https://www.sprinterbus.net/shared/scripts/jquery-box-slider-master/js/effects/box-slider-fx-fade.js

1; (function (w, $, undefined) {
2
3    w.jqBoxSlider.registerAnimator('fade', (function () {
4
5        var adaptor = {};
6
7        // setup slide and box css
8        adaptor.initialize = function ($box, $slides, settings) {
9            adaptor._cacheOriginalCSS($box, 'box', settings);
10            adaptor._cacheOriginalCSS($slides, 'slides', settings);
11
12            if ('static inherit'.indexOf($box.css('position')) !== -1) {
13                $box.css('position', 'relative');
14            }
15
16            $box.css({ height: $slides.eq(0).height(), overflow: 'hidden' });
17            $slides
18                .css({ position: 'absolute', top: 0, left: 0 })
19                .filter(':gt(0)').hide();
20        };
21
22        // fade current out and next in
23        adaptor.transition = function (settings) {
24            settings.$nextSlide.fadeIn(settings.speed);
25            settings.$currSlide.fadeOut(settings.speed);
26        };
27
28        // reset the original css
29        adaptor.destroy = function ($box, settings) {
30            $box.children().css(settings.origCSS.slides);
31            $box.css(settings.origCSS.box);
32        };
33        //console.log(adaptor)
34        return adaptor;
35
36    }()));
37
38}(window, jQuery || Zepto));