#ifndef OSG_TIMER
#define OSG_TIMER 1

#include <osg/Export>

namespace osg {

#ifdef WIN32
	typedef __int64 Timer_t;
#else
	typedef unsigned long long Timer_t;
#endif

class SG_EXPORT Timer {

    public:

        Timer( void );
        ~Timer( void );


#ifdef WIN32
        #pragma optimize("",off)
        inline Timer_t tick( void )
        {
	    volatile Timer_t ts;
			volatile unsigned int HighPart;
            volatile unsigned int LowPart;
            _asm
            {
                xor eax, eax        //  Used when QueryPerformanceCounter()
                xor edx, edx        //  not supported or minimal overhead
                _emit 0x0f          //  desired
                _emit 0x31          //
				mov HighPart,edx
				mov LowPart,eax
            }
			//ts = LowPart | HighPart >> 32;
			*((unsigned int*)&ts) = LowPart;
            *((unsigned int*)&ts+1) = HighPart;
            return ts;
        }
        #pragma optimize("",on)
#endif
#ifdef __linux
        #define CLK(x)	  __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x))
	inline Timer_t tick( void ) {Timer_t x;CLK(x);return x;}
#endif
#ifdef __sgi
        inline  Timer_t tick( void ) { return *clk; }
#endif
        double delta_s( Timer_t t1, Timer_t t2 );
        double delta_m( Timer_t t1, Timer_t t2 );

        Timer_t delta_u( Timer_t t1, Timer_t t2 );
        Timer_t delta_n( Timer_t t1, Timer_t t2 );


    private :

        double microseconds_per_click;
        double nanoseconds_per_click;
        unsigned long *clk;
        int cycleCntrSize;
        static unsigned long dummy;

	static int inited;
	static double cpu_mhz;
	void init( void );
        
    

};


};
#endif