perf(gui): skip unchanged repaints and gate updates by tab

Add change detection to Display, WaveformDisplay, FilterDisplay,
EnvelopeDisplay, and LFODisplay so repaint() is only called when
values actually change. Gate updateVisuals() by currentTab so only
the visible tab's displays are updated each timer tick. Similarly
gate updateModList/updateMacroList to their respective tabs.

Manage dynamically created controls via ownedControls
unique_ptr vector instead of raw new leaks. Null-check parameter
lookups before creating attachments. Hold engine control lock
when reading matrix/macros/LFO shape data.

Fix envelope display curve directions (attack rising from bottom,
decay falling toward sustain, release falling toward bottom).
Add tooltip to FilterDisplay noting the approximation. Replace
ToggleButton raw param pointer with ParameterAttachment for proper
gesture handling. Sync preset and scale combos to processor state.

Source/GUI/Display.h

@@ -12,8 +12,8 @@ namespace serum
 class Display : public juce::Component
 {
 public:
-    void setTitle (const juce::String& t) { title = t; repaint(); }
+    void setTitle (const juce::String& t) { if (title != t) { title = t; repaint(); } }
-    void setValue (const juce::String& v) { value = v; repaint(); }
+    void setValue (const juce::String& v) { if (value != v) { value = v; repaint(); } }
 
     void paint (juce::Graphics& g) override;
 

Source/GUI/EnvelopeDisplay.cpp

@@ -5,7 +5,10 @@ namespace serum
 
 void EnvelopeDisplay::setParams (float a, float d, float s, float r, float c)
 {
+    if (attack == a && decay == d && sustain == s && release == r && curve == c)
+        return;
     attack = a; decay = d; sustain = s; release = r; curve = c;
+    repaint();
 }
 
 void EnvelopeDisplay::paint (juce::Graphics& g)
@@ -19,7 +22,7 @@ void EnvelopeDisplay::paint (juce::Graphics& g)
     const float atkShape = 0.3f + curve * 2.7f;
     const float decShape = 3.0f - curve * 2.7f;
 
-    // Normalise durations for display (attack 0..1, decay 0..0.6, release 0..0.6).
+    // Normalise durations for display, allowing a short sustain plateau.
     const float aSec = maps::toSeconds (attack);
     const float dSec = maps::toSeconds (decay);
     const float rSec = maps::toSeconds (release);
@@ -36,7 +39,6 @@ void EnvelopeDisplay::paint (juce::Graphics& g)
 
     juce::Path path;
     path.startNewSubPath (left, bottom);
-    path.lineTo (left, top);
 
     // Attack (curve-shaped).
     const int steps = 48;
@@ -44,7 +46,7 @@ void EnvelopeDisplay::paint (juce::Graphics& g)
     for (int i = 0; i <= steps; ++i)
     {
         const float p = (float) i / steps;
-        const float y = top + (bottom - top) * std::pow (p, atkShape);
+        const float y = bottom - (bottom - top) * std::pow (p, atkShape);
         path.lineTo (left + p * (peakX - left), y);
     }
 
@@ -53,7 +55,7 @@ void EnvelopeDisplay::paint (juce::Graphics& g)
     for (int i = 0; i <= steps; ++i)
     {
         const float p = (float) i / steps;
-        const float y = sustainY + (bottom - sustainY) * std::pow (1.0f - p, decShape);
+        const float y = sustainY + (top - sustainY) * std::pow (1.0f - p, decShape);
         path.lineTo (peakX + p * (decX - peakX), y);
     }
     path.lineTo (decX, sustainY);
@@ -64,7 +66,7 @@ void EnvelopeDisplay::paint (juce::Graphics& g)
     for (int i = 0; i <= steps; ++i)
     {
         const float p = (float) i / steps;
-        const float y = sustainY + (bottom - sustainY) * std::pow (1.0f - p, decShape);
+        const float y = bottom - (bottom - sustainY) * std::pow (1.0f - p, decShape);
         path.lineTo (relStartX + p * (right - relStartX), y);
     }
 

Source/GUI/FilterDisplay.cpp

@@ -37,7 +37,10 @@ float FilterDisplay::magnitude (float freqHz, float cutoffHz, float res, int typ
 
 void FilterDisplay::setParams (int t, float c, float r, float d, int s)
 {
+    if (type == t && cutoff == c && res == r && drive == d && slope == s)
+        return;
     type = t; cutoff = c; res = r; drive = d; slope = s;
+    repaint();
 }
 
 void FilterDisplay::paint (juce::Graphics& g)

