feat(#23): CoreAudio process tap 駆動のスペクトラムアナライザを実装

.github/workflows/test.yml

@@ -34,6 +34,7 @@ jobs:
           WARNINGS=$(grep "warning:" /tmp/build.log \
             | grep -v ".build/" \
             | grep -v 'swift-syntax.*conflicts with dependency on' \
+            | grep -v 'Conflicting identity for swift-syntax' \
             || true)
           if [ -n "$WARNINGS" ]; then
             echo "::error::Build produced warnings in project sources"

Package.swift

@@ -15,6 +15,7 @@ let package = Package(
         .package(url: "https://github.com/LebJe/TOMLKit", from: "0.6.0"),
         .package(url: "https://github.com/joshuawright11/papyrus", from: "0.6.16"),
         .package(url: "https://github.com/JohnSundell/Files", from: "4.2.0"),
+        .package(url: "https://github.com/apple/swift-atomics", from: "1.2.0"),
     ],
     targets: [
         // ── CLI (Entry Point) ──
@@ -197,21 +198,25 @@ let package = Package(
                 "TrackInteractor",
                 "ScreenInteractor",
                 "WallpaperInteractor",
+                "SpectrumInteractor",
                 "ConfigUseCase",
                 "PlaybackUseCase",
                 "LyricsUseCase",
                 "MetadataUseCase",
                 "WallpaperUseCase",
+                "SpectrumUseCase",
                 "ConfigRepository",
                 "LyricsRepository",
                 "MetadataRepository",
                 "NowPlayingRepository",
                 "WallpaperRepository",
+                "AudioCaptureRepository",
                 "ConfigDataSource",
                 "LyricsDataSource",
                 "MetadataDataSource",
                 "MediaRemoteDataSource",
                 "WallpaperDataSource",
+                "AudioTapDataSource",
                 "SQLiteDataStore",
                 "DarwinGateway",
                 "ProcessHandler",
@@ -248,6 +253,38 @@ let package = Package(
                 .product(name: "Dependencies", package: "swift-dependencies"),
             ]
         ),
+        .target(
+            name: "SpectrumInteractor",
+            dependencies: [
+                "Domain",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+
+        // ── SpectrumUseCase ──
+        .target(
+            name: "SpectrumUseCase",
+            dependencies: [
+                "Domain",
+                "FrequencyAnalyzer",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+
+        // ── AudioCaptureRepository ──
+        .target(
+            name: "AudioCaptureRepository",
+            dependencies: [
+                "Domain",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+
+        // ── FrequencyAnalyzer ──
+        .target(
+            name: "FrequencyAnalyzer",
+            dependencies: []
+        ),
 
         // ── UseCase ──
         .target(
@@ -363,6 +400,13 @@ let package = Package(
                 .product(name: "Files", package: "Files"),
             ]
         ),
+        .target(
+            name: "AudioTapDataSource",
+            dependencies: [
+                "Domain",
+                .product(name: "Atomics", package: "swift-atomics"),
+            ]
+        ),
 
         // ── DataStore ──
         .target(
@@ -423,6 +467,41 @@ let package = Package(
                 .product(name: "Dependencies", package: "swift-dependencies"),
             ]
         ),
+        .testTarget(
+            name: "SpectrumInteractorTests",
+            dependencies: [
+                "SpectrumInteractor",
+                "Domain",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+        .testTarget(
+            name: "SpectrumUseCaseTests",
+            dependencies: [
+                "SpectrumUseCase",
+                "Domain",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+        .testTarget(
+            name: "AudioCaptureRepositoryTests",
+            dependencies: [
+                "AudioCaptureRepository",
+                "Domain",
+                .product(name: "Dependencies", package: "swift-dependencies"),
+            ]
+        ),
+        .testTarget(
+            name: "FrequencyAnalyzerTests",
+            dependencies: ["FrequencyAnalyzer"]
+        ),
+        .testTarget(
+            name: "AudioTapDataSourceTests",
+            dependencies: [
+                "AudioTapDataSource",
+                "Domain",
+            ]
+        ),
         .testTarget(name: "EntityTests", dependencies: ["Entity"]),
         .testTarget(
             name: "AsyncRunnableCommandTests",

README.md

@@ -195,6 +195,26 @@ angle = 15
 | `circle` | — | — | Same as omitting `shape` |
 | `polygon` | `sides` (int `3...256`) | `angle` (degrees, default `0`) | Out-of-range `sides` values fail config decoding. `angle = 0` orients one vertex straight up |
 
