let particles;

class Particle {

  constructor(x, y, targetX, targetY, color, size, easing) {

    this.x = x;

    this.y = y;

    this.targetX = targetX;

    this.targetY = targetY;

    this.color = color;

    this.size = size;

    this.easing = easing;

    this.in = true;

  }

  update() {

    let dx = this.targetX - this.x;

    this.x += dx * this.easing;

​

    let dy = this.targetY - this.y;

    this.y += dy * this.easing;

​

    if (dx < 1 && dy < 1) {

      if (this.in) {

        this.targetX = random(0,width);

        this.targetY = random(0,height);

      } else {

        this.targetX = width / 2;

        this.targetY = height / 2;

      }

      this.in = !this.in;

    }

  }

  draw() {

    noStroke();

    fill(this.color);

    square(this.x, this.y, this.size);

  }

}

function setup() {

  createCanvas(1000, 1000);

  background(20);

  particles = [];

  for (let i = 0; i < 250; i++) {

    particles.push(new Particle(random(-500,0), random(-500,height+500), width/2, height/2, color(255), 5, random(0.05, 0.1)));

  }

  frameRate(60);

}

​

let wipe_y = 0;

let wipe_spd = 1.5;

​

function draw() {

  fill(20);

  noStroke();

  rect(0,wipe_y,width,20);

  wipe_y += wipe_spd;

  if (wipe_y > height) wipe_y = 0;

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

    particles[i].update();

    particles[i].draw();

  }

}

​