DaisySP_TeensyDaisySP_Teensy/examples/modal/modal.ino

// test of DaisySP synth object for the Teensy audio library
// modal synth - not very polyphonic because it uses about 30% CPU for one resonator
// its a good starting point for polyphonic instruments in any case
// some of this code was cribbed from the Faust for Teensy Additivesynth example
// RH March 28 2021

#include <Audio.h>
#include <Metro.h>

//#define DEBUG   // comment out to remove debug code

#ifdef DEBUG
Metro five_sec=Metro(5000); // Set up a 5 second Metro for performance stats
#endif

// constants for integer to float and float to integer conversion
#define MULT_16 2147483647
#define DIV_16 4.6566129e-10

#include "daisysp.h"
using namespace daisysp;

// including the source files is a pain but that way you compile in only the modules you need
// DaisySP statically allocates memory and some modules e.g. reverb use a lot of ram
#include "physicalmodeling/resonator.cpp"
#include "physicalmodeling/modalvoice.cpp"
#include "effects/reverbsc.cpp"  // uses a LOT of ram

float samplerate=AUDIO_SAMPLE_RATE_EXACT;

// create daisySP processing objects

#define VOICES 3   // 87% CPU with 3 voices 811mhz overclock
daisysp::ModalVoice voice[VOICES];
ReverbSc   verb;  

// this is the function called by the AudioSynthDaisySP object when it needs a block of samples
void AudioSynthDaisySP::update(void)
{
  float out,sig,wetvl, wetvr;
  audio_block_t *block;

  block = allocate(); // grab an audio block
  if (!block) {
    return;
  }

  for (int i=0; i < AUDIO_BLOCK_SAMPLES; i++) {

//**** insert daisySP generators here

    sig=0; // process and sum the string voices
    for (int i=0; i< VOICES;++i) {
      sig+=voice[i].Process();
    }
    sig=sig/VOICES; // scale the sum 
//  sig=sig*5; // crank the level a bit
    verb.Process(sig, sig, &wetvl, &wetvr); 

    out=sig + wetvl*0.2;   // add in some reverb
    
// convert generated float value -1.0 to +1.0 to int16 used by Teensy Audio    
    int32_t val = out*MULT_16;
    block->data[i] = val >> 16;
  }
  transmit(block);
  release(block);
}

// teensy audio objects and patch creation

AudioOutputI2S out;
//AudioOutputUSB outUSB;
AudioControlSGTL5000 audioShield;

AudioSynthDaisySP synth;  // create the daisysp synth audio object

AudioConnection patchCord20(synth,0,out,0);
AudioConnection patchCord21(synth,0,out,1);
//AudioConnection patchCord22(synth,0,outUSB,0);
//AudioConnection patchCord23(synth,0,outUSB,1);

// frequencies for all 127 MIDI Note numbers.
//     C         C#        D         D#        E         F         F#        G         G#        A         A#        B

const float NoteNumToFreq[] = {
    8.18,     8.66,     9.18,     9.72,    10.30,    10.91,    11.56,    12.25,    12.98,    13.75,    14.57,    15.43,    
   16.35,    17.32,    18.35,    19.45,    20.60,    21.83,    23.12,    24.50,    25.96,    27.50,    29.14,    30.87,    
   32.70,    34.65,    36.71,    38.89,    41.20,    43.65,    46.25,    49.00,    51.91,    55.00,    58.27,    61.74,   
   65.41,    69.30,    73.42,    77.78,    82.41,    87.31,    92.50,    98.00,   103.82,   110.00,   116.54,   123.47, 
  130.81,   138.59,   146.83,   155.56,   164.81,   174.61,   184.99,   195.99,   207.65,   220.00,   233.08,   246.94,   
  261.63,   277.18,   293.66,   311.13,   329.63,   349.23,   369.99,   391.99,   415.31,   440.00,   466.16,   493.88,   
  523.25,   554.37,   587.33,   622.25,   659.26,   698.46,   739.99,   783.99,   830.61,   880.00,   932.32,   987.77,   
 1046.50,  1108.73,  1174.66,  1244.51,  1318.51,  1396.91,  1479.98,  1567.98,  1661.22,  1760.00,  1864.66,  1975.53,  
 2093.00,  2217.46,  2349.32,  2489.02,  2637.02,  2793.83,  2959.96,  3135.96,  3322.44,  3520.00,  3729.31,  3951.07,  
 4186.01,  4434.92,  4698.64,  4978.03,  5274.04,  5587.65,  5919.91,  6271.93,  6644.88,  7040.00,  7458.62,  7902.13,  
 8372.02,  8869.84,  9397.27,  9956.06, 10548.08, 11175.30, 11839.82, 12543.85 };