Source/GUI/FilterDisplay.h

@@ -8,13 +8,15 @@ namespace serum
 {
 
 // ===========================================================================
-// Filter frequency-response view (magnitude vs log frequency).
+// Approximate filter frequency-response view (magnitude vs log frequency).
 // ===========================================================================
-class FilterDisplay : public juce::Component
+class FilterDisplay : public juce::Component,
+                      public juce::SettableTooltipClient
 {
 public:
+    FilterDisplay() { setTooltip ("Approximate response preview; slope, drive and modulation are not modelled."); }
     void setParams (int type, float cutoff, float res, float drive, int slope);
-    void setEnabled (bool e) { enabled = e; }
+    void setEnabled (bool e) { if (enabled != e) { enabled = e; repaint(); } }
 
     void paint (juce::Graphics& g) override;
 

Source/GUI/LFODisplay.cpp

@@ -5,10 +5,16 @@ namespace serum
 
 void LFODisplay::setShapeData (const std::vector<float>& data, int s)
 {
-    steps = juce::jlimit (2, 64, s);
+    const int newSteps = juce::jlimit (2, 64, s);
-    shapeData = data;
+    const size_t dataSize = std::min (data.size(), size_t (64));
-    if ((int) shapeData.size() < 64)
+    if (steps == newSteps && shapeData.size() == 64
-        shapeData.resize (64, 0.0f);
+        && std::equal (data.begin(), data.begin() + dataSize, shapeData.begin())
+        && std::all_of (shapeData.begin() + dataSize, shapeData.end(), [] (float v) { return v == 0.0f; }))
+        return;
+
+    steps = newSteps;
+    shapeData.assign (data.begin(), data.begin() + dataSize);
+    shapeData.resize (64, 0.0f);
     repaint();
 }
 

Source/GUI/LFODisplay.h

@@ -13,7 +13,7 @@ namespace serum
 class LFODisplay : public juce::Component
 {
 public:
-    void setShape (int s) { shape = s; repaint(); }
+    void setShape (int s) { if (shape != s) { shape = s; repaint(); } }
     void setShapeData (const std::vector<float>& data, int steps);
     void setOnShapeEdited (std::function<void (const std::vector<float>&, int)> cb) { onEdited = std::move (cb); }
 

Source/GUI/ToggleButton.cpp

@@ -10,12 +10,12 @@ ToggleButton::ToggleButton (const juce::String& lbl) : label (lbl)
 
 void ToggleButton::attach (juce::AudioProcessorValueTreeState& apvts, const juce::String& paramId)
 {
-    param = apvts.getParameter (paramId);
+    attachment.reset();
-    if (param != nullptr)
+    if (auto* param = apvts.getParameter (paramId))
     {
-        state = param->getValue() > 0.5f;
         attachment = std::make_unique<juce::ParameterAttachment> (*param,
             [this] (float newValue) { setToggleState (newValue > 0.5f); });
+        attachment->sendInitialUpdate();
     }
 }
 
@@ -60,9 +60,9 @@ void ToggleButton::mouseDown (const juce::MouseEvent&)
     {
         onClick (newState);
     }
-    else if (param != nullptr)
+    else if (attachment != nullptr)
     {
-        param->setValueNotifyingHost (newState ? 1.0f : 0.0f);
+        attachment->setValueAsCompleteGesture (newState ? 1.0f : 0.0f);
     }
 
     setToggleState (newState);

Source/GUI/ToggleButton.h

@@ -35,7 +35,6 @@ public:
 private:
     bool        state = false;
     juce::String label;
-    juce::RangedAudioParameter* param = nullptr;
     std::unique_ptr<juce::ParameterAttachment> attachment;
     std::function<void (bool)> onClick;
     juce::Colour onColour = theme::accent;

