ios: karaoke vocals On/Soft/Off (1.0.6)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/Stemify/Playback/PlaybackManager.swift

@@ -19,6 +19,8 @@ enum Stems {
     }
 }
 
+enum KaraokeVocals: Int, CaseIterable { case On, Soft, Off }
+
 /// One stem's fader. [level] is the slider position; 0.8 is unity gain.
 struct StemSetting: Codable, Hashable {
     static let unity: Float = 0.8
@@ -124,7 +126,7 @@ final class PlaybackManager: StemEngineListener, @unchecked Sendable {
     private(set) var message: AppMessage?
     /// Mixes saved for single songs (by rating key), put back whenever that song starts.
     private(set) var songMixes: [String: [String: StemSetting]] = [:]
-    /// Karaoke mode: vocals out on every song, lyrics on Now Playing.
+    /// Karaoke mode: vocals on, soft or out (per settings) on every song, lyrics on Now Playing.
     private(set) var karaoke = false
     @ObservationIgnored private var preKaraokeMix: [String: StemSetting]?
 
@@ -415,11 +417,25 @@ final class PlaybackManager: StemEngineListener, @unchecked Sendable {
 
     /// The mix a song starts with: karaoke if that's on, else the song's saved mix, else cleared (or kept, per settings).
     private func startMix(_ t: Track) -> [String: StemSetting] {
-        if karaoke { return Self.karaokeMix }
+        if karaoke { return karaokeMix }
         return songMixes[t.ratingKey] ?? (settings.keepStemMix ? mix : [:])
     }
 
-    private static let karaokeMix = ["vocals": StemSetting(muted: true)]
+    /// How much of the singer is left in karaoke mode. Soft is about -12 dB, a guide under your own voice.
+    private var karaokeMix: [String: StemSetting] {
+        switch karaokeVocals {
+        case .On: return [:]
+        case .Soft: return ["vocals": StemSetting(level: 0.4)]
+        case .Off: return ["vocals": StemSetting(muted: true)]
+        }
+    }
+
+    var karaokeVocals: KaraokeVocals { KaraokeVocals(rawValue: settings.karaokeVocals) ?? .Off }
+
+    func setKaraokeVocals(_ v: KaraokeVocals) {
+        settings.karaokeVocals = v.rawValue
+        if karaoke { applyMix(karaokeMix) }
+    }
 
     /// Turning it off puts back the song's saved mix, or the one from before, unless the mix was changed meanwhile.
     func setKaraoke(_ on: Bool) {
@@ -427,9 +443,9 @@ final class PlaybackManager: StemEngineListener, @unchecked Sendable {
         karaoke = on
         if on {
             preKaraokeMix = mix
-            applyMix(Self.karaokeMix)
+            applyMix(karaokeMix)
         } else {
-            if MixPresets.normalized(mix) == Self.karaokeMix { applyMix(songMix ?? preKaraokeMix ?? [:]) }
+            if MixPresets.normalized(mix) == karaokeMix { applyMix(songMix ?? preKaraokeMix ?? [:]) }
             preKaraokeMix = nil
             changed()
         }