Develop Reference

Drawing animation to only run on scroll down

I have an icon drawn when i scroll down the page and undrawn when i scroll up.
I would like to make it draw only when i scroll down and stay this way for the rest of the session.
$(document).ready(function() {
var $dashOffset = $(".path").css("stroke-dashoffset");
$(window).scroll(function() {
var $percentageComplete = (($(window).scrollTop() / ($("html").height() - $(window).height())) * 100);
var $newUnit = parseInt($dashOffset, 10);
var $offsetUnit = $percentageComplete * ($newUnit / 100);
$(".path").css("stroke-dashoffset", $newUnit - $offsetUnit);});
var $bg = $(".background")
$(document).scroll(function(){
$bg.css({transform: $(this).scrollTop()<1 ? "scale":"scale(1,1)"});
});
});

Moving an image with 360° angle in Javascript

I am trying to make an image move 360° (not rotate) back it's course, but so far I was able to move only to a specific direction, if I add left & bottom course, then the image going diagonal to left & bottom. Here are the properties:
CSS
#circle{
background:red;
border-radius:100px;
height:100px; width:100px;
position:absolute;
}
JavaSript
(function() {
var speed = 10,
moveBox = function(){
var el = document.getElementById("circle"),
left = el.offsetLeft,
moveBy = 3;
el.style.left = left + moveBy + "px";
if(left > 200){
clearTimeout(timer);
}
};
var timer = setInterval(moveBox, speed);
}());
HTML:
<div id='circle'></div>
JsFiddle Online Demo
The problem is looping back the red circle, I want it to move to left > bottom > right > up
in a circular manner.
thanks for the help.

Using Math.sin and Math.cos to describe the circle: http://jsfiddle.net/E3peq/7/
(function() {
var speed = 10,
moveX = 0.1,
moveY = 0.1,
increment = 0.1,
amp = 10,
moveBox = function(){
var el = document.getElementById("circle"),
left = el.offsetLeft,
top = el.offsetTop;
moveX += increment;
moveY += increment;
var moveXBy = Math.cos(moveX) * amp;
var moveYBy = Math.sin(moveY) * amp;
el.style.left = (left + moveXBy) + "px";
el.style.top = (top + moveYBy) + "px";
if(left > 200){
clearTimeout(timer);
}
};
var timer = setInterval(moveBox, speed);
}());
Edit: Abraham's answer in the comments is actually a lot nicer looking than this...

make an image move inside a div randomly

I'm creating a simple game and i am stuck currently at something i have a div called 'box' and an image inside it called 'Parachute' when the game start the parachute should move randomly inside the border of the div
my code :
<div id="box">
</div>
<script type="text/javascript">
var ToAppend = "<img src='Parachute.gif' width='25px' height='25px' class='Parachute' /> ";
setInterval(function () {
for (var i = 1; i <= 2; i++) {
$("#box").append(ToAppend);
MoveParticles();
}
}, 3000);
function MoveParticles() {
$(".Parachute").each(function () {
var x = Math.floor(Math.random() * 400);
var y = Math.floor(Math.random() * 400);
$(this).animate({ "left": x + "px" }, "slow");
$(this).animate({ "top": y + "px" }, "slow");
});
}
<script>

You seem to be animating #box, not .Parachute.
Here's a demo to get you in the right track.
//let's build the chutes
for (var i = 0; i < 50; ++i) {
$('<div/>', {
class: 'chute'
}).appendTo('#box');
}
//cache a few static values
var box = $('#box');
var width = box.width();
var height = box.height();
var chute = $('.chute');
//our main animation "loop"
chute.each(function foo() {
//generate random values
var top = (Math.random() * height) | 0;
var left = (Math.random() * width) | 0;
var time = Math.random() * (800 - 400) + 400 | 0;
//animate
//we introduce a random value so that they aren't moving together
//after the animation, we call foo for the current element
//to animate the current element again
$(this).animate({
left: left,
top: top
}, time, foo);
});

