Added the functions SDL_JoystickFromPlayerIndex(), SDL_JoystickSetPlayerIndex(), SDL_GameControllerFromPlayerIndex(), and SDL_GameControllerSetPlayerIndex()
It causes the HIDAPI devices to always be opened on enumeration, which causes crashes in the Windows drivers when multiple applications are reading and writing at the same time. We can revisit this after 2.0.10 release.
Note that a single USB device is responsible for all 4 joysticks, so a large
rewrite of the DeviceDriver functions was necessary to allow a single device to
produce multiple joysticks.
The code is now reliant on SDL_PrivateJoystickAdded() and SDL_PrivateJoystickRemoved() being called correctly when devices are added or removed on Windows
Fixed a case where partial trigger pull could be bound to another button
There is a fundamental problem not resolved by this commit:
Some controllers have axes (triggers, pedals, etc.) that don't start at zero, but we're guaranteed that if we get a value that it's correct. For these controllers, the current code works, where we take the first value we get and use that as the zero point and generate axis motion starting from that point on.
Other controllers have digital axes (D-pad) that assume a zero starting point, and the first value we get is the min or max axis value when the D-pad is moved. For these controllers, the current code thinks that the zero point is the axis value after the D-pad motion and this doesn't work.
My hypothesis is that the first class of devices is more common and that we should solve for that, and add an exception to SDL_JoystickAxesCenteredAtZero() as needed for the second class of devices.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().