先不多说先上图
下面是代码部分（这里你可以根据需要改变蛇头和身体还有食物的图片，然后默认的样式是使用纯颜色的如果没有更改我的背景图片的话------改这些图开始是想搞笑一下朋友哈哈哈，请不要在意哈），还有操作键是使用 ↑ ↓ ← → ）
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title>贪食蛇</title>
<style>
.map {
width: 800px;
height: 600px;
background-color: #ccc;
position: relative;
left: 50%;
transform: translate(-50%);
}
#dv {
color: whitesmoke;
font-weight: 700;
text-align: center;
line-height: 50px;
width: 150px;
height: 50px;
position: absolute;
background-color: orange;
border-radius: 10px;
top: 50%;
left: 50%;
transform: translate(-50%);
cursor: pointer;
}
</style>
</head>
<body>
<div class="map">
<div id="dv">开始游戏</div>
</div>
<script>
//食物:是一个对象,有宽,有高,有颜色,有横纵座标
//自调用函数
(function () {
var element = []; //用来保存每个小方块食物的
function Food(x, y, width, height, color) {
this.x = x || 0;
this.y = y || 0;
this.width = width || 20;
this.height = height || 20;
this.color = color || "green";
}
//为原型添加初始化的方法(作用:在页面上显示这个食物)
//因为食物要在地图上显示,所以,需要地图的这个参数(map--就是页面上的.class=map的这个div)
Food.prototype.init = function (map) {
//先删除这个小食物
//外部无法访问,此函数在自调用函数里面
remove();
//创建div
var div = document.createElement("div");
//把div加到map里面
map.appendChild(div);
//获取div的样式
div.style.width = this.width + "px";
div.style.height = this.height + "px";
div.style.backgroundColor = this.color;
//脱离文档流
div.style.position = "absolute";
//横纵座标先停止----随机产生
this.x = parseInt(Math.random() * (map.offsetWidth / this.width)) * this.width;
this.y = parseInt(Math.random() * (map.offsetHeight / this.height)) * this.height;
div.style.left = this.x + "px";
div.style.top = this.y + "px";
//把div加入element数组中
element.push(div);
//改变食物的样式---改成自己喜欢的东西
div.style.backgroundImage = "url(" + "../images/shi.png" + ")";
div.style.backgroundRepeat = "no-repaet";
div.style.backgroundSize = "cover";
};
//私有函数
function remove() {
for (var i = 0; i < element.length; i++) {
var ele = element[i];
//找到这个子元素的父级元素,然后删除这个子元素
ele.parentNode.removeChild(ele);
//再次把element中的这个子元素删除
element.splice(i, 1);
}
}
//把Food暴露给window,外部可以使用
window.Food = Food;
}());
//自调用函数---小蛇
(function () {
//存放小蛇的每个身体部分
var element = [];
//小蛇的构造函数
function Snake(width, height, driection) {
this.width = width || 20;
this.height = height || 20;
//小蛇的身体
this.body = [{
x: 3,
y: 2,
color: "red"
},
{
x: 2,
y: 2,
color: "orange"
},
{
x: 1,
y: 2,
color: "orange"
}
];
//方向
this.driection = driection || "right";
}
//为原型添加方法---小蛇初始化的方法
Snake.prototype.init = function (map) {
//先删除之前的小蛇
remove();
//循环遍历创建div
for (var i = 0; i < this.body.length; i++) {
//数组中的每个数组元素都是一个对象
var obj = this.body[i];
//创建div
var div = document.createElement("div");
//把div加入地图map中
map.appendChild(div);
//设置div的样式
div.style.position = "absolute";
div.style.width = this.width + "px";
div.style.height = this.height + "px";
//横纵座标
div.style.left = obj.x * this.width + "px";
div.style.top = obj.y * this.height + "px";
//背景颜色
div.style.backgroundColor = obj.color;
//方向还没定
//把div加入到element数组中---目的是为了删除
//把div加入数组中
element.push(div);
//更改头部的----变成图片
if (i == 0) {
div.style.backgroundImage = "url(" + "../images/tou_03.png" + ")";
div.style.backgroundRepeat = "no-repaet";
div.style.backgroundSize = "cover";
}
//更改尾巴的样式照片
if (i != 0) {
div.style.backgroundImage = "url(" + "../images/shi.png" + ")";
div.style.backgroundRepeat = "no-repaet";
div.style.backgroundSize = "cover";
}
}
};
//为原型添加方法---小蛇动起来
Snake.prototype.move = function (food, map) {
var i = this.body.length - 1;
for (; i > 0; i--) {
this.body[i].x = this.body[i - 1].x;
this.body[i].y = this.body[i - 1].y;
}
