// Creates a field of vectors that flow in a random direction

// Changes direction when the mic input is loud (try clapping)

// Field is empty when the mic is quiet (try being silent)

// Changes color of vectors depending on amplitude

// Best way to see this is by playing a song

​

let mic;

let particles = [];

const num = 1000;

let seed = .01;

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  mic = new p5.AudioIn();

  mic.start();

  colorMode(HSB);

}

​

function draw() {

  background(color(0, 0.05));

  let micLevel = mic.getLevel();

  stroke(micLevel * 1200, 200, 200);

  if (micLevel < .025) {

      particles = [];

  } else {

    if (particles.length == 0) {

      newArray();

    }

    for (let i = 0; i < num; i ++) {

      let p = particles[i];

      point(p.x, p.y);

      let n = noise (p.x * seed, p.y * seed, frameCount * seed);

      let a = TAU * n;

      if (micLevel > .2) {

        seed = random(.01);

      }

      if (seed >= .005) {

        p.x += cos(a);

        p.y += sin(a);

      } else {

        p.x -= cos(a);

        p.y -= sin(a); 

      }

      if (!onScreen(p)) {

        p.x = random(width);

        p.y = random(height);

      }

    }

  }

}

​

function onScreen(p) {

  return p.x > 0 && p.x < width && p.y > 0 && p.y < height;

}

​

function newArray() {

  for (let i = 0; i < num; i ++) {

    particles.push(createVector(random(width), random(height)));

  }

}