More MIDI control, oscillator drift

main.cpp

@@ -14,7 +14,7 @@ using namespace std;
 #define SAMPLE_RATE 48000
 #define NUM_OSCS 7
 
-float noteToFreq(int note) {
+float noteToFreq(float note) {
     return 440 * pow(2, (note - 69) / 12.0);
 }
 
@@ -43,12 +43,11 @@ static int paCallback(
             value += state->oscs[j].tick();
         }
         value /= NUM_OSCS;
-        state->filter.setFrequency(0.21 + 0.20 * cos(M_PI * state->time));
         value = state->filter.tick(value);
-        value = 0.25 * sin(M_PI_2 * clamp(value, -1, 1));
+        value = 0.25 * clamp(value, -1, 1);
         *out++ = value;
         *out++ = value;
-        state->time += 1.0 / SAMPLE_RATE;
+        state->time += 0.5 / SAMPLE_RATE;
 
     }
     return 0;
@@ -70,14 +69,28 @@ static void ptCallback(PtTimestamp timestamp, void* userData) {
             if(vel > 0) {
                 int note = (msg >> 8) & 0x7F;
                 float centreFreq = noteToFreq(note);
-                float spreadCoeff = 0.004;
+                float spreadCoeff = 0.04;
                 for(int osc = 0, pos = -3; pos <= 3; ++osc, ++pos) {
-                    float freq = centreFreq * (1 + pos * spreadCoeff);
+                    float freq = noteToFreq(note + spreadCoeff * pos);
                     state->oscs[osc].phaseStep = (freq * 2 * M_PI) / SAMPLE_RATE;
                 }
                 state->time = 0;
             }
 
+        } else if(cmd == 0xB) {
+            int ctl = (msg >> 8) & 0x7F;
+
+            if(ctl == 0x01) {
+                int val = (msg >> 16) & 0x7F;
+                state->filter.setFrequency(val / 256.0);
+
+                /*
+                float flutterSpread = 0.001 * val / 127.0;
+                for(int osc = 0; i < NUM_OSCS; ++i) {
+                    state->oscs[i].flutterSpread = flutterSpread;
+                }
+                */
+            }
         }
 
         cout << "MIDI:";
@@ -110,8 +123,7 @@ void handlePAError(PaError err) {
 int main(void) {
     static State state;
     for(int i = 0; i < 7; ++i) {
-        float freq = 440 + i;
-        state.oscs[i].phaseStep = (freq * 2 * M_PI) / SAMPLE_RATE;
+        state.oscs[i].phaseStep = (440 * 2 * M_PI) / SAMPLE_RATE;
         state.oscs[i].phase = PIx2 * (float) rand() / RAND_MAX;
     }
     state.filter.setMode(SVFx2::MODE_LP);

oscillator.cpp

@@ -4,5 +4,7 @@ Oscillator::Oscillator() {
     mode = MODE_SAW;
     phase = 0;
     phaseStep = (440 * 2 * M_PI) / 44100;
-    value = 0; 
+    value = 0;
+    flutterSpread = 0.005;
+    flutter = 0;
 }

oscillator.h

@@ -14,6 +14,9 @@ public:
     float phase;        // current waveform phase angle (radians)
     float phaseStep;    // phase angle step per sample
     float value;        // current amplitude value
+    float flutterSpread;
+    float flutterSpeed;
+    float flutter;
 
     Oscillator();
 
@@ -60,7 +63,8 @@ public:
             value -= polyBlep(fmod(t + 0.5, 1.0)); // Layer output of Poly BLEP on top (flop)
         }
 
-        phase += phaseStep;
+        flutter += 0.01 * ((float) rand() / RAND_MAX - 0.5) - 0.00001 * flutter;
+        phase += phaseStep * (1.0 + flutterSpread * flutter);
         if(phase >= PIx2) { // wrap if phase angle >=360º
             phase -= PIx2;
         }