Merge pull request #65 from spessasus/discussion62

Add playback state preserving
spessasus · Oct 17, 2024 · 6c1bc5c · 6c1bc5c
2 parents ed21fae + 4bcb065
commit 6c1bc5c
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Showing 5 changed files with 71 additions and 10 deletions.
diff --git a/src/spessasynth_lib/sequencer/sequencer.js b/src/spessasynth_lib/sequencer/sequencer.js
@@ -28,14 +28,17 @@ import { DUMMY_MIDI_DATA, MidiData } from "../midi_parser/midi_data.js";
  * @typedef {Object} SequencerOptions
  * @property {boolean|undefined} skipToFirstNoteOn - if true, the sequencer will skip to the first note
  * @property {boolean|undefined} autoPlay - if true, the sequencer will automatically start playing the MIDI
+ * @property {boolean|unescape} preservePlaybackState - if true,
+ * the sequencer will stay paused when seeking or changing the playback rate
  */
 
 /**
  * @type {SequencerOptions}
  */
 const DEFAULT_OPTIONS = {
     skipToFirstNoteOn: true,
-    autoPlay: true
+    autoPlay: true,
+    preservePlaybackState: false
 };
 
 export class Sequencer
@@ -138,15 +141,25 @@ export class Sequencer
          * @type {boolean}
          * @private
          */
-        this._skipToFirstNoteOn = options?.skipToFirstNoteOn ?? true;
+        this._skipToFirstNoteOn = options?.skipToFirstNoteOn || true;
+        /**
+         * @type {boolean}
+         * @private
+         */
+        this._preservePlaybackState = options?.preservePlaybackState || false;
 
         if (this._skipToFirstNoteOn === false)
         {
             // setter sends message
             this._sendMessage(WorkletSequencerMessageType.setSkipToFirstNote, false);
         }
 
-        this.loadNewSongList(midiBinaries, options?.autoPlay ?? false);
+        if (this._preservePlaybackState === true)
+        {
+            this._sendMessage(WorkletSequencerMessageType.setPreservePlaybackState, true);
+        }
+
+        this.loadNewSongList(midiBinaries, options?.autoPlay || true);
 
         window.addEventListener("beforeunload", this.resetMIDIOut.bind(this));
     }
@@ -170,6 +183,27 @@ export class Sequencer
         this._sendMessage(WorkletSequencerMessageType.setSkipToFirstNote, this._skipToFirstNoteOn);
     }
 
+    /**
+     * if true,
+     * the sequencer will stay paused when seeking or changing the playback rate
+     * @returns {boolean}
+     */
+    get preservePlaybackState()
+    {
+        return this._preservePlaybackState;
+    }
+
+    /**
+     * if true,
+     * the sequencer will stay paused when seeking or changing the playback rate
+     * @param val {boolean}
+     */
+    set preservePlaybackState(val)
+    {
+        this._preservePlaybackState = val;
+        this._sendMessage(WorkletSequencerMessageType.setPreservePlaybackState, val);
+    }
+
     /**
      * @returns {number} Current playback time, in seconds
      */
@@ -186,7 +220,10 @@ export class Sequencer
 
     set currentTime(time)
     {
-        this.unpause();
+        if (!this._preservePlaybackState)
+        {
+            this.unpause();
+        }
         this._sendMessage(WorkletSequencerMessageType.setTime, time);
     }
 
@@ -395,8 +432,15 @@ export class Sequencer
                 // message data is absolute time
                 const time = this.synth.currentTime - messageData;
                 Object.entries(this.onTimeChange).forEach((callback) => callback[1](time));
-                this.unpause();
                 this._recalculateStartTime(time);
+                if (this.paused && this._preservePlaybackState)
+                {
+                    this.pausedTime = time;
+                }
+                else
+                {
+                    this.unpause();
+                }
                 break;
 
             case WorkletSequencerReturnMessageType.pause:

diff --git a/src/spessasynth_lib/sequencer/worklet_sequencer/events.js b/src/spessasynth_lib/sequencer/worklet_sequencer/events.js
@@ -65,6 +65,9 @@ export function processMessage(messageType, messageData)
         case WorkletSequencerMessageType.setSkipToFirstNote:
             this._skipToFirstNoteOn = messageData;
             break;
+
+        case WorkletSequencerMessageType.setPreservePlaybackState:
+            this.preservePlaybackState = messageData;
     }
 }
 

diff --git a/src/spessasynth_lib/sequencer/worklet_sequencer/play.js b/src/spessasynth_lib/sequencer/worklet_sequencer/play.js
@@ -254,12 +254,14 @@ export function play(resetTime = false)
     // reset the time if necesarry
     if (resetTime)
     {
+        this.pausedTime = undefined;
         this.currentTime = 0;
         return;
     }
 
     if (this.currentTime >= this.duration)
     {
+        this.pausedTime = undefined;
         this.currentTime = 0;
         return;
     }

diff --git a/src/spessasynth_lib/sequencer/worklet_sequencer/sequencer_message.js b/src/spessasynth_lib/sequencer/worklet_sequencer/sequencer_message.js
@@ -11,6 +11,7 @@
  * @property {number} changeSong               - 8 -> goForwards<boolean> if true, next song, if false, previous
  * @property {number} getMIDI                  - 9 -> (no data)
  * @property {number} setSkipToFirstNote       -10 -> skipToFirstNoteOn<boolean>
+ * @property {number} setPreservePlaybackState -11 -> preservePlaybackState<boolean>
  */
 export const WorkletSequencerMessageType = {
     loadNewSongList: 0,
@@ -23,7 +24,8 @@ export const WorkletSequencerMessageType = {
     setLoop: 7,
     changeSong: 8,
     getMIDI: 9,
-    setSkipToFirstNote: 10
+    setSkipToFirstNote: 10,
+    setPreservePlaybackState: 11
 };
 
 /**

diff --git a/src/spessasynth_lib/sequencer/worklet_sequencer/worklet_sequencer.js b/src/spessasynth_lib/sequencer/worklet_sequencer/worklet_sequencer.js
@@ -104,6 +104,12 @@ class WorkletSequencer
          * @private
          */
         this._skipToFirstNoteOn = true;
+
+        /**
+         * If true, seq will stay paused when seeking or changing the playback rate
+         * @type {boolean}
+         */
+        this.preservePlaybackState = false;
     }
 
     /**
@@ -152,15 +158,19 @@ class WorkletSequencer
         }
         this.stop();
         this.playingNotes = [];
+        const wasPaused = this.paused && this.preservePlaybackState;
         this.pausedTime = undefined;
         this.post(WorkletSequencerReturnMessageType.timeChange, currentTime - time);
-        const isNotFinished = this._playTo(time);
+        this._playTo(time);
         this._recalculateStartTime(time);
-        if (!isNotFinished)
+        if (wasPaused)
         {
-            return;
+            this.pause();
+        }
+        else
+        {
+            this.play();
         }
-        this.play();
     }
 
     /**