Source/GUI/WaveformDisplay.h

@@ -13,10 +13,10 @@ namespace serum
 class WaveformDisplay : public juce::Component
 {
 public:
-    void setWavetables (const WavetableLibrary* lib) { wtLib = lib; }
+    void setWavetables (const WavetableLibrary* lib) { if (wtLib != lib) { wtLib = lib; repaint(); } }
-    void setWaveIndex (int index) { wave = index; }
+    void setWaveIndex (int index) { if (wave != index) { wave = index; repaint(); } }
-    void setFramePosition (float pos) { wtPos = pos; }
+    void setFramePosition (float pos) { if (wtPos != pos) { wtPos = pos; repaint(); } }
-    void setEnabled (bool e) { enabled = e; }
+    void setEnabled (bool e) { if (enabled != e) { enabled = e; repaint(); } }
 
     void paint (juce::Graphics& g) override;
 

Source/PluginEditor.cpp

@@ -94,18 +94,25 @@ namespace
             knobs[(size_t) i]->setBounds (x + i * (w + gap), y, w, h);
     }
 
-    const char* kFxType[8] = { ids::fx1Type, ids::fx2Type, ids::fx3Type, ids::fx4Type,
+    constexpr auto& kFxType = paramIds::fxType;
-                               ids::fx5Type, ids::fx6Type, ids::fx7Type, ids::fx8Type };
+    constexpr auto& kFxMix = paramIds::fxMix;
-    const char* kFxMix[8]  = { ids::fx1Mix, ids::fx2Mix, ids::fx3Mix, ids::fx4Mix,
+    constexpr auto& kFxP1 = paramIds::fxP1;
-                               ids::fx5Mix, ids::fx6Mix, ids::fx7Mix, ids::fx8Mix };
+    constexpr auto& kFxP2 = paramIds::fxP2;
-    const char* kFxP1[8]   = { ids::fx1P1, ids::fx2P1, ids::fx3P1, ids::fx4P1,
+    constexpr auto& kFxP3 = paramIds::fxP3;
-                               ids::fx5P1, ids::fx6P1, ids::fx7P1, ids::fx8P1 };
+    constexpr auto& kFxP4 = paramIds::fxP4;
-    const char* kFxP2[8]   = { ids::fx1P2, ids::fx2P2, ids::fx3P2, ids::fx4P2,
+
-                               ids::fx5P2, ids::fx6P2, ids::fx7P2, ids::fx8P2 };
+    constexpr const char* kFxParamNames[(int) FxType::Count][4] = {
-    const char* kFxP3[8]   = { ids::fx1P3, ids::fx2P3, ids::fx3P3, ids::fx4P3,
+        { "P1", "P2", "P3", "P4" },
-                               ids::fx5P3, ids::fx6P3, ids::fx7P3, ids::fx8P3 };
+        { "Intensity", "Low Amount", "High Amount", "Output" },
-    const char* kFxP4[8]   = { ids::fx1P4, ids::fx2P4, ids::fx3P4, ids::fx4P4,
+        { "Rate", "Depth", "Width", "Unused" },
-                               ids::fx5P4, ids::fx6P4, ids::fx7P4, ids::fx8P4 };
+        { "Rate", "Depth", "Feedback", "Unused" },
+        { "Rate", "Depth", "Feedback", "Stages" },
+        { "Drive", "Shape", "Tone", "Output" },
+        { "Low Gain", "Mid Gain", "High Gain", "Mid Freq" },
+        { "Threshold", "Ratio", "Attack", "Release" },
+        { "Time", "Feedback", "Damping", "Ping-Pong" },
+        { "Size", "Damping", "Width", "Predelay" }
+    };
 }
 
 // ---------------------------------------------------------------------------
@@ -131,7 +138,6 @@ PluginEditor::PluginEditor (SerumAltAudioProcessor& p)
     buildMacroTab();
 
