feat: Public API improvements for external cursor api (#2116)

Author: Danielku15

src.compiler/csharp/CSharpAstTransformer.ts

@@ -703,7 +703,7 @@ export default class CSharpAstTransformer {
             sourcePath,
             '..',
             '__snapshots__',
-            `${path.basename(sourcePath).toLowerCase()}.snap`
+            `${path.basename(sourcePath)}.snap`
         );
         if (fs.existsSync(snapshotFilePath)) {
             const relative = path.relative(path.resolve(this._context.compilerOptions.baseUrl!), snapshotFilePath);

src.csharp/AlphaTab.Windows/NAudioBackingTrackOutput.cs

@@ -18,7 +18,6 @@ internal class NAudioBackingTrackOutput : IBackingTrackSynthOutput, IDisposable
         /// <inheritdoc />
         public double SampleRate => PreferredSampleRate;
 
-        private TimeSpan _padding;
         private ISynthOutputDevice? _device;
         private StreamMediaFoundationReader? _audioFileReader;
         private DirectSoundOut? _context;
@@ -43,7 +42,7 @@ public NAudioBackingTrackOutput(Action<Action> invokeUi)
 
         public void SeekTo(double time)
         {
-            _audioFileReader!.CurrentTime = TimeSpan.FromMilliseconds(time) - _padding;
+            _audioFileReader!.CurrentTime = TimeSpan.FromMilliseconds(time);
         }
 
 
@@ -52,8 +51,6 @@ public void LoadBackingTrack(BackingTrack backingTrack)
             _audioFileReader?.Dispose();
             _context?.Dispose();
 
-            _padding = TimeSpan.FromMilliseconds(backingTrack.Padding);
-
             _audioFileReader = new StreamMediaFoundationReader(new System.IO.MemoryStream(
                 backingTrack.RawAudioFile!.Buffer.Raw,
                 (int)backingTrack.RawAudioFile!.ByteOffset,
@@ -102,7 +99,7 @@ private void Close()
 
         private void UpdatePosition()
         {
-            var timePos = (_context!.PlaybackPosition + _padding).TotalMilliseconds;
+            var timePos = _context!.PlaybackPosition.TotalMilliseconds;
             _invokeUi(() => { ((EventEmitterOfT<double>)TimeUpdate).Trigger(timePos); });
         }
 

src.csharp/AlphaTab/Platform/CSharp/AlphaSynthWorkerApiBase.cs

@@ -190,9 +190,14 @@ public void SetChannelTranspositionPitch(double channel, double semitones)
         DispatchOnWorkerThread(() => { _player.SetChannelTranspositionPitch(channel, semitones); });
     }
 
-    public void LoadBackingTrack(Score score, IList<BackingTrackSyncPoint> syncPoints)
+    public void LoadBackingTrack(Score score)
     {
-        DispatchOnWorkerThread(() => { _player.LoadBackingTrack(score, syncPoints); });
+        DispatchOnWorkerThread(() => { _player.LoadBackingTrack(score); });
+    }
+
+    public void UpdateSyncPoints( IList<BackingTrackSyncPoint> syncPoints)
+    {
+        DispatchOnWorkerThread(() => { _player.UpdateSyncPoints(syncPoints); });
     }
 
     public IEventEmitter Ready { get; } = new EventEmitter();

src.kotlin/alphaTab/android/src/main/java/alphaTab/platform/android/AndroidBackingTrackSynthOutput.kt

@@ -47,7 +47,6 @@ class AndroidBackingTrackSynthOutput(
             _player.setVolume(value.toFloat(), value.toFloat())
         }
 
-    private var _padding: Int = 0
     private var _device: ISynthOutputDevice? = null
     private val _updateTimer: ScheduledExecutorService = Executors.newScheduledThreadPool(1)
     private var _updateSchedule: ScheduledFuture<*>? = null
@@ -72,7 +71,6 @@ class AndroidBackingTrackSynthOutput(
 
     override fun loadBackingTrack(backingTrack: BackingTrack) {
         _player.reset()
-        _padding = backingTrack.padding.toInt()
         _player.setAudioAttributes(
             AudioAttributes.Builder()
                 .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
@@ -98,7 +96,7 @@ class AndroidBackingTrackSynthOutput(
     }
 
     private fun updatePosition() {
-        val timePos = _player.currentPosition + _padding
+        val timePos = _player.currentPosition
         synthInvoke {
             (timeUpdate as EventEmitterOfT<Double>).trigger(timePos.toDouble())
         }

src.kotlin/alphaTab/android/src/main/java/alphaTab/platform/android/AndroidThreadAlphaSynthWorkerPlayer.kt

@@ -255,8 +255,12 @@ internal class AndroidThreadAlphaSynthWorkerPlayer : IAlphaSynth, Runnable {
         _workerQueue.add { _player?.setChannelTranspositionPitch(channel, semitones) }
     }
 
