//
// ALGONOIZER v0.1
// mai 2013
//
// Sources:
// http://countercomplex.blogspot.com/2011/10/algorithmic-symphonies-from-one-line-of.html
// http://www.bemmu.com/music/index.html
// http://wurstcaptures.untergrund.net/music/
//
// http://www.marulaberry.co.za/index.php/tutorials/code/arduino-adc/
//


// DECLARATIONS ***************************************************************
// Constantes
#define PIN_PWM                9  // Broche de sortie audio
#define PIN_BUT                2  // Broche d'entrée (boutton poussoir) (port D)
#define PIN_LFO                3  // Broche de sortie LFO (LED)         (port B)

#define MODE_NORMAL            0
#define MODE_LFOSETUP          1

#define CTRL_FRQ               0
#define CTRL_PARAM             1
#define CTRL_FUNC              2
#define CTRL_VOL               3
#define CTRL_LFO               4
#define CTRL_BUT               5

#define DEFAULT_LFOSPEED     100  // Période LFO au demarrage (en nb d'interruptions)


#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif

// ADC prescaler
const unsigned char ADC_PS_16  = (1 << ADPS2);
const unsigned char ADC_PS_32  = (1 << ADPS2) | (1 << ADPS0);
const unsigned char ADC_PS_64  = (1 << ADPS2) | (1 << ADPS1);
const unsigned char ADC_PS_128 = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);

// Variables programme
unsigned long t;   // Compteur t
int  audioOut;     // Valeur de l'échantillon audio
byte iFunction;    // Numero de la fonction audio
byte iCtrlNb;      // Numero de potentiometre
int  iParam[]   = {0, 0, 0, 0, 0, 0};
int  tmpParam[] = {0, 0, 0, 0, 0, 0};
//         iParam[0] : freq d'échantillonnage
//         iParam[1] : fonction audio
//         iParam[2] : parametre audio
//         iParam[3] : volume audio
//         iParam[4] : forme d'onde LFO
//         iParam[5] : etat du boutton poussoir

int  iIncrement;   // Increment du compteur t
int  iCount;       // Compteur pour ralentir l'incrementation de t

byte iMode = MODE_NORMAL;

// Variables temps. Mesure = nombre d'interruptions
unsigned long interruptCounter;
unsigned long timeButtonLast;
unsigned long buttonPeriod;           // Durée entre 2 appuis
unsigned long delayButSetup =  20000; // Temps d'appui pour passer en mode setup
unsigned long maxLFOPeriod  = 100000; // Temps max entre 2 appuis considéré pour definir le LFO

// Variables du LFO
int  lfoCounter;
byte lfoIndex;
long lfoOverflow;
byte lfoVal;
byte lfoWaveForm;
int  lfoParam[5] = {-1, -1, -1, 0, -1};
//         lfoParam[i] = -1      : paramètre i non modifié par le LFO
//         lfoParam[i] =  0..255 : paramètre i modifié par le LFO 
//                                 entre iParam[i] et lfoParam[i]

// Formes d'onde pour le LFO
static const uint8_t  waveTable[6][256] PROGMEM = {
  // #0 - OFF
  {
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255
  },

  // #1 - SQUARE
  {
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255, 255, 255, 255, 255, 255, 255, 255,
    255,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0,
      0,   0,   0,   0,   0,   0,   0,   0
  },
  
