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// Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "platformsurfacefilter_p.h"
#include <Qt3DRender/private/abstractrenderer_p.h>
#include <QMetaObject>
#include <QPlatformSurfaceEvent>
#include <QOffscreenSurface>
#include <QtGui/qwindow.h>
QT_BEGIN_NAMESPACE
namespace Qt3DRender {
namespace Render {
QBasicMutex PlatformSurfaceFilter::m_surfacesMutex {};
QHash<QSurface *, bool> PlatformSurfaceFilter::m_surfacesValidity;
// Surface protection
// The surface is accessible from multiple threads at 3 potential places
// 1) In here (the frontend) when we receive an event
// 2) In the RenderViewJobs
// 3) In the Renderer for the submission
// * We don't need any protection in 2) as we are just copying the pointer
// but not performing any access to the texture as all the information
// we need has been cached in the RenderSurfaceSelector element
// * This leaves us with case 1 and 3. It is important that if the surface
// is about to be destroyed that we let the time to the submission thread
// to complete whatever it is doing with a surface before we have the time
// to process the AboutToBeDestroyed event. For that we have lockSurface, releaseSurface
// on the PlatformSurfaceFilter. But that's not enough, you need to be sure that
// the surface is still valid. When locked, you can use isSurfaceValid to check
// if a surface is still accessible.
// A Surface is valid when it has been created and becomes invalid when AboutToBeDestroyed
// has been called
// SurfaceLocker is a convenience type to perform locking an surface validity check
PlatformSurfaceFilter::PlatformSurfaceFilter(QObject *parent)
: QObject(parent)
, m_obj(nullptr)
, m_surface(nullptr)
{
qRegisterMetaType<QSurface *>("QSurface*");
}
PlatformSurfaceFilter::~PlatformSurfaceFilter()
{
if (m_obj)
m_obj->removeEventFilter(this);
}
bool PlatformSurfaceFilter::eventFilter(QObject *obj, QEvent *e)
{
if (obj == m_obj && e->type() == QEvent::PlatformSurface) {
QPlatformSurfaceEvent *ev = static_cast<QPlatformSurfaceEvent *>(e);
switch (ev->surfaceEventType()) {
case QPlatformSurfaceEvent::SurfaceCreated:
// set validy to true
{
markSurfaceAsValid();
break;
}
case QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed:
// set validity to false
{
SurfaceLocker lock(m_surface);
// If we remove it, the call to isSurfaceValid will
// implicitely return false
PlatformSurfaceFilter::m_surfacesValidity.remove(m_surface);
break;
}
default:
qCritical("Unknown surface type");
Q_UNREACHABLE();
}
}
if (obj == m_obj && e->type() == QEvent::Expose) {
QExposeEvent *ev = static_cast<QExposeEvent *>(e);
Q_UNUSED(ev);
// We could use this to tell to ignore the RenderView
// at submission time since it's not exposed
}
return false;
}
void PlatformSurfaceFilter::lockSurface()
{
PlatformSurfaceFilter::m_surfacesMutex.lock();
}
void PlatformSurfaceFilter::releaseSurface()
{
PlatformSurfaceFilter::m_surfacesMutex.unlock();
}
bool PlatformSurfaceFilter::isSurfaceValid(QSurface *surface)
{
// Should be called only when the surface is locked
// with the mutex
return m_surfacesValidity.value(surface, false);
}
void PlatformSurfaceFilter::markSurfaceAsValid()
{
SurfaceLocker lock(m_surface);
PlatformSurfaceFilter::m_surfacesValidity.insert(m_surface, true);
}
SurfaceLocker::SurfaceLocker(QSurface *surface)
: m_surface(surface)
{
PlatformSurfaceFilter::lockSurface();
}
SurfaceLocker::~SurfaceLocker()
{
PlatformSurfaceFilter::releaseSurface();
}
bool SurfaceLocker::isSurfaceValid() const
{
return PlatformSurfaceFilter::isSurfaceValid(m_surface);
}
} // namespace Render
} // namespace Qt3DRender
QT_END_NAMESPACE
#include "moc_platformsurfacefilter_p.cpp"