From 93dbfa04b748e88da523afcff1a217abe8ddf525 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 26 Dec 2006 17:37:06 +0000
Subject: [PATCH] Aded new convinience methods to osg::Timer - s/getStartTick
 and time_s(), time_m() etc to help get time reletive the new start tick.

---
 include/osg/Timer | 34 +++++++++++++++++++++++++++++++---
 src/osg/Timer.cpp |  6 +++++-
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/include/osg/Timer b/include/osg/Timer
index 74f75aa13..5255d710a 100644
--- a/include/osg/Timer
+++ b/include/osg/Timer
@@ -24,7 +24,7 @@ namespace osg {
     typedef unsigned long long Timer_t;
 #endif
 
-/** Time stamper. */
+/** Timer class is used for measuring elapsed time or time between two points. */
 class OSG_EXPORT Timer {
 
     public:
@@ -32,20 +32,48 @@ class OSG_EXPORT Timer {
         Timer();
         ~Timer() {}
 
-        static const Timer* instance();
+        static Timer* instance();
 
+        /** Get the timers tick value.*/
         Timer_t tick() const;
+
+        /** Set the start.*/
+        void setStartTick() { _startTick = tick(); }
+        void setStartTick(Timer_t t) { _startTick = t; }
+        Timer_t getStartTick() const { return _startTick; }
+
         
+        /** Get elapsed time in seconds.*/
+        inline double time_s() const { return delta_s(_startTick, tick()); }
+
+        /** Get elapsed time in milliseconds.*/
+        inline double time_m() const { return delta_m(_startTick, tick()); }
+
+        /** Get elapsed time in micoseconds.*/
+        inline double time_u() const { return delta_u(_startTick, tick()); }
+
+        /** Get elapsed time in nanoseconds.*/
+        inline double time_n() const { return delta_n(_startTick, tick()); }
+        
+        /** Get the time in seconds between timer ticks t1 and t2.*/
         inline double delta_s( Timer_t t1, Timer_t t2 ) const { return (double)(t2 - t1)*_secsPerTick; }
+
+        /** Get the time in milliseconds between timer ticks t1 and t2.*/
         inline double delta_m( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e3; }
+
+        /** Get the time in microseconds between timer ticks t1 and t2.*/
         inline double delta_u( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e6; }
+
+        /** Get the time in nanoseconds between timer ticks t1 and t2.*/
         inline double delta_n( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e9; }
         
+        /** Get the the numer of ticks per second.*/
         inline double getSecondsPerTick() const { return _secsPerTick; }
 
     protected :
 
-        double _secsPerTick;
+        Timer_t _startTick;
+        double  _secsPerTick;
 
 };
 
diff --git a/src/osg/Timer.cpp b/src/osg/Timer.cpp
index fd5d28ca3..3a5c450c0 100644
--- a/src/osg/Timer.cpp
+++ b/src/osg/Timer.cpp
@@ -26,7 +26,7 @@ using namespace osg;
 // all the rest of the timer methods are implemented within the header.
 
 
-const Timer* Timer::instance()
+Timer* Timer::instance()
 {
     static Timer s_timer;
     return &s_timer;
@@ -51,6 +51,8 @@ const Timer* Timer::instance()
             notify(NOTICE)<<"Error: Timer::Timer() unable to use QueryPerformanceFrequency, "<<std::endl;
             notify(NOTICE)<<"timing code will be wrong, Windows error code: "<<GetLastError()<<std::endl;
         }
+        
+        setStartTick();        
     }
 
     Timer_t Timer::tick() const
@@ -75,6 +77,8 @@ const Timer* Timer::instance()
     Timer::Timer( void )
     {
         _secsPerTick = (1.0 / (double) 1000000);
+
+        setStartTick();        
     }
 
     Timer_t Timer::tick() const