virtual Rock* clone() const { return new Rock(*this); }
void collision_solid(const CollisionHit& hit);
HitResponse collision(GameObject& other, const CollisionHit& hit);
void update(float elapsed_time);
void write(lisp::Writer& writer);
virtual Rock* clone() const { return new Rock(*this); }
void collision_solid(const CollisionHit& hit);
HitResponse collision(GameObject& other, const CollisionHit& hit);
void update(float elapsed_time);
void write(lisp::Writer& writer);