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

CreateVisualEffectsDemo/CreateVisualEffectsDemo/CreateVisualEffectsDemoApp.swift:10 — architecture anchor

@main
struct CreateVisualEffectsDemoApp: App {
    var body: some Scene {
        WindowGroup {
            Text("You'll find the examples in the Xcode project's previews.")
                .foregroundStyle(.secondary)
                .multilineTextAlignment(.center)
        }
    }
}

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 SwiftUI.

Ownership and state

classDiagram
    Ripple *-- Int : counter
    Ripple *-- CGPoint : origin
    Ripple *-- TimeInterval : time
    Ripple *-- TimeInterval : amplitude

Ownership evidence

CreateVisualEffectsDemo/CreateVisualEffectsDemo/Ripple.swift:11 — stored dependency or nearest verified ownership anchor

    @Previewable @State var counter: Int = 0

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.

No source-visible execution, scheduling, or synchronization boundary was found in the indexed source.

@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.

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

CreateVisualEffectsDemo/CreateVisualEffectsDemo/CreateVisualEffectsDemoApp.swift:11 — representative type boundary

@main
struct CreateVisualEffectsDemoApp: App {
    // ...
            Text("You'll find the examples in the Xcode project's previews.")
    // ...
}

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

Access control

Reference code

CreateVisualEffectsDemo/CreateVisualEffectsDemo/CreateVisualEffectsDemoApp.swift:11 — representative boundary

@main
struct CreateVisualEffectsDemoApp: App {
    // ...
            Text("You'll find the examples in the Xcode project's previews.")
    // ...
}

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: CreateVisualEffectsDemoApp; Coordinator: Coordinator; Renderer: AppearanceEffectRenderer.
• Protocols: no local protocol declaration in the scanned source.
• Methods: body, onPressingChanged, gestureRecognizer, makeCoordinator, makeUIGestureRecognizer, handleUIGestureRecognizerAction, draw, elementDelay.
• Files: CreateVisualEffectsDemo/CreateVisualEffectsDemo/CreateVisualEffectsDemoApp.swift, CreateVisualEffectsDemo/CreateVisualEffectsDemo/TextTransition.swift.

Architecture takeaways

• CreateVisualEffectsDemoApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, metal_stdlib 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