通过四叉树来设计大型地图结构，可以提供遍历速度。-through Quadtree large map to design the structure, it can provide traverse speed.

四叉树基本算法 可以为初学者提供良好的借鉴与指引-Quadtree for beginners the basic algorithm can provide a good reference and guide

qtdecomp divides a square image into four equal-sized square blocks, and then tests each block to see if it meets some criterion of homogeneity. If a block meets the criterion, it is not divided any further. If it does not meet the criterion, it is s