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| − | <html>
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| − | <body>
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| − | <canvas id="myCanvas">
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| − | Your browser does not support the canvas element.
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| − | </canvas>
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| − |
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| − | <script>
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| − | (function() {
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| − | var particlesQuantity = 100,
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| − | velocity = 0.3,
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| − | maxRadius = 20;
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| − |
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| − | var canvas = document.getElementById("particlecanvas"),
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| − | context,
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| − | particles = [];
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| − |
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| − | context = canvas.getContext("2d");
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| − |
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| − | for (var i = 0; i < particlesQuantity; i++) {
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| − | var alpha = Math.random();
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| − |
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| − | particles.push({
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| − | x: Math.round(Math.random() * window.innerWidth),
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| − | y: Math.round(Math.random() * window.innerHeight),
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| − | velx: Math.random() * velocity * 2 - velocity,
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| − | vely: Math.random() * velocity * 2 - velocity,
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| − | radius: (1 - alpha) * maxRadius,
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| − | color: "rgba(" + [20, 147, 117, alpha].join(",") + ")"
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| − | });
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| − | }
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| − | initialize();
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| − |
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| − |
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| − | function resizeCanvas() {
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| − | canvas.width = window.innerWidth;
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| − | canvas.height = window.innerHeight;
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| − | }
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| − |
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| − | function render() {
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| − | context.clearRect(0, 0, window.innerWidth, window.innerHeight);
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| − |
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| − | var particle, len = particles.length;
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| − |
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| − | for (var i = 0; i < len; i++) {
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| − | particle = particles[i];
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| − | if (particle.x < 0) {
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| − | particle.velx = velocity + Math.random();
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| − | } else if (particle.x > window.innerWidth) {
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| − | particle.velx = -velocity - Math.random();
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| − | }
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| − |
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| − | if (particle.y < 0) {
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| − | particle.vely = velocity + Math.random();
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| − | } else if (particle.y > window.innerHeight) {
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| − | particle.vely = -velocity - Math.random();
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| − | }
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| − | particle.x += particle.velx;
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| − | particle.y += particle.vely;
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| − |
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| − |
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| − | context.fillStyle = particle.color;
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| − | context.beginPath();
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| − | context.arc(
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| − | particle.x,
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| − | particle.y,
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| − | particle.radius,
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| − | 0,
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| − | Math.PI * 2,
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| − | true
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| − | );
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| − | context.closePath();
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| − | context.fill();
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| − | }
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| − |
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| − | context.save();
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| − | context.restore();
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| − | }
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| − |
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| − | function distanceBetween(a, b) {
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| − | var dx = Math.pow(a.x - b.x, 2),
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| − | dy = Math.pow(a.y - b.y, 2);
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| − | return Math.sqrt(dx + dy);
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| − | }
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| − |
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| − | function initialize() {
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| − | window.addEventListener("resize", resizeCanvas, false);
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| − | window.requestAnimFrame = (function() {
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| − | return (
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| − | window.requestAnimationFrame ||
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| − | window.webkitRequestAnimationFrame ||
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| − | window.mozRequestAnimationFrame ||
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| − | window.oRequestAnimationFrame ||
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| − | window.msRequestAnimationFrame ||
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| − | function(callback) {
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| − | window.setTimeout(callback, 1000 / 60);
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| − | }
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| − | );
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| − | })();
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| − |
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| − | (function animloop() {
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| − | requestAnimFrame(animloop);
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| − | render();
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| − | })();
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| − |
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| − | resizeCanvas();
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| − | }
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| − | })();
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| − |
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| − |
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| − |
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| − | </script>
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| − |
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| − |
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| − |
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| − |
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| − |
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| − |
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| − |
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| − |
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| − |
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| − | </body>
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| − | </html>
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