public void DrawRoomsByStep(int dir)
{
_stepCreationIndex = ArrayTools.GetCircularArrayIndex(_stepCreationIndex + dir, roomHierarchyTree.Count + 1);
var roomsToDraw = roomHierarchyTree.Keys.Take(_stepCreationIndex);
graphics.Clear(Color.Transparent);
drawRooms(roomsToDraw, wallPen);
drawDoors(doors, doorPen);
}