code: def squared_toroidal_dist(p1, p2, world_size=(60, 60)):
      
      halfx = world_size[0]/2.0
      if world_size[0] == world_size[1]:
          halfy = halfx
      else:
          halfy = world_size[1]/2.0
  
      deltax = p1[0] - p2[0]
      if deltax < -halfx:
          deltax += world_size[0]
      elif deltax > halfx:
          deltax -= world_size[0]
  
      deltay = p1[1] - p2[1]
      if deltay < -halfy:
          deltay += world_size[1]
      elif deltay > halfy:
          deltay -= world_size[1]
  
      return deltax*deltax + deltay*deltay
docs: Separated out because sqrt has a lot of overhead