Use this function to add a callback to be triggered when an event is added to the event queue.
void SDL_AddEventWatch(SDL_EventFilter filter, void* userdata)
the function to call when an event happens; see Remarks for details
a pointer that is passed to filter
You can add your code example here
The function prototype for filter is:
int YourEventFilter(void* userdata, SDL_Event* event)
where YourEventFilter is the name of your function and its parameters are:
what was passed as userdata to SDL_AddEventWatch()
the event that triggered the callback
filter will be called when an event happens, and its return value is ignored.
WARNING: Be very careful of what you do in the event filter function, as it may run in a different thread!
If the quit event is generated by a signal (e.g. SIGINT), it will bypass the internal queue and be delivered to the watch callback immediately, and arrive at the next event poll.
Note: the callback is called for events posted by the user through SDL_PushEvent(), but not for disabled events, nor for events by a filter callback set with SDL_SetEventFilter(), nor for events posted by the user through SDL_PeepEvents().