let recordButton;

let isRecording = false;

let startTime;

let recordedNotes = [];

let recordingStartTime;

let isPlayingBack = false;

let playbackStartTime;

let osc;

let keyStates = {};

let notes = {

  A: 261.63, // C

  W: 277.18, // C#

  S: 293.66, // D

  E: 311.13, // D#

  D: 329.63, // E

  F: 349.23, // F

  T: 369.99, // F#

  G: 392.0, // G

  Y: 415.3, // G#

  H: 440.0, // A

  U: 466.16, // A#

  J: 493.88, // B

  K: 523.25, // C

};

​

function setup() {

  createCanvas(400, 400);

  osc = new p5.Oscillator();

  osc.setType("sine");

  osc.amp(0);

  osc.start();

​

  for (let key in notes) {

    keyStates[key] = false;

  }

​

  let recordButton = createButton("Record");

  recordButton.mousePressed(startRecording);

​

  let playButton = createButton("Play");

  playButton.mousePressed(startPlayback);

​

  let markovButton = createButton("Markov Chain");

  markovButton.mousePressed(applyMarkovChain);

}

​

function draw() {

  background(220);

  drawPianoKeys();

​

  if (isPlayingBack) {

    playbackRecordedNotes();

  }

​

  //Markov Chain transitions

  if (isMarkovChainProcessed) {

    drawMarkovChainLines();

  }

​

  // markov done rect

  if (isMarkovChainProcessed) {

    fill(0, 0, 255); // Blue

    rect(width - 50, height - 50, 40, 40); //blue rect

  }

}

​

// Function to draw lines representing Markov Chain transitions

function drawMarkovChainLines() {

  /*

  let markovModel = generateMarkovChain();

  stroke(0, 102, 153); // Set the color for the lines

​

  for (let note in markovModel) {

    let startPos = getNotePosition(note); // Get the start position of the line

​

    for (let nextNote in markovModel[note]) {

      let endPos = getNotePosition(nextNote); // Get the end position of the line

      let probability = markovModel[note][nextNote]; // Probability of transition

​

      strokeWeight(probability * 5); // Line thickness based on probability

​

      // Define control points for the Bezier curve

      let controlPoint1 = createVector(startPos.x, startPos.y - 100);

      let controlPoint2 = createVector(endPos.x, endPos.y - 100);

​

      noFill();

      bezier(startPos.x, startPos.y, controlPoint1.x, controlPoint1.y, controlPoint2.x, controlPoint2.y, endPos.x, endPos.y);

    }

  }

  */

}

​

function getNotePosition(note) {

  let x, y;

  let whiteKeyWidth = 40;

  let blackKeyWidth = 20;

  let blackKeyOffset = 30; // Offset for the black key from the start of the white key

  let startY = 100; // Y position of keys (as per your drawPianoKeys function)

  let keyHeight = 160; // Height of the keys

​

  // Define the order of the keys on the piano

  let whiteKeysOrder = ["A", "S", "D", "F", "G", "H", "J", "K"];

  let blackKeysOrder = ["W", "E", "T", "Y", "U"];

​

  let whiteKeyIndex = whiteKeysOrder.indexOf(note);

  let blackKeyIndex = blackKeysOrder.indexOf(note);

​

  if (whiteKeyIndex != -1) {

    // It's a white key

    x = 20 + whiteKeyWidth * whiteKeyIndex + whiteKeyWidth / 2; // Center of the white key

    y = startY + keyHeight / 2; // Middle of the key height

  } else if (blackKeyIndex != -1) {

    // It's a black key

    x = 20 + blackKeyOffset + whiteKeyWidth * blackKeyIndex + blackKeyWidth / 2; // Center of the black key

    y = startY + keyHeight / 2; // Middle of the key height

  } else {

    // If the note is not found, return a default position

    x = -1;

    y = -1;

  }

​

  return createVector(x, y);

}

​

function drawPianoKeys() {

  //white keys

  let whiteKeys = ["A", "S", "D", "F", "G", "H", "J", "K"];

  for (let i = 0; i < whiteKeys.length; i++) {

    let key = whiteKeys[i];

    fill(keyStates[key] ? "rgb(255,97,0)" : "white");

    rect(20 + 40 * i, 100, 40, 160);

  }

​

  //black keys

  let blackKeys = ["W", "E", "T", "Y", "U"];

  let blackKeyOffsets = [30, 70, 150, 190, 230];

  for (let i = 0; i < blackKeys.length; i++) {

    let key = blackKeys[i];

    fill(keyStates[key] ? "rgb(255,97,0)" : "black");

    rect(blackKeyOffsets[i] + 20, 100, 20, 100);

  }

}

​

function startRecording() {

  if (!isRecording) {

    recordedNotes = [];

    isRecording = true;

    recordingStartTime = millis();

    setTimeout(() => {

      isRecording = false;

    }, 20000);

  }

}

​

function keyPressed() {

  let freq = notes[key.toUpperCase()];

  if (freq) {

    keyStates[key.toUpperCase()] = true;

    osc.freq(freq);

    osc.amp(0.5, 0.1);

​

    if (isRecording) {

      recordedNotes.push({

        note: key.toUpperCase(),

        startTime: millis(),

        freq: freq,

        // Duration will be calculated on key release

      });

    }

  }

}

​

function keyReleased() {

  let freq = notes[key.toUpperCase()];

  if (freq) {

    keyStates[key.toUpperCase()] = false;

    osc.amp(0, 0.1);

