its a monosynth now

src/synth/AudioEngine.cpp

@@ -72,19 +72,23 @@ int32_t AudioEngine::process(float* out, size_t nFrames) {
 
     NoteEvent noteEvent;
     while(noteQueue_->pop(noteEvent)) {
-        std::string msg = "[NoteEvent] Type: " + std::to_string(noteEvent.type) +" Velocity: " + std::to_string(noteEvent.velocity) + " Note:" + std::to_string(noteEvent.note);
+        //std::string msg = "[NoteEvent] Type: " + std::to_string(noteEvent.type) +" Velocity: " + std::to_string(noteEvent.velocity) + " Note:" + std::to_string(noteEvent.note);
-        logger_->log("Audio", LogFlag::Debug, msg);
+        //logger_->log("Audio", LogFlag::Debug, msg);
+        noteOn_ = (noteEvent.type == NoteEventType::NoteOn) ? true : false;
+        freq_ = 440.0f * pow(2.0f, (static_cast<float>(noteEvent.note) - 69.0f) / 12.0f);
     }
 
+    const float twoPi = 2.0f*std::numbers::pi_v<float>;
+    float phaseIncrement = twoPi * freq_ / sampleRate_;
+
     for(size_t i = 0; i < nFrames; i++) {
 
         // simulate a sine wave
-        phase_ += 0.04f;
+        phase_ += phaseIncrement;
-        const float twoPi = 2.0f*std::numbers::pi_v<float>;
         if(phase_ > twoPi) {
             phase_ -= twoPi;
         }
-        float outSample = std::sin(phase_) / 4.0f;
+        float outSample = std::sin(phase_) / 4.0f * noteOn_;
 
         out[2*i] = outSample;
         out[2*i+1] = outSample;

src/synth/AudioEngine.hpp

@@ -40,6 +40,8 @@ private:
     uint32_t channels_ = 2;
 
     float phase_ = 0.0f;
+    float freq_ = 0.0f;
+    bool noteOn_ = false;
 
     LoggerService* logger_;
     ConfigService* config_;