fn crossing_add_children(
pieces: &mut Pieces,
rng: &mut LegacyRandom,
bb: BoundingBox,
dir: Dir,
depth: i32,
is_two_floored: bool,
)fn crossing_add_children(
pieces: &mut Pieces,
rng: &mut LegacyRandom,
bb: BoundingBox,
dir: Dir,
depth: i32,
is_two_floored: bool,
)