lambdaway :: fern

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_h1 [[fractal_tree]] | fern | [[koch]] | [[stars]]

_h2 1) defining functions
{pre
'{def tree 
 {lambda {:s :n :a :b :c}
  {if {< :n 0}
   then 
   else M:s T:a 
          {tree {* :s :c} {- :n 1} :a :b :c}
        T-:a T-:b
          {tree {* :s :c} {- :n 1} :a :b :c} 
        T:b M-:s}}}
-> {def tree 
 {lambda {:s :n :a :b :c}
  {if {< :n 0}
   then 
   else M:s T:a 
          {tree {* :s :c} {- :n 1} :a :b :c}
        T-:a T-:b
          {tree {* :s :c} {- :n 1} :a :b :c} 
        T:b M-:s}}}

'{def fern 
 {lambda {:size :sign}
  {if {> :size 2}
   then M:size
        T{* 70 :sign}
          {fern {* :size 0.5} {- :sign}}
        T{* {- 70} :sign}
        M:size
        T{* {- 70} :sign}
          {fern {* :size 0.5} :sign}
        T{* 70 :sign}
        T{* 7 :sign}
          {fern {- :size 1} :sign}
        T{* {- 7} :sign}
        M{* -:size 2}
   else }}}
-> {def fern 
 {lambda {:size :sign}
  {if {> :size 2}
   then M:size
        T{* 70 :sign}
          {fern {* :size 0.5} {- :sign}}
        T{* {- 70} :sign}
        M:size
        T{* {- 70} :sign}
          {fern {* :size 0.5} :sign}
        T{* 70 :sign}
        T{* 7 :sign}
          {fern {- :size 1} :sign}
        T{* {- 7} :sign}
        M{* -:size 2}
   else }}}
}

_h2 2) building objects
{pre
'{def T {tree 100 10 30 45 0.7}}
-> {def T {tree 100 10 30 45 0.7}}
'{def F {fern 25 1}}
-> {def F {fern 25 1}}
}

_h2 3) drawing

{pre
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lambdaway v.20211111