Wireworld: Difference between revisions

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(added ocaml)
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HtH. .....
HtH. .....
</pre>
</pre>

=={{header|OCaml}}==

<lang ocaml>let w = [|
" ......tH ";
" . ...... ";
" ...Ht... . ";
" .... ";
" . ..... ";
" .... ";
" tH...... . ";
" . ...... ";
" ...Ht... ";
|]

let is_head w x y =
try if w.(x).[y] = 'H' then 1 else 0
with _ -> 0

let neighborhood_heads w x y =
let n = ref 0 in
for _x = pred x to succ x do
for _y = pred y to succ y do
n := !n + (is_head w _x _y)
done;
done;
(!n)

let step w =
let n = Array.init (Array.length w) (fun i -> String.copy w.(i)) in
let width = Array.length w
and height = String.length w.(0)
in
for x = 0 to pred width do
for y = 0 to pred height do
n.(x).[y] <- (
match w.(x).[y] with
| ' ' -> ' '
| 'H' -> 't'
| 't' -> '.'
| '.' ->
(match neighborhood_heads w x y with
| 1 | 2 -> 'H'
| _ -> '.')
| _ -> assert false)
done;
done;
(n)

let print = (Array.iter print_endline)

let () =
let rec aux w =
Unix.sleep 1;
let n = step w in
print n;
aux n
in
aux w</lang>


=={{header|Python}}==
=={{header|Python}}==

Revision as of 20:32, 12 September 2009

Task
Wireworld
You are encouraged to solve this task according to the task description, using any language you may know.

Wireworld is a cellular automaton with some similarities to Conway's Game of Life. It is capable of doing sophisticated computations (e.g., calculating primeness!) with appropriate programs, and is much simpler to program for.

A wireworld arena consists of a cartesian grid of cells, each of which can be in one of four states. All cell transitions happen simultaneously. The cell transition rules are this:

Input State Output State Condition
empty empty
electron head  electron tail 
electron tail  conductor
conductor electron head  if 1 or 2 cells in the neighborhood of the cell are in the state “electron head
conductor conductor otherwise

To implement this task, create a program that reads a wireworld program from a file and displays an animation of the processing. Here is a sample description file (using “H” for an electron head, “t” for a tail, “.” for a conductor and a space for empty) you may wish to test with, which demonstrates two cycle-3 generators and an inhibit gate:

tH.........
.   .
   ...
.   .
Ht.. ......

While text-only implementations of this task are possible, mapping cells to pixels is advisable if you wish to be able to display large designs. The logic is not significantly more complex.

Ada

<lang Ada> with Ada.Text_IO; use Ada.Text_IO;

procedure Test_Wireworld is

  type Cell is (' ', 'H', 't', '.');
  type Board is array (Positive range <>, Positive range <>) of Cell;
     -- Perform one transition of the cellular automation
  procedure Wireworld (State : in out Board) is
     function "abs" (Left : Cell) return Natural is
     begin
        if Left = 'H' then
           return 1;
        else
           return 0;
        end if;
     end "abs";
     Above   : array (State'Range (2)) of Cell := (others => ' ');
     Left    : Cell := ' '; 
     Current : Cell;
  begin
     for I in State'First (1) + 1..State'Last (1) - 1 loop
        for J in State'First (2) + 1..State'Last (2) - 1 loop
           Current := State (I, J);
           case Current is
              when ' ' =>
                 null;
              when 'H' =>
                 State (I, J) := 't';
              when 't' =>
                 State (I, J) := '.';
              when '.' =>
                 if abs Above (       J - 1) + abs Above (       J) + abs Above (       J + 1) +
                    abs Left                                        + abs State (I,     J + 1) + 
                    abs State (I + 1, J - 1) + abs State (I + 1, J) + abs State (I + 1, J + 1)
                 in 1..2 then
                    State (I, J) := 'H';
                 else
                    State (I, J) := '.';
                 end if;
           end case;
           Above (J - 1) := Left;
           Left := Current;
        end loop;
     end loop;
  end Wireworld;
     -- Print state of the automation
  procedure Put (State : Board) is
  begin
     for I in State'First (1) + 1..State'Last (1) - 1 loop
        for J in State'First (2) + 1..State'Last (2) - 1 loop
           case State (I, J) is
              when ' ' => Put (' ');
              when 'H' => Put ('H');
              when 't' => Put ('t');
              when '.' => Put ('.');
           end case;
        end loop;
        New_Line;
     end loop;
  end Put;
  Oscillator : Board := ("         ", "  tH     ", " .  .... ", "  ..     ", "         ");

