From 4a9cbcdef1d13d41151ec2d478ffa85b63e3e3de Mon Sep 17 00:00:00 2001
From: 3dtours <yeunhiepanh.photo@gmail.com>
Date: Mon, 27 Jul 2026 20:04:56 +0700
Subject: [PATCH] fix: per-track instrument + ghost note visibility

soundfontPlayer.js:
- selectInstrument: respect passed channel (don't allocate new one)
- _playNoteFluid: only use _engineChMap when channel is undefined

ghostNoteExtractor.js:
- Include ALL notes from overlapping items (not clipped)
- relative_start_beat can be negative (notes before window)
- Keep original duration instead of clamping
---
 app/static/js/services/ghostNoteExtractor.js | 10 +++-----
 app/static/js/services/soundfontPlayer.js    | 24 ++++++++++++--------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/app/static/js/services/ghostNoteExtractor.js b/app/static/js/services/ghostNoteExtractor.js
index bf02e01..38a416e 100644
--- a/app/static/js/services/ghostNoteExtractor.js
+++ b/app/static/js/services/ghostNoteExtractor.js
@@ -40,17 +40,13 @@
           var noteAbsStart = itemStartBeat + (note.start_beat || 0);
           var noteAbsEnd = noteAbsStart + (note.duration_beats || 1);
 
-          if (noteAbsStart >= windowEndBeat || noteAbsEnd < windowStartBeat) continue;
-
-          var clampedStart = Math.max(noteAbsStart, windowStartBeat);
-          var clampedEnd = Math.min(noteAbsEnd, windowEndBeat);
-          var clampedDur = clampedEnd - clampedStart;
+          if (noteAbsStart >= windowEndBeat) continue;
 
           trackGhostNotes.push({
             id: 'ghost_' + (note.id || Math.random().toString(36).substr(2, 9)),
             pitch: note.pitch,
-            relative_start_beat: clampedStart - windowStartBeat,
-            duration_beats: clampedDur,
+            relative_start_beat: noteAbsStart - windowStartBeat,
+            duration_beats: (note.duration_beats || 1),
             velocity: note.velocity,
             original_track_name: track.name,
             original_track_color: track.color || '#888888'
diff --git a/app/static/js/services/soundfontPlayer.js b/app/static/js/services/soundfontPlayer.js
index 08812bb..4edc156 100644
--- a/app/static/js/services/soundfontPlayer.js
+++ b/app/static/js/services/soundfontPlayer.js
@@ -233,9 +233,13 @@
             }
             var engKey = (sfId || '') + ':' + bank + ':' + program;
             if (!_engineChMap[engKey]) {
-                var allocCh = this.allocateChannel(bank);
-                _engineChMap[engKey] = allocCh;
-                channel = allocCh;
+                if (channel === undefined || channel === null) {
+                    var allocCh = this.allocateChannel(bank);
+                    _engineChMap[engKey] = allocCh;
+                    channel = allocCh;
+                } else {
+                    _engineChMap[engKey] = channel;
+                }
             } else {
                 channel = _engineChMap[engKey];
             }
@@ -363,12 +367,14 @@
             if (synthEngine) {
                 usedBank = synthEngine.soundfont_bank || 0;
                 usedProg = synthEngine.soundfont_program || 0;
-                var engKey = (synthEngine.soundfont_id || '') + ':' + usedBank + ':' + usedProg;
-                var mappedCh = _engineChMap[engKey];
-                if (mappedCh !== undefined) {
-                    ch = mappedCh;
-                } else if (ch === undefined) {
-                    ch = usedBank === 128 ? 9 : 0;
+                if (ch === undefined) {
+                    var engKey = (synthEngine.soundfont_id || '') + ':' + usedBank + ':' + usedProg;
+                    var mappedCh = _engineChMap[engKey];
+                    if (mappedCh !== undefined) {
+                        ch = mappedCh;
+                    } else {
+                        ch = usedBank === 128 ? 9 : 0;
+                    }
                 }
                 if (ch === undefined) ch = (usedBank === 128 ? 9 : 0);
                 var sfHandle = synthEngine.soundfont_id ? _sfHandleMap.get(synthEngine.soundfont_id) : undefined;