Retina for magnificPopup lightbox gallery (Crafto HTML Template)

    if (typeof $.fn.magnificPopup === 'function') {
        var lightboxgallerygroups = {};
        $('.portfolio-box [data-group], .gallery-box [data-group]').each(function () {
            var id = $(this).attr('data-group');
            if (!lightboxgallerygroups[id]) {
                lightboxgallerygroups[id] = [];
            }
            lightboxgallerygroups[id].push(this);
        });

        $.each(lightboxgallerygroups, function () {
            $(this).magnificPopup({
                type: 'image',
                closeOnContentClick: true,
                closeBtnInside: false,
                gallery: { enabled: true },
                retina: {
                    ratio: 2,
                    replaceSrc: function(item, src) {
                        var srcset = $(item.el).attr('data-srcset');
                        return srcset && window.devicePixelRatio >= 2 ? srcset.split(' ')[0] : item.src;
                    }
                }
            });
        });
    }