File indexing completed on 2024-05-19 05:32:29

 /*
     SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "utils/softwarevsyncmonitor.h"
 
 namespace KWin
 {
 
 std::unique_ptr<SoftwareVsyncMonitor> SoftwareVsyncMonitor::create()
 {
     return std::unique_ptr<SoftwareVsyncMonitor>{new SoftwareVsyncMonitor()};
 }
 
 SoftwareVsyncMonitor::SoftwareVsyncMonitor()
 {
     connect(&m_softwareClock, &QTimer::timeout, this, &SoftwareVsyncMonitor::handleSyntheticVsync);
     m_softwareClock.setSingleShot(true);
 }
 
 int SoftwareVsyncMonitor::refreshRate() const
 {
     return m_refreshRate;
 }
 
 void SoftwareVsyncMonitor::setRefreshRate(int refreshRate)
 {
     m_refreshRate = refreshRate;
 }
 
 void SoftwareVsyncMonitor::handleSyntheticVsync()
 {
     Q_EMIT vblankOccurred(m_vblankTimestamp);
 }
 
 template<typename T>
 T alignTimestamp(const T &timestamp, const T &alignment)
 {
     return timestamp + ((alignment - (timestamp % alignment)) % alignment);
 }
 
 void SoftwareVsyncMonitor::arm()
 {
     if (m_softwareClock.isActive()) {
         return;
     }
 
     const std::chrono::nanoseconds currentTime(std::chrono::steady_clock::now().time_since_epoch());
     const std::chrono::nanoseconds vblankInterval(1'000'000'000'000ull / m_refreshRate);
 
     m_vblankTimestamp = alignTimestamp(currentTime, vblankInterval);
 
     m_softwareClock.start(std::chrono::duration_cast<std::chrono::milliseconds>(m_vblankTimestamp - currentTime));
 }
 
 } // namespace KWin
 
 #include "moc_softwarevsyncmonitor.cpp"