1SDL_AddTimer(3)                SDL API Reference               SDL_AddTimer(3)
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NAME

6       SDL_AddTimer  - Add a timer which will call a callback after the speci‐
7       fied number of milliseconds has elapsed.
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SYNOPSIS

10       #include "SDL.h"
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12       SDL_TimerID SDL_AddTimer(Uint32  interval,  SDL_NewTimerCallback  call‐
13       back, void *param);
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CALLBACK

16       /* type definition for the "new" timer callback function */
17       typedef Uint32 (*SDL_NewTimerCallback)(Uint32 interval, void *param);
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DESCRIPTION

20       Adds  a  callback function to be run after the specified number of mil‐
21       liseconds has elapsed. The callback  function  is  passed  the  current
22       timer  interval  and  the user supplied parameter from the SDL_AddTimer
23       call and returns the next timer interval. If the  returned  value  from
24       the  callback is the same as the one passed in, the periodic alarm con‐
25       tinues, otherwise a new alarm is scheduled.
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27       To cancel a currently running timer call SDL_RemoveTimer with the timer
28       ID returned from SDL_AddTimer.
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30       The  timer  callback  function  may run in a different thread than your
31       main program, and so shouldn't call any functions from  within  itself.
32       You may always call SDL_PushEvent, however.
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34       The  granularity  of  the  timer  is platform-dependent, but you should
35       count on it being at least 10 ms as this is  the  most  common  number.
36       This  means  that  if you request a 16 ms timer, your callback will run
37       approximately 20 ms later on an unloaded system. If you wanted to set a
38       flag  signaling  a  frame update at 30 frames per second (every 33 ms),
39       you might set a timer for 30 ms (see example below). If  you  use  this
40       function, you need to pass SDL_INIT_TIMER to SDL_Init.
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RETURN VALUE

43       Returns an ID value for the added timer or NULL if there was an error.
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EXAMPLES

46       my_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);
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SEE ALSO

49       SDL_RemoveTimer, SDL_PushEvent
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53SDL                         Tue 11 Sep 2001, 23:01             SDL_AddTimer(3)
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