Add fractals directory, and sierpinski triangle drawer

fractals/sierpinski_triangle.ml

@@ -0,0 +1,26 @@
+let (w, h, depth) = (63, 32, read_int()) in
+
+let map = Array.make h (Bytes.empty) in
+
+let print_map map = Array.iter (fun x->print_endline (Bytes.to_string x)) map in
+
+let rec init_map m = function
+    | -1 -> ();
+    | k -> m.(k) <- Bytes.make w '_';
+                    Bytes.fill (map.(k)) (h-1-k) (2*k+1) '1';
+                    init_map m (k-1)
+                    in
+init_map map (h-1); (* Initialize the map with a first triangle*)
+
+let clear (x,y) (w,h) =
+  let rec aux = function
+  | 0 -> Bytes.fill map.(y+h-1) x 1 '_';
+  | k -> Bytes.fill map.(y+h-k-1) (x-k) (2*k+1) '_'; aux (k-1) in
+  aux (h/2-1) in
+
+let rec draw (x,y) (w,h) = function
+  | 0 -> ();
+  | k -> clear (x,y) (w,h); draw (x,y) (w/2,h/2) (k-1); draw (x-w/4-1,y+h/2) (w/2,h/2) (k-1); draw (x+w/4+1, y+h/2) (w/2,h/2) (k-1) in
+draw (h-1, 0) (w, h) depth;
+
+print_map map;