RosettaCodeData/Task/Sierpinski-triangle-Graphical/OCaml/sierpinski-triangle-graphical.ocaml
Ingy döt Net 68f8f3e56b all tasks
2013-04-11 01:07:29 -07:00

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open Graphics
let round v =
int_of_float (floor (v +. 0.5))
let middle (x1, y1) (x2, y2) =
((x1 +. x2) /. 2.0,
(y1 +. y2) /. 2.0)
let draw_line (x1, y1) (x2, y2) =
moveto (round x1) (round y1);
lineto (round x2) (round y2);
;;
let draw_triangle (p1, p2, p3) =
draw_line p1 p2;
draw_line p2 p3;
draw_line p3 p1;
;;
let () =
open_graph "";
let width = float (size_x ()) in
let height = float (size_y ()) in
let pad = 20.0 in
let initial_triangle =
( (pad, pad),
(width -. pad, pad),
(width /. 2.0, height -. pad) )
in
let rec loop step tris =
if step <= 0 then tris else
loop (pred step) (
List.fold_left (fun acc (p1, p2, p3) ->
let m1 = middle p1 p2
and m2 = middle p2 p3
and m3 = middle p3 p1 in
let tri1 = (p1, m1, m3)
and tri2 = (p2, m2, m1)
and tri3 = (p3, m3, m2) in
tri1 :: tri2 :: tri3 :: acc
) [] tris
)
in
let res = loop 6 [ initial_triangle ] in
List.iter draw_triangle res;
ignore (read_key ())