https://www.poctep.eu/wp-content/themes/trankad/js/animate.js?ver=1.0.0

1/*
2* 15. Animate.js
3*/
4var docElem = window.document.documentElement;
5
6    function getViewportH() {
7        var client = docElem['clientHeight'],
8            inner = window['innerHeight'];
9        
10        if( client < inner )
11            return inner;
12        else
13            return client;
14    }
15
16    function scrollY() {
17        return window.pageYOffset || docElem.scrollTop;
18    }
19
20    function getOffset( el ) {
21        var offsetTop = 0, offsetLeft = 0;
22        do {
23            if ( !isNaN( el.offsetTop ) ) {
24                offsetTop += el.offsetTop;
25            }
26            if ( !isNaN( el.offsetLeft ) ) {
27                offsetLeft += el.offsetLeft;
28            }
29        } while( el = el.offsetParent )
30
31        return {
32            top : offsetTop,
33            left : offsetLeft
34        }
35    }
36
37    function inViewport( el, h ) {
38        var elH = el.offsetHeight,
39            scrolled = scrollY(),
40            viewed = scrolled + getViewportH(),
41            elTop = getOffset(el).top,
42            elBottom = elTop + elH,
43            // if 0, the element is considered in the viewport as soon as it enters.
44            // if 1, the element is considered in the viewport only when it's fully inside
45            // value in percentage (1 >= h >= 0)
46            h = h || 0;
47
48        return (elTop + elH * h) <= viewed && (elBottom) >= scrolled;
49    }
50(function ( $ ) {
51
52    'use strict';
53
54    $.fn.animateIn = function(){
55    
56        var el = $(this);
57        var height = $(window).innerHeight();
58        
59        el.css('opacity', '0');
60        
61        $(window).scroll(function(){
62            
63            el.each(function(){
64                
65                el.css('opacity', '100');
66                
67                var scrollTop  = $(window).scrollTop();
68                var obj = $(this);
69                var offset = obj.offset();
70                var top = offset.top;
71                var distance = (top - scrollTop);
72
73                if( distance < screen.availHeight-100 ){
74                    var incoming = $(this).data('animate');          
75                    $(this).addClass('animated ' + incoming);
76                }
77                
78            });
79
80        });    
81        
82    };
83
84}( jQuery ));