[script] 마우스 따라다니는 거품

<script type="text/javascript">
// <![CDATA[
var colours=new Array("#a6f", "#60f", "#60f", "#a6f", "#ccc"); // colours for top, right, bottom and left borders and background of bubbles
var bubbles=66; // maximum number of bubbles on screen
var over_or_under="over"; // set to "over" for bubbles to always be on top, or "under" to allow them to float behind other objects
 
/****************************
* JavaScript Bubble Cursor  *
*(c)2010-13 mf2fm web-design*
*  http://www.mf2fm.com/rv  *
* DON'T EDIT BELOW THIS BOX *
****************************/
var x=ox=400;
var y=oy=300;
var swide=800;
var shigh=600;
var sleft=sdown=0;
var bubb=new Array();
var bubbx=new Array();
var bubby=new Array();
var bubbs=new Array();
var sploosh=false;
 
function addLoadEvent(funky) {
  var oldonload=window.onload;
  if (typeof(oldonload)!='function') window.onload=funky;
  else window.onload=function() {
    if (oldonload) oldonload();
    funky();
  }
}
 
addLoadEvent(buble);
 
function buble() { if (document.getElementById) {
  var i, rats, div;
  for (i=0; i<bubbles; i++) {
    rats=createDiv("3px", "3px");
    rats.style.visibility="hidden";
    rats.style.zIndex=(over_or_under=="over")?"1001":"0";
 
    div=createDiv("auto", "auto");
    rats.appendChild(div);
    div=div.style;
    div.top="1px";
    div.left="0px";
    div.bottom="1px";
    div.right="0px";
    div.borderLeft="1px solid "+colours[3];
    div.borderRight="1px solid "+colours[1];
 
    div=createDiv("auto", "auto");
    rats.appendChild(div);
    div=div.style;
    div.top="0px";
    div.left="1px";
    div.right="1px";
    div.bottom="0px"
    div.borderTop="1px solid "+colours[0];
    div.borderBottom="1px solid "+colours[2];
 
    div=createDiv("auto", "auto");
    rats.appendChild(div);
    div=div.style;
    div.left="1px";
    div.right="1px";
    div.bottom="1px";
    div.top="1px";
    div.backgroundColor=colours[4];
    if (navigator.appName=="Microsoft Internet Explorer") div.filter="alpha(opacity=50)";
    else div.opacity=0.5;
    document.body.appendChild(rats);
    bubb[i]=rats.style;
  }
  set_scroll();
  set_width();
  bubble();
}}
 
function bubble() {
  var c;
  if (Math.abs(x-ox)>1 || Math.abs(y-oy)>1) {
    ox=x;
    oy=y;
    for (c=0; c<bubbles; c++) if (!bubby[c]) {
      bubb[c].left=(bubbx[c]=x)+"px";
      bubb[c].top=(bubby[c]=y-3)+"px";
      bubb[c].width="3px";
      bubb[c].height="3px"
      bubb[c].visibility="visible";
      bubbs[c]=3;
      break;
    }
  }
  for (c=0; c<bubbles; c++) if (bubby[c]) update_bubb(c);
  setTimeout("bubble()", 40);
}
 
document.onmousedown=splash;
document.onmouseup=function(){clearTimeout(sploosh);};
 
function splash() {
  ox=-1;
  oy=-1;
  sploosh=setTimeout('splash()', 100);
}
 
function update_bubb(i) {
  if (bubby[i]) {
    bubby[i]-=bubbs[i]/2+i%2;
    bubbx[i]+=(i%5-2)/5;
    if (bubby[i]>sdown && bubbx[i]>sleft && bubbx[i]<sleft+swide+bubbs[i]) {
      if (Math.random()<bubbs[i]/shigh*2 && bubbs[i]++<8) {
        bubb[i].width=bubbs[i]+"px";
        bubb[i].height=bubbs[i]+"px";
      }
      bubb[i].top=bubby[i]+"px";
      bubb[i].left=bubbx[i]+"px";
    }
    else {
      bubb[i].visibility="hidden";
      bubby[i]=0;
      return;
    }
  }
}
 
document.onmousemove=mouse;
function mouse(e) {
  if (e) {
    y=e.pageY;
    x=e.pageX;
  }
  else {
    set_scroll();
    y=event.y+sdown;
    x=event.x+sleft;
  }
}
 
window.onresize=set_width;
function set_width() {
  var sw_min=999999;
  var sh_min=999999;
  if (document.documentElement && document.documentElement.clientWidth) {
    if (document.documentElement.clientWidth>0) sw_min=document.documentElement.clientWidth;
    if (document.documentElement.clientHeight>0) sh_min=document.documentElement.clientHeight;
  }
  if (typeof(self.innerWidth)=='number' && self.innerWidth) {
    if (self.innerWidth>0 && self.innerWidth<sw_min) sw_min=self.innerWidth;
    if (self.innerHeight>0 && self.innerHeight<sh_min) sh_min=self.innerHeight;
  }
  if (document.body.clientWidth) {
    if (document.body.clientWidth>0 && document.body.clientWidth<sw_min) sw_min=document.body.clientWidth;
    if (document.body.clientHeight>0 && document.body.clientHeight<sh_min) sh_min=document.body.clientHeight;
  }
  if (sw_min==999999 || sh_min==999999) {
    sw_min=800;
    sh_min=600;
  }
  swide=sw_min;
  shigh=sh_min;
}
 
window.onscroll=set_scroll;
function set_scroll() {
  if (typeof(self.pageYOffset)=='number') {
    sdown=self.pageYOffset;
    sleft=self.pageXOffset;
  }
  else if (document.body && (document.body.scrollTop || document.body.scrollLeft)) {
    sdown=document.body.scrollTop;
    sleft=document.body.scrollLeft;
  }
  else if (document.documentElement && (document.documentElement.scrollTop || document.documentElement.scrollLeft)) {
    sleft=document.documentElement.scrollLeft;
    sdown=document.documentElement.scrollTop;
  }
  else {
    sdown=0;
    sleft=0;
  }
}
 
function createDiv(height, width) {
  var div=document.createElement("div");
  div.style.position="absolute";
  div.style.height=height;
  div.style.width=width;
  div.style.overflow="hidden";
  div.style.backgroundColor="transparent";
  return (div);
}
// ]]>
</script>

출처 : https://www.sitepoint.com/community/t/cursor-trails-scripts/241010

데모 : https://jsfiddle.net/xbmfy85f/