Truetype hinting is designed with assumption that orientation of glyph regarding pixel grid is fixed. I.e. it does not support complex affine transforms such as rotation or shear. It does work with scale transforms (if no flipping involved)
and java2d supports that.
We may still benefit from hinting in case of complex transforms if we
decompose them into scale transform S (that works with hinting engine)
and another tranform T.
Then we can first apply hinting to outline with transform S and
then apply transform T to already hinted outline.
This makes text outlook under different affine transforms more consistent
(turning off hinting makes the big difference).