Fix sound rendering for web

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_synth/lib/src/imf_renderer.dart

@@ -69,10 +69,14 @@ class ImfRenderer {
     bytes.add('data'.codeUnits);
     bytes.add(_int32ToBytes(dataSize));
 
-    // Append the actual raw audio data
-    for (int sample in pcmData) {
-      bytes.add(_int16ToBytes(sample));
+    // Append the actual raw audio data (Blazing Fast version)
+    final byteData = ByteData(dataSize);
+    for (int i = 0; i < pcmData.length; i++) {
+      // Multiply by 2 because each Int16 takes up 2 bytes.
+      // Endian.little is strictly required for the standard WAV format.
+      byteData.setInt16(i * 2, pcmData[i], Endian.little);
     }
+    bytes.add(byteData.buffer.asUint8List());
 
     return bytes.toBytes();
   }