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authorStanislaw Halik <sthalik@misaki.pl>2014-06-11 17:41:44 +0200
committerStanislaw Halik <sthalik@misaki.pl>2014-06-11 17:41:44 +0200
commitafbca18600670b900eaa0ab30a296428d66eaaaf (patch)
tree904bbca04084000503a9dffc08cba413edeaf007 /facetracknoir
parent1603c540fa807b7ff3a2384bf800ba83c61ccdeb (diff)
implement a high-precision timer
untested on OSX so far Signed-off-by: Stanislaw Halik <sthalik@misaki.pl>
Diffstat (limited to 'facetracknoir')
-rw-r--r--facetracknoir/timer.hpp67
1 files changed, 67 insertions, 0 deletions
diff --git a/facetracknoir/timer.hpp b/facetracknoir/timer.hpp
new file mode 100644
index 00000000..306bcaa7
--- /dev/null
+++ b/facetracknoir/timer.hpp
@@ -0,0 +1,67 @@
+#pragma once
+#include <time.h>
+#if defined (_WIN32)
+#include <windows.h>
+static inline void clock_gettime(int, struct timespec* ts)
+{
+ static LARGE_INTEGER freq = 0;
+
+ if (!freq)
+ (void) QueryPerformanceFrequency(&freq);
+
+ freq.QuadPart /= 1000000;
+
+ LARGE_INTEGER d;
+
+ (void) QueryPerformanceCounter(&d);
+
+ d.QuadPart = d.QuadPart / freq.QuadPart;
+
+ ts->tv_sec = d.QuadPart / 1000000;
+ ts->tv_nsec = d.QuadPart % 1000000;
+}
+
+#else
+# if defined(__MACH__)
+# define CLOCK_MONOTONIC 0
+# include <inttypes.h>
+# include <mach/mach_time.h>
+static inline void clock_gettime(int, struct timespec* ts)
+{
+ uint64_t state, nsec;
+ static mach_timebase_info_data_t sTimebaseInfo;
+ if ( sTimebaseInfo.denom == 0 ) {
+ (void) mach_timebase_info(&sTimebaseInfo);
+ }
+ state = mach_absolute_time();
+ nsec = elapsed * sTimebaseInfo.numer / sTimebaseInfo.denom;
+ ts->tv_sec = nsec / 1000000;
+ ts->tv_nsec = nsec % 1000000;
+}
+# else
+class Timer {
+private:
+ struct timespec state;
+ int conv(const struct timespec& cur)
+ {
+ return (cur.tv_sec - state.tv_sec) * 1000L + (cur.tv_nsec - state.tv_nsec) / 1000000L;
+ }
+public:
+ Timer() {
+ start();
+ }
+ int start() {
+ struct timespec cur;
+ (void) clock_gettime(CLOCK_MONOTONIC, &cur);
+ int ret = conv(cur);
+ state = cur;
+ return ret;
+ }
+ int elapsed() {
+ struct timespec cur;
+ (void) clock_gettime(CLOCK_MONOTONIC, &cur);
+ return conv(cur);
+ }
+};
+# endif
+#endif