begin

  for Step in 0..9 loop
     Put_Line ("Step" & Integer'Image (Step) & " ---------"); Put (Oscillator);
     Wireworld (Oscillator);
  end loop;

end Test_Wireworld; </lang> The solution assumes that the border of the board is empty. When transition is performed these cells are not changed. Automation transition is an in-place operation that allocates memory for to keep one row of the board size.

Step 0 ---------
 tH
.  ....
 ..
Step 1 ---------
 .t
.  H...
 ..
Step 2 ---------
 ..
.  tH..
 .H
Step 3 ---------
 ..
.  .tH.
 Ht
Step 4 ---------
 ..
H  ..tH
 t.
Step 5 ---------
 H.
t  ...t
 ..
Step 6 ---------
 tH
.  ....
 ..
Step 7 ---------
 .t
.  H...
 ..
Step 8 ---------
 ..
.  tH..
 .H
Step 9 ---------
 ..
.  .tH.
 Ht

C

Evolution is key-driven instead of being time-driven: any key (except 'q' which terminates the program) evolves the system.

Library: OpenGL
Library: GLUT

<lang c>#include <stdio.h>

  1. include <stdlib.h>
  2. include <GL/glut.h>
  3. include <assert.h>
  1. define WIDTH 20
  2. define HEIGHT 20
  3. define MAX_SIZE 256

// Pixels Per Point (every "point" is an "element" of the wireworld) int PPP = 10; int width = WIDTH, height = HEIGHT;

int win;

int fc = 0; char *field[2];


// free mem hook void freemem(void) {

 free(field[0]);
 free(field[1]);

}

// BLACK

  1. define EMPTY 0.0, 0.0, 0.0

// head WHITE

  1. define E_HEAD 1.0, 1.0, 1.0

// tail GRAY

  1. define E_TAIL 0.7, 0.7, 0.7

// conductor RED

  1. define CONDUCTOR 1.0, 0.0, 0.0
  1. define cEMPTY ' '
  2. define cHEAD 'H'
  3. define cTAIL 't'
  4. define cCONDUCTOR '.'

// GL coords are from -1 to 1

  1. define GLCOORD_X(a) ( (double)(2.0*(a))/(double)(width*PPP) - 1.0 )
  2. define GLCOORD_Y(a) ( (double)(2.0*(a))/(double)(height*PPP) - 1.0 )

// show wireworld void wireworld_show(void) {

 int j, i;
 glClearColor(EMPTY, 1.0);
 glClear(GL_COLOR_BUFFER_BIT);
 for(j=0; j < height; j++) {
   for(i=0; i < width; i++) {
     switch( *(field[fc%2] + j*width +  i) ) {
     case cTAIL:
       glColor3d(E_TAIL);
       break;
     case cHEAD:
       glColor3d(E_HEAD);
       break;
     case cCONDUCTOR:
       glColor3d(CONDUCTOR);
       break;
     default:
       glColor3d(EMPTY);
       break;
     }
     glRectd(GLCOORD_X(i*PPP), GLCOORD_Y(j*PPP), 
             GLCOORD_X((i+1)*PPP-1), GLCOORD_Y((j+1)*PPP-1));
   }
 }
 glFlush();

