Added button press to allow consistently recordable performances.

src/yaw-shepard/dsp.cpp

@@ -101,6 +101,7 @@ protected:
 			synth.setVolume(val);
 			break;
 		case kParameterButtonA:
+			if(val > 0.5f) synth.resetPhase();
 			break;
 		case kParameterButtonB:
 			break;

src/yaw-shepard/synth.cpp

@@ -4,6 +4,10 @@ Synth::Synth(double sampleRate){
     setSampleRate(48000.0, sampleRate);
 }
 
+inline void Synth::resetPhase(){
+    spectrumPhase = 0.0;
+}
+
 #define frac(x) ((x) - ((long)x))
 constexpr double MIN_VOLUME = 0.00001;
 

src/yaw-shepard/synth.h

@@ -13,16 +13,22 @@ public:
     void setPitchOffset(double in);
     void setSampleRate(double oldRate, double newRate);
     void setVolume(double in);
-    void shiftUp();
+
-    void shiftDown();
+    //For recordable performances.
+    //For now it requires a button push, but perhaps
+    //we should require time position and have the phase reset automatically
+    //on song start?
+    void resetPhase();
+
 
     //Current fundamental frequency of blit.
     double hzFund = fMin;
 
 private:
+    void shiftUp();
+    void shiftDown();
     //Phase of wavetable.
     double tablePhase = 0.0;
-    double fmPhase = 0.0;
     float volume = 0.0f;
     //Parameter in unit circle controlling pitch (varies by one octave).
     double spectrumPhase = 1.0f;