PxTime.h

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// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
 
#ifndef PX_TIME_H
#define PX_TIME_H
 
#include "foundation/PxSimpleTypes.h"
#include "foundation/PxFoundationConfig.h"
 
#if PX_LINUX
#include <time.h>
#endif
 
#if !PX_DOXYGEN
namespace physx
{
#endif
 
struct PxCounterFrequencyToTensOfNanos
{
    PxU64 mNumerator;
    PxU64 mDenominator;
    PxCounterFrequencyToTensOfNanos(PxU64 inNum, PxU64 inDenom) : mNumerator(inNum), mDenominator(inDenom)
    {
    }
 
    // quite slow.
    PxU64 toTensOfNanos(PxU64 inCounter) const
    {
        return (inCounter * mNumerator) / mDenominator;
    }
};
 
class PX_FOUNDATION_API PxTime
{
  public:
    typedef PxF64 Second;
    static const PxU64 sNumTensOfNanoSecondsInASecond = 100000000;
    // This is supposedly guaranteed to not change after system boot
    // regardless of processors, speedstep, etc.
    static const PxCounterFrequencyToTensOfNanos& getBootCounterFrequency();
 
    static PxCounterFrequencyToTensOfNanos getCounterFrequency();
 
    static PxU64 getCurrentCounterValue();
 
    // SLOW!!
    // Thar be a 64 bit divide in thar!
    static PxU64 getCurrentTimeInTensOfNanoSeconds()
    {
        PxU64 ticks = getCurrentCounterValue();
        return getBootCounterFrequency().toTensOfNanos(ticks);
    }
 
    PxTime();
    Second getElapsedSeconds();
    Second peekElapsedSeconds();
    Second getLastTime() const;
 
  private:
#if PX_LINUX || PX_APPLE_FAMILY
    Second mLastTime;
#else
    PxI64 mTickCount;
#endif
};
#if !PX_DOXYGEN
} // namespace physx
#endif
 
#endif