You could use a visited array to mark the points that have been visited, that would greatly reduce the number of calls to region_query, which in your case is being called multiple times even for a single point. But if you use a visited array, you would only have to call the region_query once for each point.
You could use a visited array to mark the points that have been visited, that would greatly reduce the number of calls to region_query, which in your case is being called multiple times even for a single point. But if you use a visited array, you would only have to call the region_query once for each point.