This is new wiki software and old wiki content. It's a work in progress!
Here's the explanation.
Be gentle, report bugs, leave feedback on pages, or just edit them yourself! Thanks!

SDL Wiki

SDL_PollEvent

Poll for currently pending events.

Syntax

int SDL_PollEvent(SDL_Event * event);

Function Parameters

event

the SDL_Event structure to be filled with the next event from the queue, or NULL

Return Value

Returns 1 if there is a pending event or 0 if there are none available.

Remarks

If event is not NULL, the next event is removed from the queue and stored in the SDL_Event structure pointed to by event. The 1 returned refers to this event, immediately stored in the SDL Event structure -- not an event to follow.

If event is NULL, it simply returns 1 if there is an event in the queue, but will not remove it from the queue.

As this function may implicitly call SDL_PumpEvents(), you can only call this function in the thread that set the video mode.

SDL_PollEvent() is the favored way of receiving system events since it can be done from the main loop and does not suspend the main loop while waiting on an event to be posted.

The common practice is to fully process the event queue once every frame, usually as a first step before updating the game's state:

while (game_is_still_running) {
    SDL_Event event;
    while (SDL_PollEvent(&event)) {  // poll until all events are handled!
        // decide what to do with this event.
    }

    // update game state, draw the current frame
}
SDL_GetEventFilter
SDL_PeepEvents
SDL_PushEvent
SDL_SetEventFilter
SDL_WaitEvent
SDL_WaitEventTimeout

CategoryAPI, CategoryEvents


[ edit | delete | history | feedback | raw ]

[ front page | index | search | recent changes | git repo | offline html ]

All wiki content is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).
Wiki powered by ghwikipp.