open window 640,512

dim p(3,2)

p(1,1)=320
p(1,2)=0

p(2,1)=640
p(2,2)=512

p(3,1)=0
p(3,2)=512

px=ran(640)
py=ran(512)

repeat
 point=max(min(3,ran(3)+1),1)
 px=((p(point,1)-px)*0.5)+px
 py=((p(point,2)-py)*0.5)+py
 fill rectangle px,py to px+1,py+1
until (1=0)
