SDL_JoyAxisEvent man page

typedef struct{
  Uint8 type;
  Uint8 which;
  Uint8 axis;
  Sint16 value;
} SDL_JoyAxisEvent;

type

SDL_JOYAXISMOTION

which

Joystick device index

axis

Joystick axis index

value

Axis value (range: -32768 to 32767)

SDL_JoyAxisEvent is a member of the SDL_Event union and is used when an event of type SDL_JOYAXISMOTION is reported.

A SDL_JOYAXISMOTION event occurs when ever a user moves an axis on the joystick. The field which is the index of the joystick that reported the event and axis is the index of the axis (for a more detailed explaination see the Joystick section). value is the current position of the axis.

SDL_Event, Joystick Functions, SDL_JoystickEventState, SDL_JoystickGetAxis