Created
May 27, 2013 21:31
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var self = window; | |
(function(self) { | |
var canvas, context, particles = [], explode = true, FPS = 60; | |
/* | |
* Init. | |
*/ | |
function init() { | |
var body = document.querySelector('body'); | |
canvas = document.createElement('canvas'); | |
canvas.width = innerWidth; | |
canvas.height = innerHeight; | |
canvas.style.backgroundColor = '#000'; | |
canvas.style.position = 'absolute'; | |
canvas.style.top = 0; | |
canvas.style.bottom = 0; | |
canvas.style.left = 0; | |
canvas.style.right = 0; | |
// Filters | |
body.appendChild(canvas); | |
// Browser supports canvas? | |
if(!!(capable)) { | |
context = canvas.getContext('2d'); | |
window.onresize = onResize; | |
createParticles(); | |
} | |
else { | |
console.error('Sorry, your browser sucks :('); | |
} | |
} | |
/* | |
* Checks if browser supports canvas element. | |
*/ | |
function capable() { | |
return canvas.getContext && canvas.getContext('2d'); | |
} | |
/* | |
* On resize window event. | |
*/ | |
function onResize() { | |
canvas.width = window.innerWidth; | |
canvas.height = window.innerHeight; | |
} | |
function createParticles() { | |
for(var step = 0, len = 200; step < len; step++) { | |
var x, y, steps; | |
steps = Math.PI * 2 * step / len; | |
x = canvas.width * 0.5 + 200 * Math.cos(steps); | |
y = canvas.height * 0.5 + 200 * Math.sin(steps); | |
particles.push({ | |
x: x, | |
y: y, | |
lineX: x, | |
lineY: y, | |
centerX: canvas.width * 0.5, | |
centerY: canvas.height * 0.5, | |
originalX: x, | |
originalY: y, | |
scale: 1, | |
radius: 3, | |
minRadius: 3, | |
maxRadius: 9, | |
orbit: 100, | |
angle: 0, | |
speed: 0.05 | |
}); | |
} | |
loop(); | |
} | |
/* | |
* Subdivision logic. | |
*/ | |
function loop() { | |
clear(); | |
update(); | |
render(); | |
requestAnimFrame(loop); | |
} | |
/* | |
* Clear the whole screen. | |
*/ | |
function clear() { | |
context.clearRect(0, 0, canvas.width, canvas.height); | |
} | |
/* | |
* Update the particles. | |
*/ | |
function update() { | |
var towards = { | |
x: Math.round(canvas.width * 0.5), | |
y: Math.round(canvas.height * 0.5) | |
}; | |
[].forEach.call(particles, function(particle, index) { | |
particle.x = particle.centerX + Math.cos(particle.angle + index) * particle.orbit; | |
particle.y = particle.centerY + Math.sin(particle.angle + index) * particle.orbit; | |
particle.scale = 1 + Math.sin(particle.angle) * 0.5; | |
particle.angle += particle.speed; | |
if(!explode) { | |
particle.centerX += (towards.x - particle.centerX) * 0.05; | |
particle.centerY += (towards.y - particle.centerY) * 0.05; | |
particle.radius += (particle.maxRadius - particle.radius) * 0.05; | |
if(Math.round(particle.centerX) === towards.x && Math.round(particle.centerY) === towards.y) | |
explode = true; | |
} | |
if(explode) { | |
particle.centerX += (particle.originalX - particle.centerX) * 0.05; | |
particle.centerY += (particle.originalY - particle.centerY) * 0.05; | |
particle.radius += (particle.minRadius - particle.radius) * 0.05; | |
if(Math.round(particle.centerX) === Math.round(particle.originalX) && Math.round(particle.centerY) === Math.round(particle.originalY)) | |
explode = false; | |
} | |
}); | |
} | |
/* | |
* Render the particles. | |
*/ | |
function render() { | |
[].forEach.call(particles, function(particle, index) { | |
context.save(); | |
context.globalAlpha = 0.5; | |
context.strokeStyle = '#ea80b0'; | |
context.lineWidth = 1; | |
context.beginPath(); | |
context.moveTo(particle.lineX, particle.lineY); | |
context.lineTo(particle.x, particle.y); | |
context.stroke(); | |
context.restore(); | |
context.save(); | |
context.translate(particle.x, particle.y); | |
context.scale(particle.scale, particle.scale); | |
context.globalCompositeOperation = 'lighter'; | |
context.globalAlpha = 1; | |
context.fillStyle = '#ea80b0'; | |
context.beginPath(); | |
context.arc(0, 0, particle.radius, 0, Math.PI * 2); | |
context.fill(); | |
context.restore(); | |
}); | |
} | |
/* | |
* Request new frame by Paul Irish. | |
* 60 FPS. | |
*/ | |
window.requestAnimFrame = (function() { | |
return window.requestAnimationFrame || | |
window.webkitRequestAnimationFrame || | |
window.mozRequestAnimationFrame || | |
window.oRequestAnimationFrame || | |
window.msRequestAnimationFrame || | |
function(callback) { | |
window.setTimeout(callback, 1000 / FPS); | |
}; | |
})(); | |
window.addEventListener ? window.addEventListener('load', init, false) : window.onload = init; | |
})(self); |
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Wow so pretty https://output.jsbin.com/rifoyu