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JavaScript

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HTML 

              
                <div class="cover-slider__wrap">
    <div class="cover-slider__inner">
            I'm essentially trying to create
    a rotating slider wipe effect
    using background-size:cover and background-position:center.
    </div>
    <ul class="cover-slider">
        <li class="cover-slider__slide">
            <span class="hide">Alt Tag</span>
        </li>
        <li class="cover-slider__slide">
            <span class="hide">Alt Tag</span>
        </li>
        <li class="cover-slider__slide">
            <span class="hide">Alt Tag</span>
        </li>
        <li class="cover-slider__slide">
            <span class="hide">Alt Tag</span>
        </li>
    </ul>
</div>
!

CSS 

              
                @import "compass/css3";

.cover-slider__wrap {
    position: relative;
    max-width: 640px;
    height: 480px;
    margin: 2em auto;
    padding: 5em 1em;
    color: #fff;
    line-height: 2;
    font-family: 'Trebuchet MS', sans-serif;
    font-weight: bold;
    box-shadow: 0 0 .5em rgba(#000,.5);
}
.cover-slider__inner {
    position: relative;
    min-height: 40em;
    text-align: center;
    z-index: 10;
}
.cover-slider {
    backface-visibility: hidden;
}
.cover-slider__slide {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 100%;
    padding: 0;
    margin: 0;
    background-size: cover;
    background-position: center;
    list-style: none;
    z-index: 0;
    opacity: .5;
    &.active {
        animation-duration: 2500ms;
        animation-name: slidein;
        animation-fill-mode: forwards;
    }
    &.inactive {
        animation-duration: 2500ms;
        animation-name: slideout;
        animation-fill-mode: forwards;
    }
    @keyframes slidein {
        from {
            left: 0;
            right: 100%;
        }
        to {
            left: 0;
            right: 0;
        }
    }
    @keyframes slideout {
        from {
            left: 0;
            right: 0;
        }
        to {
            left: 100%;
            right: 0;
        }
    }
}
// EXTRA STUFF
// these will unfortunately be inline
// in the final product
.cover-slider__slide {
    &:nth-child(1){
        background-image: url("https://www.tcmulder.com/codepen/_fpo/photos/");
    }
    &:nth-child(2){
        background-image: url("https://www.tcmulder.com/codepen/_fpo/photos/");
    }
    &:nth-child(3){
        background-image: url("https://www.tcmulder.com/codepen/_fpo/photos/");
    }
    &:nth-child(4){
        background-image: url("https://www.tcmulder.com/codepen/_fpo/photos/");
    }
}
body {
    background: teal;
    box-sizing: border-box;
}
*, *:before, *:after {
    box-sizing: inherit;
}
.hide {
    position: absolute;
    left: -9999px;
}
!

JS 

              
                // when the dom is ready
jQuery(function($){
	// grab each slider (multiple supported)    
	$('.cover-slider').each(function(){
		// find the slides in this slider
       	var $slides = $(this).find('.cover-slider__slide');
		// get the 0 based amount of slides
        var numSlides = $slides.length - 1;
		// incrementor
        var i = 0;
       
        // rotate slides
       	var rotate = function(){
            // remove all sliding classes
            $slides.removeClass('active inactive');
            // add inactive to the current slide
            $slides.eq(i).addClass('inactive');
            // reset counter if last slide (so animates first one)
            if(i == numSlides){
                i = -1;
            }
            // add active to incremented slide (next slide)
            $slides.eq(++i).addClass('active');
            // call this every few seconds
           	var timer = window.setTimeout(rotate, 5000);
       	};
        // initialize the slider
       	rotate();
	});
});
!
999px

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