Mouse motion event structure (event.motion.*)
Defined in SDL_events.h
typedef struct SDL_MouseMotionEvent
{
Uint32 type; /**< SDL_MOUSEMOTION */
Uint32 timestamp; /**< In milliseconds, populated using SDL_GetTicks() */
Uint32 windowID; /**< The window with mouse focus, if any */
Uint32 which; /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
Uint32 state; /**< The current button state */
Sint32 x; /**< X coordinate, relative to window */
Sint32 y; /**< Y coordinate, relative to window */
Sint32 xrel; /**< The relative motion in the X direction */
Sint32 yrel; /**< The relative motion in the Y direction */
} SDL_MouseMotionEvent;