Revision control
++ // Copyright (C) 2015 Paul Lemire
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
++
++ #include "vsyncframeadvanceservice_p.h"
++ #include <Qt3DRender/private/renderlogging_p.h>
++ #include <Qt3DCore/private/qabstractframeadvanceservice_p.h>
++ #include <Qt3DCore/private/qabstractframeadvanceservice_p_p.h>
++ #include <QSemaphore>
++ #include <QElapsedTimer>
++
++ QT_BEGIN_NAMESPACE
++
++ namespace Qt3DRender {
++ namespace Render {
++
++ class VSyncFrameAdvanceServicePrivate final : public Qt3DCore::QAbstractFrameAdvanceServicePrivate
++ {
++ public:
++ explicit VSyncFrameAdvanceServicePrivate(bool drivenByRenderThread)
++ : QAbstractFrameAdvanceServicePrivate(QStringLiteral("Renderer Aspect Frame Advance Service - aligned with vsync"))
++ , m_semaphore(0)
++ , m_elapsedTimeSincePreviousFrame(0)
++ , m_drivenByRenderThread(drivenByRenderThread)
++ {
++ }
++
++ QSemaphore m_semaphore;
++ QElapsedTimer m_elapsed;
++ qint64 m_elapsedTimeSincePreviousFrame;
++ bool m_drivenByRenderThread;
++ };
++
++ VSyncFrameAdvanceService::VSyncFrameAdvanceService(bool drivenByRenderThread)
++ : QAbstractFrameAdvanceService(*new VSyncFrameAdvanceServicePrivate(drivenByRenderThread))
++ {
++ }
++
++ VSyncFrameAdvanceService::~VSyncFrameAdvanceService()
++ {
++ }
++
++ // Main Thread
++ qint64 VSyncFrameAdvanceService::waitForNextFrame()
++ {
++ Q_D(VSyncFrameAdvanceService);
++
++ d->m_semaphore.acquire(std::max(d->m_semaphore.available(), 1));
++
++ const qint64 currentTime = d->m_elapsed.nsecsElapsed();
++ qCDebug(VSyncAdvanceService) << "Elapsed nsecs since last call " << currentTime - d->m_elapsedTimeSincePreviousFrame;
++ d->m_elapsedTimeSincePreviousFrame = currentTime;
++ return currentTime;
++ }
++
++ void VSyncFrameAdvanceService::start()
++ {
++ Q_D(VSyncFrameAdvanceService);
++ d->m_elapsed.start();
++ }
++
++ /*!
++ \internal
++
++ Stops the VSyncFrameAdvanceService, releases the semaphore to allow the
++ renderer to cleanup without having to call waitForNextFrame.
++ */
++ void VSyncFrameAdvanceService::stop()
++ {
++ Q_D(VSyncFrameAdvanceService);
++ d->m_semaphore.release(1);
++ qCDebug(VSyncAdvanceService) << "Terminating VSyncFrameAdvanceService";
++ }
++
++ // Render Thread
++ void VSyncFrameAdvanceService::proceedToNextFrame()
++ {
++ Q_D(VSyncFrameAdvanceService);
++ d->m_semaphore.release(1);
++ }
++
++ } // namespace Render
++ } // namespace Qt3DRender
++
++ QT_END_NAMESPACE