Address review: sparse overrides, hfov clear, readout prune

Three fixes from PR review of the per-pane tuner:

- Sync no longer writes back. _syncAspectPanel dispatches synthetic input
  events to refresh slider labels; guard those with _aspectSyncing so the
  slider handler skips the write. Previously opening/switching a target
  populated a full override for every field (defeating sparse inherit) and
  spammed localStorage.

- Unchecking "Override held hFOV" on a pane target now clears the override
  key (via _aspectClearVal) so the pane re-inherits the base value, instead
  of pinning hfovDeg:null in the override. On the base target it still sets
  the explicit auto (null).

- _aspectPrunePanes now prunes the matching __h3dAspectReadout slot and drops
  a dangling __last, so the readout cache can't grow unbounded as songs and
  arrangements churn.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: topkoa <topkoa@gmail.com>

plugins/highway_3d/screen.js

@@ -1773,11 +1773,23 @@
         const reg = window.__h3dAspectPanes;
         if (!reg) return;
         const now = _aspectNowMs();
+        const ro = window.__h3dAspectReadout;
         Object.keys(reg).forEach((k) => {
-            if (now - (reg[k].seen || 0) > 1500) { delete reg[k]; _aspectPanesDirty = true; }
+            if (now - (reg[k].seen || 0) > 1500) {
+                delete reg[k];
+                // Prune the matching readout slot so it can't grow unbounded as
+                // songs/arrangements churn, and drop a dangling __last pointer.
+                if (ro) { delete ro[k]; if (ro.__last === k) delete ro.__last; }
+                _aspectPanesDirty = true;
+            }
         });
     }
 
+    // True while _syncAspectPanel is programmatically refreshing controls, so the
+    // synthetic 'input' events it dispatches to update labels don't write back
+    // into the tune (which would populate a full override for every field and
+    // spam localStorage). Real user input runs with this false.
+    let _aspectSyncing = false;
     // Read/write against the current edit target ('' → base, else pane override).
     function _aspectReadVal(k) {
         const base = _aspectTune();
@@ -1794,6 +1806,18 @@
         }
         _aspectPersist();
     }
+    // Clear a field: for the base target set the explicit auto value (null); for a
+    // pane target delete the override key so the pane re-inherits the base value
+    // (and drop the pane's override object once it's empty).
+    function _aspectClearVal(k) {
+        const base = _aspectTune();
+        if (!_aspectEditTarget) { base[k] = null; }
+        else {
+            const m = base.__panels, ov = m && m[_aspectEditTarget];
+            if (ov) { delete ov[k]; if (!Object.keys(ov).length) delete m[_aspectEditTarget]; }
+        }
+        _aspectPersist();
+    }
 
