// hrTimer.cpp
// a High Resolution Timer for C++ code
// from: How do I do High Resolution Timing in C++ on Windows?
//       A Very Accurate Timer
//       By David Bolton, About.com

// revised by tom bailey   16 sep 08


#include "hrTimer.h"

LARGE_INTEGER getFrequency() 
{
	LARGE_INTEGER freq;
	QueryPerformanceFrequency( &freq );
	return freq;
}

LARGE_INTEGER Timer::frequency = getFrequency();

Timer::Timer()
	: running( false )
{
	elapsedTime.QuadPart = 0;
}

void Timer::start( ) 
{
   if( !running ) {
      QueryPerformanceCounter( &startTime ) ;
      running = true;
   }
    
}

void
Timer::stop() {
   LARGE_INTEGER stopTime;
   if( running ) {
      QueryPerformanceCounter( &stopTime ) ;
      running = false;
	  elapsedTime.QuadPart += stopTime.QuadPart - startTime.QuadPart;
   }
}

double 
Timer::operator()() 
{
   if( running ) {
      stop();
      start();
      }
   return double( elapsedTime.QuadPart) / double( frequency.QuadPart );
}

void
Timer::reset() 
{
   if( running ) {
      stop();
      elapsedTime.QuadPart = 0;
      start();
      }
   else
      elapsedTime.QuadPart = 0;
}

long
Timer::qpart() 
{
	return long( elapsedTime.QuadPart );
}