Pythagoras' Tree

PythagorasTree.tq

let branches m =
  { { Vec2.rotate(π/2 - asin(4/5));
      Vec2.scale(4/5, 4/5);
      Vec2.translate(0, -1) };
    { Vec2.translate(1, -1);
      Vec2.rotate(-π/2 + asin(3/5));
      Vec2.scale(3/5, 3/5);
      Vec2.translate(1/3, 0) } }
  @ Array.map [m2 → Array.concat{m; m2}]

let square =
  {0,0; 1,0; 1,1; 0,1}
  @ Array.map Line
  @ Closed

let shape color m =
  let style = Style(Fill color, NoStroke) in
  Shape(style, Path(Contour.transform m square))

let trunks color ms = Array.map (shape color) ms

let burlyWood = Hex "deb887"

let rec tree n ms =
  if n=0 then {trunks Green ms} else
    let ms2 = Array.collect branches ms in
    Array.concat{{trunks burlyWood ms}; tree (n-1) ms2}

let () =
  tree 8 {{Vec2.translate (300, 300); Vec2.scale (100, 100)}}
  @ Array.concat
  @ Html.ofSvg (600, 600)
  @ yield