Quadtree Grammars with PostScript .
/rect { 1 dict begin /size exch def newpath 0 0 moveto size 0 rlineto 0 size rlineto size neg 0 rlineto closepath fill end } def /quadtree { 2 dict begin /size exch def /half size 2 div def size 1 eq { 0 setgray size rect } { half quadtree gsave 0 half translate 1 setgray half rect grestore gsave half 0 translate half quadtree grestore gsave half half translate half quadtree grestore } ifelse end } def 1024 quadtree showpage