  // #2 - SINUS
  {
    128, 131, 134, 137, 140, 143, 146, 149,
    152, 155, 158, 162, 165, 167, 170, 173,
    176, 179, 182, 185, 188, 190, 193, 196,
    198, 201, 203, 206, 208, 211, 213, 215,
    218, 220, 222, 224, 226, 228, 230, 232,
    234, 235, 237, 238, 240, 241, 243, 244,
    245, 246, 248, 249, 250, 250, 251, 252,
    253, 253, 254, 254, 254, 255, 255, 255,
    255, 255, 255, 255, 254, 254, 254, 253,
    253, 252, 251, 250, 250, 249, 248, 246,
    245, 244, 243, 241, 240, 238, 237, 235,
    234, 232, 230, 228, 226, 224, 222, 220,
    218, 215, 213, 211, 208, 206, 203, 201,
    198, 196, 193, 190, 188, 185, 182, 179,
    176, 173, 170, 167, 165, 162, 158, 155,
    152, 149, 146, 143, 140, 137, 134, 131,
    128, 124, 121, 118, 115, 112, 109, 106,
    103, 100,  97,  93,  90,  88,  85,  82,
     79,  76,  73,  70,  67,  65,  62,  59,
     57,  54,  52,  49,  47,  44,  42,  40,
     37,  35,  33,  31,  29,  27,  25,  23,
     21,  20,  18,  17,  15,  14,  12,  11,
     10,   9,   7,   6,   5,   5,   4,   3,
      2,   2,   1,   1,   1,   0,   0,   0,
      0,   0,   0,   0,   1,   1,   1,   2,
      2,   3,   4,   5,   5,   6,   7,   9,
     10,  11,  12,  14,  15,  17,  18,  20,
     21,  23,  25,  27,  29,  31,  33,  35,
     37,  40,  42,  44,  47,  49,  52,  54,
     57,  59,  62,  65,  67,  70,  73,  76,
     79,  82,  85,  88,  90,  93,  97, 100,
    103, 106, 109, 112, 115, 118, 121, 124
  },

  // #3 - TRIANGLE
  {
    128, 129, 131, 133, 135, 137, 139, 141,
    143, 145, 147, 149, 151, 153, 155, 157,
    159, 161, 163, 165, 167, 169, 171, 173,
    175, 177, 179, 181, 183, 185, 187, 189,
    191, 193, 195, 197, 199, 201, 203, 205,
    207, 209, 211, 213, 215, 217, 219, 221,
    223, 225, 227, 229, 231, 233, 235, 237,
    239, 241, 243, 245, 247, 249, 251, 253,
    255, 253, 251, 249, 247, 245, 243, 241,
    239, 237, 235, 233, 231, 229, 227, 225,
    223, 221, 219, 217, 215, 213, 211, 209,
    207, 205, 203, 201, 199, 197, 195, 193,
    191, 189, 187, 185, 183, 181, 179, 177,
    175, 173, 171, 169, 167, 165, 163, 161,
    159, 157, 155, 153, 151, 149, 147, 145,
    143, 141, 139, 137, 135, 133, 131, 129,
    128, 126, 124, 122, 120, 118, 116, 114,
    112, 110, 108, 106, 104, 102, 100,  98,
     96,  94,  92,  90,  88,  86,  84,  82,
     80,  78,  76,  74,  72,  70,  68,  66,
     64,  62,  60,  58,  56,  54,  52,  50,
     48,  46,  44,  42,  40,  38,  36,  34,
     32,  30,  28,  26,  24,  22,  20,  18,
     16,  14,  12,  10,   8,   6,   4,   2,
      0,   2,   4,   6,   8,  10,  12,  14,
     16,  18,  20,  22,  24,  26,  28,  30,
     32,  34,  36,  38,  40,  42,  44,  46,
     48,  50,  52,  54,  56,  58,  60,  62,
     64,  66,  68,  70,  72,  74,  76,  78,
     80,  82,  84,  86,  88,  90,  92,  94,
     96,  98, 100, 102, 104, 106, 108, 110,
    112, 114, 116, 118, 120, 122, 124, 126
  },
  
