Metronome

.gitignore

@@ -22,3 +22,8 @@ tsserver.log
 __pycache__
 
 .DS_Store
+.vscode
+*.aup3-shm
+*.aup3-wal
+*.aup3
+

src/PipeScore/Controller.ts

@@ -45,6 +45,8 @@ const state: State = {
   playback: {
     userPressedStop: false,
     playing: false,
+    playingMetronome: false,
+    beatIndicator: false,
     loading: true,
     cursor: null,
   },
@@ -136,6 +138,8 @@ function redraw() {
         loggedIn: state.isLoggedIn,
         loadingAudio: state.playback.loading,
         isPlaying: state.playback.playing,
+        isPlayingMetronome: state.playback.playingMetronome,
+        beatIndicator: state.playback.beatIndicator,
         zoomLevel: state.score.zoom,
         preview: state.preview,
         showingPageNumbers: state.score.showNumberOfPages,
@@ -150,9 +154,13 @@ function redraw() {
             state.selection.gracenote(state.score)) ||
           null,
         selectedText:
-          state.selection instanceof TextSelection ? state.selection.text : null,
+          state.selection instanceof TextSelection
+            ? state.selection.text
+            : null,
         selectedTiming:
-          state.selection instanceof TimingSelection ? state.selection.timing : null,
+          state.selection instanceof TimingSelection
+            ? state.selection.timing
+            : null,
         isLandscape: state.score.landscape,
         selectedStaves:
           (state.selection instanceof ScoreSelection &&

src/PipeScore/Events/Misc.ts

@@ -179,6 +179,8 @@ export function exportPDF(): ScoreEvent {
         userPressedStop: false,
         loading: false,
         cursor: null,
+        playingMetronome: false,
+        beatIndicator: false,
       },
       dispatch: async () => void 0,
     };
@@ -293,7 +295,11 @@ export function exportPDF(): ScoreEvent {
 export function download(): ScoreEvent {
   return async (state: State) => {
     const json = state.score.toJSON();
-    saveFile(`${state.score.name()}.pipescore`, JSON.stringify(json), 'text/json');
+    saveFile(
+      `${state.score.name()}.pipescore`,
+      JSON.stringify(json),
+      'text/json'
+    );
 
     return Update.NoChange;
   };

src/PipeScore/Events/Playback.ts

@@ -14,7 +14,7 @@
 //  You should have received a copy of the GNU General Public License
 //  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-import { playback } from '../Playback/impl';
+import { playback, playMetronome } from '../Playback/impl';
 import { ScoreSelection } from '../Selection/score';
 import type { State } from '../State';
 import type { ID } from '../global/id';
@@ -68,7 +68,7 @@ export function playbackLoopingSelection(): ScoreEvent {
 
 export function stopPlayback(): ScoreEvent {
   return async (state: State) => {
-    if (state.playback.playing) {
+    if (state.playback.playing || state.playback.playingMetronome) {
       state.playback.userPressedStop = true;
       return Update.ViewChanged;
     }
@@ -109,3 +109,19 @@ export function updateInstrument(instrument: Instrument): ScoreEvent {
     return Update.NoChange;
   };
 }
+export function startPlayMetronome(): ScoreEvent {
+  return async (state: State) => {
+    const playbackElements = state.score.play();
+    await playMetronome(state.playback);
+    return Update.NoChange;
+  };
+}
+export function updateBeatIndicator(beat: boolean): ScoreEvent {
+  return async (state: State) => {
+    if (beat !== state.playback.beatIndicator) {
+      state.playback.beatIndicator = beat;
+      return Update.ViewChanged;
+    }
+    return Update.NoChange;
+  };
+}

src/PipeScore/Playback/impl.ts

@@ -38,7 +38,13 @@ import {
   sum,
   unreachable,
 } from '../global/utils';
-import { Drone, type SoundedMeasure, SoundedPitch, SoundedSilence } from './sounds';
+import {
+  Drone,
+  type SoundedMeasure,
+  SoundedPitch,
+  SoundedSilence,
+  Tick,
+} from './sounds';
 import type { PlaybackState } from './state';
 
 function shouldDeleteBecauseOfSecondTimings(
@@ -206,7 +212,9 @@ function expandRepeats(
         }
 
         // Append the item to the current measure/part in the output
-        if (!shouldDeleteBecauseOfSecondTimings(inputIndex, timings, repeating)) {
+        if (
+          !shouldDeleteBecauseOfSecondTimings(inputIndex, timings, repeating)
+        ) {
           nlast(output).parts[partIndex].push(item);
         }
 
