Space is partitioned by a grid, and computing the list of visible entities consists in taking entities from the same cell and iterating on the neighbour cells by drawing a spiral, until the desired number of visible entities is reached.

• 空间被一个网格所划分，首先获取与要计算的实体在同一网格的实体，然后以螺旋状的方式遍历周围的网格，并添加其中的实体，直接找到足够数量的实体。