[feat]: Filter LFO (#23)

Reviewed-on: #23
Co-authored-by: HiveBeats <e1lama@protonmail.com>
Co-committed-by: HiveBeats <e1lama@protonmail.com>

inc/BandPassFilter.h

@@ -1,14 +1,17 @@
 #pragma once
+
 #include "Filter.h"
 
 class BandPassFilter : public Filter {
-  private:
-    void CalculateCoefficients() override;
+  protected:
+    float GetSampleForFilterType() override;
 
   public:
+    BandPassFilter();
     BandPassFilter(Filter* filter);
     BandPassFilter(float freq, float res, float q);
-    BandPassFilter(/* args */);
     ~BandPassFilter();
     bool IsSameFilterType(FilterType type) override { return type == BandPass; };
 };
+
+

inc/Filter.h

@@ -1,24 +1,25 @@
 #pragma once
 #include "IEffect.h"
+#include "Settings.h"
 
-enum FilterType {
-    LowPass,
-    BandPass,
-    HighPass
-};
+enum FilterType { LowPass, BandPass, HighPass };
 
 class Filter : public IEffect {
   protected:
-    float m_freq;  // cutoff frequency
-    float m_q;     // filter quantity (resonance)
-    float m_order; // filter order (peakGain)
-    /* todo: filter adsr */
-    float m_norm, m_v, m_k;
-    float m_a0, m_a1, m_a2, m_b1, m_b2;
-    float m_z1, m_z2;
-
-    void CalculateNormals();
-    virtual void CalculateCoefficients(){};
+    // float* m_output; // output buffer
+    float m_fs = SAMPLE_RATE; // sampling frequency;
+    float m_fc;    // cutoff frequency normally something like: 440.0*pow(2.0,
+                   // (midi_note - 69.0)/12.0);
+    float m_res;   // resonance 0 to 1;
+    float m_drive; // internal distortion 0 to 0.1
+    float m_freq;  
+    float m_damp; 
+    float m_notcho; // notch output
+    float m_lowo;   // low pass output
+    float m_higho;  // high pass output
+    float m_bando;  // band pass output
+    float m_peako;  // peaking output = low - high
+    virtual float GetSampleForFilterType(){ return 0.0; };
 
   public:
     Filter(/* args */);
@@ -27,9 +28,9 @@ class Filter : public IEffect {
     void Release() override final;
     float Process(float in);
     void Process(std::vector<float>& samples) override final;
-    void SetParameters(float freq, float res, float q);
-    float GetFreq() { return m_freq; }
-    float GetRes() { return m_q; }
-    float GetPeakGain() { return m_norm; }
-    virtual bool IsSameFilterType(FilterType type){ return false; };
+    void SetParameters(float freq, float res, float drive);
+    float GetFreq() { return m_fc; }
+    float GetRes() { return m_res; }
+    float GetPeakGain() { return m_drive; }
+    virtual bool IsSameFilterType(FilterType type) { return false; };
 };

inc/HighPassFilter.h

@@ -2,8 +2,8 @@
 #include "Filter.h"
 
 class HighPassFilter : public Filter {
-  private:
-    void CalculateCoefficients() override;
+  protected:
+    float GetSampleForFilterType() override;
 
   public:
     HighPassFilter();

inc/LFO.h

@@ -11,10 +11,3 @@ public:
     void SetFreq(float freq) { m_phase_dt = (this->*m_dt_function)(freq); }
 };
 
-LFO::LFO(/* args */): Oscillator(Sine, 0.f, 0.5f)
-{
-}
-
-LFO::~LFO()
-{
-}

inc/LowPassFilter.h

@@ -4,7 +4,7 @@
 
 class LowPassFilter : public Filter {
   protected:
-    void CalculateCoefficients() override;
+    float GetSampleForFilterType() override;
 
   public:
     LowPassFilter();
@@ -13,3 +13,4 @@ class LowPassFilter : public Filter {
     ~LowPassFilter();
     bool IsSameFilterType(FilterType type) override { return type == LowPass; };
 };
+

inc/Synth.h

@@ -8,6 +8,7 @@
 #include "Oscillator.h"
 #include "Settings.h"
 #include <vector>
+#include "LFO.h"
 
 class Synth {
   private:
@@ -15,7 +16,7 @@ class Synth {
     std::vector<Oscillator*> m_oscillators;
     std::vector<IEffect*> m_effects;
     std::vector<float> m_out_signal;
-    Oscillator* m_lfo;
+    LFO* m_lfo;
     void ZeroSignal();
     void GetNote();
     void TriggerNoteOnEffects();