Mouse button event structure (event.button.*)
Defined in SDL_events.h
typedef struct SDL_MouseButtonEvent
{/**< SDL_MOUSEBUTTONDOWN or SDL_MOUSEBUTTONUP */
Uint32 type; /**< In milliseconds, populated using SDL_GetTicks() */
Uint32 timestamp; /**< The window with mouse focus, if any */
Uint32 windowID; /**< The mouse instance id, or SDL_TOUCH_MOUSEID */
Uint32 which; /**< The mouse button index */
Uint8 button; /**< SDL_PRESSED or SDL_RELEASED */
Uint8 state; /**< 1 for single-click, 2 for double-click, etc. */
Uint8 clicks;
Uint8 padding1;/**< X coordinate, relative to window */
Sint32 x; /**< Y coordinate, relative to window */
Sint32 y; } SDL_MouseButtonEvent;