var?can1;
var?cam2;
var?ctx1;
var?ctx2;

var?lastTime;
var?deltaTime;

var?bgPic?=?new?Image();
var?canWidth;
var?canHeight;

var?ane;
var?fruit;

document.body.onload?=?game;

function?game()?{
	//?body...
	init();

	gameloop();
}

function?init(){
	//獲得canvas?context
	can1?=?document.getElementById("canvas1");
	can2?=?document.getElementById("canvas2");
	ctx1?=?can1.getContext('2d');
	ctx2?=?can2.getContext('2d');


	bgPic.src?=?'./src/background.jpg';
	canWidth?=?can1.width;
	canHeight?=?can1.height;

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

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

}

function?gameloop(){
	//requestAnimFrame(gameloop);

	window.requestAnimFrame(gameloop);
	
	var?now?=?Date.now();
	deltaTime?=?now?-?lastTime;
	lastTime?=?now;
	
	ane.draw();
	fruit.draw();
}

var?aneObj?=?function(){
	this.x?=?[];
	this.len?=?[];


}

aneObj.prototype.num?=?50;


aneObj.prototype.init?=?function(){
	for?(var?i?=?0;?i?<=?this.num;?i++)?{
		this.x[i]?=?i?*?16?+?Math.random()?*?20;
		this.len[i]?=?200?+?Math.random()?*?20;
	}
}

aneObj.prototype.draw?=?function(){

	ctx2.save();
	
		ctx2.globalAlpha=0.2;
		ctx2.lineWidth??=?20;
		ctx2.lineCap?=?"round";
		ctx2.strokeStyle?=?"#3b154e";	
	
	for?(var?i?=?0;?i?<?this.num;?i++)?{
		ctx2.beginPath();
		ctx2.moveTo(this.x[i],?canHeight);
		ctx2.lineTo(this.x[i],?canHeight?-?this.len[i]);

		ctx2.stroke();

	}

	ctx2.restore();
}