function?game()?{
	//?body...
	init();
	lasttime?=?Date.now();
	delttime?=?0;
	game_loop();
}
function?init?()?{
	//獲得canvas?contex
	//canvas1?用來處理魚，土壤，UI，圓圈
	can1?=?document.getElementById("canvas1");
	//canvas2?用來處理背景??？?	can2?=?document.getElementById("canvas2");
	ctx1?=?can1.getContext('2d');
	ctx2?=?can2.getContext('2d');
	bgPic.src="../SRC/bg.jpg";//文件路徑
	canWidth?=?can2.width;
	canHight?=?can2.height;
	dram_image();
}
function?game_loop?()?{
	//?body...比如魚的游動
	//該函數要對瀏覽器適配
	requestAnimFrame(game_loop);//比setTimeout?setInterval?科學?這個是根機器性能有關
	//console.log("game");
	var?now?=?Date.now();
	delttime?=?now?-?lasttime;
	lasttime?=?now;
}
/*畫canvas背景*/
function?dram_image?(){
	console.log(canHight,canWidth,bgPic);
	ctx2.drawImage(bgPic,0,0,canWidth,canHight);
}