/*******************************************************************

*

* File    : JSFX_Halloween.js © JavaScript-FX.com

*

* Created : 2001/10/16

*

* Author  : Roy Whittle www.Roy.Whittle.com

*           

* Purpose : To create animated Ghosts on the page using any user 

*		supplied image.

*

* History

* Date         Version        Description

*

* 2001-10-16	1.0		Created for javascript-fx

***********************************************************************/

/*** START OF CODE FROM JSFX_Layer.js ***/

if(!window.JSFX)

	JSFX=new Object();

JSFX.layerNo=0; 

/**********************************************************************************/

JSFX.createElem = function(htmlStr)

{

	var elem = null;



 	if(document.layers) 

	{

		elem=new Layer(2000); 

		elem.document.open(); 

		elem.document.write(htmlStr); 

		elem.document.close(); 

		elem.innerHTML = htmlStr;

	}

	else 

	if(document.all) 

	{

		var xName = "xLayer" + JSFX.layerNo++; 

		var txt = "<DIV ID='" + xName 

			+ "' STYLE=\"position:absolute;" 

			+ "visibility:hidden\">" 

			+ htmlStr 

			+ "</DIV>"; 



			document.body.insertAdjacentHTML("BeforeEnd",txt); 



		elem = document.all[xName]; 

	} 

	else 

	if (document.getElementById)

	{

		var xName="xLayer" + JSFX.layerNo++;

		var txt = ""

			+ "position:absolute;"

			+ "visibility:hidden";



		var newRange = document.createRange();



		elem = document.createElement("DIV");

		elem.setAttribute("style",txt);

		elem.setAttribute("id", xName);



		document.body.appendChild(elem);



		newRange.setStartBefore(elem);

		strFrag = newRange.createContextualFragment(htmlStr);	

		elem.appendChild(strFrag);

	}



	return elem;

}

/**********************************************************************************/

JSFX.Layer = function(newLayer) 

{

	if(!newLayer)

		return;



	if(typeof newLayer == "string")

		this.elem = JSFX.createElem(newLayer);

	else

		this.elem=newLayer;



	if(document.layers)

	{

		this.images=this.elem.document.images; 

		this.style = this.elem;

 	} 

	else 

	{

		this.images  = document.images; 

		this.style   = this.elem.style; 

	} 

} 

/**********************************************************************************/

var ns4 = (navigator.appName.indexOf("Netscape") != -1 && !document.getElementById);



/**********************************************************************************/

/*** moveTo (x,y) ***/

JSFX.Layer.prototype.moveTo = function(x,y)

{

	this.style.left = x+"px";

	this.style.top = y+"px";

}

if(ns4)

	JSFX.Layer.prototype.moveTo = function(x,y) { this.elem.moveTo(x,y); }

/**********************************************************************************/

/*** show()/hide() Visibility ***/

JSFX.Layer.prototype.show		= function() 	{ this.style.visibility = "visible"; } 

JSFX.Layer.prototype.hide		= function() 	{ this.style.visibility = "hidden"; } 

if(ns4)

{

	JSFX.Layer.prototype.show		= function() 	{ this.style.visibility = "show"; }

	JSFX.Layer.prototype.hide 		= function() 	{ this.style.visibility = "hide"; }

}

/**********************************************************************************/

/*** Opacity ***/

if(document.all)

{

	JSFX.Layer.prototype.setOpacity = function(pc)

	{

		if(this.style.filter=="")

			this.style.filter="alpha(opacity=100);";

		this.elem.filters.alpha.opacity=pc;

	}

}

else

	JSFX.Layer.prototype.setOpacity = function(pc) {return 0;}

/******* END OF CODE FROM JSFX.Layer.js ***/

/*** START OF CODE FROM JSFX.Browser.js ***/

JSFX.Browser = new Object();



if(navigator.appName.indexOf("Netscape") != -1)