@@ -236,7 +244,8 @@ function expandRepeats(
       repeatStartIndex = measureIndex;
     } else if (measure.repeatEnd && measureIndex > repeatEndIndex) {
       // If the measure has an end repeat, then set measureIndex back to repeatStartIndex
-      timingOverRepeat = timings.find((t) => t.in(inputIndexAfterMeasure)) || null;
+      timingOverRepeat =
+        timings.find((t) => t.in(inputIndexAfterMeasure)) || null;
       repeatEndIndex = measureIndex;
       // Go back to repeat
       measureIndex = repeatStartIndex - 1;
@@ -300,7 +309,9 @@ function getSoundedPitches(
         switch (e.type) {
           case 'note': {
             const duration = e.duration - currentGracenoteDuration;
-            soundedPart.push(new SoundedPitch(e.pitch, duration, ctx, currentID));
+            soundedPart.push(
+              new SoundedPitch(e.pitch, duration, ctx, currentID)
+            );
             currentGracenoteDuration = 0;
             break;
           }
@@ -371,10 +382,18 @@ async function playPitches(
   end: ID | null,
   loop: boolean
 ) {
-  const measuresToPlay = getSoundedPitches(measures, timings, context, start, end);
+  const measuresToPlay = getSoundedPitches(
+    measures,
+    timings,
+    context,
+    start,
+    end
+  );
 
   const numberOfItems = sum(
-    measuresToPlay.flatMap((measure) => measure.parts.flatMap((part) => part.length))
+    measuresToPlay.flatMap((measure) =>
+      measure.parts.flatMap((part) => part.length)
+    )
   );
 
   if (numberOfItems === 0) {
@@ -407,3 +426,21 @@ async function playPitches(
   state.userPressedStop = false;
   dispatch(updateView());
 }
+export async function playMetronome(state: PlaybackState) {
+  if (state.playing || state.loading) return;
+
+  const context = new AudioContext();
+  const tick = new Tick(context);
+  state.playingMetronome = true;
+
+  tick.start();
+  while (true) {
+    // Loop until user presses stop
+    await sleep(1000);
+    if (state.userPressedStop) break;
+  }
+  tick.stop();
+  state.userPressedStop = false;
+  state.playingMetronome = false;
+  dispatch(updateView());
+}

src/PipeScore/Playback/index.ts

@@ -49,8 +49,15 @@ export type PlaybackGracenote = {
  * @param children playback items that go between the object start and object end
  * @returns updated list of PlaybackItems, including object
  */
-export function playbackObject(id: ID, children: PlaybackItem[]): PlaybackItem[] {
-  return [{ type: 'object-start', id }, ...children, { type: 'object-end', id }];
+export function playbackObject(
+  id: ID,
+  children: PlaybackItem[]
+): PlaybackItem[] {
+  return [
+    { type: 'object-start', id },
+    ...children,
+    { type: 'object-end', id },
+  ];
 }
 
 /**
@@ -100,7 +107,11 @@ export class PlaybackMeasure {
   public repeatStart: boolean;
   public repeatEnd: boolean;
 
-  constructor(items: PlaybackItem[][], repeatStart: boolean, repeatEnd: boolean) {
+  constructor(
+    items: PlaybackItem[][],
+    repeatStart: boolean,
+    repeatEnd: boolean
+  ) {
     this.parts = items;
     this.repeatStart = repeatStart;
     this.repeatEnd = repeatEnd;

src/PipeScore/Playback/resources.ts

@@ -38,6 +38,7 @@ type InstrumentResources = {
   highg: AudioResource;
   higha: AudioResource;
   drones: AudioResource | null;
+  tick: AudioResource;
 };
 
 const ghb: InstrumentResources = {
@@ -51,6 +52,7 @@ const ghb: InstrumentResources = {
   highg: new AudioResource('GHB/highg'),
   higha: new AudioResource('GHB/higha'),
   drones: new AudioResource('GHB/drones'),
+  tick: new AudioResource('GHB/tick'),
 };
 
 const chanter: InstrumentResources = {
@@ -64,6 +66,7 @@ const chanter: InstrumentResources = {
   highg: new AudioResource('chanter/highg'),
   higha: new AudioResource('chanter/higha'),
   drones: null,
+  tick: new AudioResource('chanter/tick'),
 };
 
 /**
@@ -87,6 +90,7 @@ function loadInstrumentResources(
     resources.highg.load(context),
     resources.higha.load(context),
     resources.drones?.load(context),
+    resources.tick.load(context),
   ]);
 }
 