//判断方向---改变小蛇的头的座标位置
switch (this.driection) {
case "left":
this.body[0].x -= 1;
break;
case "right":
this.body[0].x += 1;
break;
case "top":
this.body[0].y -= 1;
break;
case "bottom":
this.body[0].y += 1;
break;
}
//判断有没有吃到食物
//小蛇的头的座标和食物的座标一致
var headX = this.body[0].x * this.width;
var headY = this.body[0].y * this.height;
//判断小蛇的头和食物座标是否相同
if (headX == food.x && headY == food.y) {
//获取小蛇的最后的尾巴
var last = this.body[this.body.length - 1];
//把最后的蛇尾复制一个,重新的加入到小蛇的body中
this.body.push({
x: last.x,
y: last.y,
color: last.color
});
//把食物删除,重新初始化食物
food.init(map);
}
};
//删除小蛇的私有函数
function remove() {
//获取数组
var i = element.length - 1;
for (; i >= 0; i--) {
var ele = element[i];
//从map地图上删除这个子元素div
ele.parentNode.removeChild(ele);
element.splice(i, 1);
}
}
window.Snake = Snake;
}());
//自调用函数---游戏对象
(function () {
var that = null;
//游戏的构造函数
function game(map) {
this.food = new Food(); //食物对象
this.snake = new Snake(); //小蛇对象
this.map = map; //地图
that = this;
}
game.prototype.init = function () {
//初始化游戏
//食物初始化
this.food.init(this.map);
//小蛇初始化
this.snake.init(this.map);
that = this;
document.getElementById("dv").onclick = function () {
document.getElementById("dv").style.display = "none";
//调用小蛇移动的方法
that.runSnake(that.food, that.map);
//调用按键的方法
that.bindKey();
}.bind(that);
};
//添加原型方法---设置小蛇可以自动跑起来
game.prototype.runSnake = function (food, map) {
//自动的去移动
var time = 90;
var fn = function () {
//此时this是window
//移动小蛇
this.snake.move(food, map);
//初始化小蛇
this.snake.init(map);
//横座标的最大值
var maxX = map.offsetWidth / this.snake.width;
//纵座标的最大值
var maxY = map.offsetHeight / this.snake.height;
//小蛇的头的座标
var headX = this.snake.body[0].x;
var headY = this.snake.body[0].y;
//判断 横座标 有没撞墙
if (headX < 0 || headX >= maxX) {
//撞墙停止定时器
clearInterval(timeId);
alert("游戏结束");
location.reload();
}
//判断 纵座标 有没撞墙
if (headY < 0 || headY >= maxY) {
clearInterval(timeId);
alert("游戏结束");
location.reload();
}
//判断 小蛇的头部 有没有 撞到自己
for (let i = 1; i < this.snake.body.length; i++) {
let x = this.snake.body[i].x;
let y = this.snake.body[i].y;
if (headX === x && headY === y) {
clearInterval(timeId);
alert("游戏结束");
location.reload();
}
}
//增加游戏难度,判断 到达一定数量的时候 加速
switch (true) {
case 5 <= this.snake.body.length && this.snake.body.length <= 10:
clearInterval(timeId);
time = 60;
timeId = setInterval(fn, time);
break;
case 10 <= this.snake.body.length && this.snake.body.length <= 15:
clearInterval(timeId);
time = 40;
timeId = setInterval(fn, time);
break;
case 15 <= this.snake.body.length:
clearInterval(timeId);
time = 30;
timeId = setInterval(fn, time);
break;
}
console.log(this.snake.body.length + "--" + "time:" + time);
}.bind(that);
//定时器小蛇自运动
var timeId = setInterval(fn, time);
};
//添加原型方法---设置用户按键,改变小蛇移动的方向
game.prototype.bindKey = function () {
//获取用户的按键,改变小蛇的移动方向
document.addEventListener("keydown", function (e) {
//获取按键的值并进行判断是,改变小蛇移动的方向
switch (e.keyCode) {
//没有bind方法时此时的this指向的是documen
case 37:
if (this.snake.driection != "right") {
this.snake.driection = "left";
}
break;
case 38:
if (this.snake.driection != "bottom") {
this.snake.driection = "top";
}
break;
case 39:
if (this.snake.driection != "left") {
this.snake.driection = "right";
}
break;
case 40:
if (this.snake.driection != "top") {
this.snake.driection = "bottom";
}
break;
}
}.bind(that), false);
};
//把game暴露给window,外部就可以访问game对象
window.game = game;
}());
//初始化游戏对象
var gm = new game(document.querySelector(".map"));
//初始化游戏---开始游戏
gm.init();
</script>
</body>
</html>
我已经尽量给以上代码注上注释。希望能帮到更多朋友更好的理解贪食蛇游戏的实现思路！
