fix: taud note with SDx not firing due to unbound inst

CLAUDE.md

@@ -165,6 +165,14 @@ Peripheral memories can be accessed using `vm.peek()` and `vm.poke()` functions,
 
 - The 'gzip' namespace in TSVM's JS programs is a misnomer: the actual 'gzip' functions (defined in CompressorDelegate.kt) call Zstd functions.
 
+## Taud Tracker Engine
+
+The Taud playback engine lives in `tsvm_core/src/net/torvald/tsvm/peripheral/AudioAdapter.kt`.
+
+### Critical Implementation Notes
+
+**Re-bind the local `inst` after any mid-tick `triggerNote`.** `applyTrackerTick` binds `var inst = instruments[voice.instrumentId]` once at the top of the per-voice loop. When the note-delay (`S$Dx`) deferred trigger fires mid-tick, `triggerNote` swaps the voice's `instrumentId` — but the rest of that tick (playback-rate recompute at the `computePlaybackRate(inst, finalPitch)` line, `advanceEnvelope`, `advancePfEnvelope`, `advanceAutoVibrato`, and the fadeout / filter-env reads of `inst.*`) keeps using the captured binding. The damage on a **never-triggered voice** (`instrumentId == 0` → stale `inst = instruments[0]`, whose `samplingRate == 0`) is that `playbackRate` is overwritten with `0.0`, freezing the sample at its start for the trigger tick — perceived as "the first delayed note on a fresh channel doesn't fire" (canonical: WHEN.taud cue 0 voice 13 pattern 0x0A row 16, inst `0x11` SD2 on a fresh play). On a warm voice the stale `inst` is a real instrument with non-zero rate, so the note sounds (at the wrong rate for one tick — a sub-perceptual glitch). Re-bind `inst = instruments[voice.instrumentId]` immediately after the note-delay fire block. Any future in-tick trigger paths (currently only S$Dx) must do the same.
+
 ## TVDOS
 
 ### TVDOS Movie Formats

assets/disk0/tvdos/bin/taut.js

@@ -4829,10 +4829,19 @@ function nudgeTickRate(delta) {
     drawAlwaysOnElems()
 }
 
+// Drop accumulated funk-repeat (S$Fx) run-state and loop-inversion masks so a fresh play
+// starts deterministic instead of inheriting a prior session's funkSpeed / inverted bytes.
+// Engine still keeps PT2-style persistence across a natural loop; older runtimes lacking the
+// API simply retain the inversions.
+function clearFunkState() {
+    if (typeof audio.resetFunkState === 'function') audio.resetFunkState(PLAYHEAD)
+}
+
 function startPlaySong() {
     restoreFullSongParams()
     reuploadPatternsIfNeeded()
     audio.stop(PLAYHEAD)
+    clearFunkState()
     audio.setCuePosition(PLAYHEAD, cueIdx)
     audio.setTrackerRow(PLAYHEAD, 0)
     cursorRow = 0
@@ -4847,6 +4856,7 @@ function startPlayCue() {
     restoreFullSongParams()
     reuploadPatternsIfNeeded()
     audio.stop(PLAYHEAD)
+    clearFunkState()
     audio.setCuePosition(PLAYHEAD, cueIdx)
     audio.setTrackerRow(PLAYHEAD, 0)
     playStartCue = cueIdx
@@ -4864,6 +4874,7 @@ function startPlayRow(fromRow, fromCue) {
     if (fromRow === undefined) fromRow = cursorRow
     if (fromCue === undefined) fromCue = cueIdx
     audio.stop(PLAYHEAD)
+    clearFunkState()
     audio.setCuePosition(PLAYHEAD, fromCue)
     audio.setTrackerRow(PLAYHEAD, fromRow)
     playStartCue = fromCue
@@ -4880,6 +4891,7 @@ function startPlayPattern() {
     audio.stop(PLAYHEAD)
     audio.setBPM(PLAYHEAD, song.bpm)
     audio.uploadCue(PREVIEW_CUE_IDX, buildPreviewCue(patternIdx))
+    clearFunkState()
     audio.setCuePosition(PLAYHEAD, PREVIEW_CUE_IDX)
     audio.setTrackerRow(PLAYHEAD, 0)
     playStartCue = PREVIEW_CUE_IDX
@@ -4896,6 +4908,7 @@ function startPlayPatternRow() {
     audio.stop(PLAYHEAD)
     audio.setBPM(PLAYHEAD, song.bpm)
     audio.uploadCue(PREVIEW_CUE_IDX, buildPreviewCue(patternIdx))
+    clearFunkState()
     audio.setCuePosition(PLAYHEAD, PREVIEW_CUE_IDX)
     audio.setTrackerRow(PLAYHEAD, patternGridRow)
     playStartCue = PREVIEW_CUE_IDX

