I never had a GC or a GC controller. So I guess you mean the conditions half-triggered and full-triggered?
Yeah, pretty much. In Sunshine for example, when you half-press the R trigger, you can shoot water and run at the same time, but if you do the full-press, Mario stops and shoots. Killer7 also uses this to some extent.
For those USB controllers without analog triggers, the option was made so that when you press and maintain LB, it acts as a modifier between Full-Press to Half-Press, for the LT / RT buttons.
So, using the DualShock 3/4 as an example for USB controller, it is normally mapped like this:
L2 = Gamecube L Full-Press / R2 = Gamecube R Full-Press
L1 = Modifier function / R1 = Gamecube Z button
Is "button rotation feature" == "looking around"? It's possible, but I don't know the button at the moment...
Nope, in this case, what i mean with "button rotation" is the native Nintendont function in which you press Select in-game and the face buttons rotate 90° on the fly, making B+A Gamecube buttons to be placed in the Y+B buttons position, since the Gamecube pad uses a pretty unique layout that can be a little weird when using it on standard controllers with diamond-shaped face buttons. This happens with any gamepad connected through USB, and of course the wireless Wii U Gamepad and Wii U Pro Controller also behave like that.
If you're interested, you could even improve the button rotation function by using LB+Back (L1+Select), which would minimize the possibility for users to press it accidentally, and also allow the Select button to be used for playing when remapping, as you already can do with your implementation, something that Nintendont lacks. The Home/Xbox button could also be improved by adding a 1 second delay, also to prevent accidental exit.
Remapping controls is possible by modifying the controller ini file.
The only buttons i couldn't remap for now using the values provided in the ini, were the 360 LT and RT.
Wanted to add: thanks for your cool work with the 360 additions. More controller options are always great.