/*-------------------------------------------------------------------------------------------
	StringBall ver2.0 for jQuery(gt Ver 1.3.2)
	Developped  by Coichiro Aso
	Copyright Codesign.verse 2009 http://codesign.verse.jp/
	Licensed under the MIT license:http://www.opensource.org/licenses/mit-license.php/
-------------------------------------------------------------------------------------------*/

(function($)
{
	$.fn.stringball = function(options)
	{

		var defaults =
		{
			camd: 1000,
			radi: 250,
			speed: 8
		};

		var options = $.extend(defaults, options);

		var target = $(this);
		var elem = $("li", target);
		var scrz = 500;
		var radi = options.radi;
		var camd = options.camd;
		var speed = options.speed;

		var offset = 0;
		var accx = 0;
		var accy = 0;
		var roteang = 0;
		var axang = 0;
		var ac = 0;
		var as = 0;
		var rotec = 0;
		var rotes = 0;
		var looptimer = 0;
		var itxpos = target.offset().left;
		var itw = target.width();
		var itypos = target.offset().top;
		var ith = target.height();

		function setini()
		{
			for(i = 0; i < elem.length; i++)
			{
				elem[i].anga = Math.PI*2/elem.length*Math.round(Math.random()*elem.length);
				elem[i].angb = Math.PI*2*Math.random();
				elem[i].fw = $(elem[i]).width();
				elem[i].fh = $(elem[i]).height();
				elem[i].xpos = radi*Math.cos(elem[i].angb)*Math.sin(elem[i].anga);
				elem[i].ypos = radi*Math.sin(elem[i].angb);
				elem[i].zpos = radi*Math.cos(elem[i].angb)*Math.cos(elem[i].anga);
			}
		}

		function setpos()
		{
			for(i = 0; i < elem.length; i++)
			{
				ac = Math.cos(axang);
				as = Math.sin(axang);
				rotec = Math.cos(roteang);
				rotes = Math.sin(roteang);
				elem[i].xpos2 = elem[i].xpos*(Math.pow(ac,2)+(1-Math.pow(ac,2))*rotec)+elem[i].ypos*(ac*as*(1-rotec))-elem[i].zpos*(as*rotes);
				elem[i].ypos2 = elem[i].xpos*(ac*as*(1-rotec))+elem[i].ypos*(Math.pow(as,2)+(1-Math.pow(as,2))*rotec)+elem[i].zpos*(ac*rotes);
				elem[i].zpos2 = elem[i].xpos*as*rotes-elem[i].ypos*ac*rotes+elem[i].zpos*rotec;
/*
				elem[i].xpos3 = elem[i].xpos2;
				elem[i].ypos3 = elem[i].ypos2*Math.cos(camh)+elem[i].zpos2*Math.sin(camh);
				elem[i].zpos3 =- elem[i].ypos2*Math.sin(camh)+elem[i].zpos2*Math.cos(camh);
*/
				elem[i].xpos = elem[i].xpos2;
				elem[i].ypos = elem[i].ypos2;
				elem[i].zpos = elem[i].zpos2;

				elem[i].scale = scrz/(camd+elem[i].zpos2);
				elem[i].rxpos = elem[i].xpos2*elem[i].scale+itw/2-elem[i].fw/2;
				elem[i].rypos = elem[i].ypos2*elem[i].scale+ith/2-elem[i].fh/2;
			}
			for(i = 0; i < elem.length; i++)
			{
				elem[i].style.left = elem[i].rxpos+"px";
				elem[i].style.top = elem[i].rypos+"px";
				elem[i].style.fontSize = elem[i].scale*100+"%";
				elem[i].style.opacity = elem[i].scale;
			}
			roteang =- (Math.max(Math.abs(accx),Math.abs(accy)))/100*speed;
			return false;
		}

		setini();
		setpos();

		target.hover(
		function()
		{
			clearInterval(looptimer);
			target.mousemove(function(e)
			{
				accx = (e.clientX-itxpos-itw/2)/itw;
				accy = (e.clientY-itypos-ith/2)/ith;
				axang = Math.PI/2+Math.atan2(accy,accx);
			});
			looptimer = setInterval(setpos,16);
		},
		function()
		{
			clearInterval(looptimer);
		});
	}
})(jQuery);