     // (Re)build the Target dropdown from the live pane registry, preserving the
     // current selection when it's still valid.
@@ -1892,7 +1916,8 @@
             const show = () => { val.textContent = (+sl.value).toFixed(f.step < 1 ? 2 : 0); };
             show();
             sl.addEventListener('input', () => {
-                _aspectWriteVal(f.k, parseFloat(sl.value)); show();
+                show();                                   // label always refreshes
+                if (!_aspectSyncing) _aspectWriteVal(f.k, parseFloat(sl.value));
             });
             row.appendChild(sl); wrap.appendChild(row);
         });
@@ -1913,11 +1938,13 @@
             sl.disabled = !cb.checked;
             sl.style.cssText = 'width:100%;';
             cb.addEventListener('change', () => {
+                if (_aspectSyncing) return;
                 sl.disabled = !cb.checked;
-                _aspectWriteVal('hfovDeg', cb.checked ? parseFloat(sl.value) : null);
+                if (cb.checked) _aspectWriteVal('hfovDeg', parseFloat(sl.value));
+                else _aspectClearVal('hfovDeg');   // base → auto (null); pane → re-inherit base
             });
             sl.addEventListener('input', () => {
-                if (cb.checked) _aspectWriteVal('hfovDeg', parseFloat(sl.value));
+                if (!_aspectSyncing && cb.checked) _aspectWriteVal('hfovDeg', parseFloat(sl.value));
             });
             row.appendChild(sl); wrap.appendChild(row);
             _aspectHfovCb = cb; _aspectHfovSl = sl;
@@ -1972,19 +1999,27 @@
     function _syncAspectPanel() {
         if (!_aspectPanelEl) return;
         _aspectBuildTargets();
-        _aspectPanelEl.querySelectorAll('input[type=checkbox][data-k]').forEach((cb) => {
+        // Guard so the synthetic 'input' events below only refresh labels and
-            cb.checked = !!_aspectReadVal(cb.dataset.k);
+        // don't write the read-back values into the target (which would turn a
-        });
+        // sparse pane override into a full one and spam localStorage).
-        _aspectPanelEl.querySelectorAll('input[type=range][data-k]').forEach((sl) => {
+        _aspectSyncing = true;
-            const v = _aspectReadVal(sl.dataset.k);
+        try {
-            if (Number.isFinite(v)) sl.value = v;
+            _aspectPanelEl.querySelectorAll('input[type=checkbox][data-k]').forEach((cb) => {
-            sl.dispatchEvent(new Event('input'));   // refresh the value label
+                cb.checked = !!_aspectReadVal(cb.dataset.k);
-        });
+            });
-        if (_aspectHfovCb) {
+            _aspectPanelEl.querySelectorAll('input[type=range][data-k]').forEach((sl) => {
-            const hv = _aspectReadVal('hfovDeg');
+                const v = _aspectReadVal(sl.dataset.k);
-            _aspectHfovCb.checked = Number.isFinite(hv);
+                if (Number.isFinite(v)) sl.value = v;
-            _aspectHfovSl.disabled = !_aspectHfovCb.checked;
+                sl.dispatchEvent(new Event('input'));   // refresh the value label only
-            if (Number.isFinite(hv)) _aspectHfovSl.value = hv;
+            });
+            if (_aspectHfovCb) {
+                const hv = _aspectReadVal('hfovDeg');
+                _aspectHfovCb.checked = Number.isFinite(hv);
+                _aspectHfovSl.disabled = !_aspectHfovCb.checked;
+                if (Number.isFinite(hv)) _aspectHfovSl.value = hv;
+            }
+        } finally {
+            _aspectSyncing = false;
         }
     }
 

tests/js/highway_3d_wide_fov.test.js

@@ -207,6 +207,34 @@ test('the target dropdown prunes dead panes and does not rebuild while focused',
         '_aspectBuildTargets must skip rebuilding while the select is focused');
 });
 
+test('programmatic sync does not write back into the tune', () => {
+    // _syncAspectPanel dispatches synthetic input events to refresh labels; the
+    // slider handler must skip the write while syncing, else opening/switching a
+    // target would populate a full override for every field.
+    assert.match(src, /_aspectSyncing\s*=\s*true[\s\S]*?finally[\s\S]*?_aspectSyncing\s*=\s*false/,
+        '_syncAspectPanel must set/reset the _aspectSyncing guard');
+    assert.match(src, /if\s*\(\s*!_aspectSyncing\s*\)\s*_aspectWriteVal\(\s*f\.k\s*,/,
+        'the slider input handler must skip the write while syncing');
+});
+
+test('unchecking hfov override clears a pane override key (re-inherits base)', () => {
+    assert.match(
+        src,
+        /function\s+_aspectClearVal\s*\(\s*k\s*\)[\s\S]*?delete\s+ov\[k\][\s\S]*?delete\s+m\[\s*_aspectEditTarget\s*\]/,
+        '_aspectClearVal must delete the pane override key (and empty object)',
+    );
+    assert.match(src, /else\s+_aspectClearVal\(\s*'hfovDeg'\s*\)/,
+        'unchecking the hfov override must call _aspectClearVal');
+});
+
+test('pruning drops the matching readout slot and a dangling __last', () => {
+    assert.match(
+        src,
+        /delete\s+reg\[k\]\s*;[\s\S]*?delete\s+ro\[k\]\s*;\s*if\s*\(\s*ro\.__last\s*===\s*k\s*\)\s*delete\s+ro\.__last/,
+        '_aspectPrunePanes must prune the readout cache alongside the registry',
+    );
+});
+
 test('the panel has a dismiss (close) control', () => {
     assert.match(
         src,