class MyElement{
  int id;
  int size = 10;
  float xpos = 0.;
  float ypos = 0.;
  float friction = 0.05;
  float xspeed = 0;  // Speed of the shape
  float yspeed = 0;  // Speed of the shape
  MyElement[] others;

  MyElement(int idin, MyElement[] othersin){
    id = idin;
    others = othersin;
  }

  void move() {
    xpos += xspeed;
    ypos += yspeed;
    if (xpos  > width) xspeed *= -1; 
    else if (xpos < 0) xspeed *= -1;
    if (ypos > height) yspeed *= -1;  
    else if (ypos < 0) yspeed *= -1;
    xpos = constrain(xpos, 0, width);
    ypos = constrain(ypos, 0, height);
    ellipse(int(xpos),int(ypos),size,size);
  }

  void collide() {
    for (int i = id + 1; i < nelements; i++) {
      if (dist(xpos,ypos,others[i].xpos,others[i].ypos) < 2*size) { 
        float angle = atan2(others[i].ypos - ypos, others[i].xpos - xpos);
        float targetX = xpos + cos(angle)*2*size ;
        float targetY = ypos + sin(angle)*2*size ;
        float ax = (targetX - others[i].xpos) * friction;
        float ay = (targetY - others[i].ypos) * friction;
        xspeed -= (ax);
        yspeed -= (ay);
        others[i].xspeed += (ax);
        others[i].yspeed += (ay);
      }
    }   
  }
}