[refactor]: c++ implementation (#13)

implemented in c++ to improve readability and simplify maintenance

Co-authored-by: HiveBeats <e1lama@protonmail.com>
Reviewed-on: #13

src/Synth.cpp

@@ -0,0 +1,39 @@
+#include "Synth.h"
+#include "Settings.h"
+#include "KeyBoard.h"
+#include "OscillatorType.h"
+
+Synth::Synth(/* args */)
+{
+    AddOscillator();
+}
+
+Synth::~Synth()
+{
+}
+
+std::vector<float> & Synth::get_note(int semitone, float beats) 
+{
+    float hz = KeyBoard::GetHzBySemitone(semitone);
+    float duration = beats * BEAT_DURATION;
+    
+    // will change after oscillator starts to be more autonomous
+    for (Oscillator* osc : m_oscillators) 
+    {
+        osc->SetFreq(hz);
+    }
+
+    return m_adder.SumOscillators(m_oscillators, duration); //todo: add other pipeline steps (e.g ADSR, Filters, FX);
+}
+
+void Synth::ProduceNoteSound(Note input) 
+{
+    float length = 1.f / input.length;
+    int semitone_shift = KeyBoard::GetSemitoneShift(input.name);
+    m_out_signal = get_note(semitone_shift, length);
+}
+
+void Synth::AddOscillator()
+{
+    m_oscillators.push_back(new Oscillator(OscillatorType::Sine, 440.f, VOLUME));
+}