package slider components into its own widget

src/synth/AudioEngine.h

@@ -29,15 +29,15 @@ private:
     // RtAudio binding for passing samples
     static int32_t audioCallback(void* outputBuffer, void* inputBuffer, uint32_t nFrames, double streamTime, RtAudioStreamStatus status, void* userData);
 
-    // calls the synth.process to generate a buffer audio samples
+    // calls the synth.process to generate a buffer of audio samples
     int32_t process(float* out, uint32_t nFrames);
 
-    ParameterStore params_;
-    NoteQueue noteQueue_;
-    Synth synth_;
+    ParameterStore params_; // stores the control parameters
+    NoteQueue noteQueue_; // stores note events for passing between threads
+    Synth synth_; // generates audio
 
+    RtAudio audio_; // audio device
     // TODO: id like a yml config file or something for these
-    RtAudio audio_;
     uint32_t sampleRate_ = 44100;
     uint32_t bufferFrames_ = 256; // time per buffer = BF/SR (256/44100 = 5.8ms)
     uint32_t channels_ = 2; // stereo

src/synth/Envelope.h

@@ -21,6 +21,7 @@ public:
 
     // setters
     void setSampleRate(float sampleRate) { sampleRate_ = sampleRate; }
+    void set(float a, float d, float s, float r) { setAttack(a); setDecay(a); setSustain(a); setRelease(a); }
     void setAttack(float seconds) { attack_ = std::max(seconds, 0.0001f); }
     void setDecay(float seconds) { decay_ = std::max(seconds, 0.0001f); }
     void setSustain(float level) { sustain_ = level; }

src/synth/Synth.cpp

@@ -73,6 +73,8 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
         for(auto& p : params_) p.update(); // TODO: profile this
 
         // process all envelopes
+        //gainEnvelope_.set(0.05f, 0.2f, 0.7f, getParam(ParamId::Osc1VolumeEnvR));
+        gainEnvelope_.setRelease(getParam(ParamId::Osc1VolumeEnvR));
         float gain = gainEnvelope_.process();
 
         // skip if no active notes
@@ -85,10 +87,13 @@ void Synth::process(float* out, uint32_t nFrames, uint32_t sampleRate) {
         float phaseInc = 2.0f * M_PI * frequency_ / static_cast<float>(sampleRate);
 
         // sample generation
+        // TODO: wavetables
+        // TODO: wavetables should be scaled by their RMS for equal loudness (prelim standard = 0.707)
         float sineSample = std::sin(phase_);
         float squareSample = -0.707f;
         if(phase_ >= M_PI) squareSample = 0.707f;
-        sampleOut = squareSample * gain;
+        float sawSample = phase_ * 4.0f / M_PI * frequency_ / static_cast<float>(sampleRate); 
+        sampleOut = sawSample * gain;
 
         // write to buffer
         out[2*i] = sampleOut; // left