​

    if (isRecording) {

      // Find the last recorded note with the same frequency that hasn't been finished yet

      let noteEvent = recordedNotes.find(

        (n) => n.freq === freq && n.duration === undefined

      );

      if (noteEvent) {

        noteEvent.duration = millis() - noteEvent.startTime;

      }

    }

  }

}

​

function startPlayback() {

  if (!isPlayingBack && recordedNotes.length > 0) {

    playbackStartTime = millis();

    isPlayingBack = true;

  }

}

​

function playbackRecordedNotes() {

  let currentTime = millis() - playbackStartTime;

  let currentNoteIndex = -1;

​

  for (let i = 0; i < recordedNotes.length; i++) {

    let note = recordedNotes[i];

    let noteStart = note.startTime;

    let noteEnd = noteStart + note.duration;

​

    if (currentTime >= noteStart && currentTime <= noteEnd) {

      if (!note.isPlaying) {

        osc.freq(note.freq);

        osc.amp(0.5, 0.1);

        note.isPlaying = true;

​

        let key = getKeyFromFrequency(note.freq);

        if (key) {

          keyStates[key] = true;

        }

​

        currentNoteIndex = i; //current note

      }

    } else if (note.isPlaying) {

      osc.amp(0, 0.1);

      note.isPlaying = false;

      let key = getKeyFromFrequency(note.freq);

      if (key) {

        keyStates[key] = false;

      }

    }

  }

​

  //Bezier curve for next note

  if (currentNoteIndex != -1 && currentNoteIndex < recordedNotes.length - 1) {

    let currentNote = recordedNotes[currentNoteIndex];

    let nextNote = recordedNotes[currentNoteIndex + 1];

​

    drawBezierCurveForNotes(currentNote.note, nextNote.note);

  }

​

  if (currentNoteIndex != -1 && currentNoteIndex < recordedNotes.length - 1) {

    let currentNote = recordedNotes[currentNoteIndex];

    let nextNote = recordedNotes[currentNoteIndex + 1];

​

    drawBezierCurveForNotes(currentNote.note, nextNote.note);

  }

}

​

function drawBezierCurveForNotes(currentNoteName, nextNoteName) {

  let startPos = getNotePosition(currentNoteName);

  let endPos = getNotePosition(nextNoteName);

​

  stroke(0, 102, 153);

  strokeWeight(2);

​

  let controlPointHeight = 150;

  let controlPoint1 = createVector(

    (startPos.x + endPos.x) / 2,

    startPos.y - controlPointHeight

  );

  let controlPoint2 = createVector(

    (startPos.x + endPos.x) / 2,

    endPos.y - controlPointHeight

  );

​

  noFill();

  bezier(

    startPos.x,

    startPos.y,

    controlPoint1.x,

    controlPoint1.y,

    controlPoint2.x,

    controlPoint2.y,

    endPos.x,

    endPos.y

  );

}

​

//key from freq

function getKeyFromFrequency(freq) {

  for (let key in notes) {

    if (notes[key] === freq) {

      return key;

    }

  }

  return null;

}

​

function generateMarkovChain() {

  let markovModel = {};

  for (let i = 0; i < recordedNotes.length - 1; i++) {

    let currentNote = recordedNotes[i].note;

    let nextNote = recordedNotes[i + 1].note;

​

    if (!markovModel[currentNote]) {

      markovModel[currentNote] = {};

    }

    if (!markovModel[currentNote][nextNote]) {

      markovModel[currentNote][nextNote] = 0;

    }

    markovModel[currentNote][nextNote] += 1;

  }

​

  //count to probabilities

  for (let currentNote in markovModel) {

    let total = 0;

    for (let nextNote in markovModel[currentNote]) {

      total += markovModel[currentNote][nextNote];

    }

    for (let nextNote in markovModel[currentNote]) {

      markovModel[currentNote][nextNote] /= total;

    }

  }

​

  return markovModel;

}

function applyMarkovChain() {

  let markovModel = generateMarkovChain();

  let newSequence = [];

  let currentNoteName = recordedNotes[0].note; //start from first note

  let cumulativeTime = 0;

​

  for (let i = 0; i < recordedNotes.length - 1; i++) {

    //recorded note iterations

    let currentNoteFreq = notes[currentNoteName]; //current note get freq

    newSequence.push({

      note: currentNoteName,

      freq: currentNoteFreq, //store freq

      startTime: cumulativeTime,

      duration: recordedNotes[i].duration, // original seq duration

    });

​

    cumulativeTime += recordedNotes[i].duration;

​

    //markov choose next note

    if (markovModel[currentNoteName]) {

      let nextNotes = markovModel[currentNoteName];

      let totalProb = 0;

      let rand = Math.random();

      for (let nextNote in nextNotes) {

        totalProb += nextNotes[nextNote];

        if (rand <= totalProb) {

          currentNoteName = nextNote;

          break;

        }

      }

    }

  }

​

  let lastNoteFreq = notes[currentNoteName];

  newSequence.push({

    note: currentNoteName,

    freq: lastNoteFreq,

    startTime: cumulativeTime,

    duration: recordedNotes[recordedNotes.length - 1].duration,

  });

​

  recordedNotes = newSequence; // new seq to recordedNotes

  startPlaybackAfterMarkov(); // playback start

  isMarkovChainProcessed = true; //markov finished flag

}

​

function startPlaybackAfterMarkov() {

  playbackStartTime = millis();

  isPlayingBack = true;

​

  for (let key in keyStates) {

    keyStates[key] = false;

  }

  for (let note of recordedNotes) {

    note.isPlaying = false;

  }

}

​