Codes for Spirals

to star_spi.main ; Spiral made of stars
cs ht
repeat 45[setpc repcount pu fd 1.5*repcount pd star_spi 1 

          repcount+3 144 repcount/80 pu home seth -10*repcount]
end

to star_spi :size :maxsize :angle :delta
if :size>:maxsize [stop]
fd :size rt :angle
star_spi :size+:delta :maxsize :angle :delta
end
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to spiral.red_t :amax ; A patern made of triangle spirals 
cs ht
rt 30 repeat 6[setpc (list repcount*20+135 0 0)
                  spiral_t 1 :amax fd :amax rt 60]
end

to spiral_t :a :amax
if :a>:amax [stop]
fd :a rt 120
fd :a+2 rt 120
fd :a+4 rt 120
spiral_t :a+6 :amax
end