architecture-mechanism.github.io/assets/js/jquery.paroller.min.js

'use strict';
/**
 * jQuery plugin paroller.js v1.4.6
 * https://github.com/tgomilar/paroller.js
 * preview: https://tgomilar.github.io/paroller/
 **/
(function(a) {
  'use strict';
  'function' == typeof define && define.amd ? define('parollerjs', ['jquery'], a) : 'object' == typeof module && 'object' == typeof module.exports ? module.exports = a(require('jquery')) : a(jQuery)
})(function(a) {
  'use strict';
  var b = Math.round;
  let c = !1,
    d = function() {
      c = !1
    },
    e = {
      bgVertical: function(a, b) {
        return a.css({
          "background-position": 'center ' + -b + 'px'
        })
      },
      bgHorizontal: function(a, b) {
        return a.css({
          "background-position": -b + 'px center'
        })
      },
      vertical: function(a, b, c, d) {
        return 'none' === d && (d = ''), a.css({
          "-webkit-transform": 'translateY(' + b + 'px)' + d,
          "-moz-transform": 'translateY(' + b + 'px)' + d,
          transform: 'translate(0,' + b + 'px)' + d,
          transition: c,
          "will-change": 'transform'
        })
      },
      horizontal: function(a, b, c, d) {
        return 'none' === d && (d = ''), a.css({
          "-webkit-transform": 'translateX(' + b + 'px)' + d,
          "-moz-transform": 'translateX(' + b + 'px)' + d,
          transform: 'translate(' + b + 'px, 0)' + d,
          transition: c,
          "will-change": 'transform'
        })
      }
    },
    f = {
      factor: function(a, b, c) {
        let d = a.data('paroller-factor'),
          e = d ? d : c.factor;
        if (576 > b) {
          let b = a.data('paroller-factor-xs'),
            d = b ? b : c.factorXs;
          return d ? d : e
        }
        if (768 >= b) {
          let b = a.data('paroller-factor-sm'),
            d = b ? b : c.factorSm;
          return d ? d : e
        }
        if (1024 >= b) {
          let b = a.data('paroller-factor-md'),
            d = b ? b : c.factorMd;
          return d ? d : e
        }
        if (1200 >= b) {
          let b = a.data('paroller-factor-lg'),
            d = b ? b : c.factorLg;
          return d ? d : e
        }
        if (1920 >= b) {
          let b = a.data('paroller-factor-xl'),
            d = b ? b : c.factorXl;
          return d ? d : e
        }
        return e
      },
      bgOffset: function(a, c) {
        return b(a * c)
      },
      transform: function(a, c, d, e) {
        return b((a - d / 2 + e) * c)
      }
    },
    g = {
      background: function(a) {
        return a.css({
          "background-position": 'unset'
        })
      },
      foreground: function(a) {
        return a.css({
          transform: 'unset',
          transition: 'unset'
        })
      }
    };
  a.fn.paroller = function(h) {
    const i = a(window).height(),
      j = a(document).height(); // default options
    return h = a.extend({
      factor: 0, // - to +
      factorXs: 0, // - to +
      factorSm: 0, // - to +
      factorMd: 0, // - to +
      factorLg: 0, // - to +
      factorXl: 0, // - to +
      transition: 'transform .1s ease', // CSS transition
      type: 'background', // foreground
      direction: 'vertical' // horizontal
    }, h), this.each(function() {
      const k = a(this);
      let l = k.outerHeight(),
        m = a(window).width(),
        n = k.offset().top,
        o = 0,
        p = function(a, b) { // console.log(`offset ${scrollOffset} => ${transform - scrollOffset}`)
          return a || (o = b), b - o
        };
      const q = k.data('paroller-type'),
        r = k.data('paroller-direction'),
        s = k.data('paroller-transition'),
        t = k.css('transform'),
        u = s ? s : h.transition,
        v = q ? q : h.type,
        w = r ? r : h.direction;
      let x = 0,
        y = f.bgOffset(n, x),
        z = f.transform(n, x, i, l);
      'background' === v ? 'vertical' === w ? e.bgVertical(k, y) : 'horizontal' === w && e.bgHorizontal(k, y) : 'foreground' === v && ('vertical' === w ? e.vertical(k, z, u, t) : 'horizontal' === w && e.horizontal(k, z, u, t)), a(window).on('resize', function() {
        let o = a(this).scrollTop();
        m = a(window).width(), n = k.offset().top, l = k.outerHeight(), x = f.factor(k, m, h), y = b(n * x);
        let q = p(a(document).scrollTop(), b((n - i / 2 + l) * x));
        c || (window.requestAnimationFrame(d), c = !0), 'background' === v ? (g.background(k), 'vertical' === w ? e.bgVertical(k, y) : 'horizontal' === w && e.bgHorizontal(k, y)) : 'foreground' === v && o <= j && (g.foreground(k), 'vertical' === w ? e.vertical(k, q, u) : 'horizontal' === w && e.horizontal(k, q, u))
      }), a(window).on('load scroll', function() {
        let g = a(this).scrollTop(),
          o = a(document).scrollTop();
        x = f.factor(k, m, h);
        let q = p(o, b((n - i / 2 + l - g) * x));
        c || (window.requestAnimationFrame(d), c = !0), 'background' === v ? 'vertical' === w ? e.bgVertical(k, y) : 'horizontal' === w && e.bgHorizontal(k, y) : 'foreground' === v && g <= j && ('vertical' === w ? e.vertical(k, q, u, t) : 'horizontal' === w && e.horizontal(k, q, u, t))
      })
    })
  }
});