//更据当前这个炸弹的生命值,来画出不同的炸弹图片
if(bomb.blood>6){ //显示最大炸弹图
var img1=new Image();
img1.src="picture/bomb_1.gif";
var x=bomb.x;
var y=bomb.y;
img1.onload=function(){
cxt.drawImage(img1,x,y,30,30);
}
}else if(bomb.blood>3){
var img2=new Image();
img2.src="picture/bomb_2.gif";
var x=bomb.x;
var y=bomb.y;
img2.onload=function(){
cxt.drawImage(img2,x,y,30,30);
}
}else {
var img3=new Image();
img3.src="picture/bomb_3.gif";
var x=bomb.x;
var y=bomb.y;
img3.onload=function(){
cxt.drawImage(img3,x,y,30,30);
}
}