drivers/gp2x/throttle.c

   1 #include <sys/time.h>
   2 #include "../common/settings.h"
   3 #include "main.h"
   4 #include "minimal.h"
   5 #include "throttle.h"
   6
   7
   8 extern uint8 PAL;
   9 extern int FSkip;
  10 static int skip_count = 0;
  11 static struct timeval tv_prev;
  12
  13 #define tvdiff(tv1, tv2) \
  14         ((tv1.tv_sec - tv2.tv_sec) * 1000000 + tv1.tv_usec - tv2.tv_usec)
  15
  16 #define tvadd(tv, usec) { \
  17         tv.tv_usec += usec; \
  18         if (tv.tv_usec >= 1000000) { \
  19                 tv.tv_sec += 1; \
  20                 tv.tv_usec -= 1000000; \
  21         } \
  22 }
  23
  24 #define tvsub(tv, usec) { \
  25         tv.tv_usec -= usec; \
  26         if (tv.tv_usec < 0) { \
  27                 tv.tv_sec -= 1; \
  28                 tv.tv_usec += 1000000; \
  29         } \
  30 }
  31
  32 void RefreshThrottleFPS(void)
  33 {
  34         skip_count = 0;
  35         if (Settings.perfect_vsync)
  36         {
  37                 gp2x_video_wait_vsync();
  38         }
  39         gettimeofday(&tv_prev, 0);
  40         tvsub(tv_prev, PAL ? 19997 : 16639);
  41 }
  42
  43 static void wait_to(struct timeval *tv_aim)
  44 {
  45         struct timeval tv_now;
  46         int diff;
  47
  48         do
  49         {
  50                 gettimeofday(&tv_now, 0);
  51                 diff = tvdiff((*tv_aim), tv_now);
  52         }
  53         while (diff > 0);
  54 }
  55
  56 #include <stdio.h>
  57 void SpeedThrottle(void)
  58 {
  59         struct timeval tv_now, tv_aim;
  60         int frame_time = PAL ? 19997 : 16639; // ~50.007, 19.997 ms/frame : ~60.1, 16.639 ms/frame
  61         int tdiff;
  62
  63         tv_aim = tv_prev;
  64         tvadd(tv_aim, frame_time);
  65
  66         gettimeofday(&tv_now, 0);
  67         tdiff = tvdiff(tv_now, tv_aim);
  68
  69 #ifdef FRAMESKIP
  70         if (Settings.frameskip >= 0)
  71         {
  72                 if (skip_count >= Settings.frameskip)
  73                         skip_count = 0;
  74                 else {
  75                         skip_count++;
  76                         FSkip = 1;
  77                 }
  78         }
  79         else if (tdiff >= frame_time)
  80         {
  81                 /* auto frameskip */
  82                 if (/*tdiff < 36*1024 &&*/ skip_count < 6) {    // limit frameskip
  83                         FSkip = 1;
  84                         skip_count++;
  85                 } else
  86                         skip_count = 0;
  87
  88                 if (tdiff < 92*1024)
  89                         tv_prev = tv_aim;
  90                 else
  91                         tv_prev = tv_now; // something went wrong, try to recover
  92                 return;
  93         }
  94         else
  95                 skip_count = 0;
  96 #endif
  97
  98         /* throttle */
  99         if (tdiff < 0)
 100         {
 101                 if (Settings.perfect_vsync)
 102                 {
 103                         if (tdiff <= (PAL ? 19997/2 : 16639/2))
 104                         {
 105                                 struct timeval tv_tmp = tv_aim;
 106                                 tvsub(tv_tmp, 5000);
 107                                 wait_to(&tv_tmp);
 108                         }
 109                         gp2x_video_wait_vsync();
 110                         gettimeofday(&tv_prev, 0);
 111                         return;
 112                 }
 113                 else
 114                 {
 115                         wait_to(&tv_aim);
 116                 }
 117         }
 118
 119         tv_prev = tv_aim;
 120 }
 121