https://ifva.com/lib/js/lemniscate.js?lang=2&cache=20261001201014&isCCCMS=

1(function ( $ ) {
2    var _ = {
3        lastScrollTop : 0,
4        direction: null,
5    };
6    $.fn.lemniscate = function(options) {
7        console.log('----------', this.selector);
8        var defaults = {
9            container : this.selector,
10        };
11
12        var o = $.extend( {}, defaults, options );
13        $.fn.lemniscate._o = o;
14        startLoop = function(){
15            $(window).on('scroll',  handler.scroll);
16            $.fn.lemniscate.clone();
17        };
18        $.fn.lemniscate.clone = function(){
19            var loop_clone = $(o.container).clone();
20            $(o.container).parent().prepend( loop_clone ).append( loop_clone );
21            setTimeout(function(){
22                $.fn.lemniscate.startPosition();
23            }, 200);
24        };
25        $.fn.lemniscate.startPosition = function(){
26            var center = $(o.container+':nth-child(2)').offset().top;
27            $(window).scrollTop(center);
28        };
29
30
31
32        $.fn.lemniscate.destroy = function(){
33            $(window).off('scroll');
34            $(window).off('mousewheel');
35        }
36        $.fn.lemniscate.debug = function(){
37            console.log(defaults , options);
38        };
39
40        startLoop();
41    };
42
43    var handler = {
44        scroll : function(){
45            var down_clone    = $($.fn.lemniscate._o.container+':last-child '),
46                win_height    = $(window).height(),
47                win_width     = $(window).width(),
48                winPos        = $(window).scrollTop(),
49                clone_top     = down_clone.offset().top,
50                loop_height   = $($.fn.lemniscate._o.container).parent().outerHeight(true);
51
52
53                        if(win_height + winPos >= loop_height ){
54                var scroll_down_loop =  down_clone.outerHeight(true) - win_height + (win_width * .03);
55                $(window).scrollTop(scroll_down_loop);
56            }else if(winPos <= 0 ){
57                var scroll_up_loop =  $($.fn.lemniscate._o.container).last().offset().top ;
58                $(window).scrollTop(scroll_up_loop);
59            }
60
61        }
62    };
63
64    if ( typeof module === "object" && typeof module.exports === "object" ) {
65        module.exports = $.fn.lemniscate;
66    }
67}(jQuery));