<!-- Original:  Adam Stock (adam@digital-biz.com) -->

<!-- (c) Copyright 1998-99 Adam L. Stock. All Rights Reserved -->
<!-- You have permission to republish this code provided -->
<!-- that you do not remove this copyright notice -->

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->

<!-- Begin

//   http://www.yourdomain.com/hanoi-img-directory/disk1.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk1h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk2.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk2h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk3.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk3h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk4.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk4h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk5.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk5h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk6.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk6h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk7.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk7h.gif
//   http://www.yourdomain.com/hanoi-img-directory/post.gif
//   http://www.yourdomain.com/hanoi-img-directory/posttop.gif


// change this to where you upload the images to your site
imgdir = "./"


function preload() {
this.length = preload.arguments.length;
for (var i = 0; i < this.length; i++) {
this[i] = new Image();
this[i].src = imgdir + preload.arguments[i];
   }
}

var pics = new preload("disk1.gif","disk2.gif",
"disk3.gif","disk4.gif","disk5.gif","disk6.gif",
"disk7.gif","pole.gif", "disk1h.gif","disk2h.gif",
"disk3h.gif","disk4h.gif","disk5h.gif","disk6h.gif",
"disk7h.gif");

var selectedr = null;
var selectedc = null;
var maxposts = 3;
var maxdisks = 7;
var all_posts = 3;
var startpost = 1;
var endpost = (startpost-1 < 0 ? maxposts-1 : startpost-1);
var disks = 7;
var imgwidth = 160;
var imgheight = 14;
var game_is_over = false;
var show_messages = false;
var board = new Array(maxposts);
board[0] = new Array(maxdisks + 1);
board[1] = new Array(maxdisks + 1);
board[2] = new Array(maxdisks + 1);

function initboard(startpost, disks) {
var len = board[0].length;
selectedc = null;
selectedr = null;
game_is_over = false;
endpost = (startpost-1 < 0 ? maxposts-1 : startpost-1);

for (i = 0; i < len; i++) {
board[0][i] = 0;
board[1][i] = 0;
board[2][i] = 0;
}
for (i = len-disks, j = 0; i < len; i++, j++) {
board[startpost][i] = len - j - 1;
   }
}

function drawall() {
for (j=0; j<board.length; j++) {
for (i=0; i<board[j].length; i++) {
draw(j,i, getName( board[j][i]));
   }
}
message("Voit aloittaa! Valitse siirrettävä kiekko.");
}

function restart(start) {
startpost = start;
disks = document.forms[0].disc.options[document.forms[0].disc.selectedIndex].text;
initboard(startpost,disks);
drawall();
theAnim = new Animation();
}
initboard(startpost, disks);

function getName( num ) {
if (num == 0) return "post.gif";
return "disk" + num + ".gif";
}

function message(str, force) {
if (force || !game_is_over && !show_messages)
document.disp.message.value = str;
}

function messageadd(str) {
if (!game_is_over)
document.disp.message.value = document.disp.message.value + "\n" + str;
}

function isempty(num) {
for (i = 0; i < board[num].length; i++) {
if ( board[num][i] != 0) return false;
}
return true;
}

function topmost(num) {
for (i = 0; i < board[num].length; i++) {
if (board[num][i] != 0) return  i;
}
return -1; 
}

function ispost(i,j) {
return (board[j][i] == 0);
}

function istopdisk(i,j) {
return (board[j][i-1] == 0);
}

function drawboard() {
document.writeln("<div class=keskella>");
document.writeln("<h2>The Towers of Hanoi</h2><p>");
document.writeln("<table width=500 cellspacing=0 cellpadding=0 border=0 align=center>");
document.write("<tr>");
for (j = 0; j < board.length; j++) {
document.write("<td>");
document.write("<a href='javascript:clicked("+0+","+j+")'><img src='" + imgdir + "posttop.gif' border=0></a><br>");
for (i=0; i< board[0].length; i++) {
document.write("<a href='javascript:clicked("+i+","+j+")'>");
document.write("<img src='" + imgdir + getName(board[j][i]) + "' name='pos"+ j + i + "' border=0><br>");
document.write("</a>");
}
document.writeln("</td>");
}
document.write("</tr></table>");
document.write("<form name='disp'><textarea name='message' wrap=virtual rows=2 cols=40></textarea><br>" +
"Kiekkoja: <select name=\"disc\" size=1><option>3<option>4<option>5<option>6<option selected>7</select><input "
+"type=button value=\"Aloita peli\" onClick=\"restart(startpost);\"><input "
+"type=button value=\"Ratkaise!\" onClick=\"restart(startpost);setTimeout('hanoi(disks,startpost,endpost)',300)\"></form>");
document.writeln("</div>");
}

