Finalizing the Phase before testing

src/Makefile

@@ -10,7 +10,7 @@ OBJS = main.o kernel.o minidexed.o config.o userinterface.o uimenu.o \
        mididevice.o midikeyboard.o serialmididevice.o pckeyboard.o \
        sysexfileloader.o performanceconfig.o perftimer.o \
        effect_compressor.o effect_platervbstereo.o \
-       fx.o fx_tape_delay.o fx_shimmer_reverb.o fx_rack.o \
+       fx.o fx_phaser.o fx_tape_delay.o fx_shimmer_reverb.o fx_rack.o \
        uibuttons.o midipin.o
 
 OPTIMIZE = -O3

src/fx_phaser.cpp

@@ -2,17 +2,19 @@
 
 #include <cmath>
 
-PhaserStage::PhaserStage(float32_t sampling_rate, float32_t frequency, float32_t q) :
+PhaserParameter::PhaserParameter(float32_t sampling_rate, float32_t frequency, float32_t q) :
     FXBase(sampling_rate),
     frequency_(frequency),
     q_(q)
 {
-    memset(this->z1, 0, 2 * sizeof(float32_t));
-    memset(this->z2, 0, 2 * sizeof(float32_t));
     this->computeCoefficients();
 }
 
-void PhaserStage::computeCoefficients()
+PhaserParameter::~PhaserParameter()
+{
+}
+
+void PhaserParameter::computeCoefficients()
 {
     float32_t w0 = 2.0f * PI * this->getFrequency() / this->getSamplingRate();
     float32_t alpha = sin(w0) / (2.0f * this->q_);
@@ -23,36 +25,125 @@ void PhaserStage::computeCoefficients()
     this->b2 = this->a2;
 }
 
+void PhaserParameter::setFrequency(float32_t frequency)
+{
+    this->frequency_ = constrain(frequency, 0.1, 10.0);
+    this->computeCoefficients();
+}
+
+float32_t PhaserParameter::getFrequency() const
+{
+    return this->frequency_;
+}
+
+void PhaserParameter::setQ(float32_t q)
+{
+    this->q_ = constrain(q, 0.5f, 10.0f);
+    this->computeCoefficients();
+}
+
+float32_t PhaserParameter::getQ() const
+{
+    return this->q_;
+}
+
+
+
+// PhaserStage implementation
+PhaserStage::PhaserStage(float32_t sampling_rate, PhaserParameter* params) :
+    FXBase(sampling_rate),
+    params_(params)
+{
+    memset(this->z1, 0, 2 * sizeof(float32_t));
+    memset(this->z2, 0, 2 * sizeof(float32_t));
+}
+
 void PhaserStage::process(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR)
 {
-    outL = (this->a0 * inL + this->a1 * this->z1[0] + this->a2 * this->z2[0]) / this->a0;
+    outL = (this->params_->a0 * inL + this->params_->a1 * this->z1[0] + this->params_->a2 * this->z2[0]) / this->params_->a0;
     this->z2[0] = this->z1[0];
     this->z2[0] = inL;
 
-    outR = (this->a0 * inR + this->a1 * this->z1[1] + this->a2 * this->z2[1]) / this->a0;
+    outR = (this->params_->a0 * inR + this->params_->a1 * this->z1[1] + this->params_->a2 * this->z2[1]) / this->params_->a0;
     this->z2[1] = this->z1[1];
     this->z2[1] = inR;
 }
 
-void PhaserStage::setFrequency(float32_t frequency)
+
+
+// Phaser implementation
+Phaser::Phaser(float32_t sampling_rate, float32_t frequency, float32_t q) : 
+    FX(sampling_rate),
+    params_(sampling_rate, frequency, q),
+    phase_(0.0f),
+    phase_increment_(0.0f)
 {
-    this->frequency_ = constrain(frequency, 0.0, 10.0);
-    this->computeCoefficients();
+    this->phase_increment_ = 2.0f * PI * frequency / this->getSamplingRate();
+    for(unsigned i = 0; i < NUM_PHASER_STAGES; ++i)
+    {
+        this->stages_[i] = new PhaserStage(sampling_rate, &this->params_);
+    }
 }
 
-float32_t PhaserStage::getFrequency() const
+Phaser::~Phaser()
 {
-    return this->frequency_;
+    for(unsigned i = 0; i < NUM_PHASER_STAGES; ++i)
+    {
+        delete this->stages_[i];
+    }
 }
 
