Tao.Sdl SDK Documentation

Sdl.SDL_AddTimer Method 

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

[Visual Basic]
Public Shared Function SDL_AddTimer( _
   ByVal interval As Integer, _
   ByVal callback As SDL_NewTimerCallback _
) As SDL_TimerID
[C#]
public static SDL_TimerID SDL_AddTimer(
   int interval,
   SDL_NewTimerCallback callback
);

Parameters

interval
The timer interval.
callback
The callback to run.

Return Value

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

Remarks

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, 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.

Binds to C-function call in SDL_timer.h:

extern DECLSPEC SDL_TimerID SDLCALL
            SDL_AddTimer(Uint32 interval,
            SDL_NewTimerCallback callback, void *param)

See Also

Sdl Class | Tao.Sdl Namespace