add createImageBitmap polyfill

the changes i made to the image pipeline required stuff that needs a polyfill, so here it is!

index.html

@@ -216,6 +216,7 @@
 </html>
 
 <!-- SCRIPTS -->
+<script src="scripts/lib/createImageBitmap.js"></script>
 <script src="scripts/lib/tickable_observer.js"></script>
 <script src="scripts/lib/helpers.js"></script>
 <script src="scripts/lib/rsvp.min.js"></script>

scripts/lib/createImageBitmap.js

@@ -0,0 +1,33 @@
+/*
+* Safari and Edge polyfill for createImageBitmap
+* https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/createImageBitmap
+*
+* Support source image types Blob and ImageData.
+*
+* From: https://dev.to/nektro/createimagebitmap-polyfill-for-safari-and-edge-228
+* Updated by Yoan Tournade <yoan@ytotech.com>
+*/
+if (!('createImageBitmap' in window)) {
+	window.createImageBitmap = async function (data) {
+		return new Promise((resolve,reject) => {
+			let dataURL;
+			if (data instanceof Blob) {
+				dataURL = URL.createObjectURL(data);
+			} else if (data instanceof ImageData) {
+				const canvas = document.createElement('canvas');
+				const ctx = canvas.getContext('2d');
+				canvas.width = data.width;
+				canvas.height = data.height;
+				ctx.putImageData(data,0,0);
+				dataURL = canvas.toDataURL();
+			} else {
+				throw new Error('createImageBitmap does not handle the provided image source type');
+			}
+			const img = document.createElement('img');
+			img.addEventListener('load',function () {
+				resolve(this);
+			});
+			img.src = dataURL;
+		});
+	};
+}