feat: add metronome feature

OpenUtau.Core/PlaybackManager.cs

@@ -90,7 +90,7 @@ public class ToneGenerator : ISignalSource {
 
         private readonly object _lockObj = new object();
 
-        public ToneGenerator() {}
+        public ToneGenerator() { }
 
         public ToneGenerator(float gain) {
             this.gain = gain;
@@ -166,6 +166,134 @@ private void CleanupTones() {
         }
     }
 
+    public class MetronomeGenerator : ISignalSource {
+        private const int SampleRate = 44100;
+
+        private TimeAxis? timeAxis;
+        private int startTick;
+
+        public bool Enabled { get; set; }
+
+        public MetronomeGenerator() {
+        }
+
+        public void SetProject(UProject project, int startTick) {
+            timeAxis = project.timeAxis;
+            this.startTick = startTick;
+        }
+
+        public bool IsReady(int position, int count) => true;
+
+        public int Mix(int position, float[] buffer, int offset, int count) {
+            if (!Enabled || timeAxis == null) {
+                return position + count;
+            }
+
+            double startFrame = position / 2.0;
+            double endFrame = (position + count) / 2.0;
+
+            double startProjectMs =
+                timeAxis.TickPosToMsPos(startTick)
+                + startFrame * 1000.0 / SampleRate;
+
+            double endProjectMs =
+                timeAxis.TickPosToMsPos(startTick)
+                + endFrame * 1000.0 / SampleRate;
+
+            const double clickLengthMs = 50.0;
+            double searchStartMs = Math.Max(0, startProjectMs - clickLengthMs);
+            double searchStartTickExact = timeAxis.MsPosToNonExactTickPos(searchStartMs);
+            double endTickExact = timeAxis.MsPosToNonExactTickPos(endProjectMs);
+
+            int currentTick = (int)Math.Floor(searchStartTickExact);
+
+            timeAxis.TickPosToBarBeat(
+                currentTick,
+                out int bar,
+                out int beat,
+                out _);
+
+            int clickTick = timeAxis.BarBeatToTickPos(bar, beat);
+
+            if (clickTick < currentTick) {
+                timeAxis.NextBarBeat(
+                    bar,
+                    beat,
+                    out bar,
+                    out beat);
+
+                clickTick = timeAxis.BarBeatToTickPos(bar, beat);
+            }
+
+            int clickLengthSamples = (int)(SampleRate * clickLengthMs / 1000.0);
+
+            while (clickTick < endTickExact) {
+                double clickMs = timeAxis.TickPosToMsPos(clickTick);
+                double startMs = timeAxis.TickPosToMsPos(startTick);
+
+                double clickFrame = (clickMs - startMs) * SampleRate / 1000.0;
+                double relativeFrame = clickFrame - startFrame;
+                int frame = (int)Math.Round(relativeFrame);
+
+                if (frame + clickLengthSamples > 0 && frame < count / 2) {
+                    AddClick(
+                        buffer,
+                        offset,
+                        frame,
+                        beat == 0,
+                        count);
+                }
+
+                timeAxis.NextBarBeat(
+                    bar,
+                    beat,
+                    out bar,
+                    out beat);
+
+                clickTick = timeAxis.BarBeatToTickPos(bar, beat);
+            }
+
+            return position + count;
+        }
+
+        private static void AddClick(
+            float[] buffer,
+            int offset,
+            int frame,
+            bool accent,
+            int count) {
+
+            const double clickLengthMs = 50.0;
+            const float volume = 0.5f;
+
+            int clickLength = (int)(SampleRate * clickLengthMs / 1000.0);
+            double frequency = accent ? 1600.0 : 1000.0;
+            int bufferFrameCount = count / 2;
+
+            int startI = frame < 0 ? -frame : 0;
+
+            for (int i = startI; i < clickLength; ++i) {
+                int targetFrame = frame + i;
+
+                if (targetFrame >= bufferFrameCount) {
+                    break;
+                }
+
+                double t = (double)i / SampleRate;
+
+                double envelope = Math.Exp(-t * 80.0);
+
+                float sample = (float)(
+                    Math.Sin(2.0 * Math.PI * frequency * t)
+                    * envelope
+                    * volume);
+
+                buffer[offset + targetFrame * 2] += sample;
+                buffer[offset + targetFrame * 2 + 1] += sample;
+            }
+        }
+    }
+
     public class PlaybackManager : SingletonBase<PlaybackManager>, ICmdSubscriber {
         private PlaybackManager() {
             DocManager.Inst.AddSubscriber(this);
@@ -177,14 +305,16 @@ private PlaybackManager() {
             }
 
