From: Antonio Ospite <ospite@studenti.unina.it>
Date: Tue, 17 Dec 2013 23:15:44 +0000 (+0100)
Subject: Calculate the limit delay once and for all
X-Git-Url: https://git.ao2.it/experiments/fps-limit.git/commitdiff_plain

Calculate the limit delay once and for all
---

diff --git a/fps-limit.h b/fps-limit.h
index 376fb77..d19df1c 100644
--- a/fps-limit.h
+++ b/fps-limit.h
@@ -50,7 +50,7 @@
 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)
@@ -60,7 +60,7 @@ static void fps_limit_init(struct fps_limit_stats *stats, unsigned int fps)
 	clock_gettime(CLOCK_MONOTONIC, &stats->time_start);
 	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)
@@ -75,11 +75,11 @@ static void fps_limit_sleep(struct fps_limit_stats *stats)
 	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;
+		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);