SDL_JoystickGetAxis man page
SDL_JoystickGetAxis — Get the current state of an axis
Sint16 SDL_JoystickGetAxis(SDL_Joystick *joystick, int axis);
SDL_JoystickGetAxis returns the current state of the given axis on the given joystick.
On most modern joysticks the X axis is usually represented by axis 0 and the Y axis by axis 1. The value returned by SDL_JoystickGetAxis is a signed integer (-32768 to 32768) representing the current position of the axis, it maybe necessary to impose certain tolerances on these values to account for jitter. It is worth noting that some joysticks use axes 2 and 3 for extra buttons.
Returns a 16-bit signed integer representing the current position of the axis.
Sint16 x_move, y_move; SDL_Joystick *joy1; . . x_move=SDL_JoystickGetAxis(joy1, 0); y_move=SDL_JoystickGetAxis(joy1, 1);