             toneGenerator = new ToneGenerator();
+            metronomeGenerator = new MetronomeGenerator();
             editingMix = new MasterAdapter(toneGenerator);
         }
 
         public readonly ToneGenerator toneGenerator;
+        public readonly MetronomeGenerator metronomeGenerator;
         List<Fader> faders;
         MasterAdapter masterMix;
         MasterAdapter editingMix;
-        
+
         double startMs;
         public int StartTick => DocManager.Inst.Project.timeAxis.MsPosToTickPos(startMs);
         CancellationTokenSource renderCancellation;
@@ -230,15 +360,15 @@ public void PlayFile(string file) {
             if (AudioOutput.PlaybackState == PlaybackState.Playing) {
                 AudioOutput.Stop();
             }
-            try{
+            try {
                 var playSound = Wave.OpenFile(file);
                 AudioOutput.Init(playSound.ToSampleProvider());
             } catch (Exception ex) {
                 Log.Error(ex, $"Failed to load sample {file}.");
                 return;
             }
             AudioOutput.Play();
-        } 
+        }
 
         public void PlayOrPause(int tick = -1, int endTick = -1, int trackNo = -1) {
             if (PlayingMaster) {
@@ -294,8 +424,10 @@ private void StartPlayback(double startMs, MasterAdapter masterAdapter) {
             toneGenerator.EndAllTones();
 
             this.startMs = startMs;
-            var start = TimeSpan.FromMilliseconds(startMs);
-            Log.Information($"StartPlayback at {start}");
+            int startTick = DocManager.Inst.Project.timeAxis.MsPosToTickPos(startMs);
+            Log.Information($"StartPlayback at {startMs}");
+
+            metronomeGenerator.SetProject(DocManager.Inst.Project, startTick);
             masterMix = masterAdapter;
             AudioOutput.Stop();
             AudioOutput.Init(masterMix);

OpenUtau.Core/Render/RenderEngine.cs

@@ -140,7 +140,7 @@ public Tuple<WaveMix, List<Fader>> RenderMixdown(TaskScheduler uiScheduler, ref
         public Tuple<MasterAdapter, List<Fader>> RenderProject(TaskScheduler uiScheduler, ref CancellationTokenSource cancellation) {
             double startMs = project.timeAxis.TickPosToMsPos(startTick);
             var renderMixdownResult = RenderMixdown(uiScheduler, ref cancellation, wait: false);
-            var master = new MasterAdapter(renderMixdownResult.Item1);
+            var master = new MasterAdapter(renderMixdownResult.Item1, PlaybackManager.Inst.metronomeGenerator);
             master.SetPosition((int)(startMs * 44100 / 1000) * 2);
             return Tuple.Create(master, renderMixdownResult.Item2);
         }

OpenUtau.Core/SignalChain/MasterAdapter.cs

@@ -5,14 +5,16 @@ namespace OpenUtau.Core.SignalChain {
     class MasterAdapter : ISampleProvider {
         private readonly WaveFormat waveFormat;
         private readonly ISignalSource source;
+        private readonly ISignalSource? metronome;
         private int position;
 
         public WaveFormat WaveFormat => waveFormat;
         public int Waited { get; private set; }
         public bool IsWaiting { get; private set; }
-        public MasterAdapter(ISignalSource source) {
+        public MasterAdapter(ISignalSource source, ISignalSource? metronome = null) {
             waveFormat = WaveFormat.CreateIeeeFloatWaveFormat(44100, 2);
             this.source = source;
+            this.metronome = metronome;
         }
 
         public int Read(float[] buffer, int offset, int count) {
@@ -25,6 +27,7 @@ public int Read(float[] buffer, int offset, int count) {
                 return count;
             } else {
                 int pos = source.Mix(position, buffer, offset, count);
+                metronome?.Mix(position, buffer, offset, count);
                 int n = Math.Max(0, pos - position);
                 position = pos;
                 IsWaiting = false;

OpenUtau/Strings/Strings.axaml

@@ -553,6 +553,8 @@ Warning: this option removes custom presets.</system:String>
   <system:String x:Key="pianoroll.tooltip.preutter">Preutter</system:String>
   <system:String x:Key="pianoroll.tooltip.release">Release time delta</system:String>
 
+  <system:String x:Key="playback.toggle.metronom">Toggle Metronom</system:String>
+
   <system:String x:Key="prefs.advanced">Advanced</system:String>
   <system:String x:Key="prefs.advanced.beta">Beta</system:String>
   <system:String x:Key="prefs.advanced.lyricshelper">Lyrics Helper</system:String>

