https://www.mu.edu.tr/asset/js/jquery.snow.js

1/**
2 * jquery.snow - jQuery Snow Effect Plugin
3 *
4 * Available under MIT licence
5 *
6 * @version 1 (21. Jan 2012)
7 * @author Ivan Lazarevic
8 * @requires jQuery
9 * @see http://workshop.rs
10 *
11 * @params flakeChar - the HTML char to animate
12 * @params minSize - min size of snowflake, 10 by default
13 * @params maxSize - max size of snowflake, 20 by default
14 * @params newOn - frequency in ms of appearing of new snowflake, 500 by default
15 * @params flakeColors - array of colors , #FFFFFF by default
16 * @params durationMillis - stop effect after duration
17 * @example $.fn.snow({ maxSize: 200, newOn: 1000 });
18 */
19(function ($) {
20
21    $.fn.snow = function (options) {
22
23        var $flake = $('<div class="flake" />').css({ 'position': 'absolute', 'top': '-50px' }),
24            documentHeight = $(document).height(),
25            documentWidth = $(document).width(),
26            defaults = {
27                flakeChar: "&#10052;",
28                minSize: 10,
29                maxSize: 40,
30                newOn: 500,
31                flakeColor: ["#ffffff"],
32                durationMillis: null
33            },
34            options = $.extend({}, defaults, options);
35
36        $flake.html(options.flakeChar);
37
38        var interval = setInterval(function () {
39            var startPositionLeft = Math.random() * documentWidth - 100,
40                startOpacity = 0.5 + Math.random(),
41                sizeFlake = options.minSize + Math.random() * options.maxSize,
42                endPositionTop = 500,
43                endPositionLeft = startPositionLeft - 100 + Math.random() * 200,
44                durationFall = 500 * 10 + Math.random() * 5000;
45            $flake
46                .clone()
47                .appendTo('body')
48                .css(
49                    {
50                        left: startPositionLeft,
51                        opacity: startOpacity,
52                        'font-size': sizeFlake,
53                        color: options.flakeColor[Math.floor((Math.random() * options.flakeColor.length))]
54                    }
55                )
56                .animate(
57                    {
58                        top: endPositionTop,
59                        left: endPositionLeft,
60                        opacity: 0.2
61                    },
62                    durationFall,
63                    'linear',
64                    function () {
65                        $(this).remove()
66                    }
67                );
68        }, options.newOn);
69
70        if (options.durationMillis) {
71            setTimeout(function () {
72                removeInterval(interval);
73            }, options.durationMillis);
74        }
75    };
76
77})(jQuery);