Fix comb filter effect

source/PluginProcessor.cpp

@@ -131,6 +131,7 @@ void PeakEaterAudioProcessor::changeProgramName(int /* index */, juce::String co
 void PeakEaterAudioProcessor::prepareToPlay(double sampleRate, int samplesPerBlock) {
     juce::dsp::ProcessSpec const spec{sampleRate, static_cast<juce::uint32>(samplesPerBlock), 2};
     dryWet.prepare(spec);
+    dryWet.setWetLatency(54);
     inputGain.prepare(spec);
     for (auto &clipper : clippers) {
         clipper.prepare(spec);
@@ -214,7 +215,11 @@ void PeakEaterAudioProcessor::processBlock(juce::AudioBuffer<float> &buffer, juc
     for (auto &clipper : clippers) {
         clipper.setClippingType(parameterChoiceToClippingType(*mClippingType));
         clipper.setThreshold(*mCeiling);
-        clipper.setDryWetProportion(*mDryWet);
+        if (clipper.getOversamplingFactor() == static_cast<size_t>(*mOversampleRate)) {
+            auto const latency = clipper.getLatency();
+            setLatencySamples(latency);
+            dryWet.setWetLatency(latency);
+        }
     }
     outputGain.setGainDecibels(*mOutputGain);
     //-----------------------------------------------------------
@@ -234,11 +239,6 @@ void PeakEaterAudioProcessor::processBlock(juce::AudioBuffer<float> &buffer, juc
         outputGain.process(context);
         mLevelMeterPostOut->updateLevels(context.getOutputBlock());
         dryWet.setWetMixProportion(*mDryWet);
-        for (auto &clipper : clippers) {
-            if (clipper.getOversamplingFactor() == static_cast<size_t>(*mOversampleRate)) {
-                dryWet.setWetLatency(clipper.oversampler.getLatencyInSamples());
-            }
-        }
         dryWet.mixWetSamples(context.getOutputBlock());
     }
 }

source/PluginProcessor.h

@@ -69,7 +69,7 @@ class PeakEaterAudioProcessor : public juce::AudioProcessor {
     juce::AudioParameterChoice* mOversampleRate;
     juce::AudioParameterFloat* mDryWet;
 
-    juce::dsp::DryWetMixer<float> dryWet;
+    juce::dsp::DryWetMixer<float> dryWet{66};
     juce::dsp::Gain<float> inputGain;
     std::array<Clipper<float>, 6> clippers{Clipper<float>{0}, Clipper<float>{1}, Clipper<float>{2},
                                            Clipper<float>{3}, Clipper<float>{4}, Clipper<float>{5}};

source/processor/Clipper.cpp

@@ -52,9 +52,6 @@ void Clipper<SampleType>::prepare(juce::dsp::ProcessSpec const& spec) {
     preGain.prepare(oversampledSpec);
     preGain.setRampDurationSeconds(0.1f);
     //-----------------------------------------------------------
-    // Setup dry/wet
-    dryWet.prepare(oversampledSpec);
-    //-----------------------------------------------------------
     // Prepare wave shaper
     waveShaper.prepare(oversampledSpec);
     //-----------------------------------------------------------
@@ -73,7 +70,6 @@ void Clipper<SampleType>::reset() {
     oversampler.reset();
     preFilter.reset();
     preGain.reset();
-    dryWet.reset();
     waveShaper.reset();
     postGain.reset();
     postFilter.reset();
@@ -180,17 +176,13 @@ void Clipper<SampleType>::setClippingType(ClippingType const type) {
 }
 
 template <typename SampleType>
-void Clipper<SampleType>::setDryWetProportion(SampleType const proportion) {
-    // 0.0 - fully dry(un-clipped)
-    // 1.0 - fully wet(clipped)
-    // Everything above/beyond - incorrect
-    jassert(proportion >= static_cast<SampleType>(0.0) && proportion <= static_cast<SampleType>(1.0));
-    dryWet.setWetMixProportion(proportion);
+[[nodiscard]] size_t Clipper<SampleType>::getOversamplingFactor() const {
+    return oversamplingFactor;
 }
 
 template <typename SampleType>
-[[nodiscard]] size_t Clipper<SampleType>::getOversamplingFactor() const {
-    return oversamplingFactor;
+[[nodiscard]] int Clipper<SampleType>::getLatency() const {
+    return static_cast<int>(oversampler.getLatencyInSamples());
 }
 
 }  // namespace pe::processor

source/processor/Clipper.h

@@ -41,22 +41,17 @@ class Clipper {
      */
     void setClippingType(ClippingType const type);
 
-    /*! \brief Set dry/wet mixing proportion.
-     *
-     * Signal would be mixed right after the wave shaping.
-     */
-    void setDryWetProportion(SampleType const proportion);
-
     [[nodiscard]] size_t getOversamplingFactor() const;
 
-    juce::dsp::Oversampling<SampleType> oversampler;
+    /*! \brief Get latency in samples */
+    [[nodiscard]] int getLatency() const;
 
    private:
     size_t oversamplingFactor = 0;
 
     juce::dsp::ProcessorDuplicator<juce::dsp::IIR::Filter<SampleType>, juce::dsp::IIR::Coefficients<SampleType>> preFilter;
     juce::dsp::Gain<SampleType> preGain;
-    juce::dsp::DryWetMixer<SampleType> dryWet;
+    juce::dsp::Oversampling<SampleType> oversampler;
     juce::dsp::WaveShaper<SampleType> waveShaper;
     juce::dsp::Gain<SampleType> postGain;
     juce::dsp::ProcessorDuplicator<juce::dsp::IIR::Filter<SampleType>, juce::dsp::IIR::Coefficients<SampleType>> postFilter;