OpenUtau/Strings/Strings.ja-JP.axaml

@@ -401,6 +401,8 @@
     Ctrl長押しで選択</system:String>
   <system:String x:Key="pianoroll.tool.selectionv2">選択ツール (1)</system:String>
 
+  <system:String x:Key="playback.toggle.metronom">メトロノーム</system:String>
+
   <system:String x:Key="prefs.advanced">高度な設定</system:String>
   <system:String x:Key="prefs.advanced.beta">ベータ版</system:String>
   <system:String x:Key="prefs.advanced.lyricshelper">歌詞入力ヘルパー</system:String>

OpenUtau/ViewModels/MainWindowViewModel.cs

@@ -88,6 +88,8 @@ public class MainWindowViewModel : ViewModelBase, ICmdSubscriber {
         [Reactive] public string UndoText { get; set; } = ThemeManager.GetString("menu.edit.undo");
         [Reactive] public string RedoText { get; set; } = ThemeManager.GetString("menu.edit.redo");
 
+        [Reactive] public bool IsMetronomeEnabled { get; set; } = PlaybackManager.Inst.metronomeGenerator.Enabled;
+
         private ObservableCollectionExtended<MenuItemViewModel> openRecentMenuItems
             = new ObservableCollectionExtended<MenuItemViewModel>();
         private ObservableCollectionExtended<MenuItemViewModel> openTemplatesMenuItems
@@ -136,6 +138,9 @@ public MainWindowViewModel() {
                     PianoRollMaxHeight = x ? double.PositiveInfinity : 0;
                     PianoRollMinHeight = x ? ViewConstants.PianoRollMinHeight : 0;
                 });
+            this.WhenAnyValue(x => x.IsMetronomeEnabled)
+                .Subscribe(enabled =>
+                    PlaybackManager.Inst.metronomeGenerator.Enabled = enabled);
         }
 
         public void Undo() {
@@ -187,7 +192,7 @@ public void InitProject(MainWindow window) {
                 HasRecovery = true;
                 return;
             }
-          
+
             var args = Environment.GetCommandLineArgs();
             if (args.Length == 2 && File.Exists(args[1])) {
                 try {
@@ -269,7 +274,7 @@ public void SaveProject(string file = "") {
             this.RaisePropertyChanged(nameof(Title));
         }
 
