QOpenGLContext Class Reference

\inmodule QtGui More...

#include <qopenglcontext.h>

Inheritance diagram for QOpenGLContext:

Collaboration diagram for QOpenGLContext:

Public Types
enum	OpenGLModuleType { LibGL , LibGLES }
	This enum defines the type of the underlying OpenGL implementation. More...

Signals
void	aboutToBeDestroyed ()
	This signal is emitted before the underlying native OpenGL context is destroyed, such that users may clean up OpenGL resources that might otherwise be left dangling in the case of shared OpenGL contexts.
Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.
void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QOpenGLContext (QObject *parent=nullptr)
	Creates a new OpenGL context instance with parent object parent.
	~QOpenGLContext ()
	Destroys the QOpenGLContext object.
void	setFormat (const QSurfaceFormat &format)
	Sets the format the OpenGL context should be compatible with.
void	setShareContext (QOpenGLContext *shareContext)
	Makes this context share textures, shaders, and other OpenGL resources with shareContext.
void	setScreen (QScreen *screen)
	Sets the screen the OpenGL context should be valid for.
bool	create ()
	Attempts to create the OpenGL context with the current configuration.
bool	isValid () const
	Returns if this context is valid, i.e.
QSurfaceFormat	format () const
	Returns the format of the underlying platform context, if create() has been called.
QOpenGLContext *	shareContext () const
	Returns the share context this context was created with.
QOpenGLContextGroup *	shareGroup () const
	Returns the share group this context belongs to.
QScreen *	screen () const
	Returns the screen the context was created for.
GLuint	defaultFramebufferObject () const
	Call this to get the default framebuffer object for the current surface.
bool	makeCurrent (QSurface *surface)
	Makes the context current in the current thread, against the given surface.
void	doneCurrent ()
	Convenience function for calling makeCurrent with a 0 surface.
void	swapBuffers (QSurface *surface)
	Swap the back and front buffers of surface.
QFunctionPointer	getProcAddress (const QByteArray &procName) const
	Resolves the function pointer to an OpenGL extension function, identified by procName.
QFunctionPointer	getProcAddress (const char *procName) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
QSurface *	surface () const
	Returns the surface the context has been made current with.
QPlatformOpenGLContext *	handle () const
	Returns the underlying platform context.
QPlatformOpenGLContext *	shareHandle () const
	Returns the underlying platform context with which this context is sharing.
QOpenGLFunctions *	functions () const
	Get the QOpenGLFunctions instance for this context.
QOpenGLExtraFunctions *	extraFunctions () const
	Get the QOpenGLExtraFunctions instance for this context.
QSet< QByteArray >	extensions () const
	Returns the set of OpenGL extensions supported by this context.
bool	hasExtension (const QByteArray &extension) const
	Returns true if this OpenGL context supports the specified OpenGL extension, false otherwise.
bool	isOpenGLES () const
	Returns true if the context is an OpenGL ES context.
Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.
virtual	~QObject ()
	Destroys the object, deleting all its child objects.
virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.
virtual bool	eventFilter (QObject *watched, QEvent *event)
	Filters events if this object has been installed as an event filter for the watched object.
QString	objectName () const
Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.
void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
QBindable< QString >	bindableObjectName ()
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false.
bool	isWindowType () const
	Returns true if the object is a window; otherwise returns false.
bool	isQuickItemType () const
	Returns true if the object is a QQuickItem; otherwise returns false.
bool	signalsBlocked () const noexcept
	Returns true if signals are blocked; otherwise returns false.
bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).
QThread *	thread () const
	Returns the thread in which the object lives.
bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns true on success.
int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.
int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)
void	killTimer (int id)
	Kills the timer with timer identifier, id.
void	killTimer (Qt::TimerId id)
template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.
template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.
template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
const QObjectList &	children () const
	Returns a list of child objects.
void	setParent (QObject *parent)
	Makes the object a child of parent.
void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.
void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=nullptr, const QObject *receiver=nullptr, const char *member=nullptr) const
bool	disconnect (const QObject *receiver, const char *member=nullptr) const
void	dumpObjectTree () const
	Dumps a tree of children to the debug output.
void	dumpObjectInfo () const
	Dumps information about signal connections, etc.
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.
bool	setProperty (const char *name, QVariant &&value)
QVariant	property (const char *name) const
	Returns the value of the object's name property.
QList< QByteArray >	dynamicPropertyNames () const
QBindingStorage *	bindingStorage ()
const QBindingStorage *	bindingStorage () const
QObject *	parent () const
	Returns a pointer to the parent object.
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false.