define start to finish positions

I am creating a new "whack-a-mole" style game where the children have to hit the correct numbers in accordance to the question. So far it is going really well, I have a timer, count the right and wrong answers and when the game is started I have a number of divs called "characters" that appear in the container randomly at set times.
I have been given a theme of bubbles so they want me to make the "characters" start at the bottom and animate upwards. Any ideas how I would achieve this?
Here is the code that currently maps the divs to there positions in the canvas...
function moveRandom(id) {
var cPos = $('#container').offset();
var cHeight = $('#container').height();
var cWidth = $('#container').width();
var pad = parseInt($('#container').css('padding-top').replace('px', ''));
var bHeight = $('#' + id).height();
var bWidth = $('#' + id).width();
maxY = cPos.top + cHeight - bHeight - pad;
maxX = cPos.left + cWidth - bWidth - pad;
minY = cPos.top + pad;
minX = cPos.left + pad;
newY = randomFromTo(minY, maxY);
newX = randomFromTo(minX, maxX);
$('#' + id).css({
top: newY,
left: newX
}).fadeIn(1000, function() {
setTimeout(function() {
$('#' + id).fadeOut(1000);
window.cont++;
}, 7000);
});
Here is my most recent fiddle: http://jsfiddle.net/pUwKb/15/

The part below actually set the CSS (and thus the position of your element).
$('#' + id).css({
top: newY,
left: newX }).fadeIn(1000, function() {
setTimeout(function() {
$('#' + id).fadeOut(1000);
window.cont++;
}, 7000); });
You should add a function move who uses a movement variable. Small example:
function move(movement, id) {
$('#' + id).css({
top: this.css('top') + movement.y,
left: this.css('left') + movement.x
}).fadeIn(1000, function() {
setTimeout(function() {
$('#' + id).fadeOut(1000);
window.cont++;
}, 7000);
});
}
Where in movement should be an object something the like of {x: 30, y: 0} which would result in a 30 pixels movement to the right. Hope it helps!

How do i stop images rotating using mouseover?

I have created a function to rotate images, and now what I would like to do is to stop the images from rotating when I use the mouseover command. this is the js coding I have to get the images to rotate
var m = {
Z : 100,
xm : 0,
xmm : .25,
ymm : 0,
ym : 0,
mx : 0,
nx : 0,
ny : 0,
nw : 0,
nh : 0,
xR : 0,
nI : 0,
scr : 0,
img : 0,
run : function () {
m.xm += (m.xmm - m.xm) * .1;
if (m.ym < m.nw * .15) m.ym++;
m.xR += m.xm;
for (var i = 0; i < m.nI; i++){
var A = (i * 360 / m.nI) + m.xR;
var x = Math.cos(A * (Math.PI / 180));
var y = Math.sin(A * (Math.PI / 180));
var a = m.img[i];
a.style.width = ''.concat(Math.round(Math.abs(y * m.ym) + y * m.Z), 'px');
a.style.left = ''.concat(Math.round((m.nw * .5) + x * ((m.nw * .5) - (m.nw * .05)) - ((Math.abs(y * m.ym) + y * m.Z) * .5)), 'px');
a.style.height = ''.concat(Math.round(m.ym + y * m.Z), 'px');
a.style.top = ''.concat(Math.round((m.nh * .5) - (m.ym * .5) - x * (m.Z * .5) - (m.ymm * y)), 'px');
a.style.zIndex = 600 + Math.round(y);
m.setOpacity(a, (y * 50) + 100);
}
setTimeout(m.run, 30);
},

I really did not read your code in detail, but what you could probably do is set a parameter outside the function, maybe a global parameter to the function that rotates your image, call it "rotate" and set it to TRUE
Then, before you make the actual rotation, you check if this "rotate" param set to TRUE, if yes then rotate.
Now, onmouseover, all you have to do is set the "rotate" param to FALSE, and then when it its FALSE when the setTimeout trigger is expires and the function starts again, the imagee would not rotate becaues it failed your test.
Another approach is to set your setTimeout to trigger only when not on mousenotover, so if on mouse over, do not set the timeout, othersie, set the time out.
Those are just two ideas that just came to my mind reading your code, I think you can think about it and decide if those are solutions you like, and if not then I would be interested to know what you decided.
Cheers.

The next code is just an approximation, and is more like a "pseudo code" than a production code. Anyways feel free to modify as you need.
var m = {
run: function() {
this.isRunning = true;
// when complete the cycle
this.cycle = true;
},
play: function() {
this.timeout = setTimeout((function($this){
if($this.animCheck !== undefined) clearInterval($this.animCheck);
$this.run();
})(this), this.frames);
},
pause: function() {
this.animCheck = setInterval((function($this) {
// Obviously, you've to pause the animation when the cycle is finished.
if($this.cycle) clearTimeout($this.timeout);
})(this), this.frames);
return !!this.animCheck;
},
init: function() {
this.frames = 30;
this.isRunning = true;
[the element].addEventListener('mouseover', function() {
if(this.pause()) this.isRunning = false;
})
this.play();
}
};
m.init();