#include "box2d/b2_timer.h"
#if defined(_WIN32)
double b2Timer::s_invFrequency = 0.0;
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
typedef BOOL (WINAPI *SystemGetTimeFunc)(_Out_ LARGE_INTEGER *lpFrequency);
SystemGetTimeFunc systemGetTimeFunc = ::QueryPerformanceCounter;
SystemGetTimeFunc systemGetFreqFunc = ::QueryPerformanceFrequency;
int64 b2Timer::GetTicks()
{
LARGE_INTEGER largeInteger;
systemGetTimeFunc(&largeInteger);
return largeInteger.QuadPart;
}
b2Timer::b2Timer()
{
LARGE_INTEGER largeInteger;
if (s_invFrequency == 0.0)
{
systemGetFreqFunc(&largeInteger);
s_invFrequency = double(largeInteger.QuadPart);
if (s_invFrequency > 0.0)
{
s_invFrequency = 1000.0 / s_invFrequency;
}
}
m_start = GetTicks();
}
void b2Timer::Reset()
{
m_start = GetTicks();
}
float b2Timer::GetMilliseconds() const
{
int64 elapsed = GetTicks() - m_start;
return (float)(s_invFrequency * elapsed);
}
#elif defined(__linux__) || defined (__APPLE__)
#include <sys/time.h>
#include <time.h>
#if defined(__linux__)
typedef int (*SystemGetTimeFunc)(clockid_t clk_id, struct timespec *tp);
SystemGetTimeFunc systemGetTimeFunc = ::clock_gettime;
#elif defined(__APPLE__)
typedef int (*SystemGetTimeFunc)(struct timeval * tp, void * tzp);
SystemGetTimeFunc systemGetTimeFunc = ::gettimeofday;
#endif
int64 b2Timer::GetTicks()
{
static const int NSEC_PER_SEC = 1000000000;
#ifdef __linux__
timespec ts;
systemGetTimeFunc(CLOCK_MONOTONIC,&ts);
return ((int64)ts.tv_sec) * NSEC_PER_SEC + ts.tv_nsec;
#else
timeval t;
systemGetTimeFunc(&t, 0);
return ((int64)t.tv_sec) * NSEC_PER_SEC + t.tv_usec * 1000;
#endif
}
b2Timer::b2Timer()
{
Reset();
}
void b2Timer::Reset()
{
m_start = GetTicks();
}
float b2Timer::GetMilliseconds() const
{
static const float kTicksToMs = 0.000001f;
return kTicksToMs * (float)(GetTicks() - m_start);
}
#else
b2Timer::b2Timer()
{
}
void b2Timer::Reset()
{
}
float b2Timer::GetMilliseconds() const
{
return 0.0f;
}
#endif