Fixing the Tube effect so it has more presence

src/fx_components.cpp

@@ -189,7 +189,7 @@ float32_t JitterGenerator::process()
 //////////////////////////////////
 // softSaturate implemlentation //
 //////////////////////////////////
-float32_t softSaturate(float32_t in, float32_t threshold)
+float32_t softSaturator1(float32_t in, float32_t threshold)
 {
     float32_t x = std::abs(in);
     float32_t y = 0.0f;
@@ -211,3 +211,56 @@ float32_t softSaturate(float32_t in, float32_t threshold)
     
     return (in < 0.0f) ? -y : y;
 }
+
+float32_t softSaturator2(float32_t input, float32_t saturation)
+{
+    constexpr static float kTubeCurve = 4.0f;
+    constexpr static float kTubeBias  = 0.5f;
+
+    float absInput = std::abs(input);
+    float output = 0.0f;
+    if(absInput > kTubeBias)
+    {
+        output = (kTubeCurve + saturation) * (absInput - kTubeBias) / (1.0f - kTubeBias);
+    }
+    else
+    {
+        output = (kTubeCurve + saturation) * absInput / (1.0f + kTubeCurve * absInput);
+    }
+
+    // Clip the output if overdrive is set to 1
+    // output = std::min(1.0f, output);
+    if(output > 1.0f)
+    {
+        output = 1.0f;
+    }
+    else
+    {
+        output -= output * output * output / 3.0f;
+    }
+
+    if(input < 0.0f)
+    {
+        output = -output;
+    }
+
+    return output;
+}
+
+float32_t waveFolder(float32_t input, float32_t bias)
+{
+    bias = 0.5 + (2.0f - bias) / 4.0f;
+    float32_t output = std::abs(input) / bias;
+
+    if(output > 1.0f)
+    {
+        output = 2.0f - output;
+    }
+
+    if(input < 0.0f)
+    {
+        output = -output;
+    }
+
+    return output;
+}

src/fx_components.h

@@ -257,4 +257,7 @@ private:
     float32_t phase_increment_;
 };
 
-float32_t softSaturate(float32_t in, float32_t threshold);
+float32_t softSaturator1(float32_t in, float32_t threshold);
+float32_t softSaturator2(float32_t in, float32_t saturation);
+
+float32_t waveFolder(float32_t input, float32_t bias);

src/fx_engine.hpp

@@ -99,13 +99,13 @@ public:
     {
     };
 
-    template <int32_t l, typename T = Empty>
+    template <int32_t _length, typename T = Empty>
     struct Reserve
     {
         typedef T Tail;
         enum
         {
-            length = l
+            length = _length
         };
     };
 

src/fx_shimmer_reverb.cpp

@@ -8,7 +8,10 @@
 
 ShimmerReverb::ShimmerReverb(float32_t sampling_rate) : 
     FXElement(sampling_rate),
-    engine_(sampling_rate)
+    engine_(sampling_rate),
+    input_gain_(-1.0f),
+    diffusion_(-1.0f),
+    lp_(-1.0f)
 {
     this->engine_.setLFOFrequency(LFO_1, 0.5f);
     this->engine_.setLFOFrequency(LFO_2, 0.3f);

src/fx_shimmer_reverb.h

@@ -47,7 +47,7 @@ public:
     float32_t getLP() const;
 
 private:
-    typedef FxEngine<16384, FORMAT_16_BIT> Engine;
+    typedef FxEngine<16384, FORMAT_16_BIT, true> Engine;
     Engine engine_;
 
     float32_t input_gain_;

src/fx_tube.cpp

@@ -3,7 +3,9 @@
 #include <cmath>
 
 Tube::Tube(float32_t samplingRate) :
-    FXElement(samplingRate)
+    FXElement(samplingRate),
+    overdrive_(0.0f),
+    saturation_(0.0f)
 {
     this->setOverdrive(0.0f);
 }
@@ -14,14 +16,14 @@ Tube::~Tube()
 