}


  1. define THIS(I,J) *(field[fc%2] + (I) + (J)*width)
  2. define NEXT(I,J) *(field[(fc+1)%2] + (I) + (J)*width)

int count_heads(int i, int j) {

 int e = 0;
 int ax, ay;
 for(ax=-1; ax <= 1; ax++) {
   for(ay=-1; ay <= 1; ay++) {
     if ( ((i+ax) < 0) || ( (j+ay) < 0) || ( (i+ax) >= width ) ||
          ( (j+ay) >= height ) ) continue;
     if ( (ax==0) && (ay==0) ) continue;
     if ( THIS(i+ax, j+ay) == cHEAD ) e++;
   }
 }
 return e;

}

void evolve_wireworld(void) {

 int j, i;
 int ehn;
 
 for(i=0; i < width; i++) {
   for(j=0; j < height; j++) {
     switch( THIS(i, j) )
     {
     case cHEAD:
       NEXT(i, j) = cTAIL;
       break;
     case cTAIL:
       NEXT(i, j) = cCONDUCTOR;
       break;
     case cCONDUCTOR:
       ehn = count_heads(i, j);
       if ( (ehn == 1) || (ehn == 2) )
         NEXT(i, j) = cHEAD;
       else
         NEXT(i, j) = cCONDUCTOR;
       break;
     default:
       NEXT(i, j) = THIS(i, j);
     }
   }
 }
 fc++;

}


// key hit void key_hit(unsigned char k, int x, int y) {

 if ( k == 'q' )
 {
   glFinish();
   glutDestroyWindow(win);
   exit(EXIT_SUCCESS);
 } else {
   evolve_wireworld();
   wireworld_show();
 }

}


int main(int argc, char *argv[]) {

 FILE *p;
 int i, j;


 if ( argc < 2 ) {
   fprintf(stderr, "specify a wireworld initial state\n");
   exit(EXIT_FAILURE);
 }


 if ( (p = fopen(argv[1], "r")) != NULL ) {
   field[0] = malloc(MAX_SIZE*MAX_SIZE*sizeof(char)); assert(field[0] != NULL); //lazy a-check
   field[1] = malloc(MAX_SIZE*MAX_SIZE*sizeof(char)); assert(field[1] != NULL);
   atexit(freemem);
   fc = 0;
   char buf[MAX_SIZE];
   j = 0;
   while( !feof(p) && fgets(buf, MAX_SIZE, p) && ( j < MAX_SIZE )) {
     for(i=0; (buf[i] != 0) && (buf[i] != 10) && (i < MAX_SIZE); i++ ) {
       *(field[fc%2] + j*width + i) = buf[i];
     }
     for( ; i < MAX_SIZE; i++) *(field[fc%2] + j*width + i) = 0;
     j++;
   }
   
   fclose(p);
   // no more error check :)
   glutInit(&argc, argv);
   win = glutCreateWindow("Wireworld");
   glutInitWindowPosition(0,0);
   glutInitWindowSize(width*PPP, height*PPP);
   glutDisplayFunc(wireworld_show);    
   glutKeyboardFunc(key_hit);
   // (-1,-1) from lower leftmost to upper leftmost corner
   float matrix[16] = {
     1, 0, 0, 0,
     0, -1, 0, 0,
     0, 0, 1, 0,
     0, 0, 0, 1
   };
   glLoadMatrixf(matrix);
   glutMainLoop();
 } else {
   fprintf(stderr, "cannot open %s\n", argv[1]);
   exit(EXIT_FAILURE);
 }
 exit(EXIT_SUCCESS);

}</lang>

Forth

<lang forth> 16 constant w

8 constant h
rows w * 2* ;

1 rows constant row h rows constant size

create world size allot world value old old w + value new

init world size erase ;
age new old to new to old ;
foreachrow ( xt -- )
 size 0 do  I over execute  row +loop drop ;

