libgdx
Mapping doesn't include LT and RT axis
The getMapping() is pretty useful, but it only includes any buttons that might be mapped to L2/R2, but for those gamepads that have triggers the mapping should also include the axis for both the left and right trigger (LT/RT).
At least on desktop the trigger seem to be properly mapped to their axis. So instead of using the mapping I've currently just hardcoded LT to axis 4 and RT to axis 5.
If it's difficult to determine what's the axis on other platforms, maybe those would just have -1 in there until someone implements it.
IIRC the buttons are mapped to buttons on all other platforms, but I might remember wrong. I am open for all good suggestions but someone has to take a look on all the platforms for this. :)
I was testing with a bluetooth controller on android and to my surprise the trigger was mapped to both an axis and a button. So could be the case that on the other platforms the trigger is always mapped to a button. Which would make desktop the odd one out.
IDK, I handle desktop as an edge case at the moment, which would be cool to not be necessary, but it's not such a big deal to be worth much effort. I guess at least this issue can act as a documentation of this quirk for now.