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1 | #include <sys/time.h> |
2 | #include <unistd.h> |
3 | |
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4 | #include "../common/main.h" |
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5 | #include "../common/throttle.h" |
6 | #include "../common/settings.h" |
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7 | |
8 | |
9 | extern uint8 PAL; |
10 | extern int FSkip; |
11 | static int usec_aim = 0, usec_done = 0; |
12 | static int skip_count = 0; |
13 | |
14 | void RefreshThrottleFPS(void) |
15 | { |
16 | usec_aim = usec_done = skip_count = 0; |
17 | } |
18 | |
19 | void SpeedThrottle(void) |
20 | { |
21 | static struct timeval tv_prev; |
22 | struct timeval tv_now; |
23 | int delta_nom = PAL ? 19997 : 16639; // ~50.007, 19.997 ms/frame : ~60.1, 16.639 ms/frame |
24 | |
25 | |
26 | if (usec_done == 0) { // first time |
27 | usec_done = 1; |
28 | gettimeofday(&tv_prev, 0); |
29 | return; |
30 | } |
31 | |
32 | gettimeofday(&tv_now, 0); |
33 | |
34 | usec_aim += delta_nom; |
35 | if (tv_now.tv_sec != tv_prev.tv_sec) |
36 | usec_done += 1000000; |
37 | usec_done += tv_now.tv_usec - tv_prev.tv_usec; |
38 | |
39 | #ifdef FRAMESKIP |
40 | if (Settings.frameskip >= 0) |
41 | { |
42 | if (skip_count >= Settings.frameskip) |
43 | skip_count = 0; |
44 | else { |
45 | skip_count++; |
46 | FSkip = 1; |
47 | } |
48 | } |
49 | else if (usec_done > usec_aim + 1024*4) |
50 | { |
51 | /* auto frameskip */ |
52 | if (usec_done - usec_aim > 1024*32) |
53 | usec_done = usec_aim = 1; // too much behind, try to recover.. |
54 | else |
55 | FSkip = 1; |
56 | tv_prev = tv_now; |
57 | return; |
58 | } |
59 | #endif |
60 | |
61 | tv_prev = tv_now; |
62 | while (usec_done < usec_aim) |
63 | { |
64 | usleep(300); |
65 | gettimeofday(&tv_now, 0); |
66 | |
67 | if (tv_now.tv_sec != tv_prev.tv_sec) |
68 | usec_done += 1000000; |
69 | usec_done += tv_now.tv_usec - tv_prev.tv_usec; |
70 | tv_prev = tv_now; |
71 | } |
72 | usec_done = usec_done - usec_aim + 1; // reset to prevent overflows |
73 | usec_aim = 0; |
74 | } |
75 | |