LOGO-L> hilbert again

[neuwirth <neuwirth@smc.univie.ac.at>]

here is a quite different approach
to the smooth square filling hilbert curve

;to see an example do 
; hilb.curve 10 4

to arc.rt.fd :angle :size
if :angle = 0 [fd :size]
if :size = 0 [stop]
if and (:angle > 0) (:size > 0) [arc2 :angle :size stop]
if and (:angle > 0) (:size < 0) [arc2 -1 * :angle -1 * :size]
if and (:angle < 0) (:size > 0) [rt 180 arc2  :angle :size rt 
180]
if and (:angle < 0) (:size < 0) [arc2 :angle -1 * :size]
end

to bow :size :par
arc.rt.fd -90 * :par :size 
end

to bow.par.list :level
if :level = 1 [output [1]]
output (se map [-1 * ?] bow.par.list :level - 1 ~
	     1 ~
	     bow.par.list :level - 1 ~
	     -1 ~
	     bow.par.list :level - 1 ~
            1 ~
	     map [-1 * ?] bow.par.list :level - 1)
end

to hilb.curve :size :level
wiggle :size first wiggle.par.list :level
(foreach bow.par.list :level ~
         butfirst wiggle.par.list :level ~
	  [bow :size ?1 wiggle :size ?2])
end

to wiggle :size :par
arc.rt.fd -90 * :par :size / 2 
arc.rt.fd 90 * :par :size / 2 
end

to wiggle.par.list :level
if :level = 1 [output [-1 1]]
output (se map [-1 * ?] wiggle.par.list :level - 1 ~
	    wiggle.par.list :level - 1 ~
	    wiggle.par.list :level - 1 ~
	    map [-1 * ?] wiggle.par.list :level - 1 )
end


--
Erich Neuwirth <neuwirth@smc.univie.ac.at>
Computer Supported Didactics Working Group, Univ. Vienna
Visit our SunSITE at http://sunsite.univie.ac.at



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