js Clip奇思妙想之多彩渐变字效果

function colorful(obj,font,r,g,b,type){
var boxObj;
if(typeof(obj)=="string"||typeof(obj)=="number"){
boxObj = document.getElementById(obj);
}else{
boxObj = obj;
}
boxObj.innerHTML="<a href='#'>"+font+"</a>";
var num = boxObj.getElementsByTagName("a")[0].scrollWidth;
boxObj.innerHTML="";
for(var i=0;i<=num;i++){
var j=i+1;
var c=Math.round(255/num*i);
switch(Number(type)){
case 0:r=c;g=c;b=c;break;
case 1:r=c;break;
case 2:g=c;break;
case 3:b=c;break;
}
var iObj = document.createElement("A");
iObj.innerHTML=font;
iObj.style.clip="rect(auto "+j+"px auto "+i+"px)";
iObj.style.color="rgb("+r+","+g+","+b+")";
iObj.href="#";
boxObj.appendChild(iObj);
}
}