.................................0......................
..............................0......................
...........................0......................
.........................0......................
.....00000000000000000000000000
.....0.............. ....0....... ..............0
....0......... .........0......................0
....0........ ..........0......................0
...0............. .....0.....................0
..0..................0......................0
.0..................0......................0.
.0 ................0.....................0
.0................0....................0
0 ................0....................0
0................0....................0
有效的图元素为 0 构成的图形。那跟下面这个 地 有何区别?
000000000000000000000000000
………..0000000000000………
….……….000000000…………
…………….00000……………
………………00……………..