SDL_GetJoystickAxis - Get the current state of an axis control on a joystick.

       This function is available since SDL 3.2.0.

       SDL  makes  no  promises  about what part of the joystick any given axis refers to. Your game should have
       some sort of configuration UI to let users specify what each axis should be bound to. Alternately,  SDL's
       higher-level  Game  Controller  API makes a great effort to apply order to this lower-level interface, so
       you know that a specific axis is the "left thumb stick," etc.

       The value returned by SDL_GetJoystickAxis() is a  signed  integer  (-32768  to  32767)  representing  the
       current position of the axis. It may be necessary to impose certain tolerances on these values to account
       for jitter.

joystick
              an SDL_Joystick structure containing joystick information.

       axis   the axis to query; the axis indices start at index 0.

       SDL_GetJoystickAxis - Get the current state of an axis control on a joystick.

       Returns  a  16-bit  signed  integer  representing  the current position of the axis or 0 on failure; call
       SDL_GetError() for more information.

SDL_GetNumJoystickAxes(3)

Simple Directmedia Layer                           SDL 3.2.20                             SDL_GetJoystickAxis(3)

#include<SDL3/SDL_joystick.h>Sint16SDL_GetJoystickAxis(SDL_Joystick*joystick,intaxis);