Manual Pages for UNIX Operating System command usage for man SDL_AddTimer

SDL API Reference                                 SDL_AddTimer(3)



NAME
     SDL_AddTimer - Add a timer which will call a callback  after
     the specified number of milliseconds has elapsed.

SYNOPSIS
     #include "SDL.h"

     SDL_TimerID          SDL_AddTimer(Uint32           interval,
     SDL_NewTimerCallback callback, void *param);

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

DESCRIPTION
     Adds a callback function  to  be  run  after  the  specified
     number of milliseconds 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 continues,
     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,  how-
     ever.

     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.

RETURN VALUE
     Returns an ID value for the added timer or NULL if there was
     an error.

EXAMPLES
     my_timer_id = SDL_AddTimer((33/10)*10, my_callbackfunc, my_callback_param);

SEE ALSO
     SDL_RemoveTimer, SDL_PushEvent






SDL            Last change: Tue 11 Sep 2001, 23:01              1