Pure JS / CSS Image Slider With A Masking Effect

A pure JavaScript image slider that comes with a subtle masking effect using the CSS clip-path property.

How to use it:

Load the ionicons for the nav arrows of your image slider.

<link rel='stylesheet' href='ionicons.min.css'>

Create the image slider with captions using html5 figure and figcaption tags.

<div class="slider-ctr">
  <figure class="slide"><img src="1.jpeg">
    <figcaption> 
      <div class="title">Image 1</div>
      <div class="author">Author 1</div>
    </figcaption>
  </figure>
  <figure class="slide"><img src="2.jpeg">
    <figcaption> 
      <div class="title">Image 2</div>
      <div class="author">Author 2</div>
    </figcaption>
  </figure>
  <figure class="slide"><img src="3.jpeg">
    <figcaption>
      <div class="title">Image 3</div>
      <div class="author">Author 3</div>
    </figcaption>
  </figure>
  <figure class="slide text-on"><img src="4.jpeg">
    <figcaption>
      <div class="title">Image 4</div>
      <div class="author">Author 4</div>
    </figcaption>
  </figure>
  <div class="slider-control">
    <div class="control prev disabled">
      <div class="icon ion-chevron-left"></div>
    </div>
    <div class="control next">
      <div class="icon ion-chevron-right"></div>
    </div>
  </div>
</div>

The main CSS/CSS3 styles for the slider and its inner content.

.slider-ctr {
  width: 700px;
  height: 440px;
  position: absolute;
  top: 50%;
  left: 50%;
  margin-top: -220px;
  margin-left: -350px;
  box-sizing: border-box;
  border: 10px solid white;
  border-radius: 5px;
  overflow: hidden;
  box-shadow: 0 10px 15px 3px rgba(0, 0, 0, 0.15), 0 5px 20px 3px rgba(0, 0, 0, 0.1);
}
.slider-ctr:after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: linear-gradient(to bottom, transparent 70%, rgba(0, 0, 0, 0.6) 100%);
  background: -webkit-linear-gradient(to bottom, transparent 70%, rgba(0, 0, 0, 0.6) 100%);
  pointer-events: none;
  z-index: 9;
}
.slide {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  transition: 0.45s all cubic-bezier(0.65, 0.05, 0.36, 1);
  -webkit-clip-path: inset(0 0 0 0);
  clip-path: inset(0 0 0 0);
}
.slide:before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: rgba(0, 0, 0, 0.125);
}
.slide.slide-on {
  -webkit-clip-path: inset(0 100% 0 0);
  clip-path: inset(0 100% 0 0);
}
.slide.text-on .title {
  transition: 0.3s all cubic-bezier(0.65, 0.05, 0.36, 1) 0.45s;
  -webkit-clip-path: inset(0 0 0 0);
  clip-path: inset(0 0 0 0);
}
.slide.text-on .author {
  transition: 0.3s all cubic-bezier(0.65, 0.05, 0.36, 1) 0.6s;
  -webkit-clip-path: inset(0 0 0 0);
  clip-path: inset(0 0 0 0);
}
.slide img { display: block; }
.slide figcaption {
  position: absolute;
  top: 30px;
  left: 30px;
}
.slide .title {
  font-size: 50px;
  margin-bottom: 2px;
  color: white;
  transition: 0.3s all cubic-bezier(0.65, 0.05, 0.36, 1) 0.45s;
  -webkit-clip-path: inset(0 0 0 100%);
  clip-path: inset(0 0 0 100%);
  font-weight: 400;
  letter-spacing: 10px;
  text-transform: uppercase;
  position: relative;
}
.slide .author {
  font-size: 16px;
  color: white;
  opacity: .8;
  transition: 0.3s all cubic-bezier(0.65, 0.05, 0.36, 1) 0.45s;
  -webkit-clip-path: inset(0 0 0 100%);
  clip-path: inset(0 0 0 100%);
  font-weight: 300;
  letter-spacing: 3px;
  position: relative;
  z-index: 9;
}

Style the slider’s nav control.

.slider-control {
  position: absolute;
  right: 30px;
  bottom: 30px;
  width: 80px;
  overflow: hidden;
  border-radius: 3px;
  box-shadow: 0 3px 3px 3px rgba(0, 0, 0, 0.15);
  z-index: 99;
}
.slider-control .control {
  width: 50%;
  height: 40px;
  display: block;
  float: left;
  text-align: center;
  line-height: 40px;
  cursor: pointer;
  transition: .3s all ease;
  background: white;
}
.slider-control .control .icon {
  pointer-events: none;
  transition: .3s all ease;
}
.slider-control .control.disabled {
  pointer-events: none;
  background: #ddd;
}
.slider-control .control.disabled .icon { opacity: .5; }

The core JavaScript to active the image slider.

// buttons
var sliderControl = document.querySelector(".slider-control");
// slides informations
var slides = document.querySelectorAll(".slide"),
    slidesLength = slides.length;
// slides array
var slidesArr = [].slice.call(slides);
// reverse array sorting
slidesArr = slidesArr.reverse();
// slide current
var slideCurrent = 0;
sliderControl.addEventListener("click", function(e){
  target = e.target;
  
  // get next button
  if(target.classList.contains("next")){
    next = e.target,
    prev = next.previousElementSibling,
    nextSlide = slidesArr[slideCurrent + 1],
    slide = slidesArr[slideCurrent];
    
    slide.classList.add("slide-on");
    slide.classList.remove("text-on");
    nextSlide.classList.add("text-on");
    
    slideCurrent += 1;
    
    if(slideCurrent > 0) {
      prev.classList.remove("disabled");
    }
    
    if(slideCurrent === slidesLength - 1){
      next.classList.add("disabled");
    }
  }
  
  // get prev button
  if(target.classList.contains("prev")){
    
    slideCurrent -= 1;
    
    prev = e.target,
    next = prev.nextElementSibling,
    prevSlide = slidesArr[slideCurrent + 1],
    slide = slidesArr[slideCurrent];
    
    prevSlide.classList.remove("text-on");
    slide.classList.remove("slide-on");
    slide.classList.add("text-on");
    
    if(slideCurrent === slidesLength - 2){
      next.classList.remove("disabled");
    }
    if(slideCurrent === 0){
      prev.classList.add("disabled");
    }
    
  }
});