/*

 <codex> 

 <abstract>CAHostTimeBase.h</abstract>

 <\codex>

*/

//=============================================================================

//  Includes

//=============================================================================

#include "CAHostTimeBase.h"

Float64 CAHostTimeBase::sFrequency = 0;

Float64 CAHostTimeBase::sInverseFrequency = 0;

UInt32  CAHostTimeBase::sMinDelta = 0;

UInt32  CAHostTimeBase::sToNanosNumerator = 0;

UInt32  CAHostTimeBase::sToNanosDenominator = 0;

UInt32  CAHostTimeBase::sFromNanosNumerator = 0;

UInt32  CAHostTimeBase::sFromNanosDenominator = 0;

bool    CAHostTimeBase::sUseMicroseconds = false;

bool    CAHostTimeBase::sIsInited = false;

#if Track_Host_TimeBase

UInt64  CAHostTimeBase::sLastTime = 0;

#endif

//=============================================================================

//  CAHostTimeBase

//

//  This class provides platform independent access to the host's time base.

//=============================================================================

void    CAHostTimeBase::Initialize()

{

    //  get the info about Absolute time

    #if TARGET_OS_MAC

        struct mach_timebase_info   theTimeBaseInfo;

        mach_timebase_info(&theTimeBaseInfo);

        sMinDelta = 1;

        sToNanosNumerator = theTimeBaseInfo.numer;

        sToNanosDenominator = theTimeBaseInfo.denom;

        sFromNanosNumerator = sToNanosDenominator;

        sFromNanosDenominator = sToNanosNumerator;

        //  the frequency of that clock is: (sToNanosDenominator / sToNanosNumerator) * 10^9

        sFrequency = static_cast<Float64>(sToNanosDenominator) / static_cast<Float64>(sToNanosNumerator);

        sFrequency *= 1000000000.0;

    #elif TARGET_OS_WIN32

        LARGE_INTEGER theFrequency;

        QueryPerformanceFrequency(&theFrequency);

        sMinDelta = 1;

        sToNanosNumerator = 1000000000ULL;

        sToNanosDenominator = *((UInt64*)&theFrequency);

        sFromNanosNumerator = sToNanosDenominator;

        sFromNanosDenominator = sToNanosNumerator;

        sFrequency = static_cast<Float64>(*((UInt64*)&theFrequency));

    #endif

    sInverseFrequency = 1.0 / sFrequency;

    #if Log_Host_Time_Base_Parameters

        DebugMessage(  "Host Time Base Parameters");

        DebugMessageN1(" Minimum Delta:          %lu", sMinDelta);

        DebugMessageN1(" Frequency:              %f", sFrequency);

        DebugMessageN1(" To Nanos Numerator:     %lu", sToNanosNumerator);

        DebugMessageN1(" To Nanos Denominator:   %lu", sToNanosDenominator);

        DebugMessageN1(" From Nanos Numerator:   %lu", sFromNanosNumerator);

        DebugMessageN1(" From Nanos Denominator: %lu", sFromNanosDenominator);

    #endif

    sIsInited = true;

}