0 constant EMPTY 1 constant HEAD 2 constant TAIL 3 constant WIRE create cstate bl c, char H c, char t c, char . c,

showrow ( i -- ) cr
 old + w over + swap do I c@ cstate + c@ emit loop ;
show ['] showrow foreachrow  ;


line ( row addr len -- )
 bounds do
   i c@
   case
   bl of EMPTY over c! endof
   'H of HEAD  over c! endof
   't of TAIL  over c! endof
   '. of WIRE  over c! endof
   endcase
   1+
 loop drop ;
load ( filename -- )
 r/o open-file throw
 init  old row + 1+  ( file row )
 begin  over pad 80 rot read-line throw
 while  over pad rot line
        row +
 repeat
 2drop close-file throw
 show cr ;


+head ( sum i -- sum )
 old + c@ HEAD = if 1+ then ;
conductor ( i WIRE -- i HEAD|WIRE )
 drop 0
 over 1- row - +head
 over    row - +head
 over 1+ row - +head
 over 1-       +head
 over 1+       +head
 over 1- row + +head
 over    row + +head
 over 1+ row + +head
 1 3 within if HEAD else WIRE then ;

\ before: empty head tail wire

create transition ' noop , ' 1+ , ' 1+ , ' conductor ,

\ after: empty tail wire head|wire

new-state ( i -- )
 dup  old + c@
 dup cells transition + @ execute
 swap new + c! ;
newrow ( i -- )
 w over + swap do I new-state loop ;
gen ['] newrow foreachrow age ;
wireworld begin gen 0 0 at-xy show key? until ;

</lang>

Output:

s" wireworld.diode" load
                
        ..      
 tH...... .Ht   
        ..      
                
                
                
                
 ok
gen show                
                
        ..      
 .tH..... Ht.   
        ..      
                
                
                
                 ok
gen show 
                
        .H      
 ..tH.... t..   
        .H      
                
                
                
                 ok
gen show 
                
        Ht      
 ...tH..H ...   
        Ht      
                
                
                
                 ok
gen show 
                
        t.      
 ....tH.t ...   
        t.      
                
                
                
                 ok
gen show 
                
        ..      
 .....tH. ...   
        ..      
                
                
                
                 ok
gen show 
                
        H.      
 ......tH ...   
        H.      
                
                
                
                 ok
gen show 
                
        tH      
 .......t ...   
        tH      
                
                
                
                 ok
gen show 
                
        .t      
 ........ H..   
        .t      
                
                
                
                 ok
gen show 
                
        ..      
 ........ tH.   
        ..      
                
                
                
                 ok
gen show 
                
        ..      
 ........ .tH   
        ..      
                
                
                
                 ok
gen show 
                
        ..      
 ........ ..t   
        ..      
                
                
                
                 ok
gen show 
                
        ..      
 ........ ...   
        ..      
                
                
                
                 ok

Haskell

<lang Haskell> import Data.List import Control.Monad import Control.Arrow import Data.Maybe

states=" Ht." shiftS=" t.."

borden bc xs = bs: (map (\x -> bc:(x++[bc])) xs) ++ [bs]

  where r = length $ head xs
        bs = replicate (r+2) bc

take3x3 = ap ((.). taken. length) (taken. length. head) `ap` borden '*'

  where taken n =  transpose. map (take n.map (take 3)).map tails

nwState xs | e =='.' && noH>0 && noH<3 = 'H'

          | otherwise = shiftS !! (fromJust $ findIndex (==e) states) 
  where e = xs!!1!!1
        noH = length $ filter (=='H') $ concat xs

runCircuit = iterate (map(map nwState).take3x3) </lang> Example executed in GHCi: <lang Haskell> oscillator= [" tH ",

            ".  ....",
            " ..    "
           ]

example = mapM_ (mapM_ putStrLn) .map (borden ' ').take 9 $ runCircuit oscillator </lang> Ouptput:

*Main> example

  tH
 .  ....
  ..


