仿微信打飞机游戏的javascript代码

内容摘要
今天闲来无事,于是就打算教一个初学javascript的女童鞋写点东西,因此为了兼顾趣味性与简易程度,果断想到了微信的打飞机小游戏
文章正文

今天闲来无事,于是就打算教一个初学javascript的女童鞋写点东西,因此为了兼顾趣味性与简易程度,果断想到了微信的打飞机小游戏。。

本来想用html5做的,但是毕竟人家才初学,连jquery都还不会,所以最终还是决定用原生的javascript。虽说相对于园内的高手们而言代码算不上优雅,效率算不上高,不过对于初学者来练手还是足以。

三个文件,main.js(主函数),entity.js(实体类与工厂类),util.js(工具类),基本原理就是把位置信息保存在对象里面,然后在setInterval里面统一对所有对象进行更新显示。程序所用到的飞机与子弹图片都是从微信上截屏得来的。

再上代码:

index.html:

<!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>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>打飞机</title>
<script type="text/javascript" src="js/util.js"></script>
<script type="text/javascript" src="js/entity.js"></script>
<script type="text/javascript" src="js/main.js"></script>
<script type="text/javascript">

window.onload=function(){
 Main.init();
 Util.g("startBtn").onclick=function(){
  Main.start();
  this.style.display="none";
 }
}
</script>
</head>
<!--
自己
敌机
子弹
-->
<body>
<div id="parent" style="
        margin: 0 auto;
        width:350px; height:480px;
        background-color:#c3c9c9;
        position: relative;
        overflow:hidden;">
 <div style="
     position:absolute;
        left:5px;
        top:5px;">积分:<span id="score">0</span></div>
    <button
     style="
      position:absolute;
         left:150px;
            top:240px;
            display:block;"
        id="startBtn">
点击开始
</button>

</div>
</body>
</html>
 

main.js:

// JavaScript Document
var Main={
 init:function(){
  Util.init();
 },
 _totalEnemies:8,
 start:function(){
  //初始化敌机
  enemyPlaneFactory.creatEnemyPlane(this._totalEnemies);
  
  //初始化自己
  selfPlane.init();
  
  //初始化子弹
  bulletFactory.creatBullet(100);
  //开始渲染画面
  this._render();
  //开始射击子弹
  this._startShoot();
  
  //初始化键盘事件响应
  this._initEvent();
 },
 
 //渲染定时器
 _render_t:null,
 _render:function(){
  this._render_t=setInterval(function(){
   var enemys=enemyPlaneFactory.enemys;
   for(var i in enemys){
    var enemy=enemys[i];
    enemy.move(0,enemy.speed);
    
    if(enemy.x+enemy.e.width>selfPlane.x+10
     &&enemy.x<selfPlane.x+selfPlane.e.width-10
     &&enemy.y+enemy.e.height>selfPlane.y+selfPlane.e.height/2
     &&enemy.y<selfPlane.y+selfPlane.e.height){
      enemy.isDied=true;
      clearInterval(Main._render_t);
      clearInterval(Main._startShoot_t);
      var b=window.confirm("对不起,您已经挂了,是否重玩?")
      if(b){
       window.location.reload();
      }
    }
    
    if(enemy.y>Util.windowHeight||enemy.isDied){
     enemy.restore();
    }
   }
   
   var bullets=bulletFactory.bullets;
   for(var i in bullets){
    var bullet=bullets[i];
    bullet.move(0,-bullet.speed);
    
    for(var i in enemys){
     var enemy=enemys[i];
     //判断子弹是否击中敌机,如果击中则隐藏子弹,杀死敌机,增加积分..
     if(bullet.y>10
      &&bullet.x>enemy.x
      &&bullet.x<enemy.x+enemy.e.width
      &&bullet.y<enemy.y+enemy.e.height){
       enemy.isDied=true;
       bullet.e.style.top=-bullet.e.height;
       selfPlane.score+=50;
       Util.scoreSpan.innerHTML=selfPlane.score+"";
     }
    }
   }
   
   
  },1000/15);
 },
 //射击定时器
 _startShoot_t:null,
 _startShoot:function(){
  var i=0;
  var bullets=bulletFactory.bullets;
  var bulletsCount=bullets.length;
  this._startShoot_t=setInterval(function(){
   if(i>=bulletsCount){
    i=0;
   }
   var bullet=bullets[i];
   bullet.moveTo(selfPlane.x+selfPlane.e.width/2-bullet.e.width/2,selfPlane.y-bullet.e.height-3);
   i++;
  },300);
 },
 keyMove:10,
 _initEvent:function(){
  window.onkeydown=function(e){
   /*
   37:左
   38:上
   39:右
   40:下
   */
   var keynum;
   var left=37,up=38,right=39,down=40;

   if(window.event){// IE
     keynum = e.keyCode
   }else if(e.which) {// Netscape/Firefox/Opera
     keynum = e.which
   }
   
   switch(keynum){
    case left:
    selfPlane.move(-Main.keyMove,0);
    break;
    case up:
    selfPlane.move(0,-Main.keyMove);
    break;
    case right:
    selfPlane.move(Main.keyMove,0);
    break;
    case down:
    selfPlane.move(0,Main.keyMove);
    break;
    
    default:
    break;
   }
   
   //console.log(keynum);
  }
  
 }
 
 
}
 

entity.js:

