added waveform selectors

src/synth/Envelope.cpp

@@ -7,6 +7,7 @@ Envelope::Envelope() {
 
 void Envelope::noteOn() {
     state_ = State::Attack;
+    // there's interntionally no envelope value_ reset here because slurs
 }
 
 void Envelope::noteOff() {
@@ -26,7 +27,7 @@ float Envelope::process() {
             state_ = State::Decay;
         }
         break;
-      case State::Decay: // TODO: if noteOff occurs during decay, release doesn't trigger until decay finishes
+      case State::Decay:
         value_ -= (1.0f - sustain_) / (decay_ * sampleRate_);
         if(value_ <= sustain_) {
             value_ = sustain_;

src/synth/ScopeBuffer.h

@@ -4,6 +4,8 @@
 #include <vector>
 #include <atomic>
 
+// the scope buffer is used by the ui to visualize the audio waveform
+// the ui thread shouldn't read directly from memory being read from/written to so it copies the data into this class 
 class ScopeBuffer {
 public:
 
@@ -22,6 +24,7 @@ public:
 
     // NOTE: there are limits to the wavelengths that the scope can show cleanly due to the size of the audio buffer
     // at a buffer size of 256 at 44100hz the min visible steady frequency is ~172hz
+    // the min visible steady frequency can be lowered by increasing buffer size (increases latency) or decreasing sample rate (decreases audio fidelity)
 private:
 
     std::vector<float> buffer_;

src/synth/Synth.cpp

@@ -94,8 +94,25 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
         // TODO: wavetables should be scaled by their RMS for equal loudness (prelim standard = 0.707)
         float sineSample = std::sin(phase_);
         float squareSample = (phase_ >= M_PI) ? 0.707f : -0.707f;
-        float sawSample = ((phase_ / M_PI) - 1.0f) / 0.577f * 0.707f; 
-        sampleOut = squareSample * gain;
+        float sawSample = ((phase_ / M_PI) - 1.0f) / 0.577f * 0.707f;
+        // switch statement will be replaced with an array index for our array of wavetables
+        switch (static_cast<int32_t>(std::round(getParam(ParamId::Osc1WaveSelector1)))) {
+        case 0:
+            sampleOut = sineSample * gain;
+            break;
+        case 1:
+            sampleOut = squareSample * gain;
+            break;
+        case 2:
+            sampleOut = sawSample * gain;
+            break;
+        case 3:
+            // TODO: no triable wave yet :(
+            sampleOut = sineSample * gain;
+            break;
+        default: // unreachable
+            break;
+        }
 
         // write to buffer
         out[2*i] = sampleOut; // left
@@ -113,6 +130,7 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
             if(!triggered) {
                 scope_->setTrigger(i); // this is where we consider the start of a waveform
                 triggered = true;
+                // TODO: investigate triggering accross buffers when a single wave period transcends a single audio buffer
             }
         }
     }