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| |
| #include "qtickclock_p.h" |
| |
| #include <QtCore/QThread> |
| |
| #include <Qt3DCore/private/corelogging_p.h> |
| |
| QT_BEGIN_NAMESPACE |
| |
| namespace Qt3DCore { |
| |
| QTickClock::QTickClock() |
| : m_tickInterval(1000000000 / 60) // Nanoseconds |
| , m_time(0) |
| { |
| } |
| |
| void QTickClock::setTickFrequency(float frequency) |
| { |
| Q_ASSERT(frequency > 0.0f); |
| m_tickInterval = static_cast<qint64>(1000000000 / frequency); |
| } |
| |
| void QTickClock::start() |
| { |
| m_timer.start(); |
| m_time = m_timer.nsecsElapsed(); |
| qCDebug(ChangeArbiter) << "tickInterval =" << m_tickInterval << "ns"; |
| } |
| |
| void QTickClock::reset() |
| { |
| m_time = 0; |
| } |
| |
| qint64 QTickClock::waitForNextTick() |
| { |
| qint64 t = m_timer.nsecsElapsed(); |
| qint64 dt = t - m_time; |
| qint64 timeToSleep = m_tickInterval - dt; |
| |
| // If we are lagging behind don't delay |
| // TODO: Do we want a mode where if we are lagging we instead wait |
| // for the next tick instead? |
| if (timeToSleep < 0) { |
| qCDebug(ChangeArbiter) << "Lagging behind desired tick interval"; |
| m_time = t; |
| return m_time; |
| } |
| |
| unsigned long sleepTimeMicroSeconds = static_cast<unsigned long>(timeToSleep / 1000); |
| //qCDebug(ChangeArbiter) << "sleeping for" << sleepTimeMicroSeconds << "us"; |
| QThread::usleep(sleepTimeMicroSeconds); |
| |
| #if defined(QT3DCORE_DEBUG_TICKCLOCK) |
| qint64 expectedWakeTime = t + sleepTimeMicroSeconds * 1000; |
| qint64 wakeTime = m_timer.nsecsElapsed(); |
| qCDebug(ChangeArbiter) << "t =" << t / 1000000 << "timeToSleep =" << timeToSleep / 1000000 |
| << "due to wake at =" << expectedWakeTime / 1000000 |
| << "actually woke at" << wakeTime / 1000000 |
| << "delta =" << (expectedWakeTime - wakeTime) / 1000000; |
| #endif |
| |
| m_time = m_timer.nsecsElapsed(); |
| return m_time; |
| } |
| |
| } // namespace Qt3DCore |
| |
| QT_END_NAMESPACE |