double Timer::getTimeSinceEpoch()
{
// The timer period (reciprocal of the frequency.)
static const double timerPeriod = getTimerPeriod();
#if defined(LOVE_LINUX)
double mt;
// Check for POSIX timers and monotonic clocks. If not supported, use the gettimeofday fallback.
#if _POSIX_TIMERS > 0 && defined(_POSIX_MONOTONIC_CLOCK) \
&& (defined(CLOCK_MONOTONIC_RAW) || defined(CLOCK_MONOTONIC))
timespec t;
#ifdef CLOCK_MONOTONIC_RAW
clockid_t clk_id = CLOCK_MONOTONIC_RAW;
#else
clockid_t clk_id = CLOCK_MONOTONIC;
#endif
if (clock_gettime(clk_id, &t) == 0)
mt = (double) t.tv_sec + (double) t.tv_nsec / 1000000000.0;
else
#endif
mt = getTimeOfDay();
return mt;
#elif defined(LOVE_MACOSX) || defined(LOVE_IOS)
return (double) mach_absolute_time() * timerPeriod;
#elif defined(LOVE_WINDOWS)
LARGE_INTEGER microTime;
QueryPerformanceCounter(µTime);
return (double) microTime.QuadPart * timerPeriod;
#endif
}
Timer::Timer()
: currTime(0)
, prevFpsUpdate(0)
, fps(0)
, averageDelta(0)
, fpsUpdateFrequency(1)
, frames(0)
, dt(0)
, timerPeriod(getTimerPeriod())
{
// Init the SDL timer system (needed for SDL_Delay.)
if (SDL_InitSubSystem(SDL_INIT_TIMER) < 0)
throw love::Exception("%s", SDL_GetError());
prevFpsUpdate = currTime = getTime();
}