參考資訊：
https://libctru.devkitpro.org/index.html
https://github.com/devkitPro/3ds-examples
https://github.com/nop90/SDL-3DS/blob/master/SDL-1.2.15/src/joystick/n3ds/SDL_sysjoystick.c
| 3DS Key | SDL Key |
|---|---|
| CPad X | JoystickAxis 0 |
| CPad Y | JoystickAxis 1 |
| A | JoystickButton 1 |
| B | JoystickButton 2 |
| X | JoystickButton 3 |
| Y | JoystickButton 4 |
| SELECT | JoystickButton 7 |
| START | JoystickButton 8 |
| L | JoystickButton 5 |
| R | JoystickButton 6 |