+### `[spectrum]`
+
+Real-time spectrum analyzer bars driven by the now-playing app's audio, rendered on the overlay. Disabled by default. Requires **macOS 14.4+** (CoreAudio process tap); on the first run macOS asks for the *System Audio Recording* permission.
+
+| Key | Type | Default | Description |
+|---|---|---|---|
+| `enabled` | boolean | `false` | Set to `true` to show the analyzer |
+| `bar_count` | number | `64` | Number of bars |
+| `bar_color` | string / array | `["#1E3A5F", "#4A9EFF"]` | Solid hex or gradient array |
+| `background_color` | string | — | Optional backdrop behind the bars |
+| `bar_width_ratio` | number | `0.7` | Bar width as a fraction of one bar slot (0–1) |
+| `min_db` | number | `-80` | Loudness floor mapped to bar height 0 |
+| `max_db` | number | `0` | Loudness ceiling mapped to bar height 1 |
+| `decay_rate` | number | `0.85` | Per-frame falloff of bar peaks (0–1) |
+| `fft_size` | number | `1024` | FFT window size (rounded down to a power of two) |
+| `placement` | string | `"bottom"` | `"bottom"`, `"top"`, or `"underlay"` (bars span the whole overlay behind the lyrics) |
+| `height_ratio` | number | `0.25` | Fraction of the overlay height the bars may occupy (ignored for `underlay`) |
+
+> **Known limitation:** the audio is tapped per *process tree* (browsers emit audio from helper subprocesses, so the whole tree must be covered). When the now-playing app is a browser, the tap captures the browser's entire audio output — every tab, not just the one playing music.
+
 ### `[ai]`
 
