<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>贪吃蛇 作者:记忆中的马肠河</title>
<script type="text/javascript">
window.onload = function () {
var snake = {
//移动方向
fangxiang: "left",
//蛇身
snakeBody: [],
box: document.getElementById("snakeBox"),
//移动
move: function () {
var timer = "";
//判断是否GameOver
var isFailed = function () {
//判断蛇头是否碰到蛇身
var isHeadRunIntoBody=function(){
var t=false;
for(var i=0;i<snake.snakeBody.length-1;i++){
if(snake.snakeBody[snake.snakeBody.length-1].x==snake.snakeBody[i].x&&
snake.snakeBody[snake.snakeBody.length-1].y==snake.snakeBody[i].y
){
t=true;
break;
}
}
return t;
}
//判断条件：是否蛇身碰到蛇头、是否蛇头碰到墙壁
if (
isHeadRunIntoBody()||
snake.snakeBody[snake.snakeBody.length - 1].x > snake.box.offsetLeft + parseInt(snake.box.style.borderWidth) + snake.box.clientWidth - 10
|| snake.snakeBody[snake.snakeBody.length - 1].x < snake.box.offsetLeft + parseInt(snake.box.style.borderWidth)
|| snake.snakeBody[snake.snakeBody.length - 1].y < snake.box.offsetTop + parseInt(snake.box.style.borderWidth)
|| snake.snakeBody[snake.snakeBody.length - 1].y > snake.box.offsetTop + parseInt(snake.box.style.borderWidth) + snake.box.clientWidth - 10
) {
//清除定时器
clearTimeout(timer);
alert("Game over!");
return false;
}
}
//存放蛇头
var snakeHead = snake.snakeBody[snake.snakeBody.length - 1];
//去除蛇尾
var sheWei = snake.snakeBody.shift();
switch (snake.fangxiang) {
case "up":
sheWei.x = snakeHead.x;
sheWei.y = snakeHead.y - 10;
break;
case "down":
sheWei.x = snakeHead.x;
sheWei.y = snakeHead.y + 10;
break;
case "left":
sheWei.x = snakeHead.x - 10;
sheWei.y = snakeHead.y;
break;
case "right":
sheWei.x = snakeHead.x + 10;
sheWei.y = snakeHead.y;
break;
default:
break;
}
//把蛇尾放到蛇头
snake.snakeBody.push(sheWei);
//每次移动蛇身，都去吃食物.
snake.eatFood();
//是否失败
var ISF = isFailed();
//如果失败，不再绘制；
if (!ISF && ISF != undefined) {
return;
} else {
snake.drawSnake();
}
//蛇身移动的定时器
timer = setTimeout(snake.move, 500);
},
drawSnake: function () {
//清空已绘制的蛇身
var bc = snake.box.childNodes;
for (var i = 0, len = bc.length; i < len; i++) {
var tn = bc[i];
if (tn) {
var tng = tn.tagName;
if (tng) {
var id = bc[i].getAttribute("id")
if (tng.toLowerCase() == "div" && id != "foodDiv") {
snake.box.removeChild(bc[i]);
//没删除一个节点索引退一步
i-=1;
}
}
}
}
//判断是否是第一次加载蛇身，如果是，则添加蛇头
if (snake.snakeBody.length == 0) {
var a = {};
do{
a.x = Math.floor(19 * Math.random()) * 10 + snake.box.offsetLeft + parseInt(snake.box.style.borderWidth);
a.y = Math.floor(19 * Math.random()) * 10 + snake.box.offsetTop + parseInt(snake.box.style.borderWidth);
}while((function(){
//第一次添加蛇头的时候不能让蛇头挨着边框
if(a.x==snake.box.offsetLeft + parseInt(snake.box.style.borderWidth)
||a.x+10==snake.box.offsetLeft + parseInt(snake.box.style.borderWidth)+snake.box.clientWidth
||a.y==snake.box.offsetTop+parseInt(snake.box.style.borderWidth)
||a.y+10==snake.box.offsetTop+parseInt(snake.box.style.borderWidth)+snake.box.clientHeight
){
return true;
}else{