  .t
 .  H...
  ..


  ..
 .  tH..
  .H


  ..
 .  .tH.
  Ht


  ..
 H  ..tH
  t.


  H.
 t  ...t
  ..


  tH
 .  ....
  ..


  .t
 .  H...
  ..


  ..
 .  tH..
  .H

(0.01 secs, 541764 bytes)

J

The example circuit: <lang J> circ0=:}: ] ;. _1 LF, 0 : 0 tH........ . .

  ...    

. . Ht.. ..... ) </lang> A 'boarding' verb board and the next cell state verb nwS: <lang J>

board=: ' ' ,.~ ' ' ,. ' ' , ' ' ,~ ]

nwS=: 3 : 0

 e=. (<1 1){y
 if. ('.'=e)*. e.&1 2 +/'H'=,y do. 'H' return. end.
 ' t..' {~ ' Ht.' i. e

) </lang> The 'most' powerful part is contained in the following iterating sentence, namely the dyad cut ;. [1]. In this way verb nwS can work on all the 3x3 matrices containing each cell surrounded by its 8 relevant neighbors. <lang J> (3 3 nwS;. _3 board)^: (<10) circuit</lang> Example run:

   (3 3 nwS;. _3 board)^: (<10) circ0
tH........
.   .     
   ...    
.   .     
Ht.. .....

.tH.......
H   .     
   ...    
H   .     
t... .....

H.tH......
t   .     
   ...    
t   .     
.H.. .....

tH.tH.....
.   H     
   ...    
.   .     
HtH. .....

.tH.tH....
H   t     
   HHH    
H   .     
t.tH .....

H.tH.tH...
t   .     
   ttt    
t   .     
.H.t .....

tH.tH.tH..
.   H     
   ...    
.   .     
HtH. .....

.tH.tH.tH.
H   t     
   HHH    
H   .     
t.tH .....

H.tH.tH.tH
t   .     
   ttt    
t   .     
.H.t .....

tH.tH.tH.t
.   H     
   ...    
.   .     
HtH. .....

OCaml

<lang ocaml>let w = [|

   "  ......tH              ";
   " .        ......        ";
   "  ...Ht...      .       ";
   "               ....     ";
   "               .  ..... ";
   "               ....     ";
   "  tH......      .       ";
   " .        ......        ";
   "  ...Ht...              ";
 |]

let is_head w x y =

 try if w.(x).[y] = 'H' then 1 else 0
 with _ -> 0

let neighborhood_heads w x y =

 let n = ref 0 in
 for _x = pred x to succ x do
   for _y = pred y to succ y do
     n := !n + (is_head w _x _y)
   done;
 done;
 (!n)

let step w =

 let n = Array.init (Array.length w) (fun i -> String.copy w.(i)) in
 let width = Array.length w
 and height = String.length w.(0)
 in
 for x = 0 to pred width do
   for y = 0 to pred height do
     n.(x).[y] <- (
       match w.(x).[y] with
       | ' ' -> ' '
       | 'H' -> 't'
       | 't' -> '.'
       | '.' ->
           (match neighborhood_heads w x y with
           | 1 | 2 -> 'H'
           | _ -> '.')
       | _ -> assert false)
   done;
 done;
 (n)

let print = (Array.iter print_endline)

let () =

 let rec aux w =
   Unix.sleep 1;
   let n = step w in
   print n;
   aux n
 in
 aux w</lang>

Python

<lang python> Wireworld implementation.

from io import StringIO from collections import namedtuple from pprint import pprint as pp import copy

WW = namedtuple('WW', 'world, w, h') head, tail, conductor, empty = allstates = 'Ht. '


infile = StringIO(\ tH......... . .

  ...

