SDL_JoystickGetAxis (3) - Linux Man Pages
SDL_JoystickGetAxis: Get the current state of an axis
NAMESDL_JoystickGetAxis - Get the current state of an 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.
Sint16 x_move, y_move; SDL_Joystick *joy1; . . x_move=SDL_JoystickGetAxis(joy1, 0); y_move=SDL_JoystickGetAxis(joy1, 1);