/*

Example Javascript Animation Techniques by Hesido.com;

2 different reusable examples.

Attribution is not required, but is welcome, you can also take out the comments

updated: 16.05.06

*/

if (document.getElementById && document.getElementsByTagName) {

if (window.addEventListener) window.addEventListener('load', initAnims, false);

else if (window.attachEvent) window.attachEvent('onload', initAnims);

}



function initAnims() {



//Init Background Position Animation

	classChange(document.getElementById('animmenu'),'scriptactive','noscript')

	var animElements = document.getElementById('animmenu').getElementsByTagName('a');

	for(var i=0; i<animElements.length; i++) {

		animElements[i].bgMove= {

		cPos:[-15,50],

		pUnit:['px','%']

		} //set Memory and position value units.

		animElements[i].onmouseover = backPosChange;

		animElements[i].onmouseout = backPosRestore;

		}



	function backPosChange() {

		doBackPosChange(this,this.bgMove,this.bgMove.cPos, [-1,50], 10, 15, 0.3) ;

	}



	function backPosRestore() {

		doBackPosChange(this,this.bgMove,this.bgMove.cPos, [-20,50], 10, 15, 0.3);

	}





}



function doBackPosChange(elem,vrH,startPos,endPos,steps,intervals,powr) {

//Animcode by www.hesido.com

	if (vrH.intID) window.clearInterval(vrH.intID);

	var actStep = 0;

	vrH.intID = window.setInterval(

		function() {

			vrH.cPos = [

				easeInOut(startPos[0],endPos[0],steps,actStep,powr),

				easeInOut(startPos[1],endPos[1],steps,actStep,powr)

				];

			elem.style.backgroundPosition = vrH.cPos[0]+vrH.pUnit[0]+' '+vrH.cPos[1]+vrH.pUnit[1];

			actStep++;

			if (actStep > steps) window.clearInterval(vrH.intID);

		}

		,intervals)

}



function easeInOut(minValue,maxValue,totalSteps,actualStep,powr) {

//Generic Animation Step Value Generator By www.hesido.com

	totalSteps = Math.max(totalSteps,1)

	var delta = maxValue - minValue;

	var stepp = minValue+(Math.pow(((1 / totalSteps)*actualStep),powr)*delta);

	return Math.ceil(stepp)

}



function classChange(elem,addClass,remClass) {

//Add + remove classnames function by www.hesido.com

	if (!elem.className) elem.className = '';

	var clsnm = elem.className;

	if (addClass && !clsnm.match(RegExp("\\b"+addClass+"\\b"))) clsnm = clsnm.replace(/(\S$)/,'$1 ')+addClass;

	if (remClass) clsnm = clsnm.replace(RegExp("(\\s*\\b"+remClass+"\\b(\\s*))*","g"),'$2');

	elem.className=clsnm;

	}



/* debug code  */

function showError(str) {

if (window.opera) opera.postError('|'+str+'|');

else alert('|'+str+'|');

}