// for polyphony - an array of all current notes. 
// Value -1 means the note is off (not sounding).

int StoredNotes[VOICES];

void setup() { 
  Serial.begin(38400);

#ifdef DEBUG
  while (!Serial) {
    // wait for Arduino Serial Monitor to be ready
  }
  Serial.println("starting setup");  
#endif

  for (int i=0; i< VOICES;++i) {  
      StoredNotes[i]=-1;  // initialize the note allocation array
      voice[i].Init(samplerate);       // initialize the voice object
  }

// initialize the reverb object and set its initial parameters
  verb.Init(samplerate);
  verb.SetFeedback(0.87);
  verb.SetLpFreq(10000.0f);
    
  // Enable the AudioShield
  AudioMemory(10);  // only uses 2 blocks
  Serial.println("enabling audio shield");    
  audioShield.enable();
  audioShield.volume(0.4);


  // Handles for the USB MIDI callbacks
  usbMIDI.setHandleNoteOn(myNoteOn);
  usbMIDI.setHandleNoteOff(myNoteOff);
  usbMIDI.setHandleControlChange(myControlChange);
  usbMIDI.setHandleAfterTouchPoly(myAfterTouch);
#ifdef DEBUG  
  Serial.println("finished setup");  
#endif
}


// Only looking for incoming MIDI events in the loop()
// myNoteOn(), myNoteOff() and myControlChange() will be processed on incoming MIDI messages.

void loop() {
  usbMIDI.read();

#ifdef DEBUG
  // DEBUG - Microcontroller Load Check
    if (five_sec.check() == 1)
    {
      Serial.print("Proc = ");
      Serial.print(AudioProcessorUsage());
      Serial.print(" (");    
      Serial.print(AudioProcessorUsageMax());
      Serial.print("),  Mem = ");
      Serial.print(AudioMemoryUsage());
      Serial.print(" (");    
      Serial.print(AudioMemoryUsageMax());
      Serial.println(")");
    }
#endif 
}

// Callback for incoming NoteOn messages
// Handling the voice allocation here.

void myNoteOn(byte channel, byte note, byte velocity) {
  int i=0;
  while( i < VOICES){
    if (StoredNotes[i] == -1) {  // if voice is idle
      StoredNotes[i] = int(note); // allocate this voice
      voice[i].SetFreq(NoteNumToFreq[note]);  
      voice[i].Trig();
      break;
    }
    ++i;
  }  
}

// Callback for incoming NoteOff messages
// Releasing voices to be re-allocated here.

void myNoteOff(byte channel, byte note, byte velocity) {
  for (int i=0; i < VOICES; ++i){
    int k = int(note); 
    if (StoredNotes[i] == k) { // if this voice matches the note we are silencing
      StoredNotes[i] = -1; // deallocate the voice
    }
  }
}


// Callback for incoming CC messages
// I'm using an external MIDI controller (Arturia Beatstep) to set voice parameters
// you can also do this with pots and AnalogRead()

void myControlChange(byte channel, byte control, byte value) {
  float val = float(value) / 127; // convert to 0-1

  for (int i=0; i < VOICES; ++i){
    switch (control) {
      case 101:
        voice[i].SetBrightness(val);
        break;
      case 102:
        voice[i].SetDamping(val);    
        break;
      case 103:
        voice[i].SetStructure(val);    
        break;
      default:
        break;
    }
  }
}

// Callback for incoming Aftertouch messages

void myAfterTouch(byte channel, byte note, byte value) {
    float val = float(value) / 127; // convert to 0-1
    
}