// http://youtube.com/thecodingtrain

// http://codingtra.in

​

// Recaman Sequence Music

// https://youtu.be/pYnaBQgnARQ

​

let attackLevel = 1;

let releaseLevel = 0;

​

let attackTime = 0.01

let decayTime = 0.1;

let susPercent = 0.5;

let releaseTime = 0.5;

​

let numbers = [];

let count = 1;

let sequence = [];

let index = 0;

​

let scl = 0;

​

let arcs = [];

​

let biggest = 0;

​

let osc;

​

class Arc {

  constructor(start, end, dir) {

    this.start = start;

    this.end = end;

    this.dir = dir;

  }

​

  show() {

    let diameter = abs(this.end - this.start);

    let x = (this.end + this.start) / 2;

    stroke(255);

    strokeWeight(0.5);

    noFill();

    if (this.dir == 0) {

      arc(x, 0, diameter, diameter, PI, 0);

    } else {

      arc(x, 0, diameter, diameter, 0, PI);

    }

  }

​

}

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  frameRate(5);

​

  env = new p5.Env();

  env.setADSR(attackTime, decayTime, susPercent, releaseTime);

  env.setRange(attackLevel, releaseLevel);

​

  osc = new p5.Oscillator();

  osc.setType('sine');

  osc.amp(env);

  osc.start();

​

  numbers[index] = true;

  sequence.push(index);

}

​

function step() {

  let next = index - count;

  if (next < 0 || numbers[next]) {

    next = index + count;

  }

  numbers[next] = true;

  sequence.push(next);

​

  let a = new Arc(index, next, count % 2);

  arcs.push(a);

  index = next;

​

  let n = (index % 25) + 24;

  let freq = pow(2, (n - 49) / 12) * 440;

  osc.freq(freq);

  env.play();

​

  if (index > biggest) {

    biggest = index;

  }

  count++;

}

​

function draw() {

  step();

  translate(0, height / 2);

  scl = lerp(scl, width / biggest, 0.1);

  scale(scl);

  background(0);

​

  for (let a of arcs) {

    a.show();

  }

​

  if (count > windowWidth) {

    noLoop();

  }

  //console.log(index);

}

​