v0.8.11: code cleanup, HeaderBar always visible, lazy chop real-time slices

Priority 1 bugs:
- getTailLengthSeconds() returns 5.0 (max ADSR release); was 0 — VST contract violation
- GrainEngine BPM calc: keep double arithmetic, cast at end (was discarding precision)
- Voice muteGroup default changed from 0 to 1 to match slice creation default
- AdsrEnvelope: document 0.00015f (~-76 dB) and 1.01f (asymptotic curve) magic numbers

Design cleanup:
- UIHelpers.h (new): computeDragValue(), computeZoomFactor(), UILayout::waveformVerticalScale
- HeaderBar: extract paintRow1/paintRow2; use UIHelpers::computeDragValue()
- SliceControlBar: use UIHelpers::computeDragValue() (eliminate duplication)
- ScrollZoomBar: use UIHelpers::computeZoomFactor()
- WaveformView: encapsulate sliceDrawMode; CacheKey struct; extract paint helpers; use UIHelpers
- ActionPanel/PluginEditor: use WaveformView::setSliceDrawMode/isSliceDrawModeActive()
- PluginEditor: scaleDirty bool replaces -1.0f sentinel
- VoicePool: add const getVoice() overload; document audio constants

Features:
- HeaderBar now always shows parameter controls (Row1+Row2) even with no sample loaded;
  waveform area already shows drop hint so HeaderBar was redundant
- Lazy chop: slices now appear in the UI immediately on each MIDI note press instead
  of waiting until lazy chop is stopped (uiSnapshotDirty was gated behind midiSelectsSlice)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tucktuckg00se

src/PluginEditor.cpp

@@ -150,10 +150,7 @@ bool IntersectEditor::keyPressed (const juce::KeyPress& key)
     // A — Add Slice mode
     if (code == 'A')
     {
-        waveformView.sliceDrawMode = ! waveformView.sliceDrawMode;
-        waveformView.setMouseCursor (waveformView.sliceDrawMode
-            ? juce::MouseCursor::IBeamCursor
-            : juce::MouseCursor::NormalCursor);
+        waveformView.setSliceDrawMode (! waveformView.isSliceDrawModeActive());
         repaint();
         return true;
     }
@@ -275,10 +272,11 @@ void IntersectEditor::timerCallback()
         viewportChanged = true;
     }
 
-    // Check if scale changed (lastScale starts at -1 so first tick always applies)
+    // Check if scale changed; scaleDirty forces application on first timer tick
     float scale = processor.apvts.getRawParameterValue (ParamIds::uiScale)->load();
-    if (scale != lastScale)
+    if (scaleDirty || scale != lastScale)
     {
+        scaleDirty = false;
         lastScale = scale;
         setTransform (juce::AffineTransform::scale (scale));
         IntersectLookAndFeel::setMenuScale (scale);

src/PluginEditor.h

@@ -30,7 +30,8 @@ class IntersectEditor : public juce::AudioProcessorEditor,
     void loadUserSettings();
 
     IntersectProcessor& processor;
-    float lastScale = -1.0f;  // sentinel so first timer tick always applies
+    float lastScale = 1.0f;   // last applied scale value, compared each tick
+    bool scaleDirty = true;   // forces scale application on first timer tick
     float lastZoom = -1.0f;
     float lastScroll = -1.0f;
     int timerHz = 30;

src/PluginProcessor.cpp

@@ -905,12 +905,11 @@ void IntersectProcessor::processMidi (const juce::MidiBuffer& midi)
             {
                 // Any MIDI note places a chop boundary at the playhead
                 int newSliceIdx = lazyChop.onNote (note, voicePool, sliceManager);
-                if (midiSelectsSlice.load (std::memory_order_relaxed) && newSliceIdx >= 0)
+                if (newSliceIdx >= 0)
                 {
-                    const int previous = sliceManager.selectedSlice.load (std::memory_order_relaxed);
-                    sliceManager.selectedSlice.store (newSliceIdx, std::memory_order_relaxed);
-                    if (previous != newSliceIdx)
-                        uiSnapshotDirty.store (true, std::memory_order_release);
+                    uiSnapshotDirty.store (true, std::memory_order_release);
+                    if (midiSelectsSlice.load (std::memory_order_relaxed))
+                        sliceManager.selectedSlice.store (newSliceIdx, std::memory_order_relaxed);
                 }
             }
             else