. . Ht.. ......\ )

def readfile(f):

   'file > initial world configuration'
   world  = f.readlines()
   world  = [row.rstrip('\r\n') for row in world]
   height = len(world)
   width  = max(len(row) for row in world)
   # fill right and frame in empty cells
   nonrow = [ " %*s " % (-width, "") ]
   world  = ( nonrow
              + [ " %*s " % (-width, row) for row in world ]
              + nonrow[:] )    
   world = [list(row) for row in world]
   return WW(world, width, height)

def newcell(currentworld, x, y):

   istate = currentworld[y][x]
   assert istate in allstates, 'Wireworld cell set to unknown value "%s"' % istate
   if istate == head:
       ostate = tail
   elif istate == tail:
       ostate = conductor
   elif istate == empty:
       ostate = empty
   else: # istate == conductor
       n = sum( currentworld[y+dy][x+dx] == head
                for dx,dy in ( (-1,-1), (-1,+0), (-1,+1),
                               (+0,-1),          (+0,+1),
                               (+1,-1), (+1,+0), (+1,+1) ) )
       ostate = head if 1 <= n <= 2 else conductor
   return ostate

def nextgen(ww):

   'compute next generation of wireworld'
   world, width, height = ww
   newworld = copy.deepcopy(world)
   for x in range(1, width+1):
       for y in range(1, height+1):
           newworld[y][x] = newcell(world, x, y)
   return WW(newworld, width, height)

def world2string(ww):

   return '\n'.join( .join(row[1:-1]).rstrip() for row in ww.world[1:-1] )

ww = readfile(infile) infile.close()

for gen in range(10):

   print ( ("\n%3i " % gen) + '=' * (ww.w-4) + '\n' )
   print ( world2string(ww) )
   ww = nextgen(ww)

</lang>

Sample Output

  0 =======

tH.........
.   .
   ...
.   .
Ht.. ......

  1 =======

.tH........
H   .
   ...
H   .
t... ......

  2 =======

H.tH.......
t   .
   ...
t   .
.H.. ......

  3 =======

tH.tH......
.   H
   ...
.   .
HtH. ......

  4 =======

.tH.tH.....
H   t
   HHH
H   .
t.tH ......

  5 =======

H.tH.tH....
t   .
   ttt
t   .
.H.t ......

  6 =======

tH.tH.tH...
.   H
   ...
.   .
HtH. ......

  7 =======

.tH.tH.tH..
H   t
   HHH
H   .
t.tH ......

  8 =======

H.tH.tH.tH.
t   .
   ttt
t   .
.H.t ......

  9 =======

tH.tH.tH.tH
.   H
   ...
.   .
HtH. ......

Ruby

Library: Ruby/Tk

The GUI is somewhat "halfway", in that it animates a text widget so it's not "real" graphics. <lang ruby>require 'tk'

