Full page parallax > 공책

<style>
@import url(https://fonts.googleapis.com/css?family=Indie+Flower);
html, body {
  overflow: hidden;
}

.background {
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center center;
  overflow: hidden;
  will-change: transform;
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  height: 130vh;
  position: fixed;
  width: 100%;
  -webkit-transform: translateY(30vh);
      -ms-transform: translateY(30vh);
          transform: translateY(30vh);
  -webkit-transition: all 1.2s cubic-bezier(0.22, 0.44, 0, 1);
          transition: all 1.2s cubic-bezier(0.22, 0.44, 0, 1);
}
.background:before {
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.3);
}
.background:first-child {
  background-image: url(https://i.imgur.com/2tQoKAI.jpg);
  -webkit-transform: translateY(-15vh);
      -ms-transform: translateY(-15vh);
          transform: translateY(-15vh);
}
.background:first-child .content-wrapper {
  -webkit-transform: translateY(15vh);
      -ms-transform: translateY(15vh);
          transform: translateY(15vh);
}
.background:nth-child(2) {
  background-image: url(https://i.imgur.com/Yl0v8sU.jpg);
}
.background:nth-child(3) {
  background-image: url(https://i.imgur.com/ZzAc6qY.jpg);
}

/* Set stacking context of slides */
.background:nth-child(1) {
  z-index: 3;
}

.background:nth-child(2) {
  z-index: 2;
}

.background:nth-child(3) {
  z-index: 1;
}

.content-wrapper {
  height: 100vh;
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
  -webkit-justify-content: center;
      -ms-flex-pack: center;
          justify-content: center;
  text-align: center;
  -webkit-flex-flow: column nowrap;
      -ms-flex-flow: column nowrap;
          flex-flow: column nowrap;
  color: #fff;
  font-family: Montserrat;
  text-transform: uppercase;
  -webkit-transform: translateY(40vh);
      -ms-transform: translateY(40vh);
          transform: translateY(40vh);
  will-change: transform;
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  -webkit-transition: all 1.7s cubic-bezier(0.22, 0.44, 0, 1);
          transition: all 1.7s cubic-bezier(0.22, 0.44, 0, 1);
}
.content-title {
  font-size: 12vh;
  line-height: 1.4;
}

.background.up-scroll {
  -webkit-transform: translate3d(0, -15vh, 0);
          transform: translate3d(0, -15vh, 0);
}
.background.up-scroll .content-wrapper {
  -webkit-transform: translateY(15vh);
      -ms-transform: translateY(15vh);
          transform: translateY(15vh);
}
.background.up-scroll + .background {
  -webkit-transform: translate3d(0, 30vh, 0);
          transform: translate3d(0, 30vh, 0);
}
.background.up-scroll + .background .content-wrapper {
  -webkit-transform: translateY(30vh);
      -ms-transform: translateY(30vh);
          transform: translateY(30vh);
}

.background.down-scroll {
  -webkit-transform: translate3d(0, -130vh, 0);
          transform: translate3d(0, -130vh, 0);
}
.background.down-scroll .content-wrapper {
  -webkit-transform: translateY(40vh);
      -ms-transform: translateY(40vh);
          transform: translateY(40vh);
}
.background.down-scroll + .background:not(.down-scroll) {
  -webkit-transform: translate3d(0, -15vh, 0);
          transform: translate3d(0, -15vh, 0);
}
.background.down-scroll + .background:not(.down-scroll) .content-wrapper {
  -webkit-transform: translateY(15vh);
      -ms-transform: translateY(15vh);
          transform: translateY(15vh);
}

</style>

<div class="container">
  <section class="background">
    <div class="content-wrapper">
      <p class="content-title">Full Page Parallax Effect</p>
      <p class="content-subtitle">Scroll down!</p>
    </div>
  </section>
  <section class="background">
    <div class="content-wrapper">
      <p class="content-title">Amazon forest</p>
      <p class="content-subtitle">All the rendered pixels are super reall</p>
    </div>
  </section>
  <section class="background">
    <div class="content-wrapper">
      <p class="content-title">Fireflies.</p>
      <p class="content-subtitle">Long-exposure photo of fireflies in a darkened Japanese forest</p>
    </div>
  </section>
</div>


  <script src='https://code.jquery.com/jquery-2.1.4.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.min.js'></script>
      <script id="rendered-js" >
var ticking = false;
var isFirefox = (/Firefox/i.test(navigator.userAgent));

var scrollSensitivitySetting = 30; // Increase/decrease to change sensitivity to trackpad gestures (up = less sensitive; down = more sensitive) 

var slideDurationSetting = 600; 
// Amount of time for which slide is "locked"

var currentSlideNumber = 0;

var totalSlideNumber = $(".background").length;


function parallaxScroll(evt) {
  if (isFirefox) {
    // Set delta for Firefox
    delta = evt.detail * (-120);
  } else {
    // Set delta for all other browsers
    delta = evt.wheelDelta;
  }

  if (ticking != true) {
    if (delta <= -scrollSensitivitySetting) {
      //Down scroll
      ticking = true;
      if (currentSlideNumber !== totalSlideNumber - 1) {
        currentSlideNumber++;
        nextItem();
      }
      slideDurationTimeout(slideDurationSetting);
    }
    if (delta >= scrollSensitivitySetting) {
      //Up scroll
      ticking = true;
      if (currentSlideNumber !== 0) {
        currentSlideNumber--;
      }
      previousItem();
      slideDurationTimeout(slideDurationSetting);
    }
  }
}


function slideDurationTimeout(slideDuration) {
  setTimeout(function() {
    ticking = false;
  }, slideDuration);
}

// Event listeners
var mousewheelEvent = isFirefox ? "DOMMouseScroll" : "wheel";
window.addEventListener(mousewheelEvent, _.throttle(parallaxScroll, 60), false);

// Slide motion
function nextItem() {
  var $previousSlide = $(".background").eq(currentSlideNumber - 1);
  $previousSlide.removeClass("up-scroll").addClass("down-scroll");
}

function previousItem() {
  var $currentSlide = $(".background").eq(currentSlideNumber);
  $currentSlide.removeClass("down-scroll").addClass("up-scroll");
}
</script>