chore: use native base64

scripts/build_help.mjs

@@ -6,7 +6,7 @@ const homedir = new URL('../openchemlib/src/main/resources/html/', import.meta.u
 const pngNames = await readdir(new URL('editor', homedir)).then(files => files.filter(file => file.endsWith('.png')))
 const images = {}
 for (const pngName of pngNames) {
-  const blob = await readFile(new URL(`editor/${pngName}`, homedir))
+  const blob = await readFile(new URL(`editor/${pngName}`, homedir), 'base64')
   const encoded = toBase64URL(blob, 'image/png')
   images[pngName] = encoded
 }
@@ -23,45 +23,6 @@ html = html.replace('<link type="text/css" href="../styles.css" rel="stylesheet"
 
 await writeFile(new URL('../help.html', import.meta.url), html)
 
-/*
- * base64-arraybuffer
- * https://github.com/niklasvh/base64-arraybuffer
- *
- * Copyright (c) 2012 Niklas von Hertzen
- * Licensed under the MIT license.
- */
-
-function encode(bytes) {
-
-  const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
-
-  // Use a lookup table to find the index.
-  const lookup = new Uint8Array(256);
-  for (let i = 0; i < chars.length; i++) {
-    lookup[chars.charCodeAt(i)] = i;
-  }
-
-  let i;
-  let len = bytes.length;
-  let base64 = '';
-
-  for (i = 0; i < len; i += 3) {
-    base64 += chars[bytes[i] >> 2];
-    base64 += chars[((bytes[i] & 3) << 4) | (bytes[i + 1] >> 4)];
-    base64 += chars[((bytes[i + 1] & 15) << 2) | (bytes[i + 2] >> 6)];
-    base64 += chars[bytes[i + 2] & 63];
-  }
-
-  if (len % 3 === 2) {
-    base64 = `${base64.substring(0, base64.length - 1)}=`;
-  } else if (len % 3 === 1) {
-    base64 = `${base64.substring(0, base64.length - 2)}==`;
-  }
-
-  return base64;
-}
-
-function toBase64URL(bytes, type) {
-  const base64 = encode(bytes);
+function toBase64URL(base64, type) {
   return `data:${type};base64,${base64}`;
 }