JS_based animation-3

code
			<div class="img-magnifier-container">
				<img id="myimage" src="../images/2018-Sh-02.jpg" width="800" height="400">
			</div>
			<style>
				.img-magnifier-container { position:relative; margin-left: 15vw;}
				.img-magnifier-glass { position: absolute; border: 0.1vw solid #000; border-radius: 50%; cursor: none; /*Set the size of the magnifier glass:*/ width: 6vw;height: 6vw;}
			</style>
			<script>
				function magnify(imgID, zoom) {
					var img, glass, w, h, bw;
					img = document.getElementById(imgID);
					/*create and insert magnifier glass:*/
					glass = document.createElement("DIV");
					glass.setAttribute("class", "img-magnifier-glass");
					img.parentElement.insertBefore(glass, img);
					glass.style.backgroundImage = "url('" + img.src + "')";
					glass.style.backgroundRepeat = "no-repeat";
					glass.style.backgroundSize = (img.width * zoom) + "px " + (img.height * zoom) + "px";
					bw = 3;
					w = glass.offsetWidth / 2;
					h = glass.offsetHeight / 2;
					/*execute a function when someone moves the magnifier glass over the image or touches the screen:*/
					glass.addEventListener("mousemove", moveMagnifier);
					img.addEventListener("mousemove", moveMagnifier);
					glass.addEventListener("touchmove", moveMagnifier);
					img.addEventListener("touchmove", moveMagnifier);
					function moveMagnifier(e) {
					var pos, x, y;
					e.preventDefault();
					pos = getCursorPos(e);
					x = pos.x;
					y = pos.y;
					/*prevent the magnifier glass from being positioned outside the image:*/
					if (x > img.width - (w / zoom)) {x = img.width - (w / zoom);}
					if (x < w / zoom) {x = w / zoom;}
					if (y > img.height - (h / zoom)) {y = img.height - (h / zoom);}
					if (y < h / zoom) {y = h / zoom;}
					/*set the position of the magnifier glass:*/
					glass.style.left = (x - w) + "px";
					glass.style.top = (y - h) + "px";
					/*display what the magnifier glass "sees":*/
					glass.style.backgroundPosition = "-" + ((x * zoom) - w + bw) + "px -" + ((y * zoom) - h + bw) + "px";
					}
					function getCursorPos(e) {
					var a, x = 0, y = 0;
					e = e || window.event;
					a = img.getBoundingClientRect();
					x = e.pageX - a.left;
					y = e.pageY - a.top;
					x = x - window.pageXOffset;
					y = y - window.pageYOffset;
					return {x : x, y : y};
					}
				}
					/* Initiate Magnify Function with the id of the image, and the strength of the magnifier glass:*/
					magnify("myimage", 3);
			</script>
JS_based animation - image magnifier glass
