After posting my last message, i searched if it was a problem specific to my system,
that XBCD driver transmits negative values for triggers pressure.
And so after several keywords combination alchemy, approx. 5 years old posts browsing and many dead URLs,
i found some answers, but also more interestingly, a working solution.
So, it appears that XBCD drivers have been especially configured to transmit values from 0 to -32767 on trigger key press, on purpose :
The negative values of Z and RZ were selected as defaults for the split axis profile after testing in a number of titles, and finding that the positive ranges treated them as always being depressed once calibrated, some of these titles include some Racing titles such as Need for speed, adventure titles such as tombraider legend, and other titles that can use the triggers when assigned.
http://vba-m.com/forum/thread-668.htmlAlso seeing how my setup behaved in FBA, i wasn't so sure about my MAME settings...
Because if FBA was seeing the the trigger pressure as full axis going positive max to negative min,
wasn't MAME setting "Joy 1 Axe Z -" actually starting detecting pressure from half trigger pressing?
And after retrying some games, yes, MAME was starting detecting trigger pressure from half of the trigger pressing!
It isn't the case for some PC games i play, like Burnout Paradise, which detects the full trigger pressure.
So i searched for possible alternatives
and found a much better X360 controller home-made driver,
which also allows separate axes for triggers, but then is ten times more configurable,
especially on how those trigger should transmit their pressure!
So this is the driver to use:
http://lavendy.net/special/driver/x360c/index.htmlThe page is in Japanese but the .en.zip versions got full English text in the joystick control panel.
Also the installation of this driver, and how it is integrated in the OS, are much more cleaner than XBCD.
And then, after tweaking the configuration of this driver, triggers work now perfectly fine on FBA!
I attached screenshots of the working triggers configuration in this driver.
Now if you excuse me, i have to get back to Super Hang On.
Thanks again for such a great emulator, games really run smoother than with MAME on my setup.