Sdl event loop. SDL_Event is a union of all event structures used in SDL.
Sdl event loop. h> #include <stdlib. May 20, 2025 · We'll cover both the callback-based main loop and the traditional event polling loop, showing how each can be implemented and their respective advantages. These are just a few of the wide variety of events that we can receive and I strongly recommend reading up about the other types in the SDL_Event documentation. This is done with the function SDL_PollEvent (). May 25, 2024 · The event queue will then store them in the order the events occurred waiting for you to process them. SDL_PollEvent removes the next event from the event queue. SDL supports keyboard, mouse, and joystick input as well as changing applications, quitting the application, resizing windows, and updating the contents of windows. When you want to find out what events occured so you can process them, you poll the event queue to get the most recent event by calling SDL_PollEvent. SDL_Event is a union of all event structures used in SDL. Jun 7, 2025 · The only event type we care about here is the SDL_EVENT_QUIT type which happens when the user X's out the window. state & SDL_APPACTIVE ) { if ( event. 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. As this function may implicitly call SDL_PumpEvents (), you can only call this function in the thread that set the video mode. . Event Examples Filtering and Handling Events #include <stdio. If there are no events on the queue it returns 0, otherwise it returns 1. Jun 10, 2015 · Just wanted to mention the SDL_QUIT event is generated by clicking the X icon on the upper right of the SDL window, not by pressing the Escape key. Each time the event loop is run, you must pull each event off the event queue (in order) to process the input. SDL Event Loop If your game doesn’t read input from the player, you don’t have much of a game. I hope you understand - I found Python examples but they look like weird and wrong - they write like "Latin". From there you can go on to perform other update logic that isn't dependent on system events. Completing the Main Loop The final part of our main loop will take care of Apr 23, 2025 · This chapter describes how keyboard and event handling in general works in Free Pascal and SDL 2. 0. Mac OS X developers Jun 2, 2019 · Without event-loop means you should use SDL_Delay() then game window will close automacally. For information about handling specific input events within your main loop, see Input Handling. active. SDL_Event is a union of all event structures used in SDL, using it is a simple matter of knowing which union member relates to which event type. Dec 16, 2014 · Just loop through frame_events, which you can retrieve via the global function GetFrameEvents, in your HandleInput functions instead of your while loops on SDL_PollEvent. If it does, we set the quit flag to true which will break the main loop after this iteration of the loop is done. gain ) { printf("App activated\n"); } else { printf("App iconified\n"); } } } break; case SDL_MOUSEBUTTONDOWN: { Uint8 *keys; keys = SDL_GetKeyState Description The SDL_Event union is the core to all event handling is SDL, its probably the most important structure after SDL_Surface. You can also create your own events, which you may remember if you read the previous section of this article. h" /* This function may run in a separate event thread */ int FilterEvents(const SDL_Event *event) { static int boycott = 1; /* This quit event signals the closing of the window */ if ( (event->type == SDL_QUIT) && boycott ) { In your programs, you will always have an event (or "game," or "main") loop that processes these events and runs your program based on the input. Aug 20, 2013 · The SDL_QUIT event occurs when the user closes our window, SDL_KEYDOWN occurs when a key is pressed and SDL_MOUSEBUTTONDOWN occurs if a mouse button is pressed. The main loop would look like this: 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. First off, we create an empty SDL_Event structure. Feb 10, 2021 · LazyFoo's Tutorials use SDL_PollEvent in within it's own loop inside the main loop, to ensure all events are handled and not only the 1st one. We use a while loop to process each event in turn. Remarks The SDL_Event structure is the core of all event handling in SDL. h> #include "SDL. This lesson explains the fundamental concept of the application loop - the engine that drives real-time programs. exit(1); } /* Loop waiting for ESC+Mouse_Button */ while ( SDL_WaitEvent(&event) >= 0 ) { switch (event. The SDL_PollEvent function takes a pointer to an SDL_Event structure that is to be filled with event information. type) { case SDL_ACTIVEEVENT: { if ( event. Step-by-step guide on creating the SDL2 application and event loops for interactive games. May 30, 2019 · void update() { SDL_Event event; while(SDL_PollEvent(&event)) { // Handle Event } // Other Update Logic } This will keep calling polling events until there are no more in the queue, at which point SDL_PollEvent returns 0 thus ending the event loop. 1sozhlubdfewejgroczoirxyqyiyuqbtrjztllhrlmditbj8dr