SDL_!PushEvent?- Pushes an event onto the event queue
The event queue can actually be used as a two way
communication channel. Not only can events be read from the
queue, but the user can also push their own events onto it.
event is a pointer to the event structure you wish to
push onto the queue.
Pushing device input events onto the queue doesn't modify
the state of the device within SDL.
Returns 0 on success or -1 if the event
couldn't be pushed.