Rain with depth field.
rain=350
dim x(rain)
dim y(rain)
dim z(rain)
dim ht(rain)
dim sp(rain)
dim x1(rain)
dim z1(rain)
for a=1 to rain
x(a)=int(ran(640))
y(a)=int(ran(512))
z(a)=int(ran(500))-10
ht(a)=(1/((512-z(a))/10))*200
sp(a)=ht(a)/2
x1(a)=x(a)
z1(a)=z(a)
next a
open window 640,512
repeat
setdrawbuf vm
vm=1-vm
setdispbuf vm
clear window
setrgb 1,100,100,256
fill rectangle 1,1 to 639,511
setrgb 1,256,256,256
for a=1 to rain
y(a)=y(a)+sp(a)
if y(a)>520 y(a)=-20
line x(a),y(a) to x(a),y(a)-ht(a)/3
next a
until(1=0)