Circle(Circle* prev, float r, float rate, float theta) {
this->inUse = true;
this->position = prev->getPosOnR();
this->radius = r;
this->rate = rate;
this->theta = theta;
this->prev = prev;
}
void update(float delta) {
theta += rate * delta;
if (prev != 0) {
position = prev->getPosOnR();
}
}