return false;
}
})());
snake.snakeBody.push(a);
}
//遍历存放蛇的数组并绘制在页面上
for (var b in snake.snakeBody) {
var d = document.createElement("div");
d.style.backgroundColor = 'red'; d.style.border = "0px solid green"; d.style.position = 'absolute'; d.style.zIndex = '1';
d.style.width = '10px'; d.style.height = '10px';
d.style.left = snake.snakeBody[b].x + "px"; d.style.top = snake.snakeBody[b].y + "px";
snake.box.appendChild(d);
}
return snake;
},
eatFood: function () {
var foodObj = food.getFood();
//判断蛇头是否与食物重合，如果是，则把食物作为蛇头
if (
snake.snakeBody[snake.snakeBody.length - 1].x == foodObj.offsetLeft
&& snake.snakeBody[snake.snakeBody.length - 1].y == foodObj.offsetTop
) {
var o = {};
switch (snake.fangxiang) {
case "left":
o.x = snake.snakeBody[snake.snakeBody.length - 1].x - 10;
o.y = snake.snakeBody[snake.snakeBody.length - 1].y;
break;
case "right":
o.x = snake.snakeBody[snake.snakeBody.length - 1].x + 10;
o.y = snake.snakeBody[snake.snakeBody.length - 1].y;
break;
case "up":
o.x = snake.snakeBody[snake.snakeBody.length - 1].x;
o.y = snake.snakeBody[snake.snakeBody.length - 1].y - 10;
break;
case "down":
o.x = snake.snakeBody[snake.snakeBody.length - 1].x;
o.y = snake.snakeBody[snake.snakeBody.length - 1].y + 10;
break;
default:
break;
}
//把原来的食物删除
snake.box.removeChild(foodObj);
//把吃到的食物加到蛇头
snake.snakeBody.push(o);
//重新绘制食物
food.foodMake();
}
}
}
var food = {
//生成食物
foodMake: function () {
//定义食物出现的位置
var x, y;
do {
x = Math.floor(19 * Math.random()) * 10 + snake.box.offsetLeft + parseInt(snake.box.style.borderWidth);
y = Math.floor(19 * Math.random()) * 10 + snake.box.offsetTop + parseInt(snake.box.style.borderWidth);
} while ((function () {
//蛇身是否在该位置，如果蛇身和食物重合则重新生成食物
var t = false;
for (var o in snake.snakeBody) {
t = snake.snakeBody[o].x == x && snake.snakeBody[o].y == y
if (t) {
break;
}
}
return t;
})());
var d = document.createElement("div");
d.style.backgroundColor = 'red'; d.style.border = "0px solid green"; d.style.position = 'absolute'; d.style.zIndex = '1';
d.style.width = '10px'; d.style.height = '10px'; d.setAttribute("id", "foodDiv"); //设置食物的ID用于区别蛇身
d.style.top = x + "px"; d.style.left = y + "px";
return snake.box.appendChild(d); //返回新生成的食物
},
//得到食物
getFood: function () {
return document.getElementById("foodDiv");
}
}
//先绘制食物
food.foodMake();
//绘制并移动蛇身
snake.drawSnake().move();
//控制方向键
document.onkeydown = function (event) {
var e = event || window.event;
switch (e.keyCode) {
case 37:
if (snake.fangxiang != "right") {
snake.fangxiang = "left";
}
break;
case 38:
if (snake.fangxiang != "down") {
snake.fangxiang = "up";
}
break;
case 39:
if (snake.fangxiang != "left") {
snake.fangxiang = "right";
}
break;
case 40:
if (snake.fangxiang != "up") {
snake.fangxiang = "down";
}
default:
break;
}
}
}
</script>
</head>
<body style='text-align: center'>
<div id='snakeBox' style='border: 1px solid black; width: 200px; height: 200px'>
</div>
</body>
</html>