-void PhaserStage::setQ(float32_t q)
+void Phaser::process(float32_t* left_input, float32_t* right_input, float32_t* left_output, float32_t* right_output, size_t nSamples)
 {
-    this->q_ = constrain(q, 0.1f, 1.0f);
-    this->computeCoefficients();
+    float sampleL;
+    float sampleR;
+    for(unsigned i = 0; i < nSamples; ++i)
+    {
+        // Process the input sample through each stage of the phaser
+        sampleL = *left_input;
+        sampleR = *right_input;
+        for(unsigned s = 0; s < NUM_PHASER_STAGES; ++s)
+        {
+            this->stages_[s]->process(sampleL, sampleR, sampleL, sampleR);
+        }
+
+        // Modulate the output of the phaser using the LFO 
+        *left_output = sampleL * (0.5f + 0.5f * cos(this->phase_));
+        *right_output = sampleR * (0.5f + 0.5f * cos(this->phase_));;
+
+        // Update the phase of the LFO
+        this->phase_ += this->phase_increment_;
+        if(this->phase_ > 2.0f * PI) {
+            this->phase_ -= 2.0 * PI;
         }
 
-float32_t PhaserStage::getQ() const
+        // Move to next input sample
+        ++left_input;
+        ++right_input;
+
+        // Move to next output sample
+        ++left_output;
+        ++right_output;
+    }
+}
+
+void Phaser::setFrequency(float32_t frequency)
 {
-    return this->q_;
+    this->params_.setFrequency(frequency);
+    this->phase_increment_ = 2.0f * PI * frequency / this->getSamplingRate();
+}
+
+float32_t Phaser::getFrequency() const
+{
+    return this->params_.getFrequency();
 }
 
+void Phaser::setQ(float32_t q)
+{
+    this->params_.setQ(q);
+}
+
+float32_t Phaser::getQ() const
+{
+    return this->params_.getQ();
+}

src/fx_phaser.h

@@ -20,14 +20,16 @@
 
 #include "fx.h"
 
-class PhaserStage : public FXBase
+class PhaserStage;
+
+class PhaserParameter : public FXBase
 {
-    DISALLOW_COPY_AND_ASSIGN(PhaserStage);
+    friend class PhaserStage;
+    DISALLOW_COPY_AND_ASSIGN(PhaserParameter);
 
 public:
-    PhaserStage(float32_t sampling_rate, float32_t frequency = 0.5f, float32_t q = 1.0f);
-
-    void process(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR);
+    PhaserParameter(float32_t sampling_rate, float32_t frequency = 0.5f, float32_t q = 1.0f);
+    virtual ~PhaserParameter();
 
     void setFrequency(float32_t frequency);
     inline float32_t getFrequency() const;
@@ -42,6 +44,19 @@ private:
     float32_t q_;                   // Q factor for the filters
 
     float32_t a0, a1, a2, b1, b2;   // Coefficients for the stage's filter
+};
+
+class PhaserStage : public FXBase
+{
+    DISALLOW_COPY_AND_ASSIGN(PhaserStage);
+
+public:
+    PhaserStage(float32_t sampling_rate, PhaserParameter* params);
+
+    void process(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR);
+
+private:
+    PhaserParameter* params_;   // All paremters of the phaser including the inner coefficients
     float32_t z1[2], z2[2];     // State variables for the stage's filter
 };
 
@@ -52,11 +67,20 @@ class Phaser : public FX
     DISALLOW_COPY_AND_ASSIGN(Phaser);
 
 public:
-    Phaser(float32_t sampling_rate, float32_t frequency, float32_t q);
+    Phaser(float32_t sampling_rate, float32_t frequency = 0.5f, float32_t q = 1.0f);
     virtual ~Phaser();
 
     virtual void process(float32_t* left_input, float32_t* right_input, float32_t* left_output, float32_t* right_output, size_t nSamples) override;
 
+    void setFrequency(float32_t frequency);
+    inline float32_t getFrequency() const;
+
+    void setQ(float32_t q);
+    inline float32_t getQ() const;
+
 private:
-    PhaserStage stages_[NUM_PHASER_STAGES];
+    PhaserParameter params_;
+    float32_t phase_;           // Current phase of the LFO
+    float32_t phase_increment_; // Amount to increment the phase at each sample
+    PhaserStage* stages_[NUM_PHASER_STAGES];
 };

src/fx_rack.cpp

@@ -45,6 +45,7 @@ FXRack::FXRack(float32_t sampling_rate) :
     FX(sampling_rate),
     fx_chain_()
 {
+    this->registerFX(new Phaser(sampling_rate));
     this->registerFX(new TapeDelay(sampling_rate));
     this->registerFX(new ShimmerReverb(sampling_rate));
 }

src/fx_rack.h

@@ -20,6 +20,7 @@
 #pragma once
 
 #include "fx.h"
+#include "fx_phaser.h"
 #include "fx_tape_delay.h"
 #include "fx_shimmer_reverb.h"