void spawn(struct entity def, int x, int y);
void add_health(struct entity *entity, int health);
void add_score(int s);
void spawn(struct entity def, int x, int y);
void add_health(struct entity *entity, int health);
void add_score(int s);
void set_color(struct color color, bool bg);
struct color light_color(struct color color, double light);
void register_air_function(struct generator_function func);
void set_color(struct color color, bool bg);
struct color light_color(struct color color, double light);
void register_air_function(struct generator_function func);