     setTab (0);
-    applyUiScale();
     startTimerHz (30);
 }
 
@@ -163,9 +169,11 @@ Knob* PluginEditor::makeKnob (juce::Component* parent, const juce::String& name,
                               const juce::String& paramId, std::function<juce::String (float)> fmt,
                               const juce::String& tooltip)
 {
-    auto* k = new Knob (name, std::move (fmt));
+    auto control = std::make_unique<Knob> (name, std::move (fmt));
+    auto* k = control.get();
+    ownedControls.push_back (std::move (control));
     parent->addAndMakeVisible (k);
-    if (paramId.isNotEmpty())
+    if (paramId.isNotEmpty() && processor.parameters.getParameter (paramId) != nullptr)
         sliderAttachments.push_back (std::make_unique<juce::AudioProcessorValueTreeState::SliderAttachment> (
             processor.parameters, paramId, *k));
     k->setTooltip (tooltip.isNotEmpty() ? tooltip : name);
@@ -175,11 +183,13 @@ Knob* PluginEditor::makeKnob (juce::Component* parent, const juce::String& name,
 juce::ComboBox* PluginEditor::makeCombo (juce::Component* parent, const juce::String& paramId,
                                          const juce::StringArray& items, const juce::String& tooltip)
 {
-    auto* c = new juce::ComboBox();
+    auto control = std::make_unique<juce::ComboBox>();
+    auto* c = control.get();
+    ownedControls.push_back (std::move (control));
     c->addItemList (items, 1);
     c->setSelectedItemIndex (0, juce::dontSendNotification);
     parent->addAndMakeVisible (c);
-    if (paramId.isNotEmpty())
+    if (paramId.isNotEmpty() && processor.parameters.getParameter (paramId) != nullptr)
         comboAttachments.push_back (std::make_unique<juce::AudioProcessorValueTreeState::ComboBoxAttachment> (
             processor.parameters, paramId, *c));
     if (tooltip.isNotEmpty())
@@ -190,7 +200,9 @@ juce::ComboBox* PluginEditor::makeCombo (juce::Component* parent, const juce::St
 ToggleButton* PluginEditor::makeToggle (juce::Component* parent, const juce::String& label,
                                         const juce::String& paramId, const juce::String& tooltip)
 {
-    auto* t = new ToggleButton (label);
+    auto control = std::make_unique<ToggleButton> (label);
+    auto* t = control.get();
+    ownedControls.push_back (std::move (control));
     parent->addAndMakeVisible (t);
     if (paramId.isNotEmpty())
         t->attach (processor.parameters, paramId);
@@ -430,11 +442,11 @@ void PluginEditor::buildModTab()
         envDisplays[(size_t) i].setBounds (layout::padding, layout::titleHeight,
                                            colW - 2 * layout::padding, layout::envDisplayHeight);
 
-        const char* idsA[4] = { ids::env1A, ids::env2A, ids::env3A, ids::env4A };
+        const auto& idsA = paramIds::envAttack;
-        const char* idsD[4] = { ids::env1D, ids::env2D, ids::env3D, ids::env4D };
+        const auto& idsD = paramIds::envDecay;
-        const char* idsS[4] = { ids::env1S, ids::env2S, ids::env3S, ids::env4S };
+        const auto& idsS = paramIds::envSustain;
-        const char* idsR[4] = { ids::env1R, ids::env2R, ids::env3R, ids::env4R };
+        const auto& idsR = paramIds::envRelease;
-        const char* idsC[4] = { ids::env1Curve, ids::env2Curve, ids::env3Curve, ids::env4Curve };
+        const auto& idsC = paramIds::envCurve;
 
         std::vector<Knob*> knobs = {
             makeKnob (&envPanels[(size_t) i], "Attack", idsA[i], formatSeconds, "Attack time (0.5 ms - 12 s)"),
@@ -455,13 +467,13 @@ void PluginEditor::buildModTab()
         lfoPanels[(size_t) i].setBounds (gridX (i, colW, colGap), lfoTop, colW, lfoH);
         modView.addAndMakeVisible (lfoPanels[(size_t) i]);
 
-        const char* rate[4]  = { ids::lfo1Rate, ids::lfo2Rate, ids::lfo3Rate, ids::lfo4Rate };
+        const auto& rate = paramIds::lfoRate;
-        const char* sync[4]  = { ids::lfo1Sync, ids::lfo2Sync, ids::lfo3Sync, ids::lfo4Sync };
+        const auto& sync = paramIds::lfoSync;
-        const char* beat[4]  = { ids::lfo1Beat, ids::lfo2Beat, ids::lfo3Beat, ids::lfo4Beat };
+        const auto& beat = paramIds::lfoBeat;
-        const char* shape[4] = { ids::lfo1Shape, ids::lfo2Shape, ids::lfo3Shape, ids::lfo4Shape };
+        const auto& shape = paramIds::lfoShape;
-        const char* phase[4] = { ids::lfo1Phase, ids::lfo2Phase, ids::lfo3Phase, ids::lfo4Phase };
+        const auto& phase = paramIds::lfoPhase;
-        const char* fade[4]  = { ids::lfo1Fade, ids::lfo2Fade, ids::lfo3Fade, ids::lfo4Fade };
+        const auto& fade = paramIds::lfoFade;
-        const char* delay[4] = { ids::lfo1Delay, ids::lfo2Delay, ids::lfo3Delay, ids::lfo4Delay };
+        const auto& delay = paramIds::lfoDelay;
 
