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AG_CUSTOMEVENTLOOP(3)	    Library Functions Manual	 AG_CUSTOMEVENTLOOP(3)

NAME
       AG_CustomEventLoop -- agar GUI custom event loop	example

SYNOPSIS
       #include	<agar/core.h>
       #include	<agar/gui.h>

DESCRIPTION
       In  general, most Agar GUI applications will use	the standard Agar-Core
       event loop, AG_EventLoop(3), since it uses the most efficient event-no-
       tification  mechanism  available	 for  the   target   platform	(e.g.,
       kqueue(2), select(2), etc.)

       However,	 Agar-GUI  applications	are not	required to use	AG_EventLoop()
       at all, and may use an application-specific  event  loop	 routine.   To
       simplify	  writing   of	 custom	  event	  loops,   Agar	 provides  the
       AG_GetNextEvent(3), AG_ProcessEvent(3) and AG_ProcessTimeouts(3)	 func-
       tions.	Low-level  driver  events  are represented by the transparent,
       driver-independent AG_DriverEvent structure (see	AG_Driver(3)  for  de-
       tails and examples).

CUSTOM EVENT LOOP EXAMPLE
       The  following event loop redraws Agar windows whenever needed (the re-
       draw frequency being limited to some nomimal frame rate), processes in-
       put events, and executes	timer callbacks	(using	an  inefficient	 delay
       loop):

       void
       MY_GenericEventLoop(void	*obj)
       {
	       AG_Window *win;
	       Uint32 t1, t2;

	       t1 = AG_GetTicks();
	       for (;;)	{
		       t2 = AG_GetTicks();
		       if (t2 -	t1 >= rNom) {
			       AG_WindowDrawQueued();

			       t1 = AG_GetTicks();
			       rCur = rNom - (t1-t2);
			       if (rCur	< 1) { rCur = 1; }
		       } else if (AG_PendingEvents(NULL)) {
			       AG_DriverEvent dev;

			       if (AG_GetNextEvent(NULL, &dev) == 1)
				       AG_ProcessEvent(NULL, &dev);
		       } else {
			       AG_ProcessTimeouts(t2);
			       AG_Delay(1);
		       }
		       AG_WindowProcessQueued();
	       }
       }

SEE ALSO
       AG_Delay(3),  AG_Driver(3),  AG_Event(3), AG_EventLoop(3), AG_Timer(3),
       AG_Window(3)

HISTORY
       The  AG_CustomEventLoop	routine	 first	appeared  in  Agar  1.0.   The
       AG_GetNextEvent() interface appeared in Agar 1.4.0.

Agar 1.7		       December	21, 2022	 AG_CUSTOMEVENTLOOP(3)

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