class WireWorld

 EMPTY = ' '
 HEAD = 'H'
 TAIL = 't'
 CONDUCTOR = '.'
 def initialize(string)
   max_row = 0
   @grid = string.each_line.collect do |line|
             line.chomp!
             max_row = [max_row, line.length].max
             line.each_char.collect do |char| 
               case char
               when EMPTY, HEAD, TAIL, CONDUCTOR then char
               else EMPTY
               end 
             end
           end
   @original_grid = Marshal.restore(Marshal.dump @grid)   # this is a deep copy
   @width = max_row
   @height = @grid.length
   pad_grid
 end
 # initialize from a file
 def self.open(filename)
   self.new(File.read(filename))
 end
 def reset
   @grid = @original_grid
 end
 # ensure all rows are the same length by padding short rows with empty cells
 def pad_grid
   @grid.each do |row|
     if @width > row.length
       row.concat(Array.new(@width - row.length, EMPTY))
     end
   end
 end
 # the "to_string" method
 def to_s
   @grid.inject() {|str, row| str << row.join() << "\n"}
 end
 # transition all cells simultaneously
 def transition
   @grid = @grid.each_with_index.collect do |row, y| 
             row.each_with_index.collect do |state, x| 
               transition_cell(state, x, y)
             end
           end
 end
 # how to transition a single cell
 def transition_cell(current, x, y)
   case current
   when EMPTY then EMPTY
   when HEAD  then TAIL
   when TAIL  then CONDUCTOR
   else neighbours_with_state(HEAD, x, y).between?(1,2) ? HEAD : CONDUCTOR
   end
 end
 # given a position in the grid, find the neighbour cells with a particular state
 def neighbours_with_state(state, x, y)
   count = 0
   ([x-1, 0].max .. [x+1, @width-1].min).each do |xx|
     ([y-1, 0].max .. [y+1, @height-1].min).each do |yy|
       next if x == xx and y == yy
       count += 1 if state(xx, yy) == state
     end
   end
   count
 end
 # return the state of a cell given a cartesian coordinate
 def state(x, y)
   @grid[y][x]
 end
 # run a simulation up to a limit of transitions, or until a recurring
 # pattern is found
 # This will print text to the console
 def run(iterations = 25)
   seen = []
   count = 0
   loop do
     puts self
     puts
     if seen.include?(@grid)
       puts "I've seen this grid before... after #{count} iterations"
       break
     end
     if count == iterations
       puts "ran through #{iterations} iterations"
       break
     end
     seen << @grid
     count += 1
     transition
   end
 end
 # the gui version
 def run_tk
   @tk_root = TkRoot.new("title" => "WireWorld")
   @tk_text = TkText.new(@tk_root, 
                 :width => @width, 
                 :height => @height, 
                 :font => 'courier')
   @tk_text.insert('end', self.to_s).state('disabled')
   @tk_after_interval = 150
   faster_cmd = proc {@tk_after_interval = [25, @tk_after_interval-25].max}
   slower_cmd = proc {@tk_after_interval += 25}
   reset_cmd = proc {self.reset}
   close_cmd = proc do
     @tk_root.after_cancel(@tk_after_id)
     @tk_root.destroy
   end
   controls = TkFrame.new(@tk_root)
   [ TkButton.new(controls, :text => 'Slower', :command => slower_cmd),
     TkButton.new(controls, :text => 'Faster', :command => faster_cmd),
     TkButton.new(controls, :text => 'Reset',  :command => reset_cmd),
     TkButton.new(controls, :text => 'Close',  :command => close_cmd),
   ].each {|btn| btn.pack(:expand => 1, :fill => 'x', :side => 'left')}
   @tk_text.pack(:expand => 1, :fill => 'both')
   controls.pack(:fill => 'x')
   @tk_after_id = @tk_root.after(500) {animate}
   Tk.mainloop
 end
 def animate
   transition 
   @tk_text.state('normal') \
           .delete('1.0','end') \
           .insert('end', self.to_s) \
           .state('disabled')
   @tk_after_id = @tk_root.after(@tk_after_interval) {animate}
 end

end

  1. this is the "2 Clock generators and an XOR gate" example from the wikipedia page

ww = WireWorld.new <<WORLD

 ......tH
.        ......
 ...Ht...      .
              ....
              .  ..... 
              ....
 tH......      .
.        ......
 ...Ht...

WORLD

ww.run ww.reset ww.run_tk puts 'bye'</lang>

Tcl

Works with: Tcl version 8.6


Library: Tk

<lang tcl>package require Tcl 8.6 package require Tk

  1. The color scheme.
  2. The order is: empty, conductor, electronTail, electronHead

set colors "#000000 #000080 #8080ff #ffffff"

  1. Encapsulate the per-cell logic in a class to simplify it

oo::class create wireCell {

   variable X Y S0 S1 Neighbours

   constructor {state x y} {

upvar 1 at at

set X $x set Y $y

switch -- $state { conductor { set S0 1 } electronTail { set S0 2 } electronHead { set S0 3 } default { return -code error "invalid state name \"$state\"" } } set at($x,$y) [self]

