https://vivamarketing.cz/wp-content/themes/optimizewp/assets/js/modules/plugins/parallax.min.js?ver=5.8.3

1
2/*
3 Plugin: jQuery Parallax
4 Version 1.1.3
5 Author: Ian Lunn
6 Twitter: @IanLunn
7 Author URL: http://www.ianlunn.co.uk/
8 Plugin URL: http://www.ianlunn.co.uk/plugins/jquery-parallax/
9
10 Dual licensed under the MIT and GPL licenses:
11 http://www.opensource.org/licenses/mit-license.php
12 http://www.gnu.org/licenses/gpl.html
13 */
14
15(function( $ ){
16    "use strict";
17
18    var $window = $(window);
19    var windowHeight = $window.height();
20
21    $window.resize(function () {
22        windowHeight = $window.height();
23    });
24
25    $.fn.parallax = function(xpos, speedFactor, outerHeight) {
26        var $this = $(this);
27        var getHeight;
28        var firstTop;
29        var paddingTop = 0;
30
31        //get the starting position of each element to have parallax applied to it
32        $this.each(function(){
33            firstTop = $this.offset().top;
34        });
35
36        if (outerHeight) {
37            getHeight = function(jqo) {
38                return jqo.outerHeight(true);
39            };
40        } else {
41            getHeight = function(jqo) {
42                return jqo.height();
43            };
44        }
45
46        // setup defaults if arguments aren't specified
47        if (arguments.length < 1 || xpos === null) xpos = "50%";
48        if (arguments.length < 2 || speedFactor === null) speedFactor = 0.1;
49        if (arguments.length < 3 || outerHeight === null) outerHeight = true;
50
51        // function to be called whenever the window is scrolled or resized
52        function update(){
53            var pos = $window.scrollTop();
54
55            $this.each(function(){
56                var $element = $(this);
57                var top = $element.offset().top;
58                var height = getHeight($element);
59
60                // Check if totally above or totally below viewport
61                if (top + height < pos || top > pos + windowHeight) {
62                    return;
63                }
64
65                $this.css('backgroundPosition', xpos + " " + Math.round((firstTop - pos) * speedFactor) + "px");
66            });
67        }
68
69        $window.bind('scroll', update).resize(update);
70        update();
71    };
72})(jQuery);