https://cancer.org.my/wp-content/themes/Total/assets/js/core/scrolly.js?ver=4.6.1

1/*
2 * Project: Scrolly2 - Background Image Parallax
3 * Originally based on Scrolly by Victor C. / Octave & Octave web agency
4 * Rewritten and heavily adjusted by Benjamin Intal / Gambit
5 */
6(function ( $, window, document, undefined ) {
7
8    var pluginName = 'scrolly2';
9
10    function Plugin( element, options ) {
11        this.$element = $(element);
12        this.init();
13    }
14
15    Plugin.prototype.init = function () {
16
17        // Declare vars
18        var self               = this;
19            this.startPosition = 0;
20            this.offsetTop     = this.$element.offset().top;
21            this.height        = this.$element.outerHeight(true);
22            this.velocity      = this.$element.attr('data-velocity');
23            this.direction     = this.$element.attr('data-direction');
24
25        // Bind so that we don't refresh everytime
26        $(window).bind('scroll', function() {
27			self.scrolly2();
28        });
29    };
30
31    Plugin.prototype.scrolly2 = function() {
32        
33        // Check if the element is inside our viewport, if it's not, don't do anything
34        var viewTop = $(window).scrollTop() - 20; // with leeway
35        var viewBottom = $(window).scrollTop() + $(window).height() + 20; // with leeway
36        var elemTop = this.$element.offset().top;
37        var elemBottom = this.$element.offset().top + this.$element.height();
38
39        if ( elemTop >= viewBottom || elemBottom <= viewTop ) {
40            return;
41        }
42
43        // If the element is below the fold, then we need to
44        // make sure that when we first see the element,
45        // our background image should be in the starting position
46        if ( this.$element.offset().top > $(window).height() ) {
47            if ( this.direction !== 'none' ) {
48                this.startPosition = (this.$element.offset().top - $(window).height()) * Math.abs(this.velocity);
49            }
50        }
51
52        // Calculate position
53        var position = this.startPosition + $(window).scrollTop() * this.velocity;
54
55        // Adjust position
56        var xPos = "50%";
57        var yPos = "50%";
58        if ( this.direction === 'left' ) {
59            xPos = position + 'px';
60        } else if ( this.direction === 'right' ) {
61            xPos = 'calc(100% + ' + -position + 'px)';
62        } else if ( this.direction === 'down' ) {
63            // yPos = 'calc(100% + ' + (-position) + 'px)';
64            // Use this one for background-attachment: fixed
65            var offset = - ( $(window).height() -
66                         this.$element.offset().top -
67                         this.$element.height() -
68                         parseInt( this.$element.css('paddingTop') ) -
69                         parseInt( this.$element.css('paddingBottom') ) );
70            yPos = 'calc(100% + ' + ( offset - $(window).scrollTop() - position ) + 'px)';
71        } else { // up
72            // yPos = position + 'px';
73            // Use this one for background-attachment: fixed
74            yPos = ( this.$element.offset().top - $(window).scrollTop() + position ) + 'px';
75        }
76        this.$element.css( { backgroundPosition: xPos + ' ' + yPos } );
77    };
78
79    $.fn[pluginName] = function ( options ) {
80        return this.each(function () {
81            if (!$.data(this, 'plugin_' + pluginName)) {
82                $.data(this, 'plugin_' + pluginName, new Plugin( this, options ));
83            }
84        });
85    };
86
87})(jQuery, window, document);