   }

   # Method used to allow each (non-background) cell to know about its
   # surrouding non-background cells. This makes the connectivity
   # calculations much simpler and faster!
   method initConnectivity {} {

upvar 1 at at foreach dx {-1 -1 -1 0 0 1 1 1} dy {-1 0 1 -1 1 -1 0 1} { set pos [expr {$X+$dx}],[expr {$Y+$dy}] if {[info exists at($pos)]} { lappend Neighbours $at($pos) } }

   }

   method state {} {return $S0}
   method x {} {return $X}
   method y {} {return $Y}

   # Perform the transition in two stages, so that we can do the transition
   # "simultaneously" across all cells. The transition0 method calculates
   # what state we're going to change to, and the transition1 method actually
   # moves to the state.
   method transition0 {} {

if {$S0 == 3} { set S1 2 } elseif {$S0 == 2} { set S1 1 } else { set count 0 foreach n $Neighbours { incr count [expr {[$n state] == 3}] } set S1 [expr {($count == 1 || $count == 2) ? 3 : 1}] }

   }
   method transition1 {} {

set S0 $S1

   }

}

  1. A subclass that knows how to display state changes on the GUI

oo::class create GUIwireCell {

   superclass wireCell
   variable S0 S1 X Y
   constructor {state x y} {

global colors next $state $x $y pixels put [lindex $colors $S0] -to $X $Y

   }
   method transition1 {} {

# Only do the plot of the state changed; more efficient if {$S0 != $S1} { global colors pixels put [lindex $colors [next]] -to $X $Y }

   }

}

  1. How to load a layout/program from a file

proc loadWires filename {

   global cells colors

   # Read the file in
   set f [open $filename]
   set data [read $f]
   close $f

   # Initialize the list of interacting cells and the connectivity map
   set cells {}
   array set at {}

   # Calculate the width of the program
   set lines [split $data \n]
   set len 0
   foreach line $lines {

if {[string length $line] > $len} { set len [string length $line] }

   }

   # Create the arena image
   image create photo pixels

   # Initialize the image to "empty cell"s; interacting parts will be overlaid
   pixels put [lindex $colors 0] -to 0 0 $len [llength $lines]

   # Parse the input data and create the interacting cells
   set y 0
   foreach line $lines {

set x 0 foreach char [split $line {}] { switch $char { H { lappend cells [GUIwireCell new electronHead $x $y] } t { lappend cells [GUIwireCell new electronTail $x $y] } . { lappend cells [GUIwireCell new conductor $x $y] } } incr x } incr y

   }

   # Now inform each cell about its connectivity
   foreach cell $cells {

$cell initConnectivity

   }
   unset at

}

  1. How to save the current state as a layout that [loadWires] can load

proc saveWires {filename} {

   global cells
   # Make a grid of empty characters of the right size
   set chs [lrepeat [image height pixels] [lrepeat [image width pixels] " "]]
   # Transcribe the non-empty cells into the grid
   foreach cell $cells {

lset chs [$cell y] [$cell x] [string index " .tH" [$cell state]]

   }
   # Write the characters to stdout or a file
   if {$filename eq "-"} {set f stdout} else {set f [open $filename w]}
   foreach row $chs {

puts $f [join $row ""]

   }
   if {$f ne "stdout"} {close $f}

}

  1. How to perform the animation timestep

proc timeStep {t} {

   global cells

   # Arm the transition for all interacting cells
   foreach cell $cells {

$cell transition0

   }
   # Perform the transition for all interacting cells
   foreach cell $cells {

$cell transition1

   }

   # Reschedule
   after $t [list timeStep $t]

}

  1. Initialize the GUI (such as it is) and load and start the animation

wm title . "Wireworld: [lindex $argv 0]" loadWires [lindex $argv 0] pack [label .l -image pixels] bind . <KeyPress> {saveWires -} after 1000 timeStep 250</lang>