const num = 2000;

const noiseScale = 0.01

const particles = [];

​

function setup() {

  createCanvas(600, 600);

  for(let i = 0; i < num; i++) {

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

    stroke(255)

  }

}

​

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);

    let a = TAU * n

    p.x += cos(a) 

    p.y += sin(a)

    if (!onScreen(p)) {

      p.x = random(width)

      p.y = random(height)

    }

  }

}

​

function mousePressed() {

  noiseSeed(millis())

}

​

function onScreen(v) {

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

}