Static Public Member Functions
static QOpenGLContext *	currentContext ()
	Returns the last context which called makeCurrent in the current thread, or \nullptr, if no context is current.
static bool	areSharing (QOpenGLContext *first, QOpenGLContext *second)
	Returns true if the first and second contexts are sharing OpenGL resources.
static OpenGLModuleType	openGLModuleType ()
	Returns the underlying OpenGL implementation type.
static bool	supportsThreadedOpenGL ()
	Returns true if the platform supports OpenGL rendering outside the main (gui) thread.
static QOpenGLContext *	globalShareContext ()
Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe
static QMetaObject::Connection	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType *context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)
template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	\threadsafe
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.
template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object *receiver, Func2 slot)
template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const QObject *receiver, void **zero)

Friends
class	QOpenGLContextResourceBase
class	QOpenGLPaintDevice
class	QOpenGLGlyphTexture
class	QOpenGLTextureGlyphCache
class	QOpenGLEngineShaderManager
class	QOpenGLFramebufferObject
class	QOpenGLFramebufferObjectPrivate
class	QOpenGL2PaintEngineEx
class	QOpenGL2PaintEngineExPrivate
class	QSGDistanceFieldGlyphCache
class	QWidgetPrivate
class	QAbstractOpenGLFunctionsPrivate
class	QOpenGLTexturePrivate

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe
Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.
int	senderSignalIndex () const
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.
bool	isSignalConnected (const QMetaMethod &signal) const
virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.
virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.
virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.
virtual void	connectNotify (const QMetaMethod &signal)
virtual void	disconnectNotify (const QMetaMethod &signal)
	QObject (QObjectPrivate &dd, QObject *parent=nullptr)
Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Properties inherited from QObject
QString	objectName
	the name of this object
Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.
template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

\inmodule QtGui

Since

5.0

The QOpenGLContext class represents a native OpenGL context, enabling OpenGL rendering on a QSurface.

QOpenGLContext represents the OpenGL state of an underlying OpenGL context. To set up a context, set its screen and format such that they match those of the surface or surfaces with which the context is meant to be used, if necessary make it share resources with other contexts with setShareContext(), and finally call create(). Use the return value or isValid() to check if the context was successfully initialized.

A context can be made current against a given surface by calling makeCurrent(). When OpenGL rendering is done, call swapBuffers() to swap the front and back buffers of the surface, so that the newly rendered content becomes visible. To be able to support certain platforms, QOpenGLContext requires that you call makeCurrent() again before starting rendering a new frame, after calling swapBuffers().

If the context is temporarily not needed, such as when the application is not rendering, it can be useful to delete it in order to free resources. You can connect to the aboutToBeDestroyed() signal to clean up any resources that have been allocated with different ownership from the QOpenGLContext itself.

Once a QOpenGLContext has been made current, you can render to it in a platform independent way by using Qt's OpenGL enablers such as QOpenGLFunctions, QOpenGLBuffer, QOpenGLShaderProgram, and QOpenGLFramebufferObject. It is also possible to use the platform's OpenGL API directly, without using the Qt enablers, although potentially at the cost of portability. The latter is necessary when wanting to use OpenGL 1.x or OpenGL ES 1.x.

For more information about the OpenGL API, refer to the official \l{http://www.opengl.org}{OpenGL documentation}.

For an example of how to use QOpenGLContext see the \l{OpenGL Window Example}{OpenGL Window} example.

Definition at line 66 of file qopenglcontext.h.

Member Enumeration Documentation

OpenGLModuleType

enum QOpenGLContext::OpenGLModuleType

This enum defines the type of the underlying OpenGL implementation.

\value LibGL OpenGL \value LibGLES OpenGL ES 2.0 or higher

Since

5.3

Enumerator
LibGL
LibGLES

Definition at line 109 of file qopenglcontext.h.

