desc:Gaussian Humanization

slider1:0.33<0,1.78,0.01>timing standard deviation (ms)
slider2:1<0,30,1>velocity standard deviation
slider3:0<-50,50>timing shift (ms) [read-only]
slider4:0<-127,127,1>velocity shift [read-only]

@init
  
  buffer = 0;
  blockLength = 128;
  memset(0, 0, blockLength);
  bufferCounter = 0;

  NOTE_ON = 9;
  NOTE_OFF = 8;
  AFTERTCH = 10;

  previousBeatPosition = -1;
  previousOffset = -1;
  positionShift = 0;

  noteNumberIndex = 1;
  while ( noteNumberIndex < 128 ) (
    lastNoteOffIndexArray[noteNumberIndex] = -1;
    noteNumberIndex += 1;
  );

@block

  while (

    midirecv(offset, msg1, msg23) ? (

      // we're in a new block now
      // we no longer have access to the last note off
      (offset == 0) ? (
        
          noteNumberIndex = 1;
          while ( noteNumberIndex < 128 ) (
            lastNoteOffIndexArray[noteNumberIndex] = -1;
            noteNumberIndex += 1;
          );
      );

      

      minimumPosition = 0;
      maximumPosition = samplesblock - 1;
      noteNumber = msg23 & 127;

      messageType = (msg1 / 16) | 0;
      velocity = (msg23 / 256) | 0;
      
      (messageType == NOTE_ON && velocity > 0) ? (


        // generate normal deviates
        while (
          v1 = 2.0 * rand(1) - 1.0;
          v2 = 2.0 * rand(1) - 1.0;
          s = v1 * v1 + v2 * v2;
          s >= 1.0 || s == 0;
        );
        multiplier = sqrt(-2.0 * log(s) / s);
        v1 *= multiplier;
        v2 *= multiplier;


        (beat_position == previousBeatPosition) ? (

          offset = previousOffset;

        ) : (

          // when offset is 0 we can't adjust the previous note off, so we can't normalize this note
          // we already can't move it negative because of minimumPosition
          // we also can't move it positive because it will create a gap
          (offset == 0) ? (
            
            positionShift = 0;
            slider3 = 0;

          ) : (

            oldOffsetForDebugger = offset;
            // adjust position
            unboundedTimeShiftInMilliseconds = v1*slider1;
            unboundedPositionShift = unboundedTimeShiftInMilliseconds * srate / 1000;

            unboundedNewPosition = offset + unboundedPositionShift;
            newPosition = unboundedNewPosition;

            (newPosition < minimumPosition) ? (
              newPosition = minimumPosition;
            );

            (newPosition > maximumPosition) ? (
              newPosition = maximumPosition;
            );

            positionShift = newPosition - offset;

            offset = newPosition;

            timeShiftInMilliseconds = positionShift * 1000 / srate;
            slider3 = timeShiftInMilliseconds;
          );

          sliderchange(2^2);
          previousOffset = offset;
        );

        // adjust the position of the note's last note off, to avoid overlapping notes or gaps
        (lastNoteOffIndexArray[noteNumber] > -1) ? (
          buffer[lastNoteOffIndexArray[noteNumber]] += positionShift;
        );

        // adjust velocity
        unboundedVelocityShift = floor(v2*slider2 + 0.5);

        unboundedAdjustedVelocity = velocity + unboundedVelocityShift;
        adjustedVelocity = unboundedAdjustedVelocity;

        (adjustedVelocity < 1) ? (
          adjustedVelocity = 1;
        );

        (adjustedVelocity > 127) ? (
          adjustedVelocity = 127;
        );

        velocityShift = adjustedVelocity - velocity;

        adjustedVelocity |= 0;
        msg23 = noteNumber + adjustedVelocity * 256;
        slider4 = velocityShift;
        sliderchange(2^3);

        previousBeatPosition = beat_position;
      );

      (messageType == NOTE_OFF || (messageType == NOTE_ON && velocity < 1)) ? (
        lastNoteOffIndexArray[noteNumber] = blockLength+bufferCounter;        
      ); 

      buffer[blockLength+bufferCounter] = offset;
      buffer[blockLength+bufferCounter+1] = msg1;
      buffer[blockLength+bufferCounter+2] = msg23;
      bufferCounter += 3;
    );
  );

  // Find everything in the buffer that is due
  // to be played back in this block.
  i = 0;
  while (
    (i < bufferCounter) ? (
      offset = buffer[blockLength + i];

      (offset < samplesblock) ? (
        midisend(offset, buffer[blockLength+i+1], buffer[blockLength+i+2]);
        memcpy(blockLength+i, blockLength+i+3, bufferCounter-i);
        bufferCounter -= 3;
      ) : (
        buffer[blockLength+i] -= samplesblock;
        i += 3;
      );
    );
  );