Add fallbacks for systems without proper monotonic clocks (e.g. OS X).

[movit] / main.cpp

diff --git a/main.cpp b/main.cpp
index 9a9a3eac7b7df1c380d28879ac4b12401abb4615..93f8c0cb1823d45e5ae4b8a719d6daa5d38bd73f 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -227,9 +227,14 @@ int main(int argc, char **argv)
 
        make_hsv_wheel_texture();
 
-       struct timespec start, now;
        int frame = 0, screenshot = 0;
+#if _POSIX_C_SOURCE >= 199309L
+       struct timespec start, now;
        clock_gettime(CLOCK_MONOTONIC, &start);
+#else
+       struct timeval start, now;
+       gettimeofday(&start, NULL);
+#endif
 
        while (!quit) {
                SDL_Event event;
@@ -280,9 +285,15 @@ int main(int argc, char **argv)
                check_error();
 
 #if 1
+#if _POSIX_C_SOURCE >= 199309L
                clock_gettime(CLOCK_MONOTONIC, &now);
                double elapsed = now.tv_sec - start.tv_sec +
                        1e-9 * (now.tv_nsec - start.tv_nsec);
+#else
+               gettimeofday(&now, NULL);
+               double elapsed = now.tv_sec - start.tv_sec +
+                       1e-6 * (now.tv_usec - start.tv_usec);
+#endif
                printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
                        frame, elapsed, frame / elapsed,
                        1e3 * elapsed / frame);