  // #4 - RAMP UP
  {
      0,   1,   2,   3,   4,   5,   6,   7,
      8,   9,  10,  11,  12,  13,  14,  15,
     16,  17,  18,  19,  20,  21,  22,  23,
     24,  25,  26,  27,  28,  29,  30,  31,
     32,  33,  34,  35,  36,  37,  38,  39,
     40,  41,  42,  43,  44,  45,  46,  47,
     48,  49,  50,  51,  52,  53,  54,  55,
     56,  57,  58,  59,  60,  61,  62,  63,
     64,  65,  66,  67,  68,  69,  70,  71,
     72,  73,  74,  75,  76,  77,  78,  79,
     80,  81,  82,  83,  84,  85,  86,  87,
     88,  89,  90,  91,  92,  93,  94,  95,
     96,  97,  98,  99, 100, 101, 102, 103,
    104, 105, 106, 107, 108, 109, 110, 111,
    112, 113, 114, 115, 116, 117, 118, 119,
    120, 121, 122, 123, 124, 125, 126, 127,
    128, 128, 129, 130, 131, 132, 133, 134,
    135, 136, 137, 138, 139, 140, 141, 142,
    143, 144, 145, 146, 147, 148, 149, 150,
    151, 152, 153, 154, 155, 156, 157, 158,
    159, 160, 161, 162, 163, 164, 165, 166,
    167, 168, 169, 170, 171, 172, 173, 174,
    175, 176, 177, 178, 179, 180, 181, 182,
    183, 184, 185, 186, 187, 188, 189, 190,
    191, 192, 193, 194, 195, 196, 197, 198,
    199, 200, 201, 202, 203, 204, 205, 206,
    207, 208, 209, 210, 211, 212, 213, 214,
    215, 216, 217, 218, 219, 220, 221, 222,
    223, 224, 225, 226, 227, 228, 229, 230,
    231, 232, 233, 234, 235, 236, 237, 238,
    239, 240, 241, 242, 243, 244, 245, 246,
    247, 248, 249, 250, 251, 252, 253, 254
  },
  
  // #5 - RAMP DOWN
  {
    255, 254, 253, 252, 251, 250, 249, 248,
    247, 246, 245, 244, 243, 242, 241, 240,
    239, 238, 237, 236, 235, 234, 233, 232,
    231, 230, 229, 228, 227, 226, 225, 224,
    223, 222, 221, 220, 219, 218, 217, 216,
    215, 214, 213, 212, 211, 210, 209, 208,
    207, 206, 205, 204, 203, 202, 201, 200,
    199, 198, 197, 196, 195, 194, 193, 192,
    191, 190, 189, 188, 187, 186, 185, 184,
    183, 182, 181, 180, 179, 178, 177, 176,
    175, 174, 173, 172, 171, 170, 169, 168,
    167, 166, 165, 164, 163, 162, 161, 160,
    159, 158, 157, 156, 155, 154, 153, 152,
    151, 150, 149, 148, 147, 146, 145, 144,
    143, 142, 141, 140, 139, 138, 137, 136,
    135, 134, 133, 132, 131, 130, 129, 128,
    128, 127, 126, 125, 124, 123, 122, 121,
    120, 119, 118, 117, 116, 115, 114, 113,
    112, 111, 110, 109, 108, 107, 106, 105,
    104, 103, 102, 101, 100,  99,  98,  97,
     96,  95,  94,  93,  92,  91,  90,  89,
     88,  87,  86,  85,  84,  83,  82,  81,
     80,  79,  78,  77,  76,  75,  74,  73,
     72,  71,  70,  69,  68,  67,  66,  65,
     64,  63,  62,  61,  60,  59,  58,  57,
     56,  55,  54,  53,  52,  51,  50,  49,
     48,  47,  46,  45,  44,  43,  42,  41,
     40,  39,  38,  37,  36,  35,  34,  33,
     32,  31,  30,  29,  28,  27,  26,  25,
     24,  23,  22,  21,  20,  19,  18,  17,
     16,  15,  14,  13,  12,  11,  10,   9,
      8,   7,   6,   5,   4,   3,   2,   1
  }
};

// ROUTINE D'INITIALISATION ***************************************************

void setup() {
  // Declaration des entrees/sorties
  pinMode(13, OUTPUT);
  pinMode(PIN_PWM, OUTPUT);
  pinMode(PIN_LFO, OUTPUT);
  pinMode(PIN_BUT, INPUT);
  digitalWrite(PIN_BUT, HIGH); // pullup
  
  // Initialisation du LFO
  lfoWaveForm = 0;
  lfoOverflow = DEFAULT_LFOSPEED;
  
  // Initialisation des registres

  // Fast ADC
  ADCSRA &= ~ADC_PS_128; // Suppression du prescaler de 128 defini par defaut
  ADCSRA |=  ADC_PS_16;  // Choix du nouveau prescaler :
                         // ADC_PS_16, ADC_PS_32, ADC_PS_64 ou ADC_PS_128
  
  // 8-bit Fast PWM (TIMER1), sans prescaler (CS10)
  TCCR1A= _BV(COM1A1) | _BV(WGM10);
  TCCR1B = _BV(CS10) | _BV(WGM12);

