designer's
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function getScale(c, height) {
var t = Math.sqrt(2 * height / c.gravity);
var scale = 4 * height / sqr(t);
return scale;
}
function sqr(x) {
return x * x;
}
function updateBounce(c) {
var bottom = getViewYOffset() + getViewHeight() - c.imageHeight;
for (var i = 0; i < c.imageCount; i++) {
var name = c.prefix + i;
var scale = c.pScale[name];
var x = getLayerX(name) + c.xSpeed[name];
var y = -scale * sqr(c.pIndex[name]) + c.pHeight[name];
if (y > 0)
y = bottom - y;
else
y = bottom;
var bounds = outOfBounds(c, x, y, c.imageWidth, c.imageHeight);
if (bounds & 1) { // left
x = 2 * getViewXOffset() - x;
c.xSpeed[name] = -c.xSpeed[name] * c.elasticity;
}
if (bounds & 2) { // right
x = 2 * (getViewXOffset() + getViewWidth() - c.imageWidth) - x;
c.xSpeed[name] = -c.xSpeed[name] * c.elasticity;
}
moveLayer(name, x, y);
if ((c.pIndex[name] += 0.5) > c.pLimit[name]) {
c.xSpeed[name] *= 1 - c.friction;
c.pIndex[name] -= Math.sqrt(c.pHeight[name] / scale);
c.pHeight[name] = Math.max(0.25, c.pHeight[name] * c.elasticity);
c.pIndex[name] = -(c.pLimit[name] = Math.sqrt(c.pHeight[name] / scale));
if (c.pHeight[name] < c.kickThreshold) {
if (c.kickOpt == 1) { // kick
c.pHeight[name] = 100 + random(getViewHeight());
c.xSpeed[name] = random(41) - 20;
scale = (c.pScale[name] = getScale(c, c.pHeight[name]));
c.pIndex[name] = -(c.pLimit[name] = Math.sqrt(c.pHeight[name] / scale));
}
else if (c.kickOpt == 2) { // drop
c.pHeight[name] = getViewHeight() + c.imageHeight + 100 + random(500);
c.pScale[name] = getScale(c, c.pHeight[name]);
c.xSpeed[name] = random(41) - 20;
c.pIndex[name] = 0;
c.pLimit[name] = Math.sqrt(c.pHeight[name] / scale);
}
}
}
}
setTimeout('updateBounce(c' + c.uid + ')', c.updateInterval);
}
msie = navigator.appVersion.indexOf("MSIE") != -1;
function layerSupport() {
return (document.all || document.layers);
}
layers = new Array();
layerX = new Array();
layerY = new Array();
cursorX = 0;
cursorY = 0;
function getViewWidth() {
if (msie)
return document.body.clientWidth;
else
return window.innerWidth;
}
function getViewHeight() {
if (msie)
return document.body.clientHeight;
else
return window.innerHeight;
}
function getViewXOffset() {
if (msie)
return document.body.scrollLeft;
else
return window.pageXOffset;
}
function getViewYOffset() {
if (msie)
return document.body.scrollTop;
else
return window.pageYOffset;
}
function getLayerX(i) {
return layerX[i];
}
function getLayerY(i) {
return layerY[i];
}
function moveLayer(i, x, y) {
layerX[i] = x;
layerY[i] = y;
if (msie) {
layers[i].style.pixelLeft = x;
layers[i].style.pixelTop = y;
}
else {
layers[i].left = x;
layers[i].top = y;
}
}
function setVisible(i, show) {
if (msie)
layers[i].style.visible = show ? "show" : "hidden";
else
layers[i].visibility = show;
}
function outOfBounds(config, x, y, w, h) {
var result = 0;
// note that fudge factor isn't used for bottom
if (x < getViewXOffset() - config.xFudge)
result |= 1; // Left
else if (x + w >= getViewXOffset() + getViewWidth() + config.xFudge)
result |= 2; // Right
if (y + h >= getViewYOffset() + getViewHeight())
result |= 4; // Bottom
else if (y < getViewYOffset() - config.yFudge)
result |= 8; // Top
return result;
}
function random(bound) {
return Math.floor(Math.random() * bound);
}
function randomX(config) {
return getViewXOffset() + random(getViewWidth() - config.imageWidth);
}
function randomY(config) {
return getViewYOffset() - config.yFudge + random(getViewHeight() + config.yFudge - config.imageHeight);
}
function setVisible(i, show) {
if (msie)
layers[i].style.visibility = show ? "" : "hidden";
else
layers[i].visibility = show ? "show" : "hide";
}
function writeImage(image, name, x, y) {
layerX[name] = x;
layerY[name] = y;
if (msie) {
document.writeln('
');
layers[name] = document.all[name];
}
else {
document.writeln('');
layers[name] = document.layers[name];
}
}
function writeImages(config) {
for (var i = 0; i < config.imageCount; i++) {
var startX = randomX(config);
var startY = config.startOnScreen ? randomY(config) : -config.imageHeight;
var name = config.prefix + i;
writeImage(config.image, name, startX, startY);
}
}
function cursorXY(e) {
cursorX = msie ? (getViewXOffset() + event.clientX) : e.pageX;
cursorY = msie ? (getViewYOffset() + event.clientY) : e.pageY;
}
function captureXY() {
if (!msie) { document.captureEvents(Event.MOUSEMOVE); }
document.onmousemove = cursorXY;
}
function config() {
this.xFudge = 0;
this.yFudge = 0;
this.updateInterval = 50;
this.startOnScreen = true;
this.imageCount = 1;
}
if (layerSupport()) {
c205 = new config();
c205.uid = 205;
c205.prefix = "y_bounce205";
c205.image = "http://us.f1.yahoofs.com/users/71a25fc8/bc/72df/__tn_/c527.jpg?ph5UocAB84AcqvE2";
c205.imageWidth = 130;
c205.imageHeight = 138;
c205.imageCount = 1;
c205.gravity = 4;
c205.friction = 0.1;
c205.elasticity = 0.50;
c205.topWall = 0;
c205.xSpeed = new Array();
c205.pHeight = new Array();
c205.pIndex = new Array();
c205.pScale = new Array();
c205.pLimit = new Array();
c205.kickThreshold = 5;
c205.kickOpt = 1;
for (var i = 0; i < c205.imageCount; i++) {
var name = c205.prefix + i;
c205.xSpeed[name] = random(41) - 20;
c205.pHeight[name] = -1 == -1 ? randomY(c205) : -1 + random(50);
c205.pScale[name] = getScale(c205, c205.pHeight[name]);
c205.pLimit[name] = Math.sqrt(c205.pHeight[name] / c205.pScale[name]);
c205.pIndex[name] = 0;
writeImage(c205.image, name, randomX(c205), c205.pHeight[name]);
}
setTimeout('updateBounce(c205)', c205.updateInterval);
}
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And if I told you that I loved you
You'd maybe think there's something wrong
I'm not a man of too many faces
The mask I wear is one
Those who speak know nothing
And find out to their cost
Like those who curse their luck in too many places
And those who smile are lost
farhang