sub get_collisions_for_aabb
{
    my ($self, $aabb) = @_;
    return () if !defined $self->{root_aabb};

    $self->{root_aabb}->get_collisions_for_aabb_rec($aabb);
}

# And in Game::Collisions::AABB:

sub get_collisions_for_aabb_rec
{
    my ($node, $target) = @_;
    $node && $node != $target
       && $node->[_MAX_X] >= $target->[_X] && $node->[_X] <= $target->[_MAX_X]
       && $node->[_MAX_Y] >= $target->[_Y] && $node->[_Y] <= $target->[_MAX_Y]
    ? ( $node->[_LEFT_NODE] || $node->[_RIGHT_NODE]
        ? ( get_collisions_for_aabb_rec($node->[_LEFT_NODE], $target),
            get_collisions_for_aabb_rec($node->[_RIGHT_NODE], $target) )
        : [ $node, $target ]
      )
    : ()
}