Constructor & Destructor Documentation

QOpenGLContext()

QOpenGLContext::QOpenGLContext ( QObject * parent = nullptr )

explicit

Creates a new OpenGL context instance with parent object parent.

Before it can be used you need to set the proper format and call create().

See also

create(), makeCurrent()

Definition at line 276 of file qopenglcontext.cpp.

References QGuiApplication::primaryScreen, and setScreen().

Here is the call graph for this function:

~QOpenGLContext()

QOpenGLContext::~QOpenGLContext

(

)

Destroys the QOpenGLContext object.

If this is the current context for the thread, doneCurrent() is also called.

Definition at line 486 of file qopenglcontext.cpp.

References QOpenGLContextPrivate::cleanMakeCurrentTracker().

Here is the call graph for this function:

Member Function Documentation

aboutToBeDestroyed

void QOpenGLContext::aboutToBeDestroyed ( )

signal

This signal is emitted before the underlying native OpenGL context is destroyed, such that users may clean up OpenGL resources that might otherwise be left dangling in the case of shared OpenGL contexts.

If you wish to make the context current in order to do clean-up, make sure to only connect to the signal using a direct connection.

Note

In Qt for Python, this signal will not be received when emitted from the destructor of QOpenGLWidget or QOpenGLWindow due to the Python instance already being destroyed. We recommend doing cleanups in QWidget::hideEvent() instead.

Referenced by QtWayland::QWaylandTextureOrphanage::admitTexture(), LinuxDmabufWlBuffer::initTexture(), WaylandEglClientBufferIntegrationPrivate::setupBufferAndCleanup(), and WaylandEglStreamClientBufferIntegrationPrivate::setupBufferAndCleanup().

Here is the caller graph for this function:

areSharing()

bool QOpenGLContext::areSharing ( QOpenGLContext * first, QOpenGLContext * second )

static

Returns true if the first and second contexts are sharing OpenGL resources.

Definition at line 239 of file qopenglcontext.cpp.

References shareGroup().

Referenced by QtWayland::QWaylandTextureOrphanage::deleteTextures(), and QOpenGLTexturePrivate::destroy().

Here is the call graph for this function:

Here is the caller graph for this function:

create()

bool QOpenGLContext::create

(

)

Attempts to create the OpenGL context with the current configuration.

The current configuration includes the format, the share context, and the screen.

If the OpenGL implementation on your system does not support the requested version of OpenGL context, then QOpenGLContext will try to create the closest matching version. The actual created context properties can be queried using the QSurfaceFormat returned by the format() function. For example, if you request a context that supports OpenGL 4.3 Core profile but the driver and/or hardware only supports version 3.2 Core profile contexts then you will get a 3.2 Core profile context.

Returns true if the native context was successfully created and is ready to be used with makeCurrent(), swapBuffers(), etc.

Note

If the context already exists, this function destroys the existing context first, and then creates a new one.

See also

makeCurrent(), format()

Definition at line 368 of file qopenglcontext.cpp.

References d, isValid(), and QGuiApplicationPrivate::platformIntegration().

Referenced by src_gui_opengl_qopenglfunctions::MyGLWindow::MyGLWindow(), QMinimalEglBackingStore::QMinimalEglBackingStore(), WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), QOpenGLWindowPrivate::initialize(), QOpenGLWidgetPrivate::initialize(), QGLXContext::queryDummyContext(), and QEglFSWindow::setBackingStore().

Here is the call graph for this function:

Here is the caller graph for this function:

currentContext()

QOpenGLContext * QOpenGLContext::currentContext ( )

static

Returns the last context which called makeCurrent in the current thread, or \nullptr, if no context is current.

Definition at line 228 of file qopenglcontext.cpp.

References QGuiGLThreadContext::context.

