Keyboard button event structure (event.key.*)
Defined in SDL_events.h
typedef struct SDL_KeyboardEvent
{
Uint32 type; /**< SDL_KEYDOWN or SDL_KEYUP */
Uint32 timestamp; /**< In milliseconds, populated using SDL_GetTicks() */
Uint32 windowID; /**< The window with keyboard focus, if any */
Uint8 state; /**< SDL_PRESSED or SDL_RELEASED */
Uint8 repeat; /**< Non-zero if this is a key repeat */
Uint8 padding2;
Uint8 padding3;
SDL_Keysym keysym; /**< The key that was pressed or released */
} SDL_KeyboardEvent;