--Olympic Rings
--Programming Competition Entry
--Erik Mackie (s0816378)
--To Run: type command "display olympicRings" into GHCI

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import LSystem

split :: Command -> [Command]
split (p :#: Sit) = split p
split (Sit :#: p) = split p
split (p :#: q) = split p ++ split q
split p = [p]

join :: [Command] -> Command
join [] = Sit
join (x:[]) = x :#: Sit
join (x:xs) = x :#: join xs

copy :: Int -> Command -> Command
copy x c = join (multiply x (split c))
           where  multiply 0 c = []
                  multiply x c = c ++ multiply (x-1) c

circle :: Distance -> Command
circle x = copy 360 (Go x :#: Turn 1)
 
twocircles :: Distance -> Command
twocircles x = GrabPen blue :#: circle x :#: Branch (GrabPen black :#:  circle (-x) )

threecircles :: Distance -> Command
threecircles x = twocircles x :#: Branch (Turn 90 :#: GrabPen yellow :#: circle x)
                 where yellow = Colour 1 1 0

fivecircles :: Distance -> Command
fivecircles x = threecircles x :#: Branch (GrabPen Inkless :#: Turn (-90) :#: Go ((360*x)/pi) :#: GrabPen green :#: circle (-x) :#: Turn (-90) :#: GrabPen red :#: circle (x))

olympicRings :: Command
olympicRings = fivecircles 1