| 1 | #include <sys/time.h> |
| 2 | #include "main.h" |
| 3 | #include "gp2x.h" |
| 4 | #include "throttle.h" |
| 5 | |
| 6 | |
| 7 | extern uint8 PAL; |
| 8 | extern int FSkip; |
| 9 | static int usec_aim = 0, usec_done = 0; |
| 10 | static int skip_count = 0; |
| 11 | |
| 12 | void RefreshThrottleFPS(void) |
| 13 | { |
| 14 | usec_aim = usec_done = skip_count = 0; |
| 15 | } |
| 16 | |
| 17 | void SpeedThrottle(void) |
| 18 | { |
| 19 | static struct timeval tv_prev; |
| 20 | struct timeval tv_now; |
| 21 | int delta_nom = PAL ? 19997 : 16639; // ~50.007, 19.997 ms/frame : ~60.1, 16.639 ms/frame |
| 22 | |
| 23 | |
| 24 | if (usec_done == 0) { // first time |
| 25 | usec_done = 1; |
| 26 | gettimeofday(&tv_prev, 0); |
| 27 | return; |
| 28 | } |
| 29 | |
| 30 | gettimeofday(&tv_now, 0); |
| 31 | |
| 32 | usec_aim += delta_nom; |
| 33 | if (tv_now.tv_sec != tv_prev.tv_sec) |
| 34 | usec_done += 1000000; |
| 35 | usec_done += tv_now.tv_usec - tv_prev.tv_usec; |
| 36 | |
| 37 | #ifdef FRAMESKIP |
| 38 | if (Settings.frameskip >= 0) |
| 39 | { |
| 40 | if (skip_count >= Settings.frameskip) |
| 41 | skip_count = 0; |
| 42 | else { |
| 43 | skip_count++; |
| 44 | FSkip = 1; |
| 45 | } |
| 46 | } |
| 47 | else if (usec_done > usec_aim + 1024*4) |
| 48 | { |
| 49 | /* auto frameskip */ |
| 50 | if (usec_done - usec_aim > 1024*32) |
| 51 | usec_done = usec_aim = 1; // too much behind, try to recover.. |
| 52 | else |
| 53 | FSkip = 1; |
| 54 | tv_prev = tv_now; |
| 55 | return; |
| 56 | } |
| 57 | #endif |
| 58 | |
| 59 | tv_prev = tv_now; |
| 60 | while (usec_done < usec_aim) |
| 61 | { |
| 62 | gettimeofday(&tv_now, 0); |
| 63 | |
| 64 | if (tv_now.tv_sec != tv_prev.tv_sec) |
| 65 | usec_done += 1000000; |
| 66 | usec_done += tv_now.tv_usec - tv_prev.tv_usec; |
| 67 | tv_prev = tv_now; |
| 68 | } |
| 69 | usec_done = usec_done - usec_aim + 1; // reset to prevent overflows |
| 70 | usec_aim = 0; |
| 71 | } |
| 72 | |