Add PitchShifter FX and simplify Diffuser

src/Makefile

@@ -12,7 +12,7 @@ OBJS = main.o kernel.o minidexed.o config.o userinterface.o uimenu.o \
        effect_compressor.o effect_platervbstereo.o \
        fx.o fx_components.o \
        fx_svf.o fx_tube.o fx_chorus.o fx_flanger.o fx_orbitone.o fx_phaser.o \
-       fx_delay.o fx_diffuser.o fx_shimmer_reverb.o fx_dry.o \
+       fx_delay.o fx_diffuser.o fx_pitch_shifter.o fx_shimmer_reverb.o fx_dry.o \
        uibuttons.o midipin.o
 
 OPTIMIZE = -O3

src/fx_diffuser.cpp

@@ -9,8 +9,6 @@ Diffuser::Diffuser(float32_t sampling_rate) :
     FXElement(sampling_rate),
     engine_(sampling_rate)
 {
-    this->engine_.setLFOFrequency(Engine::LFOIndex::LFO_1, 0.5f);
-    this->engine_.setLFOFrequency(Engine::LFOIndex::LFO_2, 0.3f);
 }
 
 Diffuser::~Diffuser()

src/fx_diffuser.h

@@ -37,7 +37,7 @@ public:
     virtual void processSample(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR) override;
 
 private:
-    typedef FxEngine<DIFFUSER_BUFFER_SIZE, Format::FORMAT_FLOAT32, true> Engine;
+    typedef FxEngine<DIFFUSER_BUFFER_SIZE, Format::FORMAT_FLOAT32, false> Engine;
     Engine engine_;
 
     IMPLEMENT_DUMP()

src/fx_pitch_shifter.cpp

@@ -0,0 +1,96 @@
+#include "fx_pitch_shifter.h"
+
+#include <cmath>
+#include <algorithm>
+
+#define ONE_POLE(out, in, coefficient) out += (coefficient) * ((in) - out);
+
+#define TAIL , -1
+
+PitchShifter::PitchShifter(float32_t sampling_rate) : 
+    FXElement(sampling_rate),
+    engine_(sampling_rate),
+    phase_(0.0f),
+    ratio_(0.0f),
+    size_(-1.0f),
+    sample_size_(0.0f)
+{
+    this->setRatio(0.5f);
+    this->setSize(0.5f);
+}
+
+PitchShifter::~PitchShifter()
+{
+}
+
+void PitchShifter::reset()
+{
+    this->engine_.reset();
+}
+
+void PitchShifter::processSample(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR)
+{
+    typedef Engine::Reserve<2047, Engine::Reserve<2047> > Memory;
+    Engine::DelayLine<Memory, 0> left;
+    Engine::DelayLine<Memory, 1> right;
+    Engine::Context c;
+
+    this->engine_.start(&c);
+    
+    this->phase_ += (1.0f - this->ratio_) / this->sample_size_;
+    if(this->phase_ >= 1.0f)
+    {
+      phase_ -= 1.0f;
+    }
+    if(this->phase_ <= 0.0f)
+    {
+      this->phase_ += 1.0f;
+    }
+
+    float tri = 2.0f * (this->phase_ >= 0.5f ? 1.0f - phase_ : phase_);
+    float phase = this->phase_ * this->sample_size_;
+    float half = phase + this->sample_size_ * 0.5f;
+    if(half >= this->sample_size_)
+    {
+      half -= this->sample_size_;
+    }
+    
+    c.load(inL);
+    c.writeAndLoad(left, 0.0f);
+    c.interpolate(left, phase, tri);
+    c.interpolate(left, half, 1.0f - tri);
+    c.writeAndLoad(outL, 0.0f);
+
+    c.load(inR);
+    c.writeAndLoad(right, 0.0f);
+    c.interpolate(right, phase, tri);
+    c.interpolate(right, half, 1.0f - tri);
+    c.writeAndLoad(outR, 0.0f);
+}
+
+void PitchShifter::setRatio(float32_t ratio)
+{
+    this->ratio_ = constrain(ratio, 0.0f, 1.0f);
+}
+
+float32_t PitchShifter::getRatio() const
+{
+    return this->ratio_;
+}
+
+void PitchShifter::setSize(float32_t size)
+{
+    size = constrain(size, 0.0f, 1.0f);
+    if(size != this->size_)
+    {
+        this->size_ = size;
+
+        float32_t target_size = 128.0f + (2047.0f - 128.0f) * size * size * size;
+        ONE_POLE(this->sample_size_, target_size, 0.05f);
+    }
+}
+
+float32_t PitchShifter::getSize() const
+{
+    return this->size_;
+}