 void Tube::processSample(float32_t inL, float32_t inR, float32_t& outL, float32_t& outR)
 {
-    outL = softSaturate(inL, this->threshold_);
+    outL = softSaturator2(inL, this->saturation_);
-    outR = softSaturate(inR, this->threshold_);
+    outR = softSaturator2(inR, this->saturation_);
 }
 
 void Tube::setOverdrive(float32_t overdrive)
 {
     this->overdrive_ = constrain(overdrive, 0.0f, 1.0f);
-    this->threshold_ = 1.0f - this->overdrive_;
+    this->saturation_ = 2.0f * this->overdrive_;
 }
 
 float32_t Tube::getOverdrive() const

src/fx_tube.h

@@ -35,5 +35,5 @@ public:
 
 private:
     float32_t overdrive_;
-    float32_t threshold_;
+    float32_t saturation_;
 };

src/test/Makefile

@@ -51,12 +51,18 @@ fx_svf.o: ../fx_svf.cpp
 fx_tube.o: ../fx_tube.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@
 
+../fx_chorus.cpp: ../fx_engine.hpp
+	touch ../fx_chorus.cpp
+
 fx_chorus.o: ../fx_chorus.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@
 
 fx_phaser.o: ../fx_phaser.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@
 
+../fx_orbitone.cpp: ../fx_engine.hpp
+	touch ../fx_orbitone.cpp
+
 fx_orbitone.o: ../fx_orbitone.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@
 
@@ -66,8 +72,8 @@ fx_flanger.o: ../fx_flanger.cpp
 fx_delay.o: ../fx_delay.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@
 
-../fx_shimmer_reverb3.cpp: ../fx_engine.hpp
+../fx_shimmer_reverb.cpp: ../fx_engine.hpp
-	touch ../fx_shimmer_reverb3.cpp
+	touch ../fx_shimmer_reverb.cpp
 
 fx_shimmer_reverb.o: ../fx_shimmer_reverb.cpp
 	$(CXX) $(DEFINES) $(INCLUDES) $(CXXFLAGS) -c $^ -o $@

src/test/fxrack_test.cpp

@@ -119,7 +119,20 @@ void testSVF(unsigned& step)
     }
 }
 
-void testFXRack(unsigned& step)
+enum FXSitch
+{
+    Tube        = 1 << 0,
+    Chorus      = 1 << 1,
+    Phaser      = 1 << 2,
+    Orbitone    = 1 << 3,
+    Flanger     = 1 << 4,
+    Delay       = 1 << 5,
+    Shimmer     = 1 << 6
+};
+
+#define Active(fxSwitch, FxID) (fxSwitch & FxID) == FxID
+
+void testFXRack(unsigned& step, unsigned fxSwitch)
 {
     cout << "Step #" << (++step) << ": Intanciation FXRack" << endl;
     FXRack *rack = new FXRack(44100.0f);
@@ -128,59 +141,42 @@ void testFXRack(unsigned& step)
     rack->setEnable(true);
     rack->setWetLevel(1.0f);
 
-    rack->getTube()->setEnable(false);
+    rack->getTube()->setEnable(Active(fxSwitch, FXSitch::Tube));
     rack->getTube()->setWetLevel(1.0f);
     rack->getTube()->setOverdrive(1.0f);
 
-    rack->getChorus()->setEnable(false);
+    rack->getChorus()->setEnable(Active(fxSwitch, FXSitch::Chorus));
     rack->getChorus()->setWetLevel(0.5f);
     rack->getChorus()->setRate(0.4f);
     rack->getChorus()->setDepth(0.5f);
     
-    rack->getPhaser()->setEnable(false);
+    rack->getPhaser()->setEnable(Active(fxSwitch, FXSitch::Phaser));
 
-    rack->getOrbitone()->setEnable(true);
+    rack->getOrbitone()->setEnable(Active(fxSwitch, FXSitch::Orbitone));
     rack->getOrbitone()->setWetLevel(0.8f);
     rack->getOrbitone()->setRate(0.4f);
     rack->getOrbitone()->setDepth(0.5f);
 
