Rotating the sprite in hand

Hello!

For a quite long time I have problem, because Minecraft item textures are by default diagonal-oriented. Sometimes it's not a problem at all, but sometimes it's just so tough to make these textures, as they lack some details compared to vertical/horizontal ones.

So, is it maybe a function that can rotate the texture which we hold in hand? It would be cool if we can run that function only for some items, so I can use it exclusively for firearms which have this problem.