Edward Rudd
Device: Logitech Rumble Gamepad F510 in Xinput mode.
Upon opening the joystick the values of the axes are queried via PollAllValues are not actually set on the device all the time.
This can easily be seen in the testjoystick or testgamecontroller test programs,as the testjoystick shows all axes in the center until one 'tickles' the triggers., and the testgamecontroller will show the triggers as 'on' until on 'tickles' the triggers.
Upon further research the culprit is the SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS hint. In the default value events are ignored until there is an active window, Thus in cases where the joystick system is initialized and controllers opened before the initial window is created & focuses, the initial values will be incorrect.
Here is my current workaround in the game I'm working on porting..
SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");
SDL_GameController* gamepad = SDL_GameControllerOpen(index);
SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "0");
Also updates the naming of these Xbox Wireless Controllers connected via USB (and thus the third-party Xbox Controller Driver) to match.
The Xbox Wireless Controller entries are now listed, in order, via USB, bia Bluetooh (with older firmware) and via Bluetooth (with firmware 3.1.1221.0).
Firmware revision 3.1.1221.0 changes the mapping of the Xbox One S
controller in Bluetooth mode. Aside from changing the layout of
other buttons, this revision also changes the triggers to act as
Accelerator and Brake axes from the simulation controls page.
The Darwin sysjoystick code didn't previously map anything at these
axes, making it impossible to detect input on these two buttons.
white.magic
The logic which decides if a device enumerated via the direct input system in the function EnumJoysticksCallback in SDL_dinputjoystick.c is processed is discarding valid joystick devices due to the assumption that devices of the type DI8DEVTYPE_SUPPLEMENTAL are not valid devices.
This change was added with 2.0.4 with this commit http://hg.libsdl.org/SDL/rev/1b9d40126645 that is linked to this bug report https://bugzilla.libsdl.org/show_bug.cgi?id=2460 which indicates that in that case devices of the type DI8DEVTYPE_SUPPLEMENTAL were not desirable as they caused a singular device to emit multiple "device added" events.
Since then there appear to have been a few fixes to handle devices that fall into various other classes in the following two commits:
http://hg.libsdl.org/SDL/rev/10ffb4787d7a and http://hg.libsdl.org/SDL/rev/6a2bbac05728
Two devices I have reports of failing to be listed when the DI8DEVTYPE_SUPPLEMENTAL type is excluded are ECS Gametric Throttle and Thrustmaster MFD Cougar.
Sam Lantinga
I verified that the OUYA controller shows up as a single device with this change, so I've reverted the change to ignore supplemental devices, leaving framework in place to easily add devices that we want to ignore.