-    rack->getFlanger()->setEnable(false);
+    rack->getFlanger()->setEnable(Active(fxSwitch, FXSitch::Flanger));
+    rack->getFlanger()->setWetLevel(0.5f);
+    rack->getFlanger()->setDelayTime(0.8f);
+    rack->getFlanger()->setFrequency(0.25f);
+    rack->getFlanger()->setDepth(0.8f);
+    rack->getFlanger()->setFeedback(0.75f);
 
-    rack->getDelay()->setEnable(false);
+    rack->getDelay()->setEnable(Active(fxSwitch, FXSitch::Delay));
     rack->getDelay()->setWetLevel(0.6f);
     rack->getDelay()->setLeftDelayTime(0.075f);
     rack->getDelay()->setLeftDelayTime(0.05f);
     rack->getDelay()->setFeedbak(0.5f);
 
-    rack->getShimmerReverb()->setEnable(false);
+    rack->getShimmerReverb()->setEnable(Active(fxSwitch, FXSitch::Shimmer));
     rack->getShimmerReverb()->setWetLevel(0.7f);
     rack->getShimmerReverb()->setInputGain(0.45f);
     rack->getShimmerReverb()->setTime(0.89f);
     rack->getShimmerReverb()->setDiffusion(0.75f);
     rack->getShimmerReverb()->setLP(0.8f);
 
-    const unsigned nSamples = 1;
-    float32_t inSamples[2][nSamples];
-    float32_t outSamples[2][nSamples];
-
-    for (unsigned i = 0; i < nSamples; ++i)
-    {
-        inSamples[0][i] = dist(gen);
-        inSamples[1][i] = dist(gen);
-    }
-
-    memset(outSamples[0], 0, nSamples * sizeof(float32_t));
-    memset(outSamples[1], 0, nSamples * sizeof(float32_t));
-
-    cout << "Step #" << (++step) << ": Run test" << endl;
-    rack->process(inSamples[0], inSamples[1], outSamples[0], outSamples[1], nSamples);
-
-    cout << "Step #" << (++step) << ": Render results" << endl;
-    for (unsigned i = 0; i < nSamples; ++i)
-    {
-        std::cout << "#" << i << " " << inSamples[0][i] << "   --> " << outSamples[0][i] << " = " << ((outSamples[0][i] - inSamples[0][i]) * 100.0f / inSamples[0][i]) << "%" << std::endl;
-    }
-
     unsigned nbRepeats = 4;
 
     unsigned size;
@@ -195,7 +191,7 @@ void testFXRack(unsigned& step)
         rack->process(samples[0], samples[1], sampleOutL + i * size, sampleOutR + i * size, size);
     }
 
-    saveWaveFile("result.wav", sampleOutL, sampleOutR, nbRepeats * size, 44100, 16);
+    saveWaveFile("result.wav", sampleOutL, sampleOutR, nbRepeats * size, static_cast<unsigned>(FS), 16);
 
     delete[] sampleOutL;
     delete[] sampleOutR;
@@ -211,10 +207,16 @@ int main()
 {
     unsigned step = 0;
 
-    testLFO(step);
+    // testLFO(step);
     // testFlutter(step);
     // testSVF(step);
-    // testFXRack(step);
+    testFXRack(step, FXSitch::Tube);
+    // testFXRack(step, FXSitch::Flanger);      // to be fixed -> feedback deletes FX effect
+    // testFXRack(step, FXSitch::Phaser);       // to be fixed -> far too load but saturation is interested
+    // testFXRack(step, FXSitch::Chorus);
+    // testFXRack(step, FXSitch::Orbitone);
+    // testFXRack(step, FXSitch::Delay);
+    // testFXRack(step, FXSitch::Shimmer);
 
     return 0;
 }

src/test/waveout.cpp

@@ -82,4 +82,6 @@ void saveWaveFile(const std::string& fileName,
         std::cerr << "Error: unsupported bit depth: " << bitsPerSample << std::endl;
         return;
     }
+
+    file.close();
 }