Inseguimento del Mouse 2
Di Trantor
<![CDATA[
<HTML>
<HEAD>
<TITLE>Inseguimento del Mouse 2</TITLE>
<link rel="stylesheet" href="../stili.css" type="text/css">
<style type="text/css"><!--
#dot0 {position:absolute}
#dot1 {position:absolute}
#dot2 {position:absolute}
#dot3 {position:absolute}
#dot4 {position:absolute}
#dot5 {position:absolute}
#dot6 {position:absolute}
#dot7 {position:absolute}
#dot8 {position:absolute}
// -->
</style>
<script type="text/javascript"><!--
var nDots = 9;
var Xpos = 0;
var Ypos = 0;
var DELTAT = .02;
var SEGLEN = 10;
var SPRINGK = 10;
var MASS = 1;
var GRAVITY = 10;
var RESISTANCE = 10;
var STOPVEL = 0.5;
var STOPACC = 0.5;
var DOTSIZE = 11;
var BOUNCE = 0.75;
var isNetscape = navigator.appName=="Netscape";
var followmouse = true;
var dots = new Array();
function init() {
for (var i = 0; i < nDots; i++) {dots[i] = new dot(i)}
for (i = 0; i < nDots; i++) {
dots[i].obj.left = dots[i].X;
dots[i].obj.top = dots[i].Y;
}
if (isNetscape) {
startanimate();
} else {
setTimeout("startanimate()", 100);
}
}
function dot(i) {
this.X = Xpos;
this.Y = Ypos;
this.dx = 0;
this.dy = 0;
if (isNetscape) {
this.obj = eval("document.dot" + i);
} else {
this.obj = eval("dot" + i + ".style");
}
}
function startanimate() {setInterval("animate()", 20)}
function MoveHandler(e) {
Xpos = e.pageX;
Ypos = e.pageY;
return true;
}
function MoveHandlerIE() {
Xpos = window.event.x + document.body.scrollLeft;
Ypos = window.event.y + document.body.scrollTop;
}
function vec(X, Y) {
this.X = X;
this.Y = Y;
}
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() {
var start = 0;
if (followmouse) {
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)}
var resist = new vec(-dots[i].dx * RESISTANCE,-dots[i].dy * RESISTANCE)
var accel = new vec((spring.X + resist.X)/ MASS,(spring.Y + resist.Y)/ MASS + GRAVITY)
dots[i].dx += (DELTAT * accel.X);
dots[i].dy += (DELTAT * accel.Y);
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;
}
dots[i].X += dots[i].dx;
dots[i].Y += dots[i].dy;
var height, width;
if (isNetscape) {
height = window.innerHeight + document.scrollTop;
width = window.innerWidth + document.scrollLeft;
} else {
height = document.body.clientHeight + document.body.scrollTop-5;
width = document.body.clientWidth + document.body.scrollLeft-5;
}
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;
}
dots[i].obj.left = dots[i].X;
dots[i].obj.top = dots[i].Y;
}
}
if (isNetscape) {
document.captureEvents(Event.MOUSEMOVE);
document.onMouseMove = MoveHandler;
} else {
document.onmousemove = MoveHandlerIE;
}
// -->
</script>
</head>
<BODY>
<div id="titolo">Inseguimento del Mouse 2</div>
<DIV id=dot0></DIV>
<DIV id=dot1><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot2><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot3><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot4><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot5><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot6><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot7><IMG src="sfera.gif" width="20" height="20"></DIV>
<DIV id=dot8><IMG src="sfera.gif" width="20" height="20"></DIV>
<script type="text/javascript">init()</SCRIPT>
<hr>
</BODY>
</HTML>
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