         makeCombo (&lfoPanels[(size_t) i], shape[i], lfoShapes, "LFO shape")->setBounds (layout::padding, comboRowY(), 110, layout::comboHeight);
         makeToggle (&lfoPanels[(size_t) i], "Sync", sync[i], "Tempo-sync LFO")->setBounds (layout::padding + 110 + layout::gap, layout::titleHeight, layout::toggleWidth, layout::toggleHeight);
@@ -533,9 +545,12 @@ void PluginEditor::buildModTab()
         const int tid = modTargetCombo.getSelectedItemIndex();
         if (tid >= 0 && tid < (int) targetEnums.size())
         {
-            processor.engine.getMatrix().addConnection (src, targetEnums[(size_t) tid],
+            {
-                                                        (float) modDepthKnob.getValue(),
+                const juce::ScopedLock lock (processor.engine.getControlLock());
-                                                        modBipolarToggle.getToggleState());
+                processor.engine.getMatrix().addConnection (src, targetEnums[(size_t) tid],
+                                                            (float) modDepthKnob.getValue(),
+                                                            modBipolarToggle.getToggleState());
+            }
             updateModList();
         }
     };
@@ -546,7 +561,12 @@ void PluginEditor::buildModTab()
     modRemoveButton.setTooltip ("Remove last modulation connection");
     modRemoveButton.onClick = [this]
     {
-        processor.engine.getMatrix().removeConnection (processor.engine.getMatrix().size() - 1);
+        {
+            const juce::ScopedLock lock (processor.engine.getControlLock());
+            auto& matrix = processor.engine.getMatrix();
+            if (matrix.size() > 0)
+                matrix.removeConnection (matrix.size() - 1);
+        }
         updateModList();
     };
     matrixPanel.addAndMakeVisible (modRemoveButton);
@@ -556,7 +576,10 @@ void PluginEditor::buildModTab()
     modClearButton.setTooltip ("Clear all modulation connections");
     modClearButton.onClick = [this]
     {
-        processor.engine.getMatrix().clear();
+        {
+            const juce::ScopedLock lock (processor.engine.getControlLock());
+            processor.engine.getMatrix().clear();
+        }
         updateModList();
     };
     matrixPanel.addAndMakeVisible (modClearButton);
@@ -599,11 +622,15 @@ void PluginEditor::buildFxTab()
         fxTypeCombos[(size_t) i]->setBounds (layout::padding, comboRowY(), 160, layout::comboHeight);
 
         const int upX = layout::padding + 160 + layout::gap;
-        fxUp[(size_t) i] = new juce::TextButton ("\xe2\x86\x91");
+        auto up = std::make_unique<juce::TextButton> ("\xe2\x86\x91");
+        fxUp[(size_t) i] = up.get();
+        ownedControls.push_back (std::move (up));
         fxUp[(size_t) i]->setBounds (upX, comboRowY(), layout::arrowWidth, layout::comboHeight);
         fxUp[(size_t) i]->setTooltip ("Move effect up");
         fxPanels[(size_t) i].addAndMakeVisible (fxUp[(size_t) i]);
-        fxDown[(size_t) i] = new juce::TextButton ("\xe2\x86\x93");
+        auto down = std::make_unique<juce::TextButton> ("\xe2\x86\x93");
+        fxDown[(size_t) i] = down.get();
+        ownedControls.push_back (std::move (down));
         fxDown[(size_t) i]->setBounds (upX + layout::arrowWidth + layout::gap, comboRowY(), layout::arrowWidth, layout::comboHeight);
         fxDown[(size_t) i]->setTooltip ("Move effect down");
         fxPanels[(size_t) i].addAndMakeVisible (fxDown[(size_t) i]);
@@ -637,8 +664,8 @@ void PluginEditor::buildMacroTab()
         macroPanels[(size_t) i].setBounds (gridX (i, colW, colGap), layout::margin, colW, macroH);
         macroView.addAndMakeVisible (macroPanels[(size_t) i]);
 
