[StainlessS]

Maybe Groucho has better code for timing stuff.

But some stuff from RT_Stats below. [EDIT: Use as you will]

AVSValue __cdecl RT_LocalTimeString(AVSValue args, void* user_data, IScriptEnvironment* env) {
    const bool file = args[0].AsBool(true);
    SYSTEMTIME  st = { 0 };
    if(file) {
        DWORD tick=GetTickCount();
        while(GetTickCount()==tick) // Wait until system clock goes TICK (prevent two separate calls returning same time)
            Sleep(0);
    }
    GetLocalTime(&st);
    char bf[64];
    if(file) {
        sprintf(bf,"%4d%02d%02d_%02d%02d%02d_%03d",st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond,st.wMilliseconds);
    } else {
        sprintf(bf,"%4d-%02d-%02d %02d:%02d:%02d.%03d",st.wYear,st.wMonth,st.wDay,st.wHour,st.wMinute,st.wSecond,st.wMilliseconds);
    }
    return env->SaveString(bf);
}

RT_LocalTimeString(Bool "file"=True)
Returns current local time as a string.
Where digits Y=Year, M=Month, D=Day, H=Hour, M=Minute, S=Second, m=millisecond.
When bool file==False, then string in format "YYYY-MM-DD HH:MM:SS.mmm"
When bool file==True (Default) string is in format "YYYYMMDD_HHMMSS_mmm"
Also when file==True, function first waits until the system tick count is incremented (about every 10ms)
before inquiring system time. This is to prevent 2 consecutive calls returning the same time string.
Perhaps useful for temporary filename generation.

AVSValue __cdecl RT_Timer(AVSValue args, void* user_data, IScriptEnvironment* env) {
    return  double(clock()) / double(CLOCKS_PER_SEC);
}


double __cdecl RT_TimerHP_Lo(void) {
    LARGE_INTEGER liPerfCounter = {0,0};
    LARGE_INTEGER liPerfFreq    = {0,0};
    bool bStat              = true;
    DWORD_PTR dwpOldMask    = SetThreadAffinityMask(GetCurrentThread(), 0x01);
    Sleep(0);
    if ((QueryPerformanceFrequency(&liPerfFreq) == 0) || (QueryPerformanceCounter(&liPerfCounter) == 0))
        bStat = false;
    double tim;
    if(!bStat) { // High precision NOT available.
        static clock_t first_time32=0;
        static bool done32=false;
        const clock_t t = clock();
        if(!done32) {
            first_time32 = t;
            done32=true;
        }
        tim = double(t-first_time32) / double(CLOCKS_PER_SEC);          // Fallback, low rez timer
    } else { // High precision IS available.
        static __int64 first_time64=0;
        static bool done64 = false;
        if(!done64) {
            first_time64 = liPerfCounter.QuadPart;
            done64=true;
        }
        tim = (double)(liPerfCounter.QuadPart-first_time64) / (double)liPerfFreq.QuadPart;
    }
    SetThreadAffinityMask(GetCurrentThread(), dwpOldMask);
    Sleep(0);
    return tim;                                                 // return double for C client
}


AVSValue __cdecl RT_TimerHP(AVSValue args, void* user_data, IScriptEnvironment* env) {
    return RT_TimerHP_Lo();                                                  // Implicit type conversion to AVSValue float
}

RT_Timer()
Returns time in seconds since start of process.
Usage:
s=RT_Timer()
Test()
e=RT_Timer()
Str=RT_String("Test Start=%.2f End=%.2f Time=%.2f secs",s,e,e-s)
SubTitle(str)
RT_Debug(str)

***
***
***

RT_TimerHP()
Returns a higher precision time than RT_Timer (If available on your system, otherwise uses same routine as RT_Timer).
Note, where RT_Timer returns time elapsed in seconds since start of process, RT_TimerHP is not defined to return anything
in particular, the only thing that is meaningful is the difference between returns from 2 calls to RT_TimerHP.
DO NOT mix times from RT_Timer with RT_TimerHP, results may be meaningless.
Usage:
s=RT_TimerHP() Test() e=RT_TimerHP()
Str=RT_String("Test Start=%.3f End=%.3f Time=%.6f secs",s,e,e-s)
SubTitle(str)

High precision timer quite often called HPET in bios setup, usually defaults to OFF. [EDIT: Presumably, High Precision Event Timer]

EDIT:

env->AddFunction("RT_LocalTimeString",         "[file]b",RT_LocalTimeString, 0);
env->AddFunction("RT_Timer",                   "",RT_Timer, 0);
env->AddFunction("RT_TimerHP",                 "",RT_TimerHP, 0);