 Optional LLM-based song title and artist extraction via any OpenAI-compatible API. When omitted, lyra uses regex-based parsing only. All three fields are required to enable this feature.
@@ -363,6 +383,11 @@ color = "#AAAAFFFF"
 radius = 60
 duration = 0.4
 idle = 1.3
+
+[spectrum]
+enabled = true
+bar_color = ["#1E3A5F", "#4A9EFF"]
+placement = "bottom"
 ```
 
 This example uses `Zen Maru Gothic` and `Zen Kaku Gothic New`. If those fonts are not installed, install them with Homebrew Cask:
@@ -382,7 +407,7 @@ api_key = "sk-..."
 
 ## Requirements
 
-- macOS 14+
+- macOS 14+ (spectrum analyzer requires macOS 14.4+)
 - Swift 6.0+
 
 ## License

Sources/AppRouter/AppRouter.swift

@@ -8,13 +8,16 @@ import Views
 @MainActor
 public final class AppRouter {
     private let bootstrap: AppDependencyBootstrap
-    private let windowFactory: @MainActor (ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, WallpaperPresenter) -> any OverlayWindow
+    private let windowFactory:
+        @MainActor (ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, SpectrumPresenter, WallpaperPresenter)
+            -> any OverlayWindow
     private let frameSchedulerFactory: @MainActor (@escaping @MainActor () -> Void) -> any FrameScheduler
     private var appPresenter: AppPresenter?
     private var headerPresenter: HeaderPresenter?
     private var lyricsPresenter: LyricsPresenter?
     private var wallpaperPresenter: WallpaperPresenter?
     private var ripplePresenter: RipplePresenter?
+    private var spectrumPresenter: SpectrumPresenter?
 
     private var appWindow: (any OverlayWindow)?
     private var frameScheduler: (any FrameScheduler)?
@@ -28,12 +31,13 @@ public final class AppRouter {
     public convenience init(launchEnvironment: AppLaunchEnvironment = .current) {
         self.init(
             bootstrap: AppDependencyBootstrap(launchEnvironment: launchEnvironment),
-            windowFactory: { layout, headerPresenter, lyricsPresenter, ripplePresenter, wallpaperPresenter in
+            windowFactory: { layout, headerPresenter, lyricsPresenter, ripplePresenter, spectrumPresenter, wallpaperPresenter in
                 AppWindow(
                     initialLayout: layout,
                     headerPresenter: headerPresenter,
                     lyricsPresenter: lyricsPresenter,
                     ripplePresenter: ripplePresenter,
+                    spectrumPresenter: spectrumPresenter,
                     wallpaperPresenter: wallpaperPresenter
                 )
             },
@@ -44,7 +48,9 @@ public final class AppRouter {
     convenience init(
         launchEnvironment: AppLaunchEnvironment,
         windowFactory:
-            @escaping @MainActor (ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, WallpaperPresenter) -> any OverlayWindow,
+            @escaping @MainActor (
+                ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, SpectrumPresenter, WallpaperPresenter
+            ) -> any OverlayWindow,
         frameSchedulerFactory: @escaping @MainActor (@escaping @MainActor () -> Void) -> any FrameScheduler
     ) {
         self.init(
@@ -57,7 +63,9 @@ public final class AppRouter {
     init(
         bootstrap: AppDependencyBootstrap,
         windowFactory:
-            @escaping @MainActor (ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, WallpaperPresenter) -> any OverlayWindow,
+            @escaping @MainActor (
+                ScreenLayout, HeaderPresenter, LyricsPresenter, RipplePresenter, SpectrumPresenter, WallpaperPresenter
+            ) -> any OverlayWindow,
         frameSchedulerFactory: @escaping @MainActor (@escaping @MainActor () -> Void) -> any FrameScheduler
     ) {
         self.bootstrap = bootstrap
@@ -83,13 +91,17 @@ public final class AppRouter {
             let ripplePresenter = RipplePresenter(
                 screenRect: CGRect(origin: layout.screenOrigin, size: layout.hostingFrame.size))
             self.ripplePresenter = ripplePresenter
+            let spectrumPresenter = SpectrumPresenter()
+            self.spectrumPresenter = spectrumPresenter
 
             headerPresenter.start()
             lyricsPresenter.start()
             ripplePresenter.start()
+            spectrumPresenter.start()
             wallpaperPresenter.start()
 
-            let window = windowFactory(layout, headerPresenter, lyricsPresenter, ripplePresenter, wallpaperPresenter)
+            let window = windowFactory(
+                layout, headerPresenter, lyricsPresenter, ripplePresenter, spectrumPresenter, wallpaperPresenter)
             appWindow = window
             window.show()
 
@@ -105,15 +117,19 @@ public final class AppRouter {
                 window?.applyWallpaperScale(scale)
             }
 
-            let onFrame: @MainActor @Sendable () -> Void =
+            // Only enabled features pay a per-frame cost: each optional
+            // handler is included in the frame fan-out only when its feature
+            // is on, so a disabled ripple/spectrum adds zero work per tick.
+            let frameHandlers: [@MainActor @Sendable () -> Void] = [
                 ripplePresenter.isEnabled
-                ? { @MainActor @Sendable [weak self] in
-                    self?.ripplePresenter?.idle()
-                    self?.lyricsPresenter?.updateActiveLineTick()
-                }
-                : { @MainActor @Sendable [weak self] in
-                    self?.lyricsPresenter?.updateActiveLineTick()
-                }
+                    ? { @MainActor @Sendable [weak self] in self?.ripplePresenter?.idle() } : nil,
+                spectrumPresenter.isEnabled
+                    ? { @MainActor @Sendable [weak self] in self?.spectrumPresenter?.tick() } : nil,
+                { @MainActor @Sendable [weak self] in self?.lyricsPresenter?.updateActiveLineTick() },
+            ].compactMap { $0 }
+            let onFrame: @MainActor @Sendable () -> Void = {
+                for handler in frameHandlers { handler() }
+            }
             let scheduler = frameSchedulerFactory(onFrame)
             self.frameScheduler = scheduler
             scheduler.start(in: window)
@@ -136,6 +152,9 @@ public final class AppRouter {
         ripplePresenter?.stop()
         defer { ripplePresenter = nil }
 
+        spectrumPresenter?.stop()
+        defer { spectrumPresenter = nil }
+
         frameScheduler?.stop()
         defer { frameScheduler = nil }
 

Sources/AudioCaptureRepository/AudioCaptureRepositoryImpl.swift

@@ -0,0 +1,25 @@
+import Dependencies
+import Domain
+
+/// Repository over the CoreAudio process-tap DataSource (#23). Captured
+/// audio has no cache layer, so orchestration is a thin forwarding of the
+/// tap lifecycle and ring-buffer reads.
+public struct AudioCaptureRepositoryImpl: Sendable {
+    @Dependency(\.audioTapDataSource) private var dataSource
+
+    public init() {}
+}
+
+extension AudioCaptureRepositoryImpl: AudioCaptureRepository {
+    public func startCapture(pid: Int) async -> Bool {
+        await dataSource.startTap(pid: pid)
+    }
+
+    public func stopCapture() async {
+        await dataSource.stopTap()
+    }
+
+    public func latestSamples(count: Int) -> [Float] {
+        dataSource.latestSamples(count: count)
+    }
+}