This adds a dropdown in the emulated G27 settings dialog ("Force
feedback direction encoding") with three options: Steering Axis
(default), Cartesian, Polar. Default is Steering Axis so existing users
see no change.
RPCS3 right now hardcodes SDL_HAPTIC_STEERING_AXIS for the spring and
constant-force effects it sends to the host wheel. That's SDL's
recommended encoding for wheels and works on the hardware the code was
written against. Some Windows DirectInput drivers (like my MOZA R3) do
not react to these affects at all. This now allows changing it to an
encoding that works.
Nico Franke