#include <time.h>
#ifdef DEBUG
-#define dbg(...) \
+#define fps_limit_dbg(...) \
do { \
printf(__VA_ARGS__); \
printf("\n"); \
fflush(stdout); \
} while(0)
#else
-#define dbg(...) do {} while(0)
+#define fps_limit_dbg(...) do {} while(0)
#endif
#define NSEC_PER_SEC 1000000000
-#define timespecsub(a, b, result) \
+#define fps_limit_timespecsub(a, b, result) \
do { \
(result)->tv_sec = (a)->tv_sec - (b)->tv_sec; \
(result)->tv_nsec = (a)->tv_nsec - (b)->tv_nsec; \
struct fps_limit_stats {
struct timespec time_start;
struct timespec time_end;
- unsigned int fps;
+ unsigned int delay;
};
static void fps_limit_init(struct fps_limit_stats *stats, unsigned int fps)
memset(stats, 0, sizeof(*stats));
clock_gettime(CLOCK_MONOTONIC, &stats->time_start);
- dbg("Init time: s: %ld, ns: %ld", stats->time_start.tv_sec, stats->time_start.tv_nsec);
+ fps_limit_dbg("Init time: s: %ld, ns: %ld", stats->time_start.tv_sec, stats->time_start.tv_nsec);
- stats->fps = fps;
+ stats->delay = NSEC_PER_SEC / fps;
}
static void fps_limit_sleep(struct fps_limit_stats *stats)
{
struct timespec elapsed;
- dbg("Start time: s: %ld, ns: %ld", stats->time_start.tv_sec, stats->time_start.tv_nsec);
+ fps_limit_dbg("Start time: s: %ld, ns: %ld", stats->time_start.tv_sec, stats->time_start.tv_nsec);
clock_gettime(CLOCK_MONOTONIC, &stats->time_end);
- dbg("End time: s: %ld, ns: %ld", stats->time_end.tv_sec, stats->time_end.tv_nsec);
+ fps_limit_dbg("End time: s: %ld, ns: %ld", stats->time_end.tv_sec, stats->time_end.tv_nsec);
- timespecsub(&stats->time_end, &stats->time_start, &elapsed);
- dbg("Elapsed s: %ld ns: %ld", elapsed.tv_sec, elapsed.tv_nsec);
+ fps_limit_timespecsub(&stats->time_end, &stats->time_start, &elapsed);
+ fps_limit_dbg("Elapsed s: %ld ns: %ld", elapsed.tv_sec, elapsed.tv_nsec);
- if (elapsed.tv_sec == 0 && elapsed.tv_nsec < NSEC_PER_SEC / stats->fps) {
+ if (elapsed.tv_sec == 0 && elapsed.tv_nsec < stats->delay) {
struct timespec remaining = {0, 0};
/* remaining delay, _relative_ to time_end */
- remaining.tv_nsec = (NSEC_PER_SEC / stats->fps) - elapsed.tv_nsec;
- dbg("Sleeping for: ns: %ld", remaining.tv_nsec);
+ remaining.tv_nsec = stats->delay - elapsed.tv_nsec;
+ fps_limit_dbg("Sleeping for: ns: %ld", remaining.tv_nsec);
clock_nanosleep(CLOCK_MONOTONIC, 0, &remaining, NULL);
}