COFFEE
c = document.getElementById 'c'
ctx = c.getContext '2d'
particles = {}
particleIndex = 0
particleNum = .9
w = window.innerWidth
h = window.innerHeight
c.width = w
c.height = h
class Particle
constructor: ->
@x = w/2
@y = h/2
@vx = do Math.random * 5 - 2.5
@vy = do Math.random * 2 - 1
@growth = ( Math.abs(@vx) + Math.abs(@vy) ) * 1
particleIndex++
particles[particleIndex] = @
@id = particleIndex
@size = do Math.random * 1
@colors = [
"rgba(233,30,99,#{do Math.random + .5})"
"rgba(255,160,0,#{do Math.random + .5})"
"rgba(139,195,74,#{do Math.random + .5})"
"rgba(33,150,243,#{do Math.random + .5})"
]
@color = @colors[Math.floor do Math.random * @colors.length]
draw: ->
@x += @vx
@y += @vy
@size += @growth
delete particles[@id] if @x > w or @y > h
ctx.fillStyle = @color
do ctx.beginPath
ctx.arc @x, @y, @size, 0*Math.PI, 2*Math.PI
do ctx.fill
setInterval ( ->
ctx.fillStyle = "rgba(224,247,250,1)"
ctx.fillRect 0, 0, w, h
new Particle() if do Math.random > particleNum
do particles[k].draw for k of particles
), 1000/60
