var babyObj = function()
{
 this.x;
 this.y;
 this.angle;
 
 this.babyTailTimer=0;
 this.babyTailCount=0;
 
 this.babyEyeTimer=0;
 this.babyEyeCount=0;
 this.babyEyeInterval=1000;
 
 this.babyBodyTimer=0;
 this.babyBodyCount=0;
}
babyObj.prototype.init = function()
{
 this.x=canWidth *0.5 - 50;
 this.y=canHeight * 0.5+ 50;
 this.angle=0;
}
babyObj.prototype.draw = function()
{
 //lerp x,y
  this.x = lerpDistance(mom.x, this.x, 0.98);
  this.y = lerpDistance(mom.y, this.y, 0.99);
 
  //lerp angle
  var deltaY = mom.y - this.y;
  var deltaX = mom.x - this.x;
  var beta = Math.atan2(deltaY,deltaX);
 
  //lerp angle
  this.angle = lerpAngle(beta, this.angle, 0.6);
 
  //baby tail count
  this.babyTailTimer +=deltaTime;
  if(this.babyTailTimer >50)
  {
   this.babyTailCount =(this.babyTailCount +1) %8;
   this.babyTailTimer %=50;
  }
 
  //baby eye
  this.babyEyeTimer += deltaTime;
  if(this.babyEyeTimer > this.babyEyeInterval)
  {
   this.babyEyeCount=(this.babyEyeCount + 1) %2;
      this.babyEyeTimer %=this.babyEyeInterval;
  
   if(this.babyEyeCount ==0)
   {
    this.babyEyeInterval =Math.random()*1500+2000;
   }else
   {
    this.babyEyeInterval =200;
   }
  }
 
  //baby body
  this.babyBodyTimer += deltaTime;
  if(this.babyBodyTimer > 300)
  {
   this.babyBodyCount=this.babyBodyCount+1;
   this.babyBodyCount %=300;
   if(this.babyBodyCount>19)
   {
    this.babyBodyCount=19;
       //game over
   }
  }
 
 //ctx1
 ctx1.save();
 //translate
 ctx1.translate(this.x,this.y);
 ctx1.rotate(this.angle);
 
 var babyTailCount =this.babyTailCount;
 ctx1.drawImage(babyTail[babyTailCount],-babyTail[babyTailCount].width*0.5+23,-babyTail[babyTailCount].height*0.5);
 var babyBodyCount =this.babyBodyCount;
 ctx1.drawImage(babyBody[babyBodyCount],-babyBody[babyBodyCount].width*0.5,-babyBody[babyBodyCount].height*0.5);
 var babyEyeCount=this.babyEyeCount;
 ctx1.drawImage(babyEye[babyEyeCount],-babyEye[babyEyeCount].width*0.5,-babyEye[babyEyeCount].height*0.5);
 
 ctx1.restore();
 
}

var can1,can2,ctx1,ctx2;
var lastTime;
var deltaTime;
var bgPic = new Image();
var canWidth,canHeight;
var ane;
var fruit;
var mom;
var baby;
var mx;
var my;
var babyTail=[];
var babyEye=[];
var babyBody=[];
document.body.onload = game;
function game(){
init();
lastTime=Date.now();
deltaTime = 0;
gameloop();
}

function init(){
//获取canvas context 
    can1=document.getElementById("canvas1");//fishes,dust,ui  circle
    ctx1=can1.getContext('2d');  
    can2=document.getElementById("canvas2");  //background,ane,fruits
    ctx2=can2.getContext('2d');

    can1.addEventListener('mousemove',onMouseMove,false);

bgPic.src = "./src/background.jpg";

canWidth = can1.width;
canHeight = can1.height;

ane = new aneObj();
ane.init();

fruit = new fruitObj();
fruit.init();

mom = new momObj();
mom.init();

baby = new babyObj();
baby.init();

mx=canWidth *0.5;
my=canHeight *0.5;

for(var i=0;i<8;i++)
{
 babyTail[i]=new Image();
 babyTail[i].src="./src/babyTail" + i + ".png";
}

for(var i=0;i<2;i++)
{
 babyEye[i]=new Image();
 babyEye[i].src="./src/babyEye" + i + ".png";
}

for(var i=0;i<20;i++)
{
 babyBody[i]=new Image();
 babyBody[i].src="./src/babyBody" + i + ".png";
}

}

function gameloop(){
window.requestAnimFrame(gameloop);
var now = Date.now();
deltaTime = now - lastTime;
lastTime = now;
if(deltaTime >40) deltaTime =40;
ctx2.drawImage(bgPic,0,0);

drawBackground();
ane.draw();
fruitMonitor();
fruit.draw();

ctx1.clearRect(0,0,canWidth,canHeight);
mom.draw();
momFruitsCollision();
baby.draw();
}
function onMouseMove(e)
{
 if(e.offSetX || e.layerX)
 {
  mx = e.offSetX == undefined ? e.layerX : e.offSetX;
  my = e.offSetY == undefined ? e.layerY : e.offSetY;
 }
}