E_P_CAN_MOVE, // can move
E_P_CAN_FALL, // can fall
E_P_FALLING, // falling
+ E_P_GROWING, // growing (element birth)
};
// properties
#define P_CAN_MOVE (1 << E_P_CAN_MOVE)
#define P_CAN_FALL (1 << E_P_CAN_FALL)
#define P_FALLING (1 << E_P_FALLING)
+#define P_GROWING (1 << E_P_GROWING)
// These are states of the magic wall.
typedef enum _magic_wall_state