Arrays en JavaScript

[Adler]

Hola

Nada, no te molestes zerokilled. Me pareció algo prefabricado y buscando un poco encontré esto que soluciona el problema

Código javascript:

<script LANGUAGE="JavaScript">
<!--
// image src
var trailsrc = "bullet.gif";
 
var nDots = 7;
var Xbpos = 0;
var Ybpos = 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 = 0;
// BOUNCE is percent of velocity retained when
// bouncing off a wall
var BOUNCE = 0.75;
 
var ff=(document.getElementById&&!document.all);
var ns=(document.layers);
var ie=(document.all);
 
// always on for now, could be played with to
// let dots fall to botton, get thrown, etc.
var followmouse = true;
var dots = new Array();
 
function init()
{
var i = 0;
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;
}
 
setTimeout("startanimate()", 10);
}
 
function dot(i)
{
this.X = Xbpos;
this.Y = Ybpos;
this.dx = 0;
this.dy = 0;
 
if (ns){
document.write("<layer id=\"mtrail"+ i +"\" ><img src='"+trailsrc+"' border=\"0\"><\/layer>");
} else if (ie||ff) {
if (i == 0) {
document.write("<div id=\"mtrail"+ i +"\" style=\"POSITION: absolute; VISIBILITY: hidden;\"><img src='"+trailsrc+"' border=\"0\"><\/div>");
} else {
document.write("<div id=\"mtrail"+ i +"\" style=\"POSITION: absolute; \"><img src='"+trailsrc+"' border=\"0\"><\/div>");
}
}
 
if (ie)
{
this.obj = eval("mtrail" + i + ".style");
} else if (ff)
{
this.obj = document.getElementById("mtrail" + i).style;
}
else
{
this.obj = eval("document.mtrail" + i);
}
}
 
function startanimate() {
setInterval("animate()", 20);
}
 
// just save mouse position for animate() to use
function MoveHandler(e)
{
if (ie) {
Xbpos = window.event.x + document.body.scrollLeft;
Ybpos = window.event.y + document.body.scrollTop;
}
else {
Xbpos = e.pageX;
Ybpos = e.pageY;
}
}
 
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;
if (followmouse) {
dots[0].X = Xbpos;
dots[0].Y = Ybpos;
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 (!ie) {
height = window.innerHeight + window.pageYOffset;
width = window.innerWidth + window.pageXOffset;
} else {
height = document.body.clientHeight + document.body.scrollTop;
width = document.body.clientWidth + document.body.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;
}
}
 
init();
if(ns)window.captureEvents(Event.MOUSEMOVE);
document.onmousemove = MoveHandler;
-->
</script>
 

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