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|
(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Pierre Weis, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 2001 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* only by permission. *)
(* *)
(***********************************************************************)
open Graphics;;
(* Simple turtle graphics *)
type turtle_state =
{ mutable x : float;
mutable y : float;
mutable heading : float };;
let t = { x = 0.0; y = 0.0; heading = 0.0 };;
let pi180 = 4.0 *. atan 1.0 /. 180.0;;
let round x =
if x >= 0.0 then int_of_float(x +. 0.5) else -(int_of_float(0.5 -. x));;
let reset() =
t.x <- float_of_int(size_x() / 2);
t.y <- float_of_int(size_y() / 2);
t.heading <- 0.0;
moveto (round t.x) (round t.y)
;;
let forward d =
t.x <- t.x +. cos(t.heading) *. d;
t.y <- t.y +. sin(t.heading) *. d;
lineto (round t.x) (round t.y)
;;
let turn a =
t.heading <- t.heading +. a *. pi180
;;
(* A table of flashy colors *)
let colors =
[| 0xff0000; 0xff6000; 0xffc000; 0xdeff00;
0x7eff00; 0x1eff00; 0x1eff00; 0x00ff42;
0x00ffa2; 0x00fcff; 0x009cff; 0x003cff;
0x2400ff; 0x8400ff; 0xe400ff; 0xff00ba |];;
(* The main drawing function *)
let rec spir dist angle angle_incr color =
if key_pressed() then () else begin
set_color colors.(color);
forward dist;
turn angle;
spir dist (angle +. angle_incr) angle_incr ((color + 1) land 15)
end
;;
(* The interaction loop *)
let message s =
let (x, y) = current_point() in
draw_string s;
let (_, height) = text_size s in
moveto x (y + height)
;;
let format f =
Printf.sprintf "%6.2f" f
;;
let rec loop dist angle_incr =
clear_graph();
set_color foreground;
moveto 0 0;
message " - d, D to decrease";
message " + i, I to increase";
message (format dist ^ " " ^ format angle_incr);
message "Distance Angle increment 'q' to quit";
reset();
spir dist 0.0 angle_incr 0;
match read_key() with
| '-' -> loop (dist -. 2.0) angle_incr
| '+' -> loop (dist +. 2.0) angle_incr
| 'd' -> loop dist (angle_incr -. 0.05)
| 'D' -> loop dist (angle_incr -. 5.0)
| 'i' -> loop dist (angle_incr +. 0.05)
| 'I' -> loop dist (angle_incr +. 5.0)
| 'q' -> ()
| _ -> loop dist angle_incr
;;
let spir () =
open_graph "";
loop 5.0 1.9;
close_graph()
;;
if !Sys.interactive then () else begin spir(); exit 0 end;;
|
