48 lines
1.0 KiB
Plaintext
48 lines
1.0 KiB
Plaintext
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& Example Ludus implementation of the Dragon curve.
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& https://en.m.wikipedia.org/wiki/L-system#Example_6:_dragon_curve
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& variables : F G
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& constants : + -
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& start : F
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& rules : (F -> F+G), (G -> F-G)
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& angle : 90°
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& F and G both mean "draw forward", + means "turn left by angle", and − means "turn right by angle"
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& set a length for each segment
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let length = 10
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& set an angle for all turns, default to 1/3 for triangles
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let angle = 0.25
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fn f!
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& define 'G' function from the grammaer
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fn g! {
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(0) -> fd!(length)
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(n) -> {
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f!(dec(n))
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rt!(angle)
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g!(dec(n))
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}
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}
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& define 'F' function from the grammaer
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fn f! {
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(0) -> fd!(length)
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(n) -> {
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f!(dec(n))
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lt!(angle)
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g!(dec(n))
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}
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}
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& this function defines the starting pattern.
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& each of the f! and g! calls expand based on the grammar at the top of this example
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fn dragon! (times) -> {
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f!(times)
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}
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& call the base function with a number of iterations
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& remember, this is exponential! high numbers can freeze your browser.
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dragon!(10)
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