SDL_AddTimer(3) SDL API Reference SDL_AddTimer(3)NAME
SDL_AddTimer- Add a timer which will call a callback after the speci‐
fied number of milliseconds has elapsed.
SDL_TimerID SDL_AddTimer(Uint32 interval, SDL_NewTimerCallback call‐
back, void *param);
/* type definition for the "new" timer callback function */
typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);
Adds a callback function to be run after the specified number of mil‐
liseconds has elapsed. The callback function is passed the current
timer interval and the user supplied parameter from the SDL_AddTimer
call and returns the next timer interval. If the returned value from
the callback is the same as the one passed in, the periodic alarm con‐
tinues, otherwise a new alarm is scheduled.
To cancel a currently running timer call SDL_RemoveTimer with the timer
ID returned from SDL_AddTimer.
The timer callback function may run in a different thread than your
main program, and so shouldn't call any functions from within itself.
You may always call SDL_PushEvent, however.
The granularity of the timer is platform-dependent, but you should
count on it being at least 10 ms as this is the most common number.
This means that if you request a 16 ms timer, your callback will run
approximately 20 ms later on an unloaded system. If you wanted to set a
flag signaling a frame update at 30 frames per second (every 33 ms),
you might set a timer for 30 ms (see example below). If you use this
function, you need to pass SDL_INIT_TIMER to SDL_Init.
Returns an ID value for the added timer or NULL if there was an error.
my_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);
SDL Tue 11 Sep 2001, 23:01 SDL_AddTimer(3)