Decode vertex attributes to interleaved buffer

Hi,

I am using the `draco_decoder_gltf.js` to decode a draco encoded gltf file. Originally the meshes' vertex attributes were stored interleaved. However I am uncertain on how to retrieve the interleaved buffer, as using the decoder seems to only allow me to retrieve each attribute separately into separate buffer. I could of course interleave them manually after retrieving, but that adds extra costly allocation which I want to circumvent if possible. Any ideas that can help me out?