back to resonant filter (svf doesn't fit the character). reduced gain before filter fixes the overflow issue

Acid/Acid.ino

@@ -7,18 +7,17 @@
 // This code is licenced under GPL v3 or later
 
 // todo:
-// add glide handling
-// add accent handling
-// test StateVariable vs Resonant filters
-// exponential envelope https://sensorium.github.io/Mozzi/doc/html/07_8_envelopes_2_ead__envelope_2_ead__envelope_8ino-example.html
+// debug accent handling that overloads the filter, also accent can be too short or too long if it's relying on midi note
+// add overdrive
+// frequency from CV (noteFreq) could be Q16n16 for consistency
 
 #include <Mozzi.h>
 #include <MIDI.h>
 #include <Oscil.h>
 #include <MetaOscil.h>
-#include <StateVariable.h>
-//#include <ADSR.h>
+#include <ResonantFilter.h>
 #include <Ead.h>
+#include <Portamento.h>
 #include <mozzi_midi.h>
 #include <IntMap.h>
 #include <FixMath.h>
@@ -100,43 +99,63 @@ Oscil <SAW_MAX_8192_AT_16384_512_NUM_CELLS, MOZZI_AUDIO_RATE> aSaw8192(SAW_MAX_8
 MetaOscil<SAW_MAX_138_AT_16384_512_NUM_CELLS, MOZZI_AUDIO_RATE, 16> aSaw {&aSaw138, &aSaw154, &aSaw182, &aSaw240, &aSaw292, &aSaw341, &aSaw390, &aSaw431, &aSaw512, &aSaw630, &aSaw744, &aSaw1170, &aSaw1638, &aSaw2730, &aSaw4096, &aSaw8192};
 
 IntMap kMapNote(         0, 4095, 24 * pitchSubSteps, 84 * pitchSubSteps );
-IntMap kMapLFOSpeed(     0, 1023, 500, 20000 );
-IntMap kMapFreqMod(      0, 1023, 0,   1023  );
-IntMap kMapResonance(    0, 1023, 200, 1     );
-IntMap kMapCutoff(       0, 1023, 1,   20    );
-IntMap kMapAttack(       0, 1023, 3,   100   );
-IntMap kMapDecayRelease( 0, 1023, 200, 2000  );
-IntMap kMapSustain(      0, 1023, 0,   255   );
+IntMap kMapCutoff(       0, 1023, 26,  100   );
+IntMap kMapEnvMod(       0, 1023, 0,   140   );
+IntMap kMapResonance(    0, 1023, 0,   255   );
+IntMap kMapDrive(        0, 1023, 0,   400   );
+IntMap kMapAttack(       0, 1023, 1,   100   );
+IntMap kMapDecay(        0, 1023, 100, 1500  );
+IntMap kMapAccentLevel(  0, 1023, 0,   128   );
 
-//ADSR <MOZZI_CONTROL_RATE, MOZZI_CONTROL_RATE> envelope;
 Ead kEnvelope(MOZZI_CONTROL_RATE);
-StateVariable <LOWPASS> lpf;
-
+LowPassFilter lpfr;
+Portamento <MOZZI_CONTROL_RATE> kGlide;
 
 //Global variables
 byte gain;
 bool MIDINotePlaying;
+bool MIDINoteFaded = true;
 bool gateIsHigh = false;
 float noteFreq;
 bool envSwitchVal;
+bool droneSwitchVal;
 byte MIDIChannel;
 byte memCode = "a"; //a = MIDI Channel stored in 1023
+int driveAmount;
+byte notePlaying;
+bool accent = false;
 
 void MIDINoteOn(byte channel, byte note, byte velocity) {
-  noteFreq = mtof((int) note);
-  kEnvelope.start();
-  //envelope.noteOn();
+  notePlaying = note;
+
+  accent = false; //reset if the previous note was accented
+  if (velocity >= 127) {
+    accent = true;
+  }
+  
+  if (!MIDINotePlaying || !droneSwitchVal) {
+    kGlide.setTime(2); //4 at 256, 2 at 512 control rate to avoid portamento glitches caused by 0
+  } else {
+    kGlide.setTime(GLIDE_TIME);
+  }
+  kGlide.start(note);
+  if (!MIDINotePlaying || !droneSwitchVal) {
+    kEnvelope.start();
+  }
   MIDINotePlaying = true;
+  MIDINoteFaded = false;
   digitalWrite(LED, LOW);
 }
 