//自身的对象
var selfPlane={
 x:0,
 y:0,
 score:0,
 e:null,
 init:function(){
  this.x=(Util.windowWidth-Util.selfPlaneElement.width)/2;//相对于父窗体的x偏移(css:left)
  this.y=Util.windowHeight-Util.selfPlaneElement.height;//相对于父窗体的y偏移(css:top)
  this.e=Util.selfPlaneElement;//对应的dom元素
  Util.selfPlaneElement.style.left=this.x+"px";
  Util.selfPlaneElement.style.top=this.y+"px";
  Util.parentElement.appendChild(this.e);
 },
 move:function(moveX,moveY){
  var x=this.x+moveX;
  var y=this.y+moveY;
  
  if(x<0-this.e.width/2||x>Util.windowWidth-this.e.width/2){
   return ;
  }
  if(y<0-this.e.height/2||y>Util.windowHeight-this.e.height/2){
   return ;
  }
  this.x=x;
  this.y=y;
  
  this.e.style.left=this.x+"px";
  this.e.style.top=this.y+"px";
 },
 moveTo:function(x,y){
  
  if(x<0-this.e.width/2||x>Util.windowWidth-this.e.width/2){
   return ;
  }
  if(y<0-this.e.height/2||y>Util.windowHeight-this.e.height/2){
   return ;
  }
  this.x=x;
  this.y=y;
  
  this.e.style.left=this.x+"px";
  this.e.style.top=this.y+"px";
 }
}


//敌机的类
var enemyPlane=function(x,y,speed){
 this.x=x;
 this.y=y;
 this.e=Util.enemyPlaneElement.cloneNode(true);
 this.e.style.left=x;
 this.e.style.top=y;
 this.e.style.display="none";
 Util.parentElement.appendChild(this.e);
 this.e.style.display="block";
 this.speed=speed;
 this.isDied=false;
}
//prototype:原型
enemyPlane.prototype.move=function(moveX,moveY){
 this.x+=moveX;
 this.y+=moveY;
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
}
//敌人复活
enemyPlane.prototype.restore=function(){
 this.x=Math.random()*(Util.windowWidth-Util.enemyPlaneElement.width);
 this.y=-Math.random()*Util.windowHeight-Util.enemyPlaneElement.height;
 this.speed=2+Math.random()*4;
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
 this.isDied=false;
}
//敌机工厂
var enemyPlaneFactory={
 enemys:[],
 creatEnemyPlane:function(n){
  for(var i=0;i<n;i++){
   //0~1 乘以窗口宽度,得到的就是从0~窗口宽度的一个随机x值
   var x=Math.random()*(Util.windowWidth-Util.enemyPlaneElement.width);
   var y=-Math.random()*Util.windowHeight-Util.enemyPlaneElement.height;
   var speed=2+Math.random()*4;
   var ep=new enemyPlane(x,y,speed);
   this.enemys.push(ep);
  }
 }
}
//子弹
var bullet=function(x,y,speed){
 this.x=x;
 this.y=y;
 this.speed=speed;
 this.e=Util.bulletElement.cloneNode(true);
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
 Util.parentElement.appendChild(this.e);
 this.isUsed=false;
}

bullet.prototype.move=function(moveX,moveY){
 this.x+=moveX;
 this.y+=moveY;
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
}
bullet.prototype.moveTo=function(X,Y){
 this.x=X;
 this.y=Y;
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
}


//子弹恢复
bullet.prototype.restore=function(){
 this.x=Main.self
 this.y=-Math.random()*Util.windowHeight-Util.enemyPlaneElement.height;
 this.speed=2+Math.random()*4;
 this.e.style.left=this.x+"px";
 this.e.style.top=this.y+"px";
}
//子弹工厂
var bulletFactory={
 bullets:[],
 creatBullet:function(n){
  for(var i=0;i<n;i++){
   var b=new bullet(0,-Util.bulletElement.height,20);
   this.bullets.push(b);
  }
 }
}
 

util.js:

// JavaScript Document
var Util={
 windowWidth:350,
 windowHeight:480,
 selfPlaneElement:null,
 enemyPlaneElement:null,
 bulletElement:null,
 parentElement:null,
 scoreSpan:null,
 g:function(id){
  return document.getElementById(id);
 },
 
 init:function(){
  this.parentElement=this.g("parent");
  
  this.selfPlaneElement=this._loadImg("images/self.gif");
  
  this.enemyPlaneElement=this._loadImg("images/boss.gif");
  
  this.bulletElement=this._loadImg("images/bullet.jpg");
  
  this.scoreSpan=this.g("score");
 },
 
 _loadImg:function(src){
  var e=document.createElement("img");
  e.style.position="absolute";
  e.src=src;
  return e;
 }
}

代码注释

作者:喵哥笔记

IDC笔记

学的不仅是技术,更是梦想!