Multiple Finger Gesture Event (event.mgesture.*)
Defined in SDL_events.h
typedef struct SDL_MultiGestureEvent
{
Uint32 type; /**< SDL_MULTIGESTURE */
Uint32 timestamp; /**< In milliseconds, populated using SDL_GetTicks() */
SDL_TouchID touchId; /**< The touch device id */
float dTheta;
float dDist;
float x;
float y;
Uint16 numFingers;
Uint16 padding;
} SDL_MultiGestureEvent;