src/PluginProcessor.h

@@ -27,7 +27,7 @@ class IntersectProcessor : public juce::AudioProcessor
     const juce::String getName() const override { return "INTERSECT"; }
     bool acceptsMidi() const override { return true; }
     bool producesMidi() const override { return true; }
-    double getTailLengthSeconds() const override { return 0.0; }
+    double getTailLengthSeconds() const override { return 5.0; }  // max ADSR release is 5000 ms
 
     int getNumPrograms() override { return 1; }
     int getCurrentProgram() override { return 0; }

src/audio/AdsrEnvelope.h

@@ -62,7 +62,7 @@ class AdsrEnvelope
             case Release:
                 // Multiply by the per-sample decay factor = exp(-5 / (releaseTime * sr))
                 level *= (1.0f - releaseCoeff);
-                if (level < 0.00015f)
+                if (level < 0.00015f)  // ≈ -76 dB, treated as inaudible; avoids infinite exponential decay
                 {
                     level = 0.0f;
                     state = Done;

src/audio/GrainEngine.cpp

@@ -4,5 +4,5 @@ float GrainEngine::calcStretchBpm (int startSample, int endSample, float timeUni
 {
     double durationSec = (endSample - startSample) / sampleRate;
     float beats = timeUnitBars * 4.0f;  // 4 beats per bar
-    return durationSec > 0.0 ? (beats / (float) durationSec) * 60.0f : 120.0f;
+    return durationSec > 0.0 ? static_cast<float> ((double) beats / durationSec * 60.0) : 120.0f;
 }

src/audio/Voice.h

@@ -26,7 +26,7 @@ struct Voice
     int          startSample  = 0;
     int          endSample    = 0;
     bool         pingPong     = false;
-    int          muteGroup    = 0;
+    int          muteGroup    = 1;  // default matches slice creation default; always overwritten in startVoice()
     bool         looping      = false;
     float        volume       = 1.0f;
     bool         releaseTail  = false;

src/audio/VoicePool.cpp

@@ -9,8 +9,8 @@
 #include <algorithm>
 #include <cmath>
 
-static constexpr int kStretchBlockSize = 128;
-static constexpr int kMaxStretchInputSamples = 8192;
+static constexpr int kStretchBlockSize = 128;        // required block size for Signalsmith Stretch processing
+static constexpr int kMaxStretchInputSamples = 8192; // max pre-roll/input feed size (empirically tuned)
 static constexpr int kMaxBungeeInputFrames = 8192;
 static constexpr int kMaxBungeeOutputFrames = 8192;
 

src/audio/VoicePool.h

@@ -68,6 +68,7 @@ class VoicePool
     int  getMaxActiveVoices() const { return maxActive; }
 
     Voice& getVoice (int idx) { return voices[idx]; }
+    const Voice& getVoice (int idx) const { return voices[idx]; }
 
     void startShiftPreview (int startSample, int bufferSize, double sr, const SampleData& sd);
     void stopShiftPreview();

src/ui/ActionPanel.cpp

@@ -25,10 +25,7 @@ ActionPanel::ActionPanel (IntersectProcessor& p, WaveformView& wv)
     }
 
     addSliceBtn.onClick = [this] {
-        waveformView.sliceDrawMode = ! waveformView.sliceDrawMode;
-        waveformView.setMouseCursor (waveformView.sliceDrawMode
-            ? juce::MouseCursor::IBeamCursor
-            : juce::MouseCursor::NormalCursor);
+        waveformView.setSliceDrawMode (! waveformView.isSliceDrawModeActive());
         repaint();
     };
 
@@ -152,7 +149,7 @@ void ActionPanel::paint (juce::Graphics& g)
     updateSnapButtonAppearance (processor.snapToZeroCrossing.load());
 
     // Highlight +SLC if in draw mode
-    if (waveformView.sliceDrawMode)
+    if (waveformView.isSliceDrawModeActive())
     {
         g.setColour (getTheme().accent.withAlpha (0.25f));
         g.fillRect (addSliceBtn.getBounds());