JavaScript实现躲避粒子小游戏的完整教程

/* 
 1.随机生成小绿球在顶部 位置随机
 3.小绿球自己运动
 4.弹性运动
 2.生成多个

 5.红球拖拽
 6.红球边界判断
 7.红球和绿球碰撞检测

 8.定时器清除
 9.坚持了多久
 （但对象编程）
*/

var game = {
 name:'游戏开始',
 redBall:document.getElementsByClassName('red')[0],
 RunTime:document.getElementsByTagName('span')[0],
 num:0,
 greenArr:[],
 flag:true,
 movePlus:{
 outer:document.getElementsByClassName('outer')[0],
 iWidth:document.getElementsByClassName('outer')[0].offsetWidth,
 iHeight:document.getElementsByClassName('outer')[0].offsetHeight,
 ispeedY:10,//小绿球的速度
 ispeedX:10
 },

 init:function(){
 console.log(this.name);
 // console.log(this.movePlus.iHeight);
 this.createBall(this.movePlus);
 this.dragRedBall(this.movePlus);
 this.runTime();
 },
 runTime:function(){
 var self = this;
 this.Timer = setInterval(function(){
  self.num++;
  self.RunTime.innerHTML = '坚持了' + self.num + '秒';
 },1000);
 },
 createBall:function(obj){
 var self = this;
 var plus = obj;

 function Green(plus){
  this.ball = document.createElement('div');
  this.ball.className = 'green';
  plus.outer.appendChild(this.ball);
  this.subWidth = Math.floor(Math.random()*(plus.iWidth - this.ball.offsetWidth));
  this.ball.style.left = this.subWidth + 'px';
  // this.subHeight = Math.floor(Math.random()*(plus.iHeight - this.ball.offsetHeight));
  // this.ball.style.top = this.subHeight + 'px';
  this.ispeedX = Math.floor(Math.random()*plus.ispeedX) + 1;
  this.ispeedY = Math.floor(Math.random()*plus.ispeedY) + 1;

  // 自定义属性
  this.iWidth = plus.iWidth;
  this.iHeight = plus.iHeight;
 }
 //先生出一个
 var greenBall = new Green(plus);
 this.greenArr.push(greenBall);

  this.creatTimer = setInterval(function(){
  var greenBall = new Green(plus);
  self.greenArr.push(greenBall)
 }, 2000);

 this.moveBall();
 },
 moveBall:function(){
 //创建定时器
 var self = this;
 // 保存window的this
 this.goTimer = setInterval(function(){

  for(var i = 0;i < self.greenArr.length;i ++){
  self.crashCheck(self.greenArr[i]);
  var newLeft = self.greenArr[i].ball.offsetLeft + self.greenArr[i].ispeedX ;
  var newTop = self.greenArr[i].ball.offsetTop + self.greenArr[i].ispeedY ;
  if(newLeft<0){
   self.greenArr[i].ispeedX *= -1;
  }
  else if(newLeft > (self.greenArr[i].iWidth - self.greenArr[i].ball.offsetWidth)){
   self.greenArr[i].ispeedX *= -1;
  }
  else if(newTop<0){
   self.greenArr[i].ispeedY *= -1;
   // self.greenArr[i].ispeedX *= -1;
  }
  else if(newTop > (self.greenArr[i].iHeight - self.greenArr[i].ball.offsetHeight)){
   self.greenArr[i].ispeedY *= -1;
   // self.greenArr[i].ispeedX *= -1;
  }
  // console.log((self.greenArr[i].iWidth - self.greenArr[i].ball.offsetWidth),(greenBall.iHeight - greenBall.ball.offsetHeight),greenBall.ispeedX,greenBall.ispeedY);
  self.greenArr[i].ball.style.left = newLeft + 'px';
  self.greenArr[i].ball.style.top = newTop + 'px';

  }
  
 },50)
 },

 dragRedBall:function(obj){
 var self = this;
 this.redBall.onmousedown = function(e){
  var lastX = e.pageX,
  lastY = e.pageY;
  // self.redBall.style.left = lastX;
  // self.redBall.style.top = lastY;
  document.onmousemove = function(e){
  var newX = e.pageX,
   newY = e.pageY;
  self.redBall.style.left = (newX - lastX) + self.redBall.offsetLeft + 'px';
  self.redBall.style.top = (newY - lastY) + self.redBall.offsetTop + 'px';
  // this.redBall.style.top = newY;
  lastX = newX;
  lastY = newY;

  //判断边界

  if(self.redBall.offsetLeft<0 && self.flag){
   alert("坚持了" + self.num + '秒' + "\n" + "游戏结束");
   self.flag = false;//加锁
   self.clearTimer();
   window.location.reload();
  }else if(self.redBall.offsetLeft>(obj.iWidth-self.redBall.offsetWidth) && self.flag){
   alert("坚持了" + self.num + '秒' + "\n" + "游戏结束");
   self.flag = false;
   self.clearTimer();
   window.location.reload();//刷新页面 游戏重开
  }else if(self.redBall.offsetTop<0 && self.flag){
   alert("坚持了" + self.num + '秒' + "\n" + "游戏结束");
   self.flag = false;
   self.clearTimer();
   window.location.reload();
  }else if(self.redBall.offsetTop>(obj.iHeight-self.redBall.offsetHeight ) && self.flag){
   alert("坚持了" + self.num + '秒' + "\n" + "游戏结束");
   self.flag = false;
   self.clearTimer();
   window.location.reload();
  }
  }

  this.onmouseup = function(){
  document.onmousemove = null;
  }
 }
 },

 crashCheck:function(greenBall){
 // var self = this;
 //效率球的圆心
 var greenX1 = greenBall.ball.offsetLeft + Math.floor(greenBall.ball.offsetWidth / 2),
  greenY1 = greenBall.ball.offsetTop + Math.floor(greenBall.ball.offsetHeight / 2),
 //小红求的圆心
  redX1 = this.redBall.offsetLeft + Math.floor(this.redBall.offsetWidth / 2),
  redY1 = this.redBall.offsetTop + Math.floor(this.redBall.offsetHeight / 2);
 // console.log(greenX1,greenY1,redX1,redY1);
 // debug成功
 //x1 - x2,y1 - y2 的绝对值
 var dx = Math.abs(greenX1 - redX1),
  dy = Math.abs(greenY1 - redY1);
 // console.log(dx,dy);
 var dis = Math.floor(Math.sqrt(Math.pow(dx,2) + Math.pow(dy,2)));
 // console.log(dis);
 var R = greenBall.ball.offsetWidth/2 + this.redBall.offsetWidth/2;

 if(dis < R && this.flag){
  alert("坚持了" + this.num + '秒' + "\n" + "游戏结束");
  this.flag = false;
  this.clearTimer();
  window.location.reload();
 }

 }, 

 clearTimer:function(){
 clearInterval(this.goTimer);
 clearInterval(this.creatTimer);
 clearInterval(this.Timer);
 }
}

game.init();//入口函数