From 5a89b4f3854f2ec0811cd2adbdeb84b3445ae08f Mon Sep 17 00:00:00 2001
From: Erwin Coumans <erwin.coumans@gmail.com>
Date: Fri, 2 Jun 2017 08:18:17 -0700
Subject: [PATCH] allow b3Clock to reset to time reference 0, by default reset
 will set the reference to 'now'.

---
 examples/Utils/b3Clock.cpp | 18 +++++++++++++++++-
 examples/Utils/b3Clock.h   |  4 ++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/examples/Utils/b3Clock.cpp b/examples/Utils/b3Clock.cpp
index bcf7d13ba..de2134b56 100644
--- a/examples/Utils/b3Clock.cpp
+++ b/examples/Utils/b3Clock.cpp
@@ -88,8 +88,23 @@ b3Clock& b3Clock::operator=(const b3Clock& other)
 
 
 	/// Resets the initial reference time.
-void b3Clock::reset()
+void b3Clock::reset(bool zeroReference)
 {
+	if (zeroReference)
+	{
+		m_data->mStartTick = 0;
+#ifdef B3_USE_WINDOWS_TIMERS
+		m_data->mStartTime.QuadPart = 0;
+#else
+	#ifdef __CELLOS_LV2__
+			m_data->mStartTime = 0;
+	#else
+			m_data->mStartTime = (struct timeval){0};
+	#endif
+#endif
+
+	} else
+	{
 #ifdef B3_USE_WINDOWS_TIMERS
 	QueryPerformanceCounter(&m_data->mStartTime);
 	m_data->mStartTick = GetTickCount();
@@ -105,6 +120,7 @@ void b3Clock::reset()
 	gettimeofday(&m_data->mStartTime, 0);
 #endif
 #endif
+	}
 }
 
 /// Returns the time in ms since the last call to reset or since 
diff --git a/examples/Utils/b3Clock.h b/examples/Utils/b3Clock.h
index 10a36686a..1cdd28847 100644
--- a/examples/Utils/b3Clock.h
+++ b/examples/Utils/b3Clock.h
@@ -13,8 +13,8 @@ public:
 
 	~b3Clock();
 
-	/// Resets the initial reference time.
-	void reset();
+	/// Resets the initial reference time. If zeroReference is true, will set reference to absolute 0.
+	void reset(bool zeroReference=false);
 
 	/// Returns the time in ms since the last call to reset or since 
 	/// the b3Clock was created.