-        const char* ids[4] = { ids::macro1, ids::macro2, ids::macro3, ids::macro4 };
+        const auto& macroIds = paramIds::macros;
-        macroKnobs[(size_t) i] = makeKnob (&macroPanels[(size_t) i], MacroControls::macroName (i), ids[i], formatPercent,
+        macroKnobs[(size_t) i] = makeKnob (&macroPanels[(size_t) i], MacroControls::macroName (i), macroIds[i], formatPercent,
                                            MacroControls::macroName (i) + " macro (0-100%)");
         macroKnobs[(size_t) i]->setBounds ((colW - layout::macroKnobSize) / 2,
                                            layout::titleHeight + layout::padding,
@@ -684,8 +711,11 @@ void PluginEditor::buildMacroTab()
         const int tid = macroAssignTarget.getSelectedItemIndex();
         if (tid >= 0 && tid < (int) targetEnums.size())
         {
-            processor.engine.getMacros().addAssignment (macro, targetEnums[(size_t) tid],
+            {
-                                                        (float) macroDepthKnob.getValue());
+                const juce::ScopedLock lock (processor.engine.getControlLock());
+                processor.engine.getMacros().addAssignment (macro, targetEnums[(size_t) tid],
+                                                            (float) macroDepthKnob.getValue());
+            }
             updateMacroList();
         }
     };
@@ -696,7 +726,10 @@ void PluginEditor::buildMacroTab()
     macroClearButton.setTooltip ("Clear all macro assignments");
     macroClearButton.onClick = [this]
     {
-        processor.engine.getMacros().clear();
+        {
+            const juce::ScopedLock lock (processor.engine.getControlLock());
+            processor.engine.getMacros().clear();
+        }
         updateMacroList();
     };
     macroAssignPanel.addAndMakeVisible (macroClearButton);
@@ -715,10 +748,15 @@ void PluginEditor::buildMacroTab()
 
 void PluginEditor::swapFxSlots (int a, int b)
 {
+    if (a < 0 || b < 0 || a >= kNumFxSlots || b >= kNumFxSlots || a == b)
+        return;
+
     auto swapParam = [this] (const char* pa, const char* pb)
     {
         auto* p1 = processor.parameters.getParameter (pa);
         auto* p2 = processor.parameters.getParameter (pb);
+        if (p1 == nullptr || p2 == nullptr)
+            return;
         const float v1 = p1->getValue();
         const float v2 = p2->getValue();
         p1->setValueNotifyingHost (v2);
@@ -748,6 +786,7 @@ void PluginEditor::setTab (int index)
     tabMod.setToggleState   (currentTab == 2, juce::dontSendNotification);
     tabFx.setToggleState    (currentTab == 3, juce::dontSendNotification);
     tabMacro.setToggleState (currentTab == 4, juce::dontSendNotification);
+    timerCallback();
 }
 
 void PluginEditor::cycleTab (int delta)
@@ -791,92 +830,139 @@ void PluginEditor::applyUiScale()
 void PluginEditor::updateVisuals()
 {
     const auto& apvts = processor.parameters;
-    auto gv = [&] (const char* id) { return apvts.getRawParameterValue (id)->load(); };
+    auto gv = [&] (const char* id)
+    {
+        if (auto* value = apvts.getRawParameterValue (id))
+            return value->load();
+        return 0.0f;
+    };
 
     masterDisplay.setValue (formatPercent (gv (ids::master)));
 
     // Waveforms.
-    const int waveA = juce::jlimit (0, kNumWavetables - 1, (int) std::llround (gv (ids::oscAWave) * (kNumWavetables - 1)));
+    if (currentTab == 0)
-    const int waveB = juce::jlimit (0, kNumWavetables - 1, (int) std::llround (gv (ids::oscBWave) * (kNumWavetables - 1)));
+    {
-    oscAWave.setWaveIndex (waveA);
+        const int waveA = juce::jlimit (0, kNumWavetables - 1, (int) std::llround (gv (ids::oscAWave) * (kNumWavetables - 1)));
-    oscAWave.setFramePosition (gv (ids::oscAWtPos));
+        const int waveB = juce::jlimit (0, kNumWavetables - 1, (int) std::llround (gv (ids::oscBWave) * (kNumWavetables - 1)));
-    oscAWave.setEnabled (gv (ids::oscAOn) > 0.5f);
+        oscAWave.setWaveIndex (waveA);
-    oscBWave.setWaveIndex (waveB);
+        oscAWave.setFramePosition (gv (ids::oscAWtPos));
-    oscBWave.setFramePosition (gv (ids::oscBWtPos));
+        oscAWave.setEnabled (gv (ids::oscAOn) > 0.5f);
-    oscBWave.setEnabled (gv (ids::oscBOn) > 0.5f);
+        oscBWave.setWaveIndex (waveB);
-    oscAWave.repaint();
+        oscBWave.setFramePosition (gv (ids::oscBWtPos));
-    oscBWave.repaint();
+        oscBWave.setEnabled (gv (ids::oscBOn) > 0.5f);
+    }
 
