Bay window curtain track

Does anyone know a good product to use for bay windows. Mine are rectangular bays, so the angles are 90 degrees.

Can i get track where you pull a curtain all the way round the 90 degree bend and so have two curtains or do i have to have 2 side curtains plus two curtains for the central section ?

This would mean i would just use straight rails and not have to bother about the angles.