src/fx_pitch_shifter.h

@@ -0,0 +1,56 @@
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+//
+// fx_shimmer_reverb3.h
+//
+// Stereo Pitch Shifter proposed in the context of the MiniDexed project 
+// It is adapted from the Pitch Shifter that could be found on Cloud EuroRack module from Mutable Instrruments
+//
+#pragma once
+
+#include "fx_components.h"
+#include "fx_engine.hpp"
+
+#define PITCH_SHIFTER_BUFFER_SIZE 4096
+
+class PitchShifter : public FXElement
+{
+    DISALLOW_COPY_AND_ASSIGN(PitchShifter);
+
+public:
+    PitchShifter(float32_t sampling_rate);
+    virtual ~PitchShifter();
+
+    virtual void reset() override;
+    virtual void processSample(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR) override;
+
+    void setRatio(float32_t ratio);
+    float32_t getRatio() const;
+
+    void setSize(float32_t size);
+    float32_t getSize() const;
+
+private:
+    typedef FxEngine<PITCH_SHIFTER_BUFFER_SIZE, Format::FORMAT_FLOAT32, false> Engine;
+    Engine engine_;
+
+    float32_t phase_;
+    float32_t ratio_;
+    float32_t size_;
+    float32_t sample_size_;
+  
+    IMPLEMENT_DUMP()
+    IMPLEMENT_INSPECT(return 0u;)
+};

src/fx_tube.cpp

@@ -1,5 +1,7 @@
 #include "fx_tube.h"
 
+#include <cmath>
+
 Tube::Tube(float32_t samplingRate) :
     FXElement(samplingRate),
     overdrive_(1.0f),
@@ -21,14 +23,14 @@ void Tube::reset()
 void Tube::processSample(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR)
 {
     float32_t x = inL * this->saturator_factor_;
-    float32_t abs_x = std::abs(x);
-    float32_t sat_x = std::log(1.0f + abs_x) * this->gain_factor_;
+    float32_t abs_x = abs(x);
+    float32_t sat_x = log(1.0f + abs_x) * this->gain_factor_;
     
     outL = inL > 0 ? sat_x : -sat_x;
 
     x = inR * this->saturator_factor_;
-    abs_x = std::abs(x);
-    sat_x = std::log(1.0f + abs_x) * this->gain_factor_;
+    abs_x = abs(x);
+    sat_x = log(1.0f + abs_x) * this->gain_factor_;
 
     outR = inR > 0 ? sat_x : -sat_x;
 }
@@ -42,7 +44,7 @@ void Tube::setOverdrive(float32_t overdrive)
     {
         this->overdrive_ = overdrive;
         this->saturator_factor_ = 1.0f + N * overdrive;
-        this->gain_factor_ = this->OutputLevelCorrector / std::log(1.0f + this->saturator_factor_);
+        this->gain_factor_ = this->OutputLevelCorrector / log(1.0f + this->saturator_factor_);
     }
 }
 

src/test/Makefile

@@ -33,8 +33,9 @@ FX__SRCS += ../fx_phaser.cpp
 FX__SRCS += ../fx_orbitone.cpp
 FX__SRCS += ../fx_flanger.cpp
 FX__SRCS += ../fx_delay.cpp
-FX__SRCS += ../fx_diffuser.cpp
 FX__SRCS += ../effect_platervbstereo.cpp
+FX__SRCS += ../fx_diffuser.cpp
+FX__SRCS += ../fx_pitch_shifter.cpp
 FX__SRCS += ../fx_shimmer_reverb.cpp
 FX__SRCS += ../fx_dry.cpp
 FX__SRCS += ../fx_rack.cpp

src/test/test_unitFXTuning.cpp

@@ -8,6 +8,8 @@
 #include "../fx_phaser.h"
 #include "../fx_delay.h"
 #include "../effect_platervbstereo.h"
+#include "../fx_diffuser.h"
+#include "../fx_pitch_shifter.h"
 #include "../fx_shimmer_reverb.h"
 
 TEST(UnitFXTuning, Dry)
@@ -114,6 +116,28 @@ TEST(UnitFXTuning, PlateReverb)
     CLEANUP_AUDIO_TEST(inSamples, outSamples);
 }
 
+TEST(UnitFXTuning, Diffuser)
+{
+    Diffuser fx(SAMPLING_FREQUENCY);
+
+    PREPARE_AUDIO_TEST(size, inSamples, outSamples, full_test_name);
+    SIMPLE_AUDIO_LOOP(inSamples, outSamples, size, inL, inR, outL, outR, fx);
+    SAVE_AUDIO_RESULTS(full_test_name, outSamples, size);
+    CLEANUP_AUDIO_TEST(inSamples, outSamples);
+}
+
+TEST(UnitFXTuning, PitchShifter)
+{
+    PitchShifter fx(SAMPLING_FREQUENCY);
+    fx.setSize(0.2f);
+    fx.setRatio(0.8f);
+
+    PREPARE_AUDIO_TEST(size, inSamples, outSamples, full_test_name);
+    SIMPLE_AUDIO_LOOP(inSamples, outSamples, size, inL, inR, outL, outR, fx);
+    SAVE_AUDIO_RESULTS(full_test_name, outSamples, size);
+    CLEANUP_AUDIO_TEST(inSamples, outSamples);
+}
+
 TEST(UnitFXTuning, ShimmerReverb)
 {
     ShimmerReverb fx(SAMPLING_FREQUENCY);