Can you explain how to use SDL timers to trigger events at regular intervals?

Question

Ryan McCombe · Accepted Answer

SDL timers are a useful tool to perform actions at set intervals, independent of your main game loop. Here's a simple way to set up a timer that triggers every second:

1#include <SDL.h>
2#include <iostream>
3
4Uint32 my_callback(Uint32 interval, void* param) {
5  std::cout << "Timer callback triggered!\n";
6  // Return the interval to reset the timer
7  return interval;
8}
9
10int main(int argc, char** argv) {
11  SDL_Init(SDL_INIT_TIMER);
12  SDL_TimerID my_timer_id = SDL_AddTimer(
13    1000, my_callback, NULL
14  );
15
16  bool running = true;
17  SDL_Event event;
18  while (running) {
19    while (SDL_PollEvent(&event)) {
20      if (event.type == SDL_QUIT) running = false;
21    }
22  }
23
24  SDL_RemoveTimer(my_timer_id);
25  SDL_Quit();
26  return 0;
27}

1Timer callback triggered!
2Timer callback triggered!
3Timer callback triggered!

This timer will call my_callback() every 1000 milliseconds (1 second), and it will print a message to the console each time it is triggered.

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