85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/* FCE Ultra - NES/Famicom Emulator
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*
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* Copyright notice for this file:
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* Copyright (C) 2002 Xodnizel
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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static uint64 tmethod, tfreq;
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static uint64 desiredfps;
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static void RefreshThrottleFPS(void) {
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desiredfps = FCEUI_GetDesiredFPS() >> 8;
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}
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static uint64 GetCurTime(void) {
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if (tmethod) {
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uint64 tmp;
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/* Practically, LARGE_INTEGER and uint64 differ only by signness and name. */
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QueryPerformanceCounter((LARGE_INTEGER*)&tmp);
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return(tmp);
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} else
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return((uint64)GetTickCount());
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}
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static void InitSpeedThrottle(void) {
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tmethod = 0;
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if (QueryPerformanceFrequency((LARGE_INTEGER*)&tfreq)) {
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tmethod = 1;
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} else
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tfreq = 1000;
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tfreq <<= 16; /* Adjustment for fps returned from FCEUI_GetDesiredFPS(). */
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}
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static int SpeedThrottle(void) {
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static uint64 ttime, ltime;
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waiter:
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ttime = GetCurTime();
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if ((ttime - ltime) < (tfreq / desiredfps)) {
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uint64 sleepy;
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sleepy = (tfreq / desiredfps) - (ttime - ltime);
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sleepy *= 1000;
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sleepy /= tfreq >> 16;
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Sleep(sleepy);
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goto waiter;
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}
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if ((ttime - ltime) >= (tfreq * 4 / desiredfps))
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ltime = ttime;
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else {
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ltime += tfreq / desiredfps;
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if ((ttime - ltime) >= (tfreq / desiredfps))// Oops, we're behind!
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return(1);
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}
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return(0);
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}
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// Quick code for internal FPS display.
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uint64 FCEUD_GetTime(void) {
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return(GetCurTime());
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}
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uint64 FCEUD_GetTimeFreq(void) {
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return(tfreq >> 16);
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}
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