808 Snare Drum Synth

source/PluginProcessor.cpp

@@ -1,18 +1,20 @@
 #include "PluginProcessor.h"
 #include "PluginEditor.h"
 
-TorchDrumProcessor::TorchDrumProcessor() : synthController(drumSynth, parameters)
+TorchDrumProcessor::TorchDrumProcessor() : synthController(snare808, parameters)
 {
     // Add synthesizer parameters
-    drumSynth.getParameters().add(*this);
+    //drumSynth.getParameters().add(*this);
+    snare808.getParameters().add(*this);
 
     // Add controller parameters
     parameters.add(*this);
 }
 
 void TorchDrumProcessor::prepareToPlay(double sampleRate, int samplesPerBlock)
 {
-    drumSynth.prepare(sampleRate, samplesPerBlock);
+    //drumSynth.prepare(sampleRate, samplesPerBlock);
+    snare808.prepare(sampleRate, samplesPerBlock);
     synthController.prepare(sampleRate, samplesPerBlock);
     juce::ignoreUnused(samplesPerBlock);
 }
@@ -41,7 +43,7 @@ void TorchDrumProcessor::processBlock(juce::AudioBuffer<float>& buffer,
         synthController.process(inputSample);
 
         // Process the synthesizer
-        float synthSample = drumSynth.process();
+        float synthSample = snare808.process();
         for (int channel = 0; channel < buffer.getNumChannels(); ++channel)
         {
             auto* channelData = buffer.getWritePointer(channel);

source/PluginProcessor.h

@@ -2,6 +2,7 @@
 
 #include "Parameters.h"
 #include "Synth/DrumSynth.h"
+#include "Synth/Snare808.h"
 #include "SynthController.h"
 #include <shared_plugin_helpers/shared_plugin_helpers.h>
 
@@ -22,6 +23,7 @@ class TorchDrumProcessor : public PluginHelpers::ProcessorBase
 
 private:
     Parameters parameters;
-    DrumSynth drumSynth;
+    //DrumSynth drumSynth;
+    Snare808 snare808;
     SynthController synthController;
 };

source/Synth/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_subdirectory(Modules)
 
 target_sources(${BaseTargetName} PRIVATE
-        DrumSynth.cpp)
+        DrumSynth.cpp
+        Snare808.cpp)