  // Activation de l'interruption de debordement pour TIMER1
  TIMSK1 = _BV(TOIE1);

  // Phase-Correct PWM sur TIMER2 (canal B)
  TCCR2A = _BV(COM2B1) | _BV(WGM20);
  TCCR2B = _BV(CS22);
}

// ROUTINE D'INTERRUPTION *****************************************************

ISR(TIMER1_OVF_vect) {
  // TIMER1 deborde a une freq de 62.5kHz (ou 7.8kHz)

  // Incremente les compteurs
  interruptCounter++;  
  lfoCounter++;
  
  // Traitement alterne du LFO et de l'audio
  // => frequence d'echantillonnage audio /2 (31kHz)
  if (interruptCounter % 2) {
    // Calcul du LFO
    if (lfoCounter >= lfoOverflow) {
      if (lfoWaveForm > 0) lfoVal = pgm_read_byte(&waveTable[lfoWaveForm][lfoIndex]);
      else lfoVal = 0;
      if (iMode == MODE_NORMAL) OCR2B = lfoVal;
      lfoIndex++;
      lfoCounter = 0;
    }
    
    return;
  }

  // Prepare et envoie l'échantillon audio vers la sortie PWM
  byte out = audioOut >> 8;
  uint16_t oscenv = out * (tmpParam[CTRL_VOL]>>2);
  out = (oscenv >> 8);

  OCR1A = out;
  
  // Incremente le compteur t
  if (iIncrement < 0) {
    iCount++;
    if (iCount >= -iIncrement){
        iCount = 0;
        t++;
    }
  }
  else {
    t = t + max(1, iIncrement);
  }

  // Calcul de l'échantillon
  switch (iFunction) {
    case 0:
      audioOut = t>>6^t&0x25|t+(t^t>>(tmpParam[CTRL_PARAM]>>6))-t*((t%24?2:6)&t>>11)^t<<1&(t&0x256?t>>4:t>>10);
      break;
    case 1:
      audioOut = (t*(t>>5|t>>8))>>(t>>(tmpParam[CTRL_PARAM]>>6));
      break;
    case 2:  
      audioOut = t*(t>>(tmpParam[CTRL_PARAM]>>6)&t>>8&123&t>>3);
      break;
    case 3:
      audioOut = t*(t>>8*(t>>(tmpParam[CTRL_PARAM]>>6)|t>>8)&(20|(t>>19)*5>>t|t>>3));
      break;
    case 4:
      audioOut = (~t/100|(t*(tmpParam[CTRL_PARAM]>>6)))^(t*3&(t>>5));
      break;
    case 5:
      audioOut = t>>(tmpParam[CTRL_PARAM]>>6)|t>>(tmpParam[3]>>6);
      break;
    case 6:
      audioOut = t * ((t>>(tmpParam[CTRL_PARAM]>>6)|t>>(tmpParam[3]>>6))&74&t>>15);
      break;
    case 7:
      audioOut = (t*(5+tmpParam[CTRL_PARAM]>>6)&t>>7);
      break;
    case 8:
      audioOut = t & tmpParam[CTRL_PARAM];
      break;
    case 9:
      audioOut = ((((5&((3 *(23*(4^t)))+t))*(9*((15>>((9&((t&12)^15))>>5))*2)))*((((t*(t*8))>>10)&t)>>(tmpParam[CTRL_PARAM]>>6)))^15);
      break;
    case 10:
      audioOut = ((t*5&t>>7)|(t*3&t>>(tmpParam[CTRL_PARAM]>>6)));
      break;
    case 11:
      audioOut = (t|t>>(1+(tmpParam[CTRL_PARAM]>>6)));
      break;
    case 12:
      audioOut = t>>(tmpParam[CTRL_PARAM]>>6)^t&0x25|t + (t^t>>(1+(tmpParam[3]>>6))) - t*((t%24?2:6)&t>>11)^t<<1&(t&0x256?t>>4:t>>10);
      break;
    case 13:
      audioOut = ((t*t)>>((((8*t)&(t>>t))>>((11>>t)&(8|8)))+(((t+8)*((((t|11)*(t+11))+((t&8)>>(t+11)))*(((11>>8)|(t|8))>>((t>>8)|(11&8)))))+((t>>11)-(8|11)))));
      break;
    case 14:
      audioOut = t&t>>(1+(tmpParam[CTRL_PARAM]>>6));
      break;
    case 15:
      audioOut = (t^(t>>(1+(tmpParam[CTRL_PARAM]>>6)))) + (t^t>>(1+(tmpParam[3]>>6)));
      break;  
    default:
      break;
  }
}

