JavaScript preprocessors can help make authoring JavaScript easier and more convenient. For instance, CoffeeScript can help prevent easy-to-make mistakes and offer a cleaner syntax and Babel can bring ECMAScript 6 features to browsers that only support ECMAScript 5.
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s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.
You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.
If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.
You can also link to another Pen here, and we'll pull the JavaScript from that Pen and include it. If it's using a matching preprocessor, we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.
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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.
<div style="height:100%;background:#000">
<canvas id="can" style="background:#111"></canvas>
</div>
<div class="item">
<span data-color='{"red":255,"green":165,"blue":0}'>Hover me</span>
</div>
html {height:100%;padding:0;margin:0;background:#000}
body {padding:0;margin:0;height:100%;line-height:1.3rem;font-family: 'Quicksand', sans-serif}
.item {width:100px;height:20px;text-align:center;padding:10px;background:rgba(255,255,255,0.3);position:absolute;left:50%;top:50%}
var Stars = function()
{
var me = this;
var canEle = document.getElementById('can');
var can = canEle.getContext('2d');
var height = 0;
var width = 0;
var mdDefault = 150;
var mdHover = 500;
var mdDec = true;
var max = 200;
var distance = 100;
var mouseDistance = mdDefault;
var stars = new Array(max);
var mouse = {
x : width / 2,
y : height / 2
};
var defaultRed = 255;
var defaultGreen = 255;
var defaultBlue = 255;
var red = defaultRed;
var green = defaultGreen;
var blue = defaultBlue;
var targetRed = red;
var targetGreen = green;
var targetBlue = blue;
var speedDefault = 1;
var speedHover = 15;
var speed = speedDefault;
var maxTime = 0;
var minTime = 1000;
var moving = false;
var lastTime = new Date();
var arcCache = {};
me.start = function()
{
if (navigator.appVersion.match('Chrome')) {
max = 300;
}
resize();
createStars();
//setInterval(run, 1000 / 30);
run();
document.onmousemove = mousemove;
$('span[href]').click(function() {
$('span[href]').not($(this)).css('opacity', 0);
location.href = $(this).attr('href');
return false;
});
$('.item').hover(function() {
//moving = true;
mdDec = false;
speed = speedHover;
var color = c = $(this).children().eq(0).data('color');
if (!color) {
targetRed = defaultRed;
targetGreen = defaultGreen;
targetBlue = defaultBlue;
} else {
targetRed = color.red;
targetGreen = color.green;
targetBlue = color.blue;
}
}, function() {
moving = false;
mdDec = true;
speed = speedDefault;
targetRed = defaultRed;
targetGreen = defaultGreen;
targetBlue = defaultBlue;
});
};
var mousemove = function(e)
{
mouse.x = e.pageX;
mouse.y = e.pageY;
};
var run = function()
{
clean();
drawStars();
};
var drawStars = function()
{
for (var i = 0; i < max; i++) {
stars[i].connected = [];
}
var time = new Date();
setColors();
can.lineWidth = 1;
var dist = 0.0;
if (mdDec && mouseDistance > mdDefault) {
mouseDistance -= 80;
} else if (!mdDec && mouseDistance < mdHover) {
mouseDistance += 80;
}
for (var i = 0; i < max; i++) {
if (!moving) {
moveStar(stars[i]);
}
var star = stars[i];
dist = Math.sqrt(Math.pow(star.x - mouse.x, 2) + Math.pow(star.y - mouse.y, 2));
if (dist < mouseDistance * 2) {
can.fillStyle = 'rgb('.concat(red, ',', green, ',', blue, ')');
} else {
can.fillStyle = 'rgba('.concat(red, ',', green, ',', blue, ', 0.3)');
}
can.fillRect(star.x, star.y, star.size / 2, star.size);
can.beginPath();
if (dist < mouseDistance) {
star.arc = true;
for (var j = 0; j < max; j++) {
var refStar = stars[j];
if (star == refStar || refStar.connected.indexOf(star) != -1) {
