const num = 1000;

​

const noiseScale = 0.01/2;

​

function setup() {

  createCanvas(400, 400);

  for(let i = 0; i < num; i ++) {

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

  }

  stroke(255);

  // For a cool effect try uncommenting this line

  // And comment out the background() line in draw

  // stroke(255, 50);

  clear();

}

​

function draw() {

  background(0, 10);

  for(let i = 0; i < num; i ++) {

    let p = particles[i];

    point(p.x, p.y);

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

    let a = TAU * n;

    p.x += cos(a);

    p.y += sin(a);

    if(!onScreen(p)) {

      p.x = random(width);

      p.y = random(height);

    }

  }

}

​

function mouseReleased() {

  noiseSeed(millis());

}

​

function onScreen(v) {

  return v.x >= 0 && v.x <= width && v.y >= 0 && v.y <= height;

}