LOGO-L> revised spiral for yehuka's galery

[MHELHEFNY@FRCU.EUN.EG]

;Hello Everybody !
;This is the revised code for a spiral which I recommended for Yehuda's Galary.
;The code of my previous post took 25 seconds on my 166 Mhz pentium;now it
;takes only 11 seconds. This is achieved by:
;1- increasing the step from 12 to 15
;2- eliminating the fourth side of the square befor polyend(the polygon
;need not to be a closed one).
;You can do the same in all my previous posts
;Best Regards
;Mhelhefny
;---------------
to go
   cs ht setsc 0
   perspective
   setpc [0 0 128]
   grid 12 grid1 12
   shade 250 80 20 
   polyview
end

to grid :step
for [x 0 360 :step][for [z 0 500 :step][
polystart pd
                   setxyz x y z 
make "x :x+ :step  setxyz x y z 
make "z :z+ :step  setxyz x y z 
make "x :x- :step  setxyz x y z 
;make "z :z- :step  setxyz x y z 
polyend
]pu]
end

to grid1 :step
for [x 0 360 :step][for [z 0 580 :step][
polystart pd
                   setxyz x1 y z1 
make "x :x+ :step  setxyz x1 y z1 
make "z :z+ :step  setxyz x1 y z1 
make "x :x- :step  setxyz x1 y z1 
;make "z :z- :step  setxyz x1 y z1 
polyend
]pu]
end

to shade :f :g :h
ask -3[setxyz :f :g :h]
polyview
End

to x
op :x*(sin :z)/6
end

to x1
op 130 *(sin :x)/6
end

to y
op -80+ :z/6
end

to z
op :x*(cos :z)/6
end

to z1
op 130*(cos :x)/6
end
;-------------
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