     // Filters.
-    filter1Display.setParams ((int) std::llround (gv (ids::f1Type) * 6.0f), gv (ids::f1Cutoff), gv (ids::f1Res),
+    if (currentTab == 1)
-                              gv (ids::f1Drive), (int) std::llround (gv (ids::f1Slope) * 2.0f));
+    {
-    filter1Display.setEnabled (gv (ids::f1On) > 0.5f);
+        filter1Display.setParams ((int) std::llround (gv (ids::f1Type) * 6.0f), gv (ids::f1Cutoff), gv (ids::f1Res),
-    filter2Display.setParams ((int) std::llround (gv (ids::f2Type) * 6.0f), gv (ids::f2Cutoff), gv (ids::f2Res),
+                                  gv (ids::f1Drive), (int) std::llround (gv (ids::f1Slope) * 2.0f));
-                              gv (ids::f2Drive), (int) std::llround (gv (ids::f2Slope) * 2.0f));
+        filter1Display.setEnabled (gv (ids::f1On) > 0.5f);
-    filter2Display.setEnabled (gv (ids::f2On) > 0.5f);
+        filter2Display.setParams ((int) std::llround (gv (ids::f2Type) * 6.0f), gv (ids::f2Cutoff), gv (ids::f2Res),
-    filter1Display.repaint();
+                                  gv (ids::f2Drive), (int) std::llround (gv (ids::f2Slope) * 2.0f));
-    filter2Display.repaint();
+        filter2Display.setEnabled (gv (ids::f2On) > 0.5f);
+    }
 
     // Envelopes.
-    const char* a[4] = { ids::env1A, ids::env2A, ids::env3A, ids::env4A };
+    if (currentTab == 2)
-    const char* d[4] = { ids::env1D, ids::env2D, ids::env3D, ids::env4D };
-    const char* s[4] = { ids::env1S, ids::env2S, ids::env3S, ids::env4S };
-    const char* r[4] = { ids::env1R, ids::env2R, ids::env3R, ids::env4R };
-    const char* c[4] = { ids::env1Curve, ids::env2Curve, ids::env3Curve, ids::env4Curve };
-    for (int i = 0; i < kNumEnvelopes; ++i)
     {
-        envDisplays[(size_t) i].setParams (gv (a[i]), gv (d[i]), gv (s[i]), gv (r[i]), gv (c[i]));
+        const auto& a = paramIds::envAttack;
-        envDisplays[(size_t) i].repaint();
+        const auto& d = paramIds::envDecay;
+        const auto& s = paramIds::envSustain;
+        const auto& r = paramIds::envRelease;
+        const auto& c = paramIds::envCurve;
+        for (int i = 0; i < kNumEnvelopes; ++i)
+            envDisplays[(size_t) i].setParams (gv (a[i]), gv (d[i]), gv (s[i]), gv (r[i]), gv (c[i]));
     }
 
     // LFOs.
-    const char* lshape[4] = { ids::lfo1Shape, ids::lfo2Shape, ids::lfo3Shape, ids::lfo4Shape };
+    if (currentTab == 2)
-    for (int i = 0; i < kNumLfos; ++i)
     {
-        lfoDisplays[(size_t) i].setShape ((int) std::llround (gv (lshape[i]) * 6.0f));
+        const auto& lshape = paramIds::lfoShape;
-        lfoDisplays[(size_t) i].setShapeData (processor.engine.getLfos()[(size_t) i].getShapeData(),
+        const juce::ScopedLock lock (processor.engine.getControlLock());
-                                              processor.engine.getLfos()[(size_t) i].getShapeSteps());
+        for (int i = 0; i < kNumLfos; ++i)
-        lfoDisplays[(size_t) i].repaint();
+        {
+            const auto& lfo = processor.engine.getLfos()[(size_t) i];
+            lfoDisplays[(size_t) i].setShape ((int) std::llround (gv (lshape[i]) * 6.0f));
+            lfoDisplays[(size_t) i].setShapeData (lfo.getShapeData(), lfo.getShapeSteps());
+        }
+    }
+
+    if (currentTab == 3)
+    {
+        for (int i = 0; i < kNumFxSlots; ++i)
+        {
+            const int type = juce::jlimit (0, (int) FxType::Count - 1,
+                (int) std::llround (gv (kFxType[i]) * ((int) FxType::Count - 1)));
+            for (int p = 0; p < 4; ++p)
+            {
+                auto* knob = fxKnobs[(size_t) i][(size_t) p + 1];
+                const juce::String name = kFxParamNames[type][p];
+                if (knob->getName() != name)
+                {
+                    knob->setName (name);
+                    knob->setTooltip (name == "Unused" ? "Not used by this effect"
+                        : name + " (normalised 0-100%)");
+                    knob->repaint();
+                }
+            }
+        }
     }
 