// BOUCLE PRINCIPALE **********************************************************

void loop() {
  unsigned long timeNow = interruptCounter;
  unsigned long butDuration;
  int ctrlVal;
  byte stateButton;
  
  // Lecture des potentiometres (1 par boucle)
  ctrlVal = analogRead(iCtrlNb);
  if (iMode == MODE_NORMAL) {
    iParam[iCtrlNb] = ctrlVal;
  }
  else {
    // MODE_LFOSETUP
    if (abs(iParam[iCtrlNb] - ctrlVal) > 10) {
      // Le potentiometre iCtrlNb a été modifié
      lfoParam[iCtrlNb] = ctrlVal;
    }
  }
  iCtrlNb++;
  
  if (iCtrlNb >= CTRL_BUT) {
    // Lecture boutton
    stateButton = PIND  & (1 << PIN_BUT);
    
    if (iParam[CTRL_BUT] != stateButton) {
      // Changement d'etat
      iParam[CTRL_BUT] = stateButton;
      if (iParam[CTRL_BUT] == 0) {
        // boutton enfoncé
        if (timeButtonLast > 0) {
          // calcul du temps entre 2 pressions
          if (timeNow > timeButtonLast) buttonPeriod = timeNow - timeButtonLast;
          else buttonPeriod = timeNow + (429496729 - timeButtonLast);
          
          // Définit la durée du LFO
          if (buttonPeriod < maxLFOPeriod) {
            lfoOverflow = buttonPeriod >> 8;
            timeButtonLast = 0;
          }
          else timeButtonLast = timeNow;
        }
        else timeButtonLast = timeNow;
      }
      else {
        // bouton relaché
        // repasse en mode normal
        iMode = MODE_NORMAL;
      }
    }
    else {
      // pas de changement d'état
      if (iParam[CTRL_BUT] == 0) {
        // boutton enfoncé
        if (timeNow > timeButtonLast) butDuration = timeNow - timeButtonLast;
        else butDuration = timeNow + (429496729 - timeButtonLast);
        
        if (butDuration > delayButSetup) {
          // Annule la mesure de la periode du LFO
          timeButtonLast = 0;
          // Change de mode
          if (iMode == MODE_NORMAL) {
            iMode = MODE_LFOSETUP;
            OCR2B = 255;
            resetLFOParams();
          }
        }
      }
    }
    
    // Remise à zéro du compteur de potentiometres
    iCtrlNb = 0;
  }
  
  // Modulation (LFO)
  for (int i=0; i<5; i++) {
    if (iMode == MODE_NORMAL) {
      if (lfoWaveForm > 0) {
        if (lfoParam[i] == -1) tmpParam[i] = iParam[i];
        else tmpParam[i] = map(lfoVal, 0, 255, min(lfoParam[i], iParam[i]), max(lfoParam[i], iParam[i]));
      }
      else tmpParam[i] = iParam[i];
    }
    else tmpParam[i] = iParam[i];
  }

  // Affectation la fonction audio
  if ( (tmpParam[CTRL_FUNC] >> 6) != iFunction)
   iFunction = (tmpParam[CTRL_FUNC] >> 6);
  
  // Affectation de la forme d'onde du LFO
  byte newLFOWaveForm = map(tmpParam[CTRL_LFO],0,1023,0,5);
  if ( newLFOWaveForm != lfoWaveForm) lfoWaveForm = newLFOWaveForm;

  // Mise à jour de l'incrément
  iIncrement = tmpParam[CTRL_FRQ]>>1 - 4;
}

// ROUTINES DIVERSES **********************************************************

void resetLFOParams() {
  for (int i=0; i<5; i++) lfoParam[i] = -1;
}