terranmon.txt

@@ -2409,8 +2409,9 @@ TODO:
     [x] expose song table on UI (test with `insaniq2.taud`)
     [x] 0x0000 - no-op; 0x0001 - key-off; 0x0002 - note-cut 0x0010..0x001F - INT0..INTF
         [ ] establish hooks for the interrupts
-    [ ] Samples and Instruments view (viewer on taut.js; editor on separate .js)
+    [x] Samples and Instruments view (viewer on taut.js; editor on separate .js)
         follow the ImpulseTracker design first, then improve from there
+    [ ] Sample desig for instrument in Pitch-Volume space (one rectangle = one patch). If undefined, the old sample pointer falls thru
 
 TODO - list of demo songs that MUST ship with Microtone:
     * 4THSYM (rename to Fourth Symmetriad) — excellent piece for demonstrating NNAs and filter envelopes

tsvm_core/src/net/torvald/tsvm/AudioJSR223Delegate.kt

@@ -315,6 +315,13 @@ class AudioJSR223Delegate(private val vm: VM) {
         getPlayhead(playhead)?.resetParams()
     }
 
+    /** Clear funk-repeat (S$Fx) state (per-voice run-state + per-instrument loop-inversion masks)
+     *  without disturbing tempo / volume / position. Call on a fresh play-from-start so stale funk
+     *  state from a prior playback doesn't bleed into the replay. */
+    fun resetFunkState(playhead: Int) {
+        getPlayhead(playhead)?.resetFunkState()
+    }
+
     fun purgeQueue(playhead: Int) {
         getPlayhead(playhead)?.purgeQueue()
     }

tsvm_core/src/net/torvald/tsvm/peripheral/AudioAdapter.kt

@@ -2905,7 +2905,7 @@ class AudioAdapter(val vm: VM) : PeriBase(VM.PERITYPE_SOUND) {
         for (vi in 0 until ts.voices.size) {
             val voice = ts.voices[vi]
             if (!voice.active && voice.noteDelayTick < 0) continue
-            val inst = instruments[voice.instrumentId]
+            var inst = instruments[voice.instrumentId]
 
             // Note cut. Zero noteVolume / rowVolume (silence this note) but leave channelVolume
             // alone — IT's note cut stops the sample, it doesn't reset chan->global_volume.
@@ -2921,6 +2921,13 @@ class AudioAdapter(val vm: VM) : PeriBase(VM.PERITYPE_SOUND) {
                 maybeSpawnBackgroundForNNA(ts, voice, vi)
                 triggerNote(voice, voice.delayedNote, voice.delayedInst, voice.delayedVol)
                 voice.noteDelayTick = -1
+                // triggerNote may have swapped in a new instrument; re-bind so the rest of this
+                // tick's per-voice work (playbackRate at L3090, envelope/fadeout/auto-vibrato)
+                // uses the instrument that just fired, not the one the voice held on entry. On a
+                // never-triggered voice the stale binding is instruments[0] (samplingRate 0),
+                // which would zero playbackRate and freeze the sample — the "first note on a
+                // fresh channel via S$Dx is silent" bug.
+                inst = instruments[voice.instrumentId]
             }
 
             if (!voice.active) {
@@ -4094,6 +4101,20 @@ class AudioAdapter(val vm: VM) : PeriBase(VM.PERITYPE_SOUND) {
             }
         }
 
+        /** Clear funk-repeat (S$Fx) state only — per-voice run-state plus the per-instrument
+         *  loop-inversion masks — without touching tempo / volume / position. taut calls this on
+         *  every fresh play-from-start so accumulated inversions and a stale funkSpeed don't bleed
+         *  from a prior session into the replay; full resetParams would also clobber bpm / tickRate /
+         *  volume, which a replay must preserve. Masks still persist across a natural song loop. */
+        fun resetFunkState() {
+            trackerState?.voices?.forEach {
+                it.funkSpeed = 0
+                it.funkAccumulator = 0
+                it.funkWritePos = 0
+            }
+            parent.instruments.forEach { it.funkMask = null }
+        }
+
         fun purgeQueue() {
             pcmQueue.clear()
             if (isPcmMode) {