-    override fun loadBackingTrack(score: Score, syncPoints: List<BackingTrackSyncPoint>) {
-        _workerQueue.add { _player?.loadBackingTrack(score, syncPoints) }
+    override fun loadBackingTrack(score: Score) {
+        _workerQueue.add { _player?.loadBackingTrack(score) }
+    }
+
+    override fun updateSyncPoints(syncPoints: List<BackingTrackSyncPoint>) {
+        _workerQueue.add { _player?.updateSyncPoints(syncPoints) }
     }
 
     override val ready: IEventEmitter = EventEmitter()

src/AlphaTabApiBase.ts

@@ -721,16 +721,16 @@ export class AlphaTabApiBase<TSettings> {
 
     private appendRenderResult(result: RenderFinishedEventArgs, isLast: boolean): void {
         // resizing the canvas and wrapper elements at the end is enough
-        // it avoids flickering on resizes and re-renders. 
+        // it avoids flickering on resizes and re-renders.
         // the individual partials are anyhow sized correctly
-        if(isLast) {
+        if (isLast) {
             this.canvasElement.width = result.totalWidth;
             this.canvasElement.height = result.totalHeight;
             if (this._cursorWrapper) {
                 this._cursorWrapper.width = result.totalWidth;
                 this._cursorWrapper.height = result.totalHeight;
             }
-        }        
+        }
 
         if (result.width > 0 || result.height > 0) {
             this.uiFacade.beginAppendRenderResults(result);
@@ -1441,7 +1441,7 @@ export class AlphaTabApiBase<TSettings> {
     }
 
     /**
-     * 
+     *
      * @returns true if a new player was created, false if no player was created (includes destroy & reuse of the current one)
      */
     private setupOrDestroyPlayer(): boolean {
@@ -1495,9 +1495,9 @@ export class AlphaTabApiBase<TSettings> {
     }
 
     /**
-     * Re-creates the midi for the current score and loads it. 
+     * Re-creates the midi for the current score and loads it.
      * @remarks
-     * This will result in the player to stop playback. Some setting changes require re-genration of the midi song. 
+     * This will result in the player to stop playback. Some setting changes require re-genration of the midi song.
      * @category Methods - Player
      * @since 1.6.0
      */
@@ -1526,10 +1526,26 @@ export class AlphaTabApiBase<TSettings> {
 
         const player = this._player;
         player.loadMidiFile(midiFile);
-        player.loadBackingTrack(score, generator.syncPoints);
+        player.loadBackingTrack(score);
+        player.updateSyncPoints(generator.syncPoints);
         player.applyTranspositionPitches(generator.transpositionPitches);
     }
 
+    /**
+     * Triggers an update of the sync points for the current score after modification within the data model
+     * @category Methods - Player
+     * @since 1.6.0
+     */
+    public updateSyncPoints() {
+        if (!this.score) {
+            return;
+        }
+
+        const score = this.score!;
+        const player = this._player;
+        player.updateSyncPoints(MidiFileGenerator.generateSyncPoints(score));
+    }
+
     /**
      * Changes the volume of the given tracks.
      * @param tracks The tracks for which the volume should be changed.

src/generated/model/BackingTrackSerializer.ts

@@ -17,15 +17,9 @@ export class BackingTrackSerializer {
             return null;
         }
         const o = new Map<string, unknown>();
-        o.set("padding", obj.padding);
         return o;
     }
     public static setProperty(obj: BackingTrack, property: string, v: unknown): boolean {
-        switch (property) {
-            case "padding":
-                obj.padding = v! as number;
-                return true;
-        }
         return false;
     }
 }

src/importer/GpifParser.ts

@@ -127,6 +127,7 @@ export class GpifParser {
     private _hasAnacrusis: boolean = false;
     private _articulationByName!: Map<string, InstrumentArticulation>;
     private _skipApplyLyrics: boolean = false;
+    private _backingTrackPadding:number = 0;
 
     private _doubleBars: Set<MasterBar> = new Set<MasterBar>();
     private _keySignatures: Map<number, [KeySignature, KeySignatureType]> = new Map<
@@ -377,7 +378,7 @@ export class GpifParser {
                     assetId = c.innerText;
                     break;
                 case 'FramePadding':
-                    backingTrack.padding = GpifParser.parseIntSafe(c.innerText, 0) / GpifParser.SampleRate * 1000;
+                    this._backingTrackPadding = GpifParser.parseIntSafe(c.innerText, 0) / GpifParser.SampleRate * 1000;
                     break;
             }
         }
@@ -2746,6 +2747,7 @@ export class GpifParser {
                         masterBar.tempoAutomations.push(automation);
                         break;
                     case AutomationType.SyncPoint:
+                        automation.syncPointValue!.millisecondOffset -= this._backingTrackPadding;
                         masterBar.addSyncPoint(automation);
                         break;
                 }

src/midi/MasterBarTickLookup.ts

@@ -56,7 +56,14 @@ export class MasterBarTickLookup {
      */
     public masterBar!: MasterBar;
 
+    /**
+     * The first beat in the bar. 
+     */
     public firstBeat: BeatTickLookup | null = null;
+
+    /**
+     * The last beat in the bar. 
+     */
     public lastBeat: BeatTickLookup | null = null;
 
     /**