     // RAVE state.
     raveButton.setToggleState (processor.isRaveEnabled());
 
+    const int program = processor.getCurrentProgram();
+    if (presetCombo.getSelectedItemIndex() != program)
+        presetCombo.setSelectedItemIndex (program, juce::dontSendNotification);
+
     // Scale change.
     if (processor.getUiScaleIndex() != currentScaleIndex)
         applyUiScale();
+    if (scaleCombo.getSelectedItemIndex() != currentScaleIndex)
+        scaleCombo.setSelectedItemIndex (currentScaleIndex, juce::dontSendNotification);
 }
 
 void PluginEditor::updateModList()
 {
     juce::String text;
-    const auto& cons = processor.engine.getMatrix().connections;
+    {
-    for (const auto& c : cons)
+        const juce::ScopedLock lock (processor.engine.getControlLock());
-        text += modSourceName (c.source) + "  ->  " + modTargetName (c.target)
+        const auto& cons = processor.engine.getMatrix().connections;
-              + "   [" + juce::String (c.depth, 2) + (c.bipolar ? ", bipolar]" : "]") + "\n";
+        for (const auto& c : cons)
-    modList.setText (text, false);
+            text += modSourceName (c.source) + "  ->  " + modTargetName (c.target)
+                  + "   [" + juce::String (c.depth, 2) + (c.bipolar ? ", bipolar]" : "]") + "\n";
+    }
+    if (modList.getText() != text)
+        modList.setText (text, false);
 }
 
 void PluginEditor::updateMacroList()
 {
     juce::String text;
-    for (int m = 0; m < kNumMacros; ++m)
     {
-        text += MacroControls::macroName (m) + ":\n";
+        const juce::ScopedLock lock (processor.engine.getControlLock());
-        const auto& assigns = processor.engine.getMacros().assignments[(size_t) m];
+        for (int m = 0; m < kNumMacros; ++m)
-        if (assigns.empty())
+        {
-            text += "   (none)\n";
+            text += MacroControls::macroName (m) + ":\n";
-        for (const auto& a : assigns)
+            const auto& assigns = processor.engine.getMacros().assignments[(size_t) m];
-            text += "   " + modTargetName (a.target) + "  [" + juce::String (a.depth, 2) + "]\n";
+            if (assigns.empty())
+                text += "   (none)\n";
+            for (const auto& a : assigns)
+                text += "   " + modTargetName (a.target) + "  [" + juce::String (a.depth, 2) + "]\n";
+        }
     }
-    macroList.setText (text, false);
+    if (macroList.getText() != text)
+        macroList.setText (text, false);
 }
 
 void PluginEditor::timerCallback()
 {
     updateVisuals();
-    updateModList();
+    if (currentTab == 2)
-    updateMacroList();
+        updateModList();
+    else if (currentTab == 4)
+        updateMacroList();
 }
 
 } // namespace serum

Source/PluginEditor.h

@@ -99,6 +99,8 @@ private:
     juce::TextButton macroAssignButton, macroClearButton;
     juce::TextEditor macroList;
 
+    std::vector<std::unique_ptr<juce::Component>> ownedControls;
+
     // --- attachments ---
     std::vector<std::unique_ptr<juce::AudioProcessorValueTreeState::SliderAttachment>> sliderAttachments;
     std::vector<std::unique_ptr<juce::AudioProcessorValueTreeState::ComboBoxAttachment>> comboAttachments;