@@ -98,8 +102,8 @@ export function getInstrumentResources(): InstrumentResources {
   return settings.instrument === Instrument.Chanter
     ? chanter
     : settings.instrument === Instrument.GHB
-      ? ghb
-      : unreachable(settings.instrument);
+    ? ghb
+    : unreachable(settings.instrument);
 }
 
 // This is in a function (rather than at the top level)

src/PipeScore/Playback/sounds.ts

@@ -17,7 +17,7 @@
 //  Drone and SoundedPitch classes enable playback of drones and notes (including gracenotes).
 
 import { dispatch } from '../Controller';
-import { updatePlaybackCursor } from '../Events/Playback';
+import { updateBeatIndicator, updatePlaybackCursor } from '../Events/Playback';
 import type { ID } from '../global/id';
 import type { Pitch } from '../global/pitch';
 import { settings } from '../global/settings';
@@ -59,6 +59,46 @@ export class Drone {
   }
 }
 
+/**
+/**
+ * Metronome tick playback.
+ */
+export class Tick {
+  private sample: Sample;
+  private stopped = false;
+
+  constructor(context: AudioContext) {
+    const tick = getInstrumentResources().tick;
+    this.sample = tick && new Sample(tick, context);
+  }
+
+  /**
+   * Start the metronome tick, looping forever until .stop() is called.
+   */
+  async start() {
+    const beatIndicatorDuration = 200; // duration of beat indicator on UI in ms
+    const tickLeadInDuration = 150; // Aligns the centre of the audio tick to the beat indicator in ms
+    while (!this.stopped) {
+      const duration = (1000 * 60) / settings.bpm;
+      this.sample.start(1);
+      await sleep(tickLeadInDuration);
+      dispatch(updateBeatIndicator(true));
+      await sleep(beatIndicatorDuration);
+      dispatch(updateBeatIndicator(false));
+      await sleep(duration - beatIndicatorDuration - tickLeadInDuration);
+    }
+  }
+
+  /**
+   * Stop the tick.
+   */
+  stop() {
+    if (this.sample) {
+      this.sample.stop();
+    }
+    this.stopped = true;
+  }
+}
 /**
  * Pitched note playback (used for notes and gracenotes).
  */
@@ -77,7 +117,12 @@ export class SoundedPitch {
   // see SoundedSilence for details.
   public durationIncludingTies: number;
 
-  constructor(pitch: Pitch, duration: number, ctx: AudioContext, id: ID | null) {
+  constructor(
+    pitch: Pitch,
+    duration: number,
+    ctx: AudioContext,
+    id: ID | null
+  ) {
     this.sample = new Sample(pitchToAudioResource(pitch), ctx);
     this.pitch = pitch;
     this.duration = duration;

src/PipeScore/Playback/state.ts

@@ -19,6 +19,8 @@ import type { ID } from '../global/id';
 export type PlaybackState = {
   userPressedStop: boolean;
   playing: boolean;
+  playingMetronome: boolean;
+  beatIndicator: boolean;
   loading: boolean;
   // Location of playback cursor
   cursor: ID | null;

src/PipeScore/Translations/English.ts

@@ -115,9 +115,13 @@ export const EnglishDocumentation: Documentation = {
     'Play a preview of the score, starting at the currently selected note/bar. This will only work once the samples are downloaded (if the samples need to download, you will see a notice).',
   'play-looping-selection':
     'Play the currently selected part of the score, repeating forever.',
+  'play-metronome': 'Start the metronome',
+  'stop-metronome': 'Stop the metronome',
+  beatindicator: 'Displays the beat of the metronome',
   stop: 'Stop the playback.',
   'playback-speed': 'Control the playback speed (further right is faster).',
-  'harmony-volume': 'Control how loud the harmony plays (further right is louder).',
+  'harmony-volume':
+    'Control how loud the harmony plays (further right is louder).',
   export: 'Export the score to a PDF file, that may then be shared or printed.',
   'export-bww':
     "Export the score to a BWW file, that may be opened in other applications. This is currently very new, and won't work for most scores.",
@@ -203,6 +207,7 @@ export const EnglishTextItems: TextItems = {
   playFromBeginning: 'Play from Beginning',
   playFromSelection: 'Play from Selection',
   playLoopedSelection: 'Play looped Selection',
+  playMetronome: 'Play Metronome',
   stop: 'Stop',
   playbackOptions: 'Playback Options',
   beatsPerMinute: 'beats per minute',