anchor.diff:  
               if sizeChanged then
                   let sizeInBytes = int64 <| ((InternalFormat.getSizeInBits internalFormat) * size.X * size.Y) / 8
  -                let sizeInBytes =  if textureParams.wantMipMaps then (sizeInBytes * 3L) / 2L else sizeInBytes
  +                let sizeInBytes =  if textureParams.wantMipMaps then (sizeInBytes * 4L) / 3L else sizeInBytes
                   updateTexture t.Context t.SizeInBytes sizeInBytes
                   t.SizeInBytes <- sizeInBytes
   
  
positive.code:         ]
  
  
      [<AutoOpen>]
      module private Uploads =
  
  
negative.code:                         uploadTexture3D t info image
  
                      | FileTexture(info, file) ->
                          Devil.uploadTexture2D t file info
  //                        let pi = PixImage.Create(file, PixLoadOptions.UseDevil)
  //                        let mm = PixImageMipMap [|pi|]
  //                        uploadTexture2D t info mm |> ignore
  
                      | :? NullTexture -> failwith "cannot update texture with null texture"
  
  