/*  
 *	Timer.c: Functions to invoke the Amiga timer
 *	05Jul86  - Created by Jeff Lydiatt, Vancouver, Canada.
 *
 *	Amiga Library
 *
 *	$Id: timer.c,v 1.2 90/01/16 10:27:38 crash Exp Locker: crash $
 */

#ifndef lint
static char RCSid[] = "$Id: timer.c,v 1.2 90/01/16 10:27:38 crash Exp Locker: crash $";
#endif /* lint */

#include <exec/types.h>
#include <exec/nodes.h>
#include <exec/lists.h>
#include <exec/ports.h>
#include <exec/tasks.h>
#include <exec/io.h>
#include <devices/timer.h>

#ifdef MCH_AMIGA
# include <functions.h>		/* Manx */
#else
# include <proto/exec.h>	/* Lattice */
#endif

static struct timerequest TimerIO;
static struct MsgPort *TimerPort = NULL;
static BOOL timerON;
static BOOL timerExpired;

/*--------------------------------------------------------------*/
/*	OpenTimer: return TRUE if timer opened OK					*/
/*--------------------------------------------------------------*/

BOOL OpenTimer()
{
	register struct timerequest *t = &TimerIO;
	register struct MsgPort *port;

	timerON = FALSE;
	timerExpired = TRUE;
	if (TimerPort != NULL)
		return TRUE;

	if ((port = CreatePort("Timer Port", 0L)) == NULL)
		return FALSE;
	else
		TimerPort = port;

	if (OpenDevice(TIMERNAME, UNIT_VBLANK, t, 0L)) {
		DeletePort(port);
		TimerPort = NULL;
		return FALSE;
	}
	return TRUE;
}


/*--------------------------------------------------------------*/
/*	CloseTimer: All Done with the timer.						*/
/*--------------------------------------------------------------*/

void CloseTimer()
{
	register struct timerequest *t = &TimerIO;

	if (timerON) AbortIO(t);

	CloseDevice(t);
	DeletePort(TimerPort);
	TimerPort = NULL;
}


/*--------------------------------------------------------------*/
/*	GetTimerSigBit: return Timer signal bit						*/
/*--------------------------------------------------------------*/

int	GetTimerSigBit()
{
	return TimerPort->mp_SigBit;
}


/*--------------------------------------------------------------*/
/*	StartTimer: launch the timer.								*/
/*--------------------------------------------------------------*/

void StartTimer(seconds, micros)
ULONG seconds, micros;
{
	register struct timerequest *t = &TimerIO;

	if (timerON) {
		AbortIO(t);
		(void) GetMsg(TimerPort);
		timerON = FALSE;
		timerExpired = TRUE;
	}
	t->tr_time.tv_secs    = seconds;
	t->tr_time.tv_micro   = micros;
	t->tr_node.io_Command = TR_ADDREQUEST;
	t->tr_node.io_Flags   = IOF_QUICK;
	t->tr_node.io_Error   = 0;
	t->tr_node.io_Message.mn_ReplyPort = TimerPort;
	SendIO(t);
	timerExpired = FALSE;
	timerON = TRUE;
}


/*--------------------------------------------------------------*/
/*	TimerExpired: returns TRUE if timer expired.				*/
/*--------------------------------------------------------------*/

BOOL TimerExpired()
{
	if (timerON && (CheckIO(&TimerIO.tr_node) == NULL))
		return FALSE;

	(void) GetMsg(TimerPort);
	timerExpired = TRUE;
	timerON = FALSE;

	return timerExpired;
}