source/Synth/Snare808.cpp

@@ -0,0 +1,121 @@
+/*
+==============================================================================
+
+Snare808.cpp
+
+Implementation of an 808 inspired snare drum synth
+
+==============================================================================
+*/
+
+#include "Snare808.h"
+#include <juce_audio_basics/juce_audio_basics.h>
+
+Snare808::Snare808()
+{
+    // Create all the parameter callbacks
+    parameters.addCallback(0, [this](float value)
+                           { osc1.setFrequencyHz(value); });
+    parameters.addCallback(1, [this](float value)
+                           { osc1.setModAmount(value); });
+    parameters.addCallback(2, [this](float value)
+                           { osc2.setFrequencyHz(value); });
+    parameters.addCallback(3, [this](float value)
+                           { osc2.setModAmount(value); });
+    parameters.addCallback(4, [this](float value)
+                           { freqEnv.setDecayMs(value); });
+    parameters.addCallback(5, [this](float value)
+                           { osc1Env.setDecayMs(value); });
+    parameters.addCallback(6, [this](float value)
+                           { osc2Env.setDecayMs(value); });
+    parameters.addCallback(7, [this](float value)
+                           { noiseEnv.setDecayMs(value); });
+    parameters.addCallback(8, [this](float value)
+                           { updateFilterFreq(value); });
+    parameters.addCallback(9, [this](float value)
+                           { updateFilterQ(value); });
+    parameters.addCallback(10, [this](float value)
+                           { osc1Gain.setGainDecibels(value); });
+    parameters.addCallback(11, [this](float value)
+                           { osc2Gain.setGainDecibels(value); });
+    parameters.addCallback(12, [this](float value)
+                           { noiseGain.setGainDecibels(value); });
+    parameters.addCallback(13, [this](float value)
+                           { waveshaper.setGainDecibels(value); });
+}
+
+// Prepare the synth for playback
+void Snare808::prepare(double sr, int samplesPerBlock)
+{
+    juce::ignoreUnused(samplesPerBlock);
+    sampleRate = sr;
+
+    osc1.prepare(sr);
+    osc2.prepare(sr);
+    osc1Env.prepare(sr);
+    osc2Env.prepare(sr);
+    freqEnv.prepare(sr);
+    noiseEnv.prepare(sr);
+
+    // Initial settings for the noise filter
+    noiseFilterSettings.fs = sr;
+    noiseFilterSettings.type = Biquad::Type::highpass;
+    noiseFilterSettings.peakGainDb = 0.0;
+    noiseFilterSettings.q = 0.707;
+    noiseFilterSettings.cutoff = 1000.0;
+    noiseFilter.setup(noiseFilterSettings);
+    noiseFilter.clean();
+}
+
+// Get the next sample from the synth
+float Snare808::process()
+{
+    // Frequency envelope for both oscillators
+    float freq = freqEnv.process();
+
+    // Calculate both oscillators
+    float y1 = osc1.process(freq);
+    y1 = y1 * osc1Env.process();
+    y1 = osc1Gain.process(y1);
+
+    float y2 = osc2.process(freq);
+    y2 = y2 * osc2Env.process();
+    y2 = osc2Gain.process(y2);
+
+    // Noise Signal
+    float n = noise.process();
+    n = noiseFilter.process(n);
+    n = n * noiseEnv.process();
+    n = noiseGain.process(n);
+
+    // Combine the signals
+    float y = y1 + y2 + n;
+
+    // Apply waveshaping
+    y = waveshaper.process(y);
+
+    return y;
+}
+
+// Trigger the drum
+void Snare808::trigger()
+{
+    osc1Env.trigger();
+    osc2Env.trigger();
+    freqEnv.trigger();
+    noiseEnv.trigger();
+}
+
+// Update the filter frequency
+void Snare808::updateFilterFreq(float value)
+{
+    float nyquist = 0.5f * sampleRate;
+    float freq = std::min(value, nyquist);
+    noiseFilter.setFc(freq);
+}
+
+// Update the filter Q
+void Snare808::updateFilterQ(float value)
+{
+    noiseFilter.setQ(value);
+}

source/Synth/Snare808.h

@@ -0,0 +1,63 @@
+/*
+==============================================================================
+
+DrumSynth.h
+
+Simple Drum Synth Class
+
+==============================================================================
+*/
+#pragma once
+
+#include "../Biquad.h"
+#include "Modules/ExpDecayEnvelope.h"
+#include "Modules/Gain.h"
+#include "Modules/Noise.h"
+#include "Modules/SinusoidalOscillator.h"
+#include "Modules/Tanh.h"
+#include "Snare808Parameters.h"
+#include "SynthBase.h"
+
+class Snare808 : public SynthWithParameterBase<Snare808Parameters>
+{
+public:
+    Snare808();
+    ~Snare808() = default;
+
+    // Prepare the synth for playback
+    void prepare(double sr, int samplesPerBlock) override;
+
+    // Get the next sample from the synth
+    float process() override;
+
+    // Trigger the drum
+    void trigger() override;
+
+private:
+    double sampleRate = 0.0;
+
+    // Sound sources
+    SinusoidalOscillator osc1;
+    SinusoidalOscillator osc2;
+    WhiteNoise noise;
+
+    // Envelopes
+    ExpDecayEnvelope freqEnv;
+    ExpDecayEnvelope osc1Env;
+    ExpDecayEnvelope osc2Env;
+    ExpDecayEnvelope noiseEnv;
+
+    // Filters
+    Biquad noiseFilter;
+    Biquad::Settings noiseFilterSettings;
+
+    // Mixing and Waveshaping
+    Gain osc1Gain;
+    Gain osc2Gain;
+    Gain noiseGain;
+    Tanh waveshaper;
+
+    // Parameter Update Functions
+    void updateFilterFreq(float value);
+    void updateFilterQ(float value);
+};

