Pressure-sensitive pen motion event structure (event.pmotion.*)
Defined in <SDL3/SDL_events.h>
typedef struct SDL_PenMotionEvent
{/**< SDL_EVENT_PEN_MOTION */
SDL_EventType type;
Uint32 reserved;/**< In nanoseconds, populated using SDL_GetTicksNS() */
Uint64 timestamp; /**< The window with pen focus, if any */
SDL_WindowID windowID; /**< The pen instance id */
SDL_PenID which; /**< Complete pen input state at time of event */
SDL_PenInputFlags pen_state; float x; /**< X coordinate, relative to window */
float y; /**< Y coordinate, relative to window */
} SDL_PenMotionEvent;
Depending on the hardware, you may get motion events when the pen is not touching a tablet, for tracking a pen even when it isn't drawing. You should listen for SDL_EVENT_PEN_DOWN and SDL_EVENT_PEN_UP events, or check pen_state & SDL_PEN_INPUT_DOWN
to decide if a pen is "drawing" when dealing with pen motion.
This struct is available since SDL 3.1.3.