-        public void ImportTracks(UProject[] loadedProjects, bool importTempo){
+        public void ImportTracks(UProject[] loadedProjects, bool importTempo) {
             if (loadedProjects == null || loadedProjects.Length < 1) {
                 return;
             }
@@ -314,7 +319,7 @@ public void ImportMidi(string file) {
                 var track = new UTrack(project);
                 track.TrackNo = project.tracks.Count;
                 part.trackNo = track.TrackNo;
-                if(part.name != "New Part"){
+                if (part.name != "New Part") {
                     track.TrackName = part.name;
                 }
                 part.AfterLoad(project, track);
@@ -400,7 +405,7 @@ public void RefreshTimelineContextMenu(int tick) {
         /// Remap a tick position from the old time axis to the new time axis without changing its absolute position (in ms).
         /// Note that this can only be used on positions, not durations.
         /// </summary>
-        private int RemapTickPos(int tickPos, TimeAxis oldTimeAxis, TimeAxis newTimeAxis){
+        private int RemapTickPos(int tickPos, TimeAxis oldTimeAxis, TimeAxis newTimeAxis) {
             double msPos = oldTimeAxis.TickPosToMsPos(tickPos);
             return newTimeAxis.MsPosToTickPos(msPos);
         }
@@ -409,41 +414,41 @@ private int RemapTickPos(int tickPos, TimeAxis oldTimeAxis, TimeAxis newTimeAxis
         /// Remap the starting and ending positions of all the notes and parts in the whole project 
         /// from the old time axis to the new time axis, without changing their absolute positions in ms.
         /// </summary>
-        public void RemapTimeAxis(TimeAxis oldTimeAxis, TimeAxis newTimeAxis){
+        public void RemapTimeAxis(TimeAxis oldTimeAxis, TimeAxis newTimeAxis) {
             var project = DocManager.Inst.Project;
-            foreach(var part in project.parts){
+            foreach (var part in project.parts) {
                 var partOldStartTick = part.position;
                 var partNewStartTick = RemapTickPos(part.position, oldTimeAxis, newTimeAxis);
-                if(partNewStartTick != partOldStartTick){
+                if (partNewStartTick != partOldStartTick) {
                     DocManager.Inst.ExecuteCmd(new MovePartCommand(
                         project, part, partNewStartTick, part.trackNo));
                 }
-                if(part is UVoicePart voicePart){
+                if (part is UVoicePart voicePart) {
                     var partOldDuration = voicePart.Duration;
                     var partNewDuration = RemapTickPos(partOldStartTick + voicePart.duration, oldTimeAxis, newTimeAxis) - partNewStartTick;
-                    if(partNewDuration != partOldDuration) {
+                    if (partNewDuration != partOldDuration) {
                         DocManager.Inst.ExecuteCmd(new ResizeVoicePartCommand(
                             project, voicePart, partNewDuration - partOldDuration, false));
                     }
                     var noteCommands = new List<UCommand>();
-                    foreach(var note in voicePart.notes){
+                    foreach (var note in voicePart.notes) {
                         var noteOldStartTick = note.position + partOldStartTick;
                         var noteOldEndTick = note.End + partOldStartTick;
                         var noteOldDuration = note.duration;
                         var noteNewStartTick = RemapTickPos(noteOldStartTick, oldTimeAxis, newTimeAxis);
                         var noteNewEndTick = RemapTickPos(noteOldEndTick, oldTimeAxis, newTimeAxis);
                         var deltaPosTickInPart = (noteNewStartTick - partNewStartTick) - (noteOldStartTick - partOldStartTick);
-                        if(deltaPosTickInPart != 0){
+                        if (deltaPosTickInPart != 0) {
                             noteCommands.Add(new MoveNoteCommand(voicePart, note, deltaPosTickInPart, 0));
                         }
                         var noteNewDuration = noteNewEndTick - noteNewStartTick;
                         var deltaDur = noteNewDuration - noteOldDuration;
-                        if(deltaDur != 0){
+                        if (deltaDur != 0) {
                             noteCommands.Add(new ResizeNoteCommand(voicePart, note, deltaDur));
                         }
                         //TODO: expression curve remapping, phoneme timing remapping
                     }
-                    foreach(var command in noteCommands){
+                    foreach (var command in noteCommands) {
                         DocManager.Inst.ExecuteCmd(command);
                     }
                 }

OpenUtau/Views/MainWindow.axaml

@@ -220,7 +220,7 @@
             <RowDefinition Height="4"/>
           </Grid.RowDefinitions>
           <Panel Grid.Row="1" Grid.Column="0" HorizontalAlignment="Stretch" VerticalAlignment="Top" Height="24">
-            <Border Classes="playback" Width="72" HorizontalAlignment="Left" Margin="4,0">
+            <Border Classes="playback" Width="92" HorizontalAlignment="Left" Margin="4,0">
               <Grid>
                 <TextBlock Width="28" HorizontalAlignment="Left"
                           Background="Transparent" PointerPressed="OnEditTimeSignature">
@@ -231,14 +231,27 @@
                     </MultiBinding>
                   </TextBlock.Text>
                 </TextBlock>
-                <TextBlock Width="42" HorizontalAlignment="Right"
+                <TextBlock Width="42" HorizontalAlignment="Center"
                             Background="Transparent" PointerPressed="OnEditBpm">
                   <TextBlock.Text>
                     <MultiBinding StringFormat="{}{0:#0.00}">
                       <Binding Path="PlaybackViewModel.Bpm"/>
                     </MultiBinding>
                   </TextBlock.Text>
                 </TextBlock>
+                <ToggleButton Classes="toolbar" Margin="0" Padding="1" Height="18" Width="18" HorizontalAlignment="Right"
+                  IsChecked="{Binding IsMetronomeEnabled}" ToolTip.Tip="{DynamicResource playback.toggle.metronom}">
+                  <Path Classes="stroked"
+                        Data="M1.5 15.5 L3.8 3.5 Q4 2.5 5 2.5 H8 Q9 2.5 9.2 3.5 L11.5 15.5 Z
+                              M5.8 2.8 L5.8 12.8
+                              M4.9 5 H6.7 V6.5 H4.9 Z
+                              M3.6 5.5 H4.5
+                              M3.3 7.2 H4.5
+                              M3 8.9 H4.5
+                              M2.7 10.6 H4.5
+                              M2.4 12.3 H4.5
+                              M1.2 15.5 H11.8"/>
+                </ToggleButton>
               </Grid>
             </Border>
             <Border Classes="playback" Width="88" HorizontalAlignment="Center">