[fceu.git] / drivers / win / throttle.c

/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Ben Parnell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

static uint64 tmethod,tfreq;
static uint64 desiredfps;

static void RefreshThrottleFPS(void)
{
 desiredfps=FCEUI_GetDesiredFPS()>>8;
}

static uint64 GetCurTime(void)
{
 if(tmethod)
 {
  uint64 tmp;

  /* Practically, LARGE_INTEGER and uint64 differ only by signness and name. */
  QueryPerformanceCounter((LARGE_INTEGER*)&tmp);

  return(tmp);
 }
 else
  return((uint64)GetTickCount());

}

static void InitSpeedThrottle(void)
{
 tmethod=0;
 if(QueryPerformanceFrequency((LARGE_INTEGER*)&tfreq))
 {
  tmethod=1;
 }
 else
  tfreq=1000;
 tfreq<<=16;    /* Adjustment for fps returned from FCEUI_GetDesiredFPS(). */
}


static void SpeedThrottle(void)
{
 static uint64 ttime,ltime;

 waiter:

 ttime=GetCurTime();

                            
 if( (ttime-ltime) < (tfreq/desiredfps) )
  goto waiter;
 if( (ttime-ltime) >= (tfreq*4/desiredfps))
  ltime=ttime;
 else
  ltime+=tfreq/desiredfps;
}
Commit	Line	Data
c62d2810	1	/* FCE Ultra - NES/Famicom Emulator
	2	*
	3	* Copyright notice for this file:
	4	* Copyright (C) 2002 Ben Parnell
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	static uint64 tmethod,tfreq;
	22	static uint64 desiredfps;
	23
	24	static void RefreshThrottleFPS(void)
	25	{
	26	desiredfps=FCEUI_GetDesiredFPS()>>8;
	27	}
	28
	29	static uint64 GetCurTime(void)
	30	{
	31	if(tmethod)
	32	{
	33	uint64 tmp;
	34
	35	/* Practically, LARGE_INTEGER and uint64 differ only by signness and name. */
	36	QueryPerformanceCounter((LARGE_INTEGER*)&tmp);
	37
	38	return(tmp);
	39	}
	40	else
	41	return((uint64)GetTickCount());
	42
	43	}
	44
	45	static void InitSpeedThrottle(void)
	46	{
	47	tmethod=0;
	48	if(QueryPerformanceFrequency((LARGE_INTEGER*)&tfreq))
	49	{
	50	tmethod=1;
	51	}
	52	else
	53	tfreq=1000;
	54	tfreq<<=16; /* Adjustment for fps returned from FCEUI_GetDesiredFPS(). */
	55	}
	56
	57
	58	static void SpeedThrottle(void)
	59	{
	60	static uint64 ttime,ltime;
	61
	62	waiter:
	63
	64	ttime=GetCurTime();
65
66
67	if( (ttime-ltime) < (tfreq/desiredfps) )
68	goto waiter;
69	if( (ttime-ltime) >= (tfreq*4/desiredfps))
70	ltime=ttime;
71	else
72	ltime+=tfreq/desiredfps;
73	}