no longer zeroing _delta_time if nanosecond element of difference between last and next time is negative

src/engine.c

@@ -75,7 +75,6 @@ int _engine_run() {
 	while(g_context.running) {
 		timespec_get(&next_time, TIME_UTC);
 		_delta_time = timespec_to_sec(next_time) - timespec_to_sec(start_last_frame);
-		if(next_time.tv_nsec < start_last_frame.tv_nsec) _delta_time = 0;
 		start_last_frame = next_time;
 		_handle_events();
 		update_input();