The custom event structure.
Defined in SDL_syswm.h
struct SDL_SysWMmsg
{
SDL_version version;
SDL_SYSWM_TYPE subsystem;
union
{
#if defined(SDL_VIDEO_DRIVER_WINDOWS)
struct {
HWND hwnd; /**< The window for the message */
UINT msg; /**< The type of message */
WPARAM wParam; /**< WORD message parameter */
LPARAM lParam; /**< LONG message parameter */
} win;
#endif
#if defined(SDL_VIDEO_DRIVER_X11)
struct {
XEvent event;
} x11;
#endif
#if defined(SDL_VIDEO_DRIVER_DIRECTFB)
struct {
DFBEvent event;
} dfb;
#endif
#if defined(SDL_VIDEO_DRIVER_COCOA)
struct
{
/* Latest version of Xcode clang complains about empty structs in C v. C++:
error: empty struct has size 0 in C, size 1 in C++
*/
int dummy;
/* No Cocoa window events yet */
} cocoa;
#endif
#if defined(SDL_VIDEO_DRIVER_UIKIT)
struct
{
int dummy;
/* No UIKit window events yet */
} uikit;
#endif
#if defined(SDL_VIDEO_DRIVER_VIVANTE)
struct
{
int dummy;
/* No Vivante window events yet */
} vivante;
#endif
#if defined(SDL_VIDEO_DRIVER_OS2)
struct
{
BOOL fFrame; /**< TRUE if hwnd is a frame window */
HWND hwnd; /**< The window receiving the message */
ULONG msg; /**< The message identifier */
MPARAM mp1; /**< The first first message parameter */
MPARAM mp2; /**< The second first message parameter */
} os2;
#endif
/* Can't have an empty union */
int dummy;
} msg;
};