source/Synth/Snare808Parameters.h

@@ -0,0 +1,76 @@
+/*
+==============================================================================
+
+DrumSynthParameters.h
+
+Class to hold the parameters for the drum synth
+
+==============================================================================
+*/
+
+#pragma once
+
+#include "SynthParameterBase.h"
+
+struct Snare808Parameters : public SynthParameterBase
+{
+    Snare808Parameters()
+    {
+        addParameter(osc1Freq);
+        addParameter(osc1Mod);
+        addParameter(osc2Freq);
+        addParameter(osc2Mod);
+        addParameter(freqEnvDecay);
+        addParameter(osc1Decay);
+        addParameter(osc2Decay);
+        addParameter(noiseEnvDecay);
+        addParameter(noiseFilterFreq);
+        addParameter(noiseFilterQ);
+        addParameter(osc1Gain);
+        addParameter(osc2Gain);
+        addParameter(noiseGain);
+        addParameter(tanhGain);
+    }
+
+    juce::AudioParameterFloat* osc1Freq =
+        new juce::AudioParameterFloat({ "osc1_freq", 1 }, "Osc 1 Freq (Hz)", 20.f, 2000.f, 180.f);
+
+    juce::AudioParameterFloat* osc1Mod =
+        new juce::AudioParameterFloat({ "osc1_mod", 1 }, "Osc 1 Mod", -1.0f, 2.f, 0.4f);
+
+    juce::AudioParameterFloat* osc2Freq =
+        new juce::AudioParameterFloat({ "osc2_freq", 1 }, "Osc 2 Freq (Hz)", 20.f, 2000.f, 240.f);
+
+    juce::AudioParameterFloat* osc2Mod =
+        new juce::AudioParameterFloat({ "osc2_mod", 1 }, "Osc 2 Mod", -1.0f, 2.f, 0.3f);
+
+    juce::AudioParameterFloat* freqEnvDecay =
+        new juce::AudioParameterFloat({ "freq_env_decay", 1 }, "Freq Env Decay (ms)", 10.f, 2000.f, 50.f);
+
+    juce::AudioParameterFloat* osc1Decay =
+        new juce::AudioParameterFloat({ "osc1_decay", 1 }, "Osc 1 Decay (ms)", 10.f, 2000.f, 200.f);
+
+    juce::AudioParameterFloat* osc2Decay =
+        new juce::AudioParameterFloat({ "osc2_decay", 1 }, "Osc 2 Decay (ms)", 10.f, 2000.f, 150.f);
+
+    juce::AudioParameterFloat* noiseEnvDecay =
+        new juce::AudioParameterFloat({ "noise_env_decay", 1 }, "Noise Decay (ms)", 10.f, 2000.f, 200.f);
+
+    juce::AudioParameterFloat* noiseFilterFreq =
+        new juce::AudioParameterFloat({ "noise_filter_freq", 1 }, "Noise Filter (Hz)", 20.f, 24000.f, 2500.f);
+
+    juce::AudioParameterFloat* noiseFilterQ =
+        new juce::AudioParameterFloat({ "noise_filter_q", 1 }, "Noise Filter (Q)", 0.5f, 10.f, 2.f);
+
+    juce::AudioParameterFloat* osc1Gain =
+        new juce::AudioParameterFloat({ "osc1_gain", 1 }, "Osc 1 Gain", -60.0f, 6.0f, -6.f);
+
+    juce::AudioParameterFloat* osc2Gain =
+        new juce::AudioParameterFloat({ "osc2_gain", 1 }, "Osc 2 Gain", -60.0f, 6.0f, -12.f);
+
+    juce::AudioParameterFloat* noiseGain =
+        new juce::AudioParameterFloat({ "noise_gain", 1 }, "Noise Gain", -60.0f, 6.0f, -4.f);
+
+    juce::AudioParameterFloat* tanhGain =
+        new juce::AudioParameterFloat({ "tanh_gain", 1 }, "Waveshape In", -24.0f, 24.0f, -12.f);
+};