Function SDL_GetRelativeMouseState 

pub unsafe extern "C" fn SDL_GetRelativeMouseState(
    x: *mut c_int,
    y: *mut c_int,
) -> Uint32

Retrieve the relative state of the mouse.

The current button state is returned as a button bitmask, which can be tested using the SDL_BUTTON(X) macros (where X is generally 1 for the left, 2 for middle, 3 for the right button), and x and y are set to the mouse deltas since the last call to SDL_GetRelativeMouseState() or since event initialization. You can pass NULL for either x or y.

\param x a pointer filled with the last recorded x coordinate of the mouse \param y a pointer filled with the last recorded y coordinate of the mouse \returns a 32-bit button bitmask of the relative button state.

\since This function is available since SDL 2.0.0.

\sa SDL_GetMouseState