voice tuning correct

plugin/ic29.cpp

@@ -30,7 +30,10 @@ Synth::Synth() {
 
 void Synth::buildTables(double sampleRate) {
     for (uint8_t i = 0; i < 104; i++) {
-        pitchTable[i] = 440.0f * powf(2, (i - 45) / 12.0f) / sampleRate;
+        // slightly flat middle C from ROM divider table
+        // actually adjusted a little so that the notes are bang on
+        // on the real synth the tuning knob is tweaked a little off to pull it in
+        pitchTable[i] = 260.15f * powf(2, (i - 36) / 12.0f) / sampleRate;  
     }
 }
 
@@ -39,25 +42,22 @@ void Synth::run() {
     // callled once every 4.3ms block of samples
 
     for (uint8_t i = 0; i < NUM_VOICES; i++) {
-        ic29.voices[i].env.run();
-        ic29.voices[i].calcPitch();
+        ic29.voices[i].update();
     }
 }
 
 void Synth::voiceOn(uint8_t voice, uint8_t note) {
     // enable synth voice, start it all running
     voice &= 0x7f;
-    ic29.voices[voice].env.on();
-
-    // FIXME determine if we need to reset the counter
-    ic29.voices[voice].note = note;
+    ic29.voices[voice].on(note);
 }
 
 void Synth::voiceOff(uint8_t voice) {
     // enable synth voice, start it all running
     voice &= 0x7f;
-    ic29.voices[voice].env.off();
+    ic29.voices[voice].off();
 }
+
 void Synth::basePitch() {
     uint16_t pitch = 0x1818;
 
@@ -104,7 +104,7 @@ Voice::Voice() {
 }
 
 void Voice::calcPitch() {
-    uint16_t target = (note - 24) << 8;
+    uint16_t target = note << 8;
 
     if (ic29.portaCoeff != 0) {
         // porta up
@@ -121,6 +121,14 @@ void Voice::calcPitch() {
         pitch = target;
     }
 
+    pitch += 0x1818; //ic29.masterPitch;
+
+    if (pitch < 0x3000) pitch = 0x3000;  // lowest note
+    if (pitch > 0x9700) pitch = 0x6700;  // highest note
+
+    pitch -= 0x3000;
+    //pitch &= 0xff00;
+
     double o1 = ic29.pitchTable[pitch >> 8];
     double o2 = ic29.pitchTable[(pitch >> 8) + 1];
     double frac = (pitch & 0xff) / 255.0;
@@ -128,6 +136,27 @@ void Voice::calcPitch() {
     omega = ((o2 - o1) * frac) + o1;
 }
 
+void Voice::update() {
+    // calculate the once-per-block values
+    env.run();
+    calcPitch();
+    // do filter values
+}
+
+void Voice::on(uint8_t key) {
+    voiceState = V_ON;
+    note = key;
+    env.on();
+}
+
+void Voice::off() {
+    // I need to rethink this bit FIXME
+    voiceState = V_OFF;
+    if (!ic29.sustained) {
+        env.off();
+    }
+}
+
 void Voice::run(float *buffer, uint32_t samples) {
     float gain = env.level / 16384.0;
     gain *= 0.125;

plugin/ic29.hpp

@@ -31,6 +31,11 @@ class Envelope {
     void off() {
         phase = ENV_RLS;
     }
+
+    bool inRelease() {
+        return phase == ENV_RLS;
+    }
+
     uint16_t level;
 
     // private:
@@ -45,18 +50,21 @@ class Envelope {
 class Voice {
    public:
     Voice();
-    void run();
     uint8_t note = 0x3c;  // middle C
+    void run(float *buffer, uint32_t samples);
+    void update();
+    void on(uint8_t note);
+    void off();
 
-    // private:
+   private:
     Envelope env;             // calculated envelope value
     uint16_t pitch = 0x1818;  // calculated pitch value with porta and master pitch etc
-    float phase=0, omega=0;
+    float phase = 0, omega = 0;
     enum { V_DONE,
            V_OFF,
            V_ON } voiceState;
+
     void calcPitch();
-   void run(float *buffer, uint32_t samples);
 };
 
 class Synth {
@@ -77,11 +85,11 @@ class Synth {
     uint16_t masterPitch;  // sum of bend and LFO, plus any other pitch-setting value
                            // protected:
     uint16_t envAtk, envDcy, envStn, envRls;
-    int16_t portaCoeff;
+    int8_t portaCoeff;
+    bool sustained;
     double pitchTable[104];
 
-    
-   //private:
+    // private:
     int16_t lfoPitch;
     int16_t bendPitch;
     Voice voices[NUM_VOICES];