continue;
}
if (
Math.abs(star.x - refStar.x) < distance &&
Math.abs(star.y - refStar.y) < distance
) {
star.connected.push(refStar);
drawRelation(star, refStar);
}
}
} else {
star.arc = false;
}
can.stroke();
can.closePath();
}
for (var i = 0; i < max; i++) {
if (stars[i].arc) {
arc(stars[i]);
}
}
var nDate = new Date();
var time = nDate.getTime() - time.getTime();
if (time > maxTime) {
maxTime = time;
}
if (time < minTime) {
minTime = time;
}
can.fillStyle = '#fff';
can.fillText('PROCESS TIME PER FRAME - cur: ' + time, 10, 20);
can.fillText('PROCESS TIME PER FRAME - max: ' + maxTime, 10, 40);
can.fillText('PROCESS TIME PER FRAME - min: ' + minTime, 10, 60);
var avFps = parseInt(1000 / time + 15);
var fps = parseInt(nDate.getTime() - lastTime.getTime());
if (fps > avFps) {
fps = avFps;
}
can.fillText('possible FPS: ' + avFps, 10, 80);
can.fillText('current FPS: ' + fps, 10, 100);
lastTime = new Date();
setTimeout(run, (1000 / 30) - time); //sollte am Ende stehen, damit sich die Prozedur nicht überholen kann
};
var arc = function(star)
{
var r = star.size * 2;
can.drawImage(star.cache, star.x - r, star.y - r, r * 2, r * 2);
}
var setColors = function()
{
var percent = 10;
if (targetRed != red) {
var tick = Math.floor(Math.abs(targetRed - red) / percent);
if (targetRed > red) {
red += tick;
} else {
red -= tick;
}
}
if (targetGreen != green) {
var tick = Math.floor(Math.abs(targetGreen - green) / percent);
if (targetGreen > green) {
green += tick;
} else {
green -= tick;
}
}
if (targetBlue != blue) {
var tick = Math.floor(Math.abs(targetBlue - blue) / percent);
if (targetBlue > blue) {
blue += tick;
} else {
blue -= tick;
}
}
can.fillStyle = 'rgb('.concat(red, ',', green, ',', blue, ')');
can.strokeStyle = 'rgba('.concat(red, ',', green, ',', blue, ', 0.3)');
}
var drawRelation = function(star, refStar)
{
can.moveTo(star.x | 0, star.y | 0);
if (true) {
can.lineTo(refStar.x | 0, refStar.y | 0);
return;
} else {
var midX = Math.max(star.x, refStar.x) - (Math.max(star.x, refStar.x) - Math.min(star.x, refStar.x)) / 2;
var midY = Math.max(star.y, refStar.y) - (Math.max(star.y, refStar.y) - Math.min(star.y, refStar.y)) / 2;
if (star.curve > 0) {
midX += 20;
midY += 20;
} else {
midX -= 20;
midY -= 20;
}
}
};
var moveStar = function(star)
{
star.x += star.dirX * speed;
star.y += star.dirY * speed;
if (star.y > height) {
star.dirY = Math.random() * -1;
} else if (star.y < 0) {
star.dirY = Math.random();
} else if (star.x > width) {
star.dirX = Math.random() * -1;
} else if (star.x < 0) {
star.dirX = Math.random();
}
return star;
};
var clean = function()
{
can.fillStyle = 'rgb(0, 0, 0)';
can.fillRect(0, 0, width, height);
};
var createStars = function()
{
for (var i = 0; i < max; i++) {
stars[i] = createStar();
}
};
var createStar = function()
{
var star = {
x : Math.random() * width,
y : Math.random() * height,
dirX : (Math.random() - 0.5),
dirY : (Math.random() - 0.5),
size : Math.ceil(Math.random() * 3),
curve : (Math.random() - 0.5),
line : (Math.random() - 0.5),
arc : false
};
initCache(star);
return star;
};
var initCache = function(star)
{
var cache = $(document.createElement('canvas'));
var c = cache.get(0).getContext('2d');
var r = star.size * 2;
cache.attr({
width : star.size * 4,
Height : star.size * 4
});
c.fillStyle = 'rgba(200, 200, 200, 0.5)';
c.beginPath();
c.arc(r, r, r, 0, 2*Math.PI);
c.fill();
star.cache = cache.get(0);
}
var resize = function()
{
height = canEle.parentElement.offsetHeight - 10;
width = canEle.parentElement.offsetWidth - 10;
canEle.style.width = ''.concat(width, 'px');
canEle.style.height = ''.concat(height, 'px');
canEle.setAttribute('width', width);
canEle.setAttribute('height', height);
}
};
var stars = new Stars();
stars.start();
Also see: Tab Triggers