 void MIDINoteOff(byte channel, byte note, byte velocity) {
-  //envelope.noteOff();
-  digitalWrite(LED, HIGH);
+  if (note == notePlaying || !droneSwitchVal) {
+    MIDINotePlaying = false;
+    digitalWrite(LED, HIGH);
+  }
 }
 
 long softClip(long input) {
-  int threshold = 2048;
+  int threshold = 24000;
   if (input < -threshold) {
     return -threshold + (input + threshold) / 4;
   } else if (input > threshold) {
@@ -153,7 +172,7 @@ void setup(){
   pinMode(DroneSwitch, INPUT_PULLUP);
 
   //MIDI Channel setup
-  if(!digitalRead(GateIn)) { //&& !digitalRead(DroneSwitch) && !digitalRead(EnvSwitch)) { //MIDI setup mode, first knob you rotate = MIDI channel
+  if(!digitalRead(GateIn)) { //MIDI setup mode, first knob you rotate = MIDI channel
     int knob1Orig = analogRead(Knob1);
     int knob2Orig = analogRead(Knob2);
     int knob3Orig = analogRead(Knob3);
@@ -161,7 +180,7 @@ void setup(){
     int knobAOrig = analogRead(KnobA);
     int knobDROrig = analogRead(KnobDR);
     int knobSOrig = analogRead(KnobS);
-    int threshhold = 50; //To reduce noise from the input, needs testing and fine-tuning
+    int threshhold = 50; //To reduce noise from the input
     while(true) {
       if(abs(analogRead(Knob1) - knob1Orig) > threshhold) { 
         MIDIChannel = 1;
@@ -227,9 +246,6 @@ void setup(){
 
   startMozzi();
 
-  //envelope.setAttackLevel(255);
-  kEnvelope.setAttack(3);
-
   digitalWrite(LED, HIGH);
 }
 
@@ -247,73 +263,78 @@ void updateControl(){
   int knobAVal = mozziAnalogRead(KnobA);
   int knobDRVal = mozziAnalogRead(KnobDR);
   int knobSVal = mozziAnalogRead(KnobS);
-  bool droneSwitchVal = digitalRead(DroneSwitch);
+  droneSwitchVal = digitalRead(DroneSwitch);
   envSwitchVal = digitalRead(EnvSwitch);
   bool gateInVal = !digitalRead(GateIn);
   int CVInVal = mozziAnalogRead(CVIn);
 
-  //Remap the values and assign to parameter
-  int resonance = kMapResonance(knob3Val);
-  int cutoff = kMapCutoff(knob4Val);
+  //Remap the values and assign to parameters
+  int accentLevel = kMapAccentLevel(knobSVal);
+  int baseCutoff = kMapCutoff(knob1Val);
+  int cutoff = accent? (baseCutoff + (((long)accentLevel * (100 - baseCutoff)) >> 7)) : baseCutoff;
+  int resonance = accent? (255 - (((long)(128 - accentLevel) * (255 - kMapResonance(knob2Val))) >> 7)) : kMapResonance(knob2Val);
+  int envMod = kMapEnvMod(knob3Val);
+  driveAmount = kMapDrive(knob4Val);
+  
 
   //Set pitch and play notes on trigger
-  if (!MIDINotePlaying) {
+  if (MIDINoteFaded) {
     noteFreq = mtof((float) kMapNote(CVInVal << 2) / pitchSubSteps);
     digitalWrite(LED, !gateInVal);
     if (gateInVal && !gateIsHigh) {
       gateIsHigh = true;
       kEnvelope.start();
-      //envelope.noteOn();
     } else if (!gateInVal && gateIsHigh) {
       gateIsHigh = false;
-      //envelope.noteOff();
     }
-  } /*else if (MIDINotePlaying && !envelope.playing()) {
-    MIDINotePlaying = false;
-  }*/
-
-  //Update Filter settings
-  lpf.setResonance(resonance);
-  //lpf.setCentreFreq(cutoff);
+  }
 
