index.html代码如下
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>贪吃蛇</title> <link rel="stylesheet" href="css/index.css" > </head> <body> <div id="map"> </div> <script src="js/tool.js"></script> <script src="js/food.js"></script> <script src="js/snake.js"></script> <script src="js/game.js"></script> <script src="js/main.js"></script> </body> </html>
index.css代码如下
#map {
width: 600px;
height: 400px;
background-color: #ccc;
position: relative;
}
food.js代码如下
//自调函数 开启一个新的作用域，避免命名冲突
(function () {
//局部作用域
//记录上一次创建的食物，为删除做准备
var elements=[];
var position = 'absolute';
//构造函数Food
function Food(options) {
options = options || {};
this.color = options.color || 'green';
this.width = options.width || 20;
this.height = options.height || 20;
//食物的位置
this.x = options.x || 0;
this.y = options.y || 0;
}
//把食物渲染到map上
// prototype,每个函数都具有一个子对象prototype，prototype表示了该函数的原型
// prototype表示一个类属性的集合。通过new来生成一个类的对象时，prototype对象的属性就会变成实例化对象的属性
Food.prototype.render = function (map) {
//删除之前创建的食物
remove();
//动态创建div，显示页面上的食物
var div = document.createElement('div');
map.appendChild(div);
elements.push(div);
//随机生成食物
this.x = Tool.getRandom(0,map.offsetWidth/this.width - 1)*this.width;
this.y = Tool.getRandom(0,map.offsetHeight/this.height - 1)*this.height;
//设置div样式
div.style.position = position; //脱离文档流
div.style.background = this.color;
div.style.width = this.width + 'px';
div.style.height = this.height + 'px';
div.style.left = this.x + 'px';
div.style.top = this.y + 'px';
};
function remove() {
for (var i = elements.length-1;i >= 0;i-- ){
//删除div
elements[i].parentNode.removeChild(elements[i]);
//删除数组元素
elements.splice(i,1); //第一个参数，从哪个元素开始 第二个参数，删除几个元素
}
}
//把Food构造函数 让外部可以访问
window.Food = Food;
})()
//测试
// var map = document.getElementById('map');
// var food = new Food(); //这里的Food就是window.Food
// food.render(map);
snake.js代码如下
(function () {
var position = 'absolute';
//记录之前创建的蛇
var elements = [];
function Snake(options) {
options = options || {};
//蛇节的大小
this.width = options.width || 20;
this.height = options.height || 20;
//蛇移动的方向
this.direction = options.direction || 'right';
//蛇身体（蛇节） 第一个元素是蛇头
this.body = [
{x: 5, y: 2, color: 'red'},
{x: 4, y: 2, color: 'blue'},
{x: 3, y: 2, color: 'blue'},
{x: 2, y: 2, color: 'blue'},
{x: 1, y: 2, color: 'blue'}
];
}
Snake.prototype.render = function (map) {
//删除之前创建的蛇
remove();
//把每一蛇节渲染到地图上
for (var i = 0,len = this.body.length; i<len; i++){
//蛇节
var object = this.body[i];
var div = document.createElement('div');
map.appendChild(div);
//记录当前蛇
elements.push(div);
//设置样式
div.style.position = position;
div.style.width = this.width + 'px';
div.style.height = this.height + 'px';
div.style.left = object.x * this.width + 'px';
div.style.top = object.y * this.height + 'px';
div.style.backgroundColor = object.color;
}
}
//控制蛇移动的方法
Snake.prototype.move = function (food,map) {
//控制蛇的身体移动 (当前蛇节 到 上一蛇节的位置)
for (var i = this.body.length - 1;i > 0;i--){
this.body[i].x = this.body[i - 1].x;
this.body[i].y = this.body[i - 1].y;
}
//控制蛇头的移动
//判断蛇移动的方向
var head = this.body[0];
switch (this.direction){
case 'right':
head.x += 1;
break;
case 'left':
head.x -=1;
break;
case 'top':
head.y -=1;
break;
case 'bottom':
head.y +=1;
}
//2.4判断蛇头是否和食物重合
var headX = head.x * this.width;
var headY = head.y * this.height;
if (headX === food.x && headY === food.y){
//让蛇增加一节
//获取蛇的最后一节
var last = this.body[this.body.length - 1];
this.body.push({
x:last.x,
y:last.y,
color:last.color
})
//随机在地图上重新生成食物
food.render(map);
}
}
function remove() {
for (var i = elements.length -1;i>= 0;i--){
//删除div
elements[i].parentNode.removeChild(elements[i]);
//删除数组中的元素
elements.splice(i,1);
}
}
//暴露构造函数给外部
window.Snake = Snake;
})()
//测试
// var map =document.getElementById('map');
// var sanke = new Snake();
// sanke.render(map);
game.js代码如下
//使用自调函数，创建一个新的局部作用域，防止命名冲突
(function () {
function Game(map) {
this.food = new Food();
this.snake = new Snake();
this.map = map;
that=this;
}
Game.prototype.start = function () {
//1.把蛇和食物对象渲染到地图上
this.food.render(this.map);
this.snake.render(this.map);
//2.开始游戏逻辑
//2.1 让蛇移动起来
//2.2当蛇遇到边界游戏结束
runSnake();
//2.3通过键盘控制蛇移动的方向
bindKey();
//2.4当蛇遇到食物 做相应的处理
}
function bindKey() {
document.onkeydown = function (e) {
switch (e.keyCode){
case 37:
if (that.snake.direction === 'right') return;
that.snake.direction = 'left';
break;
case 38:
if (that.snake.direction === 'bottom') return;
that.snake.direction = 'top';
break;
case 39:
if (that.snake.direction === 'left') return;
that.snake.direction = 'right';
break;
case 40:
if (that.snake.direction === 'top') return;
that.snake.direction = 'bottom';
break;
}
}
}
//
function runSnake() {
var timerId = setInterval(function () {
//让蛇走一格
//在定时器中的function中this是指向window对象的
that.snake.move(that.food,that.map);
that.snake.render(that.map);
//2.2当蛇遇到边界游戏结束
var maxX = that.map.offsetWidth / that.snake.width;
var maxY = that.map.offsetHeight / that.snake.height;
//获取蛇头的坐标
var headX = that.snake.body[0].x;
var headY = that.snake.body[0].y;
if (headX <0 || headX>=maxX){
alert('Game Over');
clearInterval(timerId);
}
if (headY <0 || headY >= maxY){
alert('Game Over');
clearInterval(timerId);
}
for (var i = that.snake.body.length - 1;i > 0;i--){
if (headX == that.snake.body[i].x && headY == that.snake.body[i].y){
alert('Game Over');
clearInterval(timerId);
break;
}
}
},300)
}
//暴露构造函数给外部
window.Game = Game;
})()
// //测试
// var map =document.getElementById('map');
// var game = new Game(map);
// game.start();
main.js代码如下
(function () {
var map =document.getElementById('map');
var game = new Game(map);
game.start();
})()
Tool.js代码如下
// 工具对象
(function () {
var Tool = {
getRandom: function (min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min + 1)) + min;
}
}
window.Tool = Tool;
})()