function draw(x,y,name) {
document.images["pos"+x+""+y].src = imgdir + name;
}

function animate(x,y,name) {
theAnim.addFrame( "pos"+x+""+y, imgdir + name);
}

function clicked(i,j) {
document.forms[0].message.focus(); // get rid of annoying outline in MSIE
document.forms[0].message.blur();

if (game_is_over)  restart(startpost = endpost);
if (!isselection() && ispost(i,j)) { message("Valitse siirrettävä kiekko."); return; }
if (!ispost(i,j)) { toggle(j); return; };
if (ispost(i,j) && selectedc == j) { message("Siirrä kiekko toiseen tappiin."); return; }
if (!legalmove(j)) { message("Laiton siirto. Yritä uudestaan."); return; }
move(j); return;
}

function legalmove(j) {
if (isempty(j)) return true;
return (board[j][topmost(j)] < board[selectedc][selectedr]);
}

function isselection() {
return selectedc != null;
}

function toggle( num ) {
var toppos = topmost(num);

if (selectedc == num && selectedr == toppos) {
selectedc = null; selectedr = null;
animate(num,toppos,"disk" + board[num][toppos] + ".gif");
message("Valitse siirrettävä kiekko.");
return;
}
if (isselection()) {
animate(selectedc,selectedr,"disk" + board[selectedc][selectedr] + ".gif");
}
selectedc = num; selectedr = toppos;
animate(num,toppos,"disk" + board[num][toppos] + "h.gif");
message("Valitse tappi johon haluat kiekon siirtää.");
}

function move( num ) {
var toppos = (!isempty(num) ? topmost(num) : board[num].length);
board[num][toppos-1] = board[selectedc][selectedr];
board[selectedc][selectedr] = 0;
animate(selectedc,selectedr,"post.gif");
animate(num,toppos-1,"disk" + board[num][toppos-1] + ".gif");
selectedc = null; selectedr = null;
message("Valitse siirrettävä kiekko.");
game_over();
}

function hanoi(no_of_disks, start_post, goal_post) {
if (no_of_disks > 0) {
var free_post = all_posts - start_post - goal_post;
hanoi (no_of_disks - 1, start_post, free_post);
show_messages = true;
toggle(start_post);
move(goal_post);
show_messages = false;
hanoi (no_of_disks - 1 , free_post, goal_post);
game_over(true);
   }
}

function game_over(forceMsg) { 
var filledpost = null;
var val = 0;
for (k = 0; k < board.length; k++)  { 
val += ( isempty(k) ? 1 : 0 ); 
if (!isempty(k)) filledpost = k;
}

if (val == 2 && isempty(startpost)) {
message("Sinä voitit!", forceMsg);
game_is_over = true;
endpost = filledpost;
}
return game_is_over;
}

//
// Animation functions
//

function Animation() {
this.imageNum = new Array();  // Array of indicies document.images to be changed
this.imageSrc = new Array();  // Array of new srcs for imageNum array
this.frameIndex = 0;          // the frame to play next
this.alreadyPlaying = false;  // semaphore to ensure we play smoothly

this.getFrameCount = getframecount;   // the total numebr of frame so far
this.moreFrames = moreframes;         // tells us if there are more frames to play
this.addFrame = addframe;             // add a frame to the animation
this.drawNextFrame = drawnextframe;   // draws the next frame
this.startAnimation = startanimation; // start the animation if necessary
}

function getframecount() {  return this.imageNum.length; }
function moreframes() {  return this.frameIndex < this.getFrameCount(); }
function startanimation() { 
if (!this.alreadyPlaying) {
theAnim.alreadyPlaying = true;
setTimeout('theAnim.drawNextFrame()',5); 
   }
}

function addframe(num, src) {
var theIndex = theAnim.imageNum.length;
theAnim.imageSrc[theIndex] = src;
theAnim.imageNum[theIndex] = num;
theAnim.startAnimation();
}

function drawnextframe() {
if (theAnim.moreFrames()) {
document.images[ theAnim.imageNum[theAnim.frameIndex] ].src = theAnim.imageSrc[theAnim.frameIndex];
theAnim.frameIndex++;
setTimeout('theAnim.drawNextFrame()', 30);
} else {
theAnim.alreadyPlaying = false;
   }
}

drawboard();
var theAnim = new Animation();
message("Voit aloittaa! Valitse siirrettävä kiekko.");
document.disp.message.value = "";
//  End -->

<!-- Script Size:  8.91 KB -->