   //Update Envelope Settings
   int attackTime = kMapAttack(knobAVal);
-  int decayReleaseTime = kMapDecayRelease(knobDRVal);
-  int sustainLevel = kMapSustain(knobSVal);
-  kEnvelope.setDecay(decayReleaseTime);
-  kEnvelope.setAttack(attackTime);
-  //envelope.setDecayLevel(sustainLevel);
-  //envelope.setTimes(attackTime, decayReleaseTime, 30000, decayReleaseTime); //30000 is so the note will sustain 30 seconds unless a noteOff comes
+  int baseDecay = kMapDecay(knobDRVal);
+  int decayTime = accent? (100 + (((long)(128 - accentLevel) * (baseDecay - 100)) >> 7)) : baseDecay;
+  kEnvelope.setDecay(decayTime);
+  kEnvelope.setAttack(accent? 1 : attackTime);
+
+  //Calculate makeup Gain
+  //makeupGain = ((long)256 * 127) / (127 + driveAmount);
 
   //Set Oscilator Frequency
-  float oscFreq = noteFreq;
-  aSquare.setFreq(oscFreq);
-  aSaw.setFreq(oscFreq); 
+  Q16n16 oscFreq;
+  if (!MIDINoteFaded) {
+    oscFreq = kGlide.next();
+    aSquare.setFreq_Q16n16(oscFreq);
+    aSaw.setFreq_Q16n16(oscFreq);
+  } else {
+    aSquare.setFreq(noteFreq);
+    aSaw.setFreq(noteFreq);
+  }
   
-  //envelope.update();
-
-  //int env = envelope.next();
   int env = kEnvelope.next();
 
-  if(!droneSwitchVal) {
-    gain = env;
-  } else {
-    gain = 255;
+  if (!MIDINotePlaying && !MIDINoteFaded && env == 0) {
+    MIDINoteFaded = true;
+    accent = false;
   }
-  lpf.setCentreFreq(env * cutoff);
 
+  gain = accent? constrain(env + (((long)env * accentLevel) >> 7), 0, 255) : env; //needs finetuning
+
+  lpfr.setCutoffFreqAndResonance(constrain(cutoff + (((long)env * envMod * cutoff)>>16), 0, 255), resonance);
 }
 
 AudioOutput updateAudio(){
   long signal;
   if(envSwitchVal) {
-    signal = aSquare.next() * 0.5;
+    signal = (aSquare.next() * 3) >> 2; //tricky way to set 0.75 gain to ~ match saw level
   } else {
-    signal = aSaw.next() * 1;
+    signal = aSaw.next();
   }
-  signal = lpf.next(signal); //filter
-  signal = (signal * gain); //envelope
-  signal = softClip((signal * (127 + driveAmount)) >> 6); //overdrive
+  signal = signal >> 2; //lowering the gain before filter to avoid filter overflow bug
+  signal = lpfr.next(signal); //filter
+  signal = (signal * gain) << 2; //envelope
+  //signal = softClip((signal * (127 + driveAmount)) >> 9); //overdrive
+  //signal = (signal * makeupGain) >> 7; //makeup gain compensation
+
   return MonoOutput::fromNBit(17, signal).clip();
 }
 

Acid/config.h

@@ -1,17 +1,16 @@
 //Settings
 const int pitchSubSteps = 16; //set how many steps are there between semitones. set to 1 to quantize to semitones
-const int driveAmount = 250;
-const bool oversamplingEnabled = false; //makes V/OCT tracking more precise, but adds a little portamento
-#define MOZZI_CONTROL_RATE 256
+#define MOZZI_CONTROL_RATE 512
+#define GLIDE_TIME 60
 
 //Hardware Definitions
-#define Knob1   A6  //Intensity
-#define Knob2   A4  //Modulator frequency ratio/Harmonics
-#define Knob3   A2  //LFO Frequency
-#define Knob4   A0  //LFO Shape
+#define Knob1   A6  //Cutoff
+#define Knob2   A4  //Resonance
+#define Knob3   A2  //Env.Mod
+#define Knob4   A0  //Overdrive
 #define KnobA   A5  //Attack
-#define KnobDR  A3  //Decay and Release
-#define KnobS   A1  //Sustain
+#define KnobDR  A3  //Decay
+#define KnobS   A1  //Accent
 #define CVIn    A7  //CV input and Pitch knob
 #define GateIn  10
 #define EnvSwitch 11