Definition binaryExpImageCubeMap
  (i : imageInfo)
  (m : cubeMipMapList)
: binaryExp :=
  let imageDataStart := cubeFaceOffset (cubeMapFaceXPos (cubeMipMapsFirst m)) in
  let encMips        := binaryExpCubeMipMaps m in
  let encMipsSize    := binarySize encMips in
  let encMipsPad     := imageDataStart - encMipsSize in
  let imageSize      := cubeMipMapImageDataSizeTotal m in
  let imageSize16    := asMultipleOf16 imageSize in
    BiRecord [
      ("cubeMipMaps", encMips);
      ("cubeMipPad",  BiReserve encMipsPad);
      ("cubeMipData", BiReserve imageSize16)
    ].
