Fix broken code and add LFO

Author: maxwellmattryan

CMakeLists.txt

@@ -48,9 +48,6 @@ if (NEO_BUILD_TESTS)
     add_neuron_test(parameter tests/core/parameter_test.cpp)
 
     add_neuron_test(oscillator tests/dsp/generators/oscillator_test.cpp)
-    add_neuron_test(adsr tests/dsp/modulators/adsr_test.cpp)
-    add_neuron_test(saturator tests/dsp/processors/saturator_test.cpp)
-    add_neuron_test(wavefolder tests/dsp/processors/wavefolder_test.cpp)
     add_neuron_test(filter tests/dsp/processors/filter_test.cpp)
 
     add_neuron_test(arithmetic tests/utils/arithmetic_test.cpp)

Makefile

@@ -13,13 +13,11 @@ oscillator \
 
 MODULATOR_MOD_DIR = dsp/modulators
 MODULATOR_MODULES = \
-adsr \
+lfo \
 
 PROCESSOR_MOD_DIR = dsp/processors
 PROCESSOR_MODULES = \
 filter \
-saturator \
-wavefolder \
 
 ######################################
 # source

include/neuron/core/base.h

@@ -3,15 +3,15 @@
 #include "neuron/core/context.h"
 #include "neuron/dsp/modulators/modulator.h"
 
-#ifdef NEO_PLUGIN_SUPPORT
+#if NEO_PLUGIN_SUPPORT
 #include <atomic>
 #endif
 
 namespace neuron {
 
     /**
-     * Describes a Neuron DSP component, capable of processing, or
-     * generating signals.
+     * Describes a "neuron", i.e. a DSP component capable of generating signals,
+     * processing signals, or modulating parameters of other neurons.
      */
     template<class N, typename P>
     class Neuron {
@@ -21,35 +21,59 @@ namespace neuron {
          */
         ~Neuron() = default;
 
-        void SetContext(const Context& context)
+        /**
+         * Sets the DSP context for this neuron, holding information
+         * such as sample rate, block size, and number of channels.
+         */
+        void SetContext(Context context)
         {
             static_cast<N*>(this)->SetContextImpl(context);
         }
 
+        /**
+         * Attaches a modulator object to a given parameter of this neuron.
+         *
+         * CAUTION: Modulators MUST be evaluated in the audio callback before
+         * any other neurons. If modulator A is modulating modulator B, then A
+         * must be evaluated before B is. A and B must both be evaluated before any
+         * of the neurons they modulate are evaluated.
+         */
         template<class M>
-        void AttachModulator(const P parameter, Modulator<M>* modulator)
+        void AttachModulator(P parameter, Modulator<M>* modulator)
         {
             static_cast<N*>(this)->AttachModulatorImpl(parameter, modulator);
         }
 
-        void DetachModulator(const P parameter)
+        /**
+         * Detaches a modulator object from a given parameter of this neuron.
+         */
+        void DetachModulator(P parameter)
         {
             static_cast<N*>(this)->DetachModulatorImpl(parameter);
         }
 
-        void SetModulationDepth(const P parameter, float depth)
+        /**
+         * Sets the modulation depth of a given parameter of this neuron, which is a value
+         * between -1.0f and 1.0f.
+         *
+         * NOTE: If no modulator has been attached then this will have no effect.
+         */
+        void SetModulationDepth(P parameter, float depth)
         {
             static_cast<N*>(this)->SetModulationDepthImpl(parameter, depth);
         }
 
-#ifdef NEO_PLUGIN_SUPPORT
+#if NEO_PLUGIN_SUPPORT
         /**
          * Attach a source via an atomic pointer to a given parameter.
          */
-        void AttachParameterToSource(const P parameter, std::atomic<float>* source)
+        void AttachParameterToSource(P parameter, std::atomic<float>* source)
         {
             static_cast<N*>(this)->AttachParameterToSourceImpl(parameter, source);
         }
 #endif
+
+    protected:
+        Context m_context = DEFAULT_CONTEXT;
     };
 }

include/neuron/core/context.h

@@ -8,7 +8,7 @@ namespace neuron {
      * that use the sample rate to calculate phase positions.
      */
     struct Context {
-        double sampleRate;
+        float sampleRate;
         int numChannels;
         int blockSize;
     };
@@ -17,6 +17,6 @@ namespace neuron {
      * The common default context, using a sample rate of 44.1kHz, stereo
      * channel configuration, and a buffer size of 16 samples.
      */
-    static Context DEFAULT_CONTEXT = { 44100.0, 2, 16 };
+    static Context DEFAULT_CONTEXT = { 44100.0f, 2, 16 };
 
