confetti.js

function confetti(){
    'use strict';


var onlyOnKonami = false;

$(function() {
// Globals
var $window = $(window)
  , random = Math.random
  , cos = Math.cos
  , sin = Math.sin
  , PI = Math.PI
  , PI2 = PI * 2
  , timer = undefined
  , frame = undefined
  , confetti = [];

// Settings
var konami = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65]
  , pointer = 0;

var particles = 150
  , spread = 40
  , sizeMin = 3
  , sizeMax = 12 - sizeMin
  , eccentricity = 10
  , deviation = 100
  , dxThetaMin = -.1
  , dxThetaMax = -dxThetaMin - dxThetaMin
  , dyMin = .13
  , dyMax = .18
  , dThetaMin = .4
  , dThetaMax = .7 - dThetaMin;

var colorThemes = [
  function() {
    return color(200 * random()|0, 200 * random()|0, 200 * random()|0);
  }, function() {
    var black = 200 * random()|0; return color(200, black, black);
  }, function() {
    var black = 200 * random()|0; return color(black, 200, black);
  }, function() {
    var black = 200 * random()|0; return color(black, black, 200);
  }, function() {
    return color(200, 100, 200 * random()|0);
  }, function() {
    return color(200 * random()|0, 200, 200);
  }, function() {
    var black = 256 * random()|0; return color(black, black, black);
  }, function() {
    return colorThemes[random() < .5 ? 1 : 2]();
  }, function() {
    return colorThemes[random() < .5 ? 3 : 5]();
  }, function() {
    return colorThemes[random() < .5 ? 2 : 4]();
  }
];
function color(r, g, b) {
  return 'rgb(' + r + ',' + g + ',' + b + ')';
}

// Cosine interpolation
function interpolation(a, b, t) {
  return (1-cos(PI*t))/2 * (b-a) + a;
}

// Create a 1D Maximal Poisson Disc over [0, 1]
var radius = 1/eccentricity, radius2 = radius+radius;
function createPoisson() {
  // domain is the set of points which are still available to pick from
  // D = union{ [d_i, d_i+1] | i is even }
  var domain = [radius, 1-radius], measure = 1-radius2, spline = [0, 1];
  while (measure) {
    var dart = measure * random(), i, l, interval, a, b, c, d;

    // Find where dart lies
    for (i = 0, l = domain.length, measure = 0; i < l; i += 2) {
      a = domain[i], b = domain[i+1], interval = b-a;
      if (dart < measure+interval) {
        spline.push(dart += a-measure);
        break;
      }
      measure += interval;
    }
    c = dart-radius, d = dart+radius;

    // Update the domain
    for (i = domain.length-1; i > 0; i -= 2) {
      l = i-1, a = domain[l], b = domain[i];
      // c---d          c---d  Do nothing
      //   c-----d  c-----d    Move interior
      //   c--------------d    Delete interval
      //         c--d          Split interval
      //       a------b
      if (a >= c && a < d)
        if (b > d) domain[l] = d; // Move interior (Left case)
        else domain.splice(l, 2); // Delete interval
      else if (a < c && b > c)
        if (b <= d) domain[i] = c; // Move interior (Right case)
        else domain.splice(i, 0, c, d); // Split interval
    }

    // Re-measure the domain
    for (i = 0, l = domain.length, measure = 0; i < l; i += 2)
      measure += domain[i+1]-domain[i];
  }

  return spline.sort();
}

// Create the overarching container
var container = document.createElement('div');
container.style.position = 'fixed';
container.style.top      = '0';
container.style.left     = '0';
container.style.width    = '100%';
container.style.height   = '0';
container.style.overflow = 'visible';
container.style.zIndex   = '9999';

// Confetto constructor
function Confetto(theme) {
  this.frame = 0;
  this.outer = document.createElement('div');
  this.inner = document.createElement('div');
  this.outer.appendChild(this.inner);

  var outerStyle = this.outer.style, innerStyle = this.inner.style;
  outerStyle.position = 'absolute';
  outerStyle.width  = (sizeMin + sizeMax * random()) + 'px';
  outerStyle.height = (sizeMin + sizeMax * random()) + 'px';
  innerStyle.width  = '100%';
  innerStyle.height = '100%';
  innerStyle.backgroundColor = theme();

  outerStyle.perspective = '50px';
  outerStyle.transform = 'rotate(' + (360 * random()) + 'deg)';
  this.axis = 'rotate3D(' +
    cos(360 * random()) + ',' +
    cos(360 * random()) + ',0,';
  this.theta = 360 * random();
  this.dTheta = dThetaMin + dThetaMax * random();
  innerStyle.transform = this.axis + this.theta + 'deg)';

  this.x = $window.width() * random();
  this.y = -deviation;
  this.dx = sin(dxThetaMin + dxThetaMax * random());
  this.dy = dyMin + dyMax * random();
  outerStyle.left = this.x + 'px';
  outerStyle.top  = this.y + 'px';

  // Create the periodic spline
  this.splineX = createPoisson();
  this.splineY = [];
  for (var i = 1, l = this.splineX.length-1; i < l; ++i)
    this.splineY[i] = deviation * random();
  this.splineY[0] = this.splineY[l] = deviation * random();

  this.update = function(height, delta) {
    this.frame += delta;
    this.x += this.dx * delta;
    this.y += this.dy * delta;
    this.theta += this.dTheta * delta;

    // Compute spline and convert to polar
    var phi = this.frame % 7777 / 7777, i = 0, j = 1;
    while (phi >= this.splineX[j]) i = j++;
    var rho = interpolation(
      this.splineY[i],
      this.splineY[j],
      (phi-this.splineX[i]) / (this.splineX[j]-this.splineX[i])
    );
    phi *= PI2;

    outerStyle.left = this.x + rho * cos(phi) + 'px';
    outerStyle.top  = this.y + rho * sin(phi) + 'px';
    innerStyle.transform = this.axis + this.theta + 'deg)';
    return this.y > height+deviation;
  };
}

function poof() {
  if (!frame) {
    // Append the container
    document.body.appendChild(container);

    // Add confetti
    var theme = colorThemes[onlyOnKonami ? colorThemes.length * random()|0 : 0]
      , count = 0;
    (function addConfetto() {
      if (onlyOnKonami && ++count > particles)
        return timer = undefined;

      var confetto = new Confetto(theme);
      confetti.push(confetto);
      container.appendChild(confetto.outer);
      timer = setTimeout(addConfetto, spread * random());
    })(0);

    // Start the loop
    var prev = undefined;
    requestAnimationFrame(function loop(timestamp) {
      var delta = prev ? timestamp - prev : 0;
      prev = timestamp;
      var height = $window.height();

      for (var i = confetti.length-1; i >= 0; --i) {
        if (confetti[i].update(height, delta)) {
          container.removeChild(confetti[i].outer);
          confetti.splice(i, 1);
        }
      }

      if (timer || confetti.length)
        return frame = requestAnimationFrame(loop);

      // Cleanup
      document.body.removeChild(container);
      frame = undefined;
    });
  }
}

$window.keydown(function(event) {
  pointer = konami[pointer] === event.which
    ? pointer+1
    : +(event.which === konami[0]);
  if (pointer === konami.length) {
    pointer = 0;
    poof();
  }
});

if (!onlyOnKonami) poof();
});

  }