This is done by:
1) Implementing said protocol in a new controller input class CemuHookUDPServer.
2) Adding functionality in the WiimoteEmu class for pushing that motion input to the emulated Wiimote and MotionPlus.
3) Suitably modifying the UI for configuring an Emulated Wii Remote.
Previously, the Qt frontend would initialize the controller
interface on starting, resulting in the cursor position being
relative to the main window, instead of the render window.
Better separation of concerns. Relegates `ControllerInterface` to
enumerating input controls, and the new `ControlReference` deals with
combining inputs and configuration expression parsing.
The SDL backend crashes when you close a joystick after SDL_Quit has
been called. Some backends don't need to be shutdown and
re-initialized everytime, we can just ask to enumerate devices again.
This adds hotplugging support to the evdev input backend. We use
libudev to monitor changes to input devices in a separate thread.
Removed devices are removed from the devices list, and new devices
are added to the list.
The effect is that controllers are usable immediately after plugging
them without having to manually refresh devices (if they were
configured to be used, of course).
Changes UpdateInput() to skip if we can't lock the mutex, instead of
potentially blocking the CPU thread and causing a short but noticeable
frame drop.
This adds RemoveDevice() to ControllerInterface, fixes ExpressionParser
and some other code to support device removals without crashing,
and adds an IsValid() method to Device, to prepare for hotplugging.
This adds RegisterHotplugCallback() to register a callback which will
be invoked by the input backends' hotplug threads when there is a new
device, so that Core (GCKeyboard, GCPad, Wiimote, Hotkey) can reload
the configuration without adding a dependency to Core from InputCommon.
This makes the device ID assigning code common to all backends, by
moving it to AddDevice() instead of copy-pasting or replicating
the logic in the backends.
Also, to prepare for hotplugging, instead of relying on a name usage
count, the new ID assigning system always starts from ID 0 and tries
to assign the first ID that is not used.
