Attractor::Attractor(Tuple &pos, Tuple &vel, double k) {
  this->x = pos.getX();
  this->y = pos.getY();
  this->vx = vel.getVX();
  this->vy = vel.getVY();
  this->k = k;
}
Attractor::Attractor(Tuple &pos, double k) {
  this->x = pos.getX();
  this->y = pos.getY();
  this->vx = 0;
  this->vy = 0;
  this->k = k;
}
Attractor::Attractor(Tuple &pos, double vx, double vy, double k) {
  this->x = pos.getX();
  this->y = pos.getY();
  this->vx = vx;
  this->vy = vy;
  this->k = k;
}
Attractor::Attractor(Tuple &src) {
  this->x = src.getX();
  this->y = src.getY();
  this->vx = 0;
  this->vy = 0;
  this->k = 1;
}