/
PerformanceTimer.cpp
46 lines (39 loc) · 1.02 KB
/
PerformanceTimer.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
#include <windows.h>
#include "PerformanceTimer.h"
#include <MMSystem.h>
#pragma comment(lib, "winmm.lib")
PerformanceTimer::PerformanceTimer(bool bCheckPerfHardware)
{
// check whether we have performance timer
__int64 m_i64PerfFrequency;
m_bPerfHardware = (bCheckPerfHardware ? QueryPerformanceFrequency((LARGE_INTEGER *) &m_i64PerfFrequency) != 0 : false);
if (m_bPerfHardware)
{
QueryPerformanceCounter((LARGE_INTEGER *) &m_i64LastTime);
m_dblTimeScale = 1.0 / m_i64PerfFrequency;
}
else
{
m_i64LastTime = timeGetTime();
m_dblTimeScale = 0.001;
}
}
PerformanceTimer::~PerformanceTimer()
{
}
void PerformanceTimer::StartTimer()
{
if (m_bPerfHardware)
QueryPerformanceCounter((LARGE_INTEGER *) &m_i64LastTime);
else
m_i64LastTime = timeGetTime();
}
double PerformanceTimer::GetTimeElapsed()
{
__int64 i64CurrentTime;
if (m_bPerfHardware)
QueryPerformanceCounter((LARGE_INTEGER *) &i64CurrentTime);
else
i64CurrentTime = timeGetTime();
return (i64CurrentTime - m_i64LastTime) * m_dblTimeScale;
}