Voronoi diagram: Difference between revisions

=={{header|OCaml}}==

{{works with|ocaml|4.07.1}}

<lang ocaml>let n_sites = 220

let size_x = 640

let size_y = 480

let sq2 ~x ~y =

(x * x + y * y)

let rand_int_range a b =

a + Random.int (b - a + 1)

let nearest_site ~site ~x ~y =

let ret = ref 0 in

let dist = ref 0 in

Array.iteri (fun k (sx, sy) ->

let d = sq2 (x - sx) (y - sy) in

if k = 0 || d < !dist then begin

dist := d;

ret := k;

end

) site;

!ret

let gen_map ~site ~rgb =

let nearest = Array.make (size_x * size_y) 0 in

let buf = Bytes.create (3 * size_x * size_y) in

for y = 0 to pred size_y do

for x = 0 to pred size_x do

nearest.(y * size_x + x) <-

nearest_site ~site ~x ~y;

done;

done;

for i = 0 to pred (size_y * size_x) do

let j = i * 3 in

let r, g, b = rgb.(nearest.(i)) in

Bytes.set buf (j+0) (char_of_int r);

Bytes.set buf (j+1) (char_of_int g);

Bytes.set buf (j+2) (char_of_int b);

done;

Printf.printf "P6\n%d %d\n255\n" size_x size_y;

print_bytes buf;

;;

let () =

Random.self_init ();

let site =

Array.init n_sites (fun i ->

(Random.int size_x,

Random.int size_y))

in

let rgb =

Array.init n_sites (fun i ->

(rand_int_range 160 255,

rand_int_range 40 160,

rand_int_range 20 140))

in

gen_map ~site ~rgb</lang>