drivers/pc/throttle.c

   1 #include <sys/time.h>
   2 #include "main.h"
   3 #include "throttle.h"
   4
   5 static uint64 tfreq;
   6 static uint64 desiredfps;
   7
   8 void RefreshThrottleFPS(void)
   9 {
  10  uint64 f=FCEUI_GetDesiredFPS();
  11  // great, a bit faster than before
  12  //f = (f*65) >> 6;
  13  desiredfps=f>>8;
  14  tfreq=1000000;
  15  tfreq<<=16;    /* Adjustment for fps returned from FCEUI_GetDesiredFPS(). */
  16 }
  17
  18 static uint64 GetCurTime(void)
  19 {
  20  uint64 ret;
  21  struct timeval tv;
  22
  23  gettimeofday(&tv,0);
  24  ret=(uint64)tv.tv_sec*1000000;
  25  ret+=tv.tv_usec;
  26  return(ret);
  27 }
  28
  29 INLINE void SpeedThrottle(void)
  30 {
  31  static uint64 ttime,ltime;
  32
  33  waiter:
  34
  35  ttime=GetCurTime();
  36
  37  if( (ttime-ltime) < (tfreq/desiredfps) )
  38  {
  39   goto waiter;
  40  }
  41  if( (ttime-ltime) >= (tfreq*4/desiredfps))
  42   ltime=ttime;
  43  else
  44   ltime+=tfreq/desiredfps;
  45 }
  46