Referenced by CurrentContext::CurrentContext(), LibHybrisEglServerBuffer::LibHybrisEglServerBuffer(), QBlitterTextureBinder::QBlitterTextureBinder(), QOpenGLExtensionMatcher::QOpenGLExtensionMatcher(), QOpenGLExtensionsPrivate::QOpenGLExtensionsPrivate(), QOpenGLFramebufferObjectFormatPrivate::QOpenGLFramebufferObjectFormatPrivate(), QOpenGLFunctionsPrivate::QOpenGLFunctionsPrivate(), QOpenGLProgramBinarySupportCheck::QOpenGLProgramBinarySupportCheck(), QOpenGLTextureGlyphCache::QOpenGLTextureGlyphCache(), QOpenGLTextureHelper::QOpenGLTextureHelper(), StateSaver::StateSaver(), QBlitterTextureBinder::~QBlitterTextureBinder(), QOpenGLFramebufferObject::~QOpenGLFramebufferObject(), QOpenGLTimeMonitor::~QOpenGLTimeMonitor(), QOpenGLTimerQuery::~QOpenGLTimerQuery(), QSurface::~QSurface(), WaylandEglClientBuffer::~WaylandEglClientBuffer(), WaylandEglStreamClientBuffer::~WaylandEglStreamClientBuffer(), QOpenGLDebugLoggerPrivate::_q_contextAboutToBeDestroyed(), QOpenGLFramebufferObject::addColorAttachment(), QOpenGL2PaintEngineEx::begin(), QOpenGL2PaintEngineEx::beginNativePainting(), QOpenGLWidgetPaintDevicePrivate::beginPaint(), QOpenGLFramebufferObject::bind(), QSGVivanteVideoMaterial::bind(), QOpenGLFramebufferObject::bindDefault(), QPlatformGraphicsBufferHelper::bindSWToTexture(), QOpenGLTextureBlitterPrivate::blit(), QOpenGLTextureBlitterPrivate::blit(), QOpenGLFramebufferObject::blitFramebuffer(), QOpenGLTexture::boundTextureId(), QOpenGLTexture::boundTextureId(), QOpenGLShader::compileSourceCode(), CurrentContext::context(), QOpenGLBuffer::create(), QOpenGLShaderPrivate::create(), QOpenGLTexturePrivate::create(), QOpenGLTextureBlitter::create(), QOpenGLTimerQueryPrivate::create(), QOpenGLTimeMonitorPrivate::create(), QOpenGLVertexArrayObjectPrivate::create(), QOpenGLTextureGlyphCache::createTextureData(), createTextureFromShm(), QOpenGLContextGroup::currentContextGroup(), currentSurfaceForCurrentContext(), QOpenGLWindow::defaultFramebufferObject(), QtWaylandClient::VulkanServerBufferIntegration::deleteOrphanedTextures(), QtWayland::QWaylandTextureOrphanage::deleteTextures(), QOpenGLTexturePrivate::destroy(), QOpenGLVertexArrayObjectPrivate::destroy(), doneCurrent(), effectiveInternalFormat(), QOpenGLWidgetPaintDevice::ensureActiveTarget(), WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), QOpenGLTextureBlitterPrivate::ensureProgram(), QWindow::event(), QOpenGLTextureGlyphCache::fillTexture(), QOpenGLEngineSharedShaders::findProgramInCache(), QOpenGLSharedResource::free(), QOpenGLConfig::Gpu::fromContext(), functions(), QOpenGLTexture::generateMipMaps(), QOpenGLTexture::generateMipMaps(), QOpenGLVersionFunctionsFactory::get(), QOpenGLFunctions::glBindFramebuffer(), QOpenGLTexture::hasFeature(), QOpenGLFramebufferObject::hasOpenGLFramebufferBlit(), QOpenGLFramebufferObject::hasOpenGLFramebufferObjects(), QOpenGLShaderProgram::hasOpenGLShaderPrograms(), QOpenGLShader::hasOpenGLShaders(), QOpenGLFramebufferObjectPrivate::initColorBuffer(), WaylandEglClientBufferIntegrationPrivate::initEglStream(), WaylandEglStreamClientBufferIntegrationPrivate::initEglStream(), QOpenGLDebugLogger::initialize(), MyGLWidget::initializeGL(), QAbstractOpenGLFunctions::initializeOpenGLFunctions(), QOpenGLFunctions_1_0::initializeOpenGLFunctions(), QOpenGLFunctions_1_1::initializeOpenGLFunctions(), QOpenGLFunctions_1_2::initializeOpenGLFunctions(), QOpenGLFunctions_1_3::initializeOpenGLFunctions(), QOpenGLFunctions_1_4::initializeOpenGLFunctions(), QOpenGLFunctions_1_5::initializeOpenGLFunctions(), QOpenGLFunctions_2_0::initializeOpenGLFunctions(), QOpenGLFunctions_2_1::initializeOpenGLFunctions(), QOpenGLFunctions_3_0::initializeOpenGLFunctions(), QOpenGLFunctions_3_1::initializeOpenGLFunctions(), QOpenGLFunctions_3_2_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_3_2_Core::initializeOpenGLFunctions(), QOpenGLFunctions_3_3_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_3_3_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_0_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_0_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_1_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_1_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_2_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_2_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_3_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_3_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_4_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_4_Core::initializeOpenGLFunctions(), QOpenGLFunctions_4_5_Compatibility::initializeOpenGLFunctions(), QOpenGLFunctions_4_5_Core::initializeOpenGLFunctions(), QOpenGLFramebufferObjectPrivate::initTexture(), LinuxDmabufWlBuffer::initTexture(), QOpenGLWidgetPrivate::invalidateFboAfterPainting(), QOpenGLWidgetPrivate::invalidateFboBeforePainting(), QOpenGLFramebufferObject::isBound(), QOpenGLShaderProgramPrivate::isCacheDisabled(), isCoreProfile(), QOpenGLTextureGlyphCache::maxTextureHeight(), QOpenGLTextureGlyphCache::maxTextureWidth(), MyGLWidget::paintGL(), paintGL(), Q_TRACE_INSTRUMENT(), qopenglfSpecialClearDepthf(), qopenglfSpecialDepthRangef(), qt_gl_functions(), qt_gl_read_framebuffer(), qt_gl_resolve_extensions(), qt_gl_resolve_features(), QGLXContext::queryDummyContext(), QOpenGLWindow::redirected(), QOpenGLFramebufferObject::release(), QOpenGLBuffer::release(), QOpenGLWidgetPrivate::render(), QSGFramebufferObjectNode::render(), QSGMapboxGLRenderNode::render(), QOpenGL2PaintEngineEx::renderHintsChanged(), QOpenGL2PaintEngineExPrivate::resetGLState(), QQuickOpenGLUtils::resetOpenGLState(), QOpenGLTextureGlyphCache::resizeTextureData(), QOpenGLProgramBinaryCache::save(), QOpenGLFramebufferObject::setAttachment(), QOpenGLTexture::setBorderColor(), QOpenGLTexture::setBorderColor(), QOpenGLTexture::setBorderColor(), QOpenGLTexture::setData(), QOpenGLTexture::setDepthStencilMode(), QOpenGLTexture::setLevelofDetailBias(), QOpenGLTexture::setLevelOfDetailRange(), QOpenGLTexture::setMaximumLevelOfDetail(), QOpenGLTexture::setMinimumLevelOfDetail(), QOpenGLTexture::setSwizzleMask(), QOpenGLTexture::setSwizzleMask(), WaylandEglClientBufferIntegrationPrivate::setupBufferAndCleanup(), WaylandEglStreamClientBufferIntegrationPrivate::setupBufferAndCleanup(), QOpenGLDebugLogger::startLogging(), QOpenGLDebugLogger::stopLogging(), QOpenGLTextureBlitter::supportsExternalOESTarget(), QOpenGLTextureBlitter::supportsRectangleTarget(), QOpenGLFramebufferObject::takeTexture(), QOpenGLTextureUploader::textureImage(), QOpenGLFramebufferObject::toImage(), QtWaylandClient::DmaBufServerBuffer::toOpenGlTexture(), QtWaylandClient::DrmServerBuffer::toOpenGlTexture(), QtWaylandClient::LibHybrisServerBuffer::toOpenGlTexture(), QOpenGLTextureBlitterPrivate::toTextureCoordinates(), QOpenGL2PaintEngineExPrivate::updateBrushTexture(), QGeoMapMapboxGLPrivate::updateSceneGraph(), QSGVivanteVideoