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vroom
11-16-2005, 05:21 AM
I have a question.. why will the Elastic Trail Script not work in Mozilla Firefox Web Browser? Thx

jscheuer1
11-16-2005, 06:17 AM
Twas writ before that browser was more than a glint in its programmer's eye. Try this version (I've published it before in these forums but just now fixed it up a little more):


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Elastic Trail Script - Updated NS4+ (to NS7.2) IE4+ FF1.0.7 Opera8</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<div id="dot0" style="position: absolute; visibility: hidden; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot1" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot2" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot3" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot4" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot5" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>
<div id="dot6" style="position: absolute; height: 11; width: 11;">
<img src="bullet.gif" height=11 width=11>
</div>

<script type="text/javascript">

/*
Elastic Trail script (By Philip Winston @ pwinston@yahoo.com, URL: http://www.geocities.com/pwinston/)
Script featured on Dynamicdrive.com
For this and 100's more DHTML scripts, visit http://dynamicdrive.com
Updated by jscheuer1 in http://dynamicdrive.com/forums for modern Mozilla and Opera8
Originally and still good in IE4+ early Netscape
*/

var nDots = 7;

var Xpos = 0;
var Ypos = 0;

// fixed time step, no relation to real time
var DELTAT = .01;
// size of one spring in pixels
var SEGLEN = 10;
// spring constant, stiffness of springs
var SPRINGK = 10;
// all the physics is bogus, just picked stuff to
// make it look okay
var MASS = 1;
// Positive XGRAVITY pulls right, negative pulls left
// Positive YGRAVITY pulls down, negative up
var XGRAVITY = 0;
var YGRAVITY = 50;
// RESISTANCE determines a slowing force proportional to velocity
var RESISTANCE = 10;
// stopping criterea to prevent endless jittering
// doesn't work when sitting on bottom since floor
// doesn't push back so acceleration always as big
// as gravity
var STOPVEL = 0.1;
var STOPACC = 0.1;
var DOTSIZE = 11;
// BOUNCE is percent of velocity retained when
// bouncing off a wall
var BOUNCE = 0.75;

/////////////////Stop Editing the Script///////////////

function iecompattest(){
return (document.compatMode && document.compatMode.indexOf("CSS")!=-1)? document.documentElement : document.body
}

var isNetscape = navigator.appName=="Netscape";


var dots = new Array();

for (i = 0; i < nDots; i++)
dots[i] = new dot(i);

// set their positions
for (i = 0; i < nDots; i++) {
dots[i].obj.left = dots[i].X;
dots[i].obj.top = dots[i].Y;
}
setInterval("animate()", 20);



function dot(i)
{
this.X = Xpos;
this.Y = Ypos;
this.dx = 0;
this.dy = 0;
if ((isNetscape)&&(!document.getElementById))
this.obj = eval("document.dot" + i);
else if (document.all)
this.obj = document.all['dot' + i].style;
else if (document.getElementById)
this.obj = document.getElementById('dot' + i).style;
else
return;
}


// just save mouse position for animate() to use
function MoveHandler(e)
{
Xpos = e.pageX;
Ypos = e.pageY;
return true;
}

// just save mouse position for animate() to use
function MoveHandlerIE() {
Xpos = window.event.x + iecompattest().scrollLeft;
Ypos = window.event.y + iecompattest().scrollTop;
}

if (isNetscape) {
document.captureEvents(Event.MOUSEMOVE);
document.onmousemove = MoveHandler;
} else {
document.onmousemove = MoveHandlerIE;
}


function vec(X, Y)
{
this.X = X;
this.Y = Y;
}

// adds force in X and Y to spring for dot[i] on dot[j]
function springForce(i, j, spring)
{
var dx = (dots[i].X - dots[j].X);
var dy = (dots[i].Y - dots[j].Y);
var len = Math.sqrt(dx*dx + dy*dy);
if (len > SEGLEN) {
var springF = SPRINGK * (len - SEGLEN);
spring.X += (dx / len) * springF;
spring.Y += (dy / len) * springF;
}
}


function animate() {
// dots[0] follows the mouse,
// though no dot is drawn there
var start = 0;
dots[0].X = Xpos;
dots[0].Y = Ypos;
start = 1;

for (i = start ; i < nDots; i++ ) {

var spring = new vec(0, 0);
if (i > 0) {
springForce(i-1, i, spring);
}
if (i < (nDots - 1)) {
springForce(i+1, i, spring);
}

// air resisitance/friction
var resist = new vec(-dots[i].dx * RESISTANCE,
-dots[i].dy * RESISTANCE);

// compute new accel, including gravity
var accel = new vec((spring.X + resist.X)/MASS + XGRAVITY,
(spring.Y + resist.Y)/ MASS + YGRAVITY);

// compute new velocity
dots[i].dx += (DELTAT * accel.X);
dots[i].dy += (DELTAT * accel.Y);

// stop dead so it doesn't jitter when nearly still
if (Math.abs(dots[i].dx) < STOPVEL &&
Math.abs(dots[i].dy) < STOPVEL &&
Math.abs(accel.X) < STOPACC &&
Math.abs(accel.Y) < STOPACC) {
dots[i].dx = 0;
dots[i].dy = 0;
}

// move to new position
dots[i].X += dots[i].dx;
dots[i].Y += dots[i].dy;

// get size of window
var height, width;
if (isNetscape) {
height = window.innerHeight + window.pageYOffset;
width = window.innerWidth + window.pageXOffset;
} else {
height = iecompattest().clientHeight + iecompattest().scrollTop-8;
width = iecompattest().clientWidth + iecompattest().scrollLeft;
}

// bounce off 3 walls (leave ceiling open)
if (dots[i].Y >= height - DOTSIZE - 1) {
if (dots[i].dy > 0) {
dots[i].dy = BOUNCE * -dots[i].dy;
}
dots[i].Y = height - DOTSIZE - 1;
}
if (dots[i].X >= width - DOTSIZE) {
if (dots[i].dx > 0) {
dots[i].dx = BOUNCE * -dots[i].dx;
}
dots[i].X = width - DOTSIZE - 1;
}
if (dots[i].X < 0) {
if (dots[i].dx < 0) {
dots[i].dx = BOUNCE * -dots[i].dx;
}
dots[i].X = 0;
}

// move img to new position
dots[i].obj.left = dots[i].X;
dots[i].obj.top = dots[i].Y;
}
}
</script>
</body>
</html>

vroom
11-16-2005, 03:53 PM
Thx for the help