constructor(x, y, r) {

    this.r = r;

    this.m = r ** 2;

    this.pos = createVector(x, y);

    this.vel = createVector(random(-1, 1), random(-1, 1));

    this.acc = createVector(0, 0);

    this.c = this.setColor();

​

    this.isOut = false;

  }

​

  attract(other) {

    if (this == other) {

      return;

    }

    let force = p5.Vector.sub(this.pos, other.pos);

    let disSq = force.magSq();

​

    let strength = (G * (this.m * other.m)) / disSq;

​

    force.setMag(strength);

    other.applyForce(force);

  }

​

  applyForce(force) {

    let f = p5.Vector.div(force, this.m);

    this.acc.add(f);

    if (this.vel.mag() > maxVel) {

      this.vel.setMag(maxVel);

    }

  }

​

  update() {

    this.vel.add(this.acc);

    this.pos.add(this.vel);

    this.acc.set(0, 0);

    this.out();

  }

​

​

  out() {

    if (this.pos.x < 0) {

      this.isOut = true;

    } else if (this.pos.x > width) {

      this.isOut = true;

    } else if (this.pos.y < 0) {

      this.isOut = true;

    } else if (this.pos.y > height) {

      this.isOut = true;

    }

  }

​

  show() {

    noStroke();

    fill(255, random(15, 30));

    ellipse(this.pos.x, this.pos.y, this.r * 2 + 11);

    fill(255, random(30, 40));

    ellipse(this.pos.x, this.pos.y, this.r * 2 + 5);

    fill(this.c);

    ellipse(this.pos.x, this.pos.y, this.r * 2);

  }

​

  setColor() {

    let colors = [

      color(244, 251, 210),

      color(255, 253, 230),

      color(245, 233, 180),

    ];

    return colors[int(random(3))];

  }

}

​