 }

include/neuron/core/parameter.h

@@ -1,12 +1,12 @@
 #pragma once
 
-#ifdef NEO_PLUGIN_SUPPORT
+#if NEO_PLUGIN_SUPPORT
 #include <atomic>
 #endif
 
 namespace neuron {
 
-#ifdef NEO_PLUGIN_SUPPORT
+#if NEO_PLUGIN_SUPPORT
     /**
      * A read-only parameter used by a DSP component to allow more
      * control and flexibility in shaping its sound.

include/neuron/dsp/generators/generator.h

@@ -5,7 +5,7 @@
 namespace neuron {
 
     /**
-     * Describes a DSP component that generates a signal without
+     * Describes a neuron that generates a signal without
      * processing an input signal.
      */
     template<class G>
@@ -22,7 +22,7 @@ namespace neuron {
          */
         void Generate(Buffer<Sample>& output)
         {
-            return static_cast<G*>(this)->GenerateImpl();
+            return static_cast<G*>(this)->GenerateImpl(output);
         }
     };
 

include/neuron/dsp/generators/oscillator.h

@@ -6,11 +6,10 @@
 #include "neuron/core/parameter.h"
 #include "neuron/dsp/generators/generator.h"
 #include "neuron/utils/waveform.h"
+#include "neuron/utils/wavetable.h"
 
 namespace neuron {
 
-    const size_t WAVETABLE_SIZE = 256;
-
     enum OscillatorParameter {
         OSC_FREQUENCY,
     };
@@ -22,13 +21,9 @@ namespace neuron {
     class Oscillator : public Generator<Oscillator>, public Neuron<Oscillator, OscillatorParameter> {
     public:
         /**
-         * Creates an oscillator generator.
-         *
-         * @param context The DSP context to be used by the oscillator.
-         * @param frequency The initial frequency of the oscillator.
-         * @return Oscillator
+         * Creates an oscillator generator that produces the given waveform at the given frequency.
          */
-        explicit Oscillator(Context& context = DEFAULT_CONTEXT, float frequency = 440.0f, Waveform waveform = Waveform::SINE);
+        explicit Oscillator(float frequency = 440.0f, Waveform waveform = Waveform::SINE);
 
         /**
          * Frees any memory allocated by the oscillator.
@@ -38,29 +33,21 @@ namespace neuron {
         /**
          * Resets the phase of the oscillator, starting it at the beginning
          * waveform position.
-         *
-         * @param
          */
         void Reset(float phase = 0.0f);
 
         /**
          * Sets the frequency of the oscillator.
-         *
-         * @param frequency The new oscillator output frequency.
          */
         void SetFrequency(float frequency);
 
         /**
          * Sets the waveform of the oscillator.
-         *
-         * @param waveform The new oscillator output waveform.
          */
         void SetWaveform(Waveform waveform);
 
         /**
          * Attaches a follower oscillator to be synced to this one.
-         *
-         * @param oscillator The oscillator that will be synced to this one.
          */
         void AttachFollower(Oscillator* oscillator);
 
@@ -74,32 +61,33 @@ namespace neuron {
         void GenerateImpl(Buffer<Sample>& output);
 
         friend class Neuron<Oscillator, OscillatorParameter>;
-        void SetContextImpl(const Context& context);
+        void SetContextImpl(Context context);
+
         template<class M>
-        void AttachModulatorImpl(OscillatorParameter parameter, Modulator<M>* modulator);
+        void AttachModulatorImpl(OscillatorParameter parameter, Modulator<M>* modulator)
+        {
+            switch (parameter) {
+                case OscillatorParameter::OSC_FREQUENCY:
+                    m_frequencyModulator = ModulationSource(modulator);
+                break;
+                default:
+                    break;
+            }
+        }
+
         void DetachModulatorImpl(OscillatorParameter parameter);
         void SetModulationDepthImpl(OscillatorParameter parameter, float depth);
-#ifdef NEO_PLUGIN_SUPPORT
+#if NEO_PLUGIN_SUPPORT
         void AttachParameterToSourceImpl(OscillatorParameter parameter, std::atomic<float>* source);
 #endif
 
     private:
-        void PopulateWavetable();
-        void IncrementPhase();
-        Sample Lerp();
-
-        Context& m_context;
-
-        Sample m_wavetable[WAVETABLE_SIZE];
-        Waveform m_waveform;
+        Wavetable m_wavetable;
 
         Parameter<float> p_frequency;
         Parameter<float> p_frequencyModulationDepth;
         ModulationSource m_frequencyModulator;
 
-        float m_phase = 0.0f;
-        float m_phaseIncrement = 0.0f;
-
         Oscillator* m_follower = nullptr;
     };