Fix laggy visualiser component on lower sample rates

Source/PluginEditor.cpp

@@ -11,6 +11,7 @@ OscirenderAudioProcessorEditor::OscirenderAudioProcessorEditor(OscirenderAudioPr
 #if JUCE_MAC
     if (audioProcessor.wrapperType == juce::AudioProcessor::WrapperType::wrapperType_Standalone) {
         usingNativeMenuBar = true;
+        menuBarModel.setMacMainMenu(&menuBarModel);
     }
 #endif
 
@@ -77,6 +78,12 @@ OscirenderAudioProcessorEditor::~OscirenderAudioProcessorEditor() {
     juce::MessageManagerLock lock;
     audioProcessor.broadcaster.removeChangeListener(this);
     audioProcessor.fileChangeBroadcaster.removeChangeListener(this);
+    
+#if JUCE_MAC
+    if (usingNativeMenuBar) {
+        menuBarModel.setMacMainMenu(nullptr);
+    }
+#endif
 }
 
 // parsersLock must be held

Source/PluginProcessor.cpp

@@ -237,6 +237,7 @@ void OscirenderAudioProcessor::prepareToPlay(double sampleRate, int samplesPerBl
 	currentSampleRate = sampleRate;
     pitchDetector.setSampleRate(sampleRate);
     synth.setCurrentPlaybackSampleRate(sampleRate);
+    retriggerMidi = true;
 }
 
 void OscirenderAudioProcessor::releaseResources() {
@@ -556,9 +557,10 @@ void OscirenderAudioProcessor::processBlock(juce::AudioBuffer<float>& buffer, ju
         }
     }
     
-    // if midi has just been disabled
-    if (prevMidiEnabled && !usingMidi) {
+    // if midi has just been disabled or we need to retrigger
+    if (!usingMidi && (retriggerMidi || prevMidiEnabled)) {
         midiMessages.addEvent(juce::MidiMessage::noteOn(1, 60, 1.0f), 17);
+        retriggerMidi = false;
     }
     
     prevMidiEnabled = usingMidi;

Source/PluginProcessor.h

@@ -327,6 +327,7 @@ private:
 
     ShapeSound::Ptr defaultSound = new ShapeSound(std::make_shared<FileParser>());
     PublicSynthesiser synth;
+    bool retriggerMidi = true;
 
     AudioWebSocketServer softwareOscilloscopeServer{*this};
     ObjectServer objectServer{*this};

Source/components/VisualiserComponent.cpp

@@ -2,6 +2,7 @@
 
 VisualiserComponent::VisualiserComponent(int numChannels, OscirenderAudioProcessor& p) : numChannels(numChannels), backgroundColour(juce::Colours::black), waveformColour(juce::Colour(0xff00ff00)), audioProcessor(p), juce::Thread("VisualiserComponent") {
     setOpaque(true);
+    resetBuffer();
     startTimerHz(60);
     startThread();
 }
@@ -58,6 +59,10 @@ void VisualiserComponent::timerCallback() {
 
 void VisualiserComponent::run() {
     while (!threadShouldExit()) {
+        if (sampleRate != (int) audioProcessor.currentSampleRate) {
+            resetBuffer();
+        }
+        
         consumer = audioProcessor.consumerRegister(tempBuffer);
         audioProcessor.consumerRead(consumer);
         setBuffer(tempBuffer);
@@ -110,26 +115,20 @@ void VisualiserComponent::paintXY(juce::Graphics& g, juce::Rectangle<float> area
     }
 
     double strength = 15;
-    double strengthLast = 5;
     double widthDivisor = 130;
-    double widthDivisorLast = 130;
     juce::Colour waveColor = waveformColour;
-    juce::Colour waveColorLast = waveColor;
-
-    for (auto& line : prevLines) {
-        line.applyTransform(transform);
-        float lengthScale = (line.getLength() + 0.001);
-        float lengthScaleLog = std::log(strengthLast * (1.f / lengthScale) + 1) / std::log(strengthLast + 1);
-        g.setColour(waveColorLast.withAlpha(std::max(0.f, std::min(lengthScaleLog, 1.f))));
-        g.drawLine(line, area.getWidth() * (lengthScaleLog * 0.3 + 0.7) / widthDivisorLast);
-    }
-    prevLines = lines;
 
     for (auto& line : lines) {
         line.applyTransform(transform);
-        float lengthScale = (line.getLength() + 0.001);
+        float normalisedLength = line.getLength() * (sampleRate / DEFAULT_SAMPLE_RATE);
+        float lengthScale = (normalisedLength + 0.001);
         float lengthScaleLog = std::log(strength * (1 / lengthScale) + 1) / std::log(strength + 1);
         g.setColour(waveColor.withAlpha(std::max(0.f, std::min(lengthScaleLog, 1.f))).withSaturation(std::pow(lengthScale, 2)));
         g.drawLine(line, area.getWidth() * (lengthScaleLog * 0.3 + 0.7) / widthDivisor);
     }
 }
+
+void VisualiserComponent::resetBuffer() {
+    sampleRate = (int) audioProcessor.currentSampleRate;
+    tempBuffer = std::vector<float>(2 * sampleRate * BUFFER_LENGTH_SECS);
+}

Source/components/VisualiserComponent.h

@@ -21,18 +21,25 @@ public:
     void mouseDown(const juce::MouseEvent& event) override;
 
 private:
+    const double BUFFER_LENGTH_SECS = 0.02;
+    const double DEFAULT_SAMPLE_RATE = 192000.0;
+    
 	juce::CriticalSection lock;
     std::vector<float> buffer;
     std::vector<juce::Line<float>> prevLines;
     int numChannels = 2;
     juce::Colour backgroundColour, waveformColour;
 	OscirenderAudioProcessor& audioProcessor;
-    std::vector<float> tempBuffer = std::vector<float>(2 * 4096);
+    int sampleRate = DEFAULT_SAMPLE_RATE;
+    
+    std::vector<float> tempBuffer;
     int precision = 4;
 
     std::atomic<bool> active = true;
     
     std::shared_ptr<BufferConsumer> consumer;
+    
+    void resetBuffer();
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(VisualiserComponent)
 };