{

	JSFX.Browser.getCanvasWidth	= function() {return innerWidth;}

	JSFX.Browser.getCanvasHeight	= function() {return innerHeight;}

	JSFX.Browser.getMinX		= function() {return(pageXOffset);}

	JSFX.Browser.getMinY		= function() {return(pageYOffset);}

	JSFX.Browser.getMaxX		= function() {return(pageXOffset+innerWidth);}

	JSFX.Browser.getMaxY		= function() {return(pageYOffset+innerHeight);}

}

else 	if(document.all)

{

	JSFX.Browser.getCanvasWidth	= function() {return document.body.clientWidth;}

	JSFX.Browser.getCanvasHeight	= function() {return document.body.clientHeight;}

	JSFX.Browser.getMinX		= function() {return(document.body.scrollLeft);}

	JSFX.Browser.getMinY		= function() {return(document.body.scrollTop);}

	JSFX.Browser.getMaxX		= function() {

		return(document.body.scrollLeft

			+document.body.clientWidth);

	}

	JSFX.Browser.getMaxY		= function() {

			return(document.body.scrollTop

				+document.body.clientHeight);

	}

} 

/*** END OF CODE FROM JSFX.Browser.js ***/

/*** START OF CODE FROM JSFX.Ghosts.js ***/



JSFX.Halloween = new Object();

JSFX.Halloween.Ghosts = new Array();

JSFX.Halloween.start = function()

{

	if(JSFX.Halloween.theTimer == null)

	{

		JSFX.Halloween.theTimer = setTimeout("JSFX.Halloween.animateAll()", 40);

	}

}

JSFX.Halloween.animateAll = function()

{

	JSFX.Halloween.theTimer = setTimeout("JSFX.Halloween.animateAll()", 40);

	var sp = JSFX.Halloween.Ghosts;

	var i;

	for(i=0 ; i<sp.length ; i++)

	{

		sp[i].animate();

	}



}

JSFX.AddGhost = function(img)

{

	var myGhost = null;

	var htmlStr = "<IMG SRC='"+img+"'>";



	myGhost = new JSFX.Layer(htmlStr);

	myGhost.op = 0;

	myGhost.x = Math.random()*JSFX.Browser.getMaxX();

	myGhost.y = Math.random()*JSFX.Browser.getMaxY();

	myGhost.dx = 0;

	myGhost.dy = 0;

	myGhost.w = 30;

	myGhost.h = 30;

	myGhost.targetX = Math.random()*JSFX.Browser.getMaxX();

	myGhost.targetY = Math.random()*JSFX.Browser.getMaxY();

	myGhost.state = "off"

	myGhost.animate = JSFX.animateGhosts;

	myGhost.hide();

	myGhost.setOpacity(this.op);

	myGhost.moveTo(myGhost.x,myGhost.y);

	JSFX.Halloween.Ghosts[JSFX.Halloween.Ghosts.length] = myGhost;

	JSFX.Halloween.start();

}

JSFX.animateGhosts = function()

{

	if(this.state == "off")

	{

		if(Math.random() > .99)

		{

			this.state="up";

			this.show();

		}

	}

	else if(this.state == "on")

	{

		if(Math.random() > .98)

			this.state="down";

	}

	else if(this.state == "up")

	{

		this.op += 2;

		this.setOpacity(this.op);

		if(this.op==100)

			this.state = "on";

	}

	else if(this.state == "down")

	{

		this.op -= 2;

		if(this.op==0)

		{

			this.hide();

			this.state = "off";

		}

		else

			this.setOpacity(this.op);

	}



	m = this;

	var X = (this.targetX - m.x);

	var Y = (this.targetY - m.y);

	var len = Math.sqrt(X*X+Y*Y);

	if(len < 1) len = 1;

	var dx = 20 * (X/len);

	var dy = 20 * (Y/len);

	var ddx = (dx - this.dx)/10;

	var ddy = (dy - this.dy)/10;

	this.dx += ddx;

	this.dy += ddy;

	m.x += this.dx;

	m.y += this.dy;

	m.moveTo(m.x, m.y);

	if(Math.random() >.95 )

	{

		this.targetX = Math.random()*(JSFX.Browser.getCanvasWidth()-150);

		this.targetY = Math.random()*(JSFX.Browser.getCanvasHeight()+JSFX.Browser.getMinY()-150);

	}

}