求大神來幫我解釋一下這段代碼！?。?/h1>

var?_al?=?[];
function?waterfall(){
?????//?計(jì)算及定位數(shù)據(jù)塊顯示分散效果
?????var?_pin?=?$("#main").find(".pin");
?????var?_pw?=?_pin.eq(0).outerWidth();
?????var?_wh?=?$(window).height()/2;
?????var?_ww?=?$(window).width();
????????
????var?_co?=?Math.floor(_ww/_pw);
????var?_pi?=?_pin.length;
????//?初始化數(shù)組
????for(var?i?in?_pin){
????????if(i<_co){
????????????_al.push(0);
????????}
????????_pin.eq(i).css({
????????????top:_wh,
????????????left:'50%',
????????????'margin-top':-(_pin.height()/2)+((Math.floor(Math.random()*10)<5?-1:1)*Math.floor(Math.random()*200)),
????????????'margin-left':-(_pin.width()/2)+((Math.floor(Math.random()*10)<5?-1:1)*Math.floor(Math.random()*200))
????????});
????}
????animateWater(_pin,0,_pw);
}
function?animateWater(_pin,_i,_pw){
????????var?_t?=?getMin(_al);
????????_pin.eq(_i).animate({
????????????left:_t*_pw,
????????????'margin':0,
????????????top:_al[_t]
????????},300,function(){
????????????_al[_t]+=_pin.eq(_i).outerHeight();
????????????_i++;
????????????animateWater(_pin,_i,_pw);
????????})
}

function?getMin(_al){
????var?_minT?=?Math.min.apply(null,_al);
????for(var?i?in?_al){
????????if(_al[i]==_minT){
????????????return?i;
????????}
????}
}

1. 'margin-top':-(_pin.height()/2)+((Math.floor(Math.random()*10)<5?-1:1)*Math.floor(Math.random()*200)),
   ?'margin-left':-(_pin.width()/2)+((Math.floor(Math.random()*10)<5?-1:1)*Math.floor(Math.random()*200))

   對(duì)于這兩行十分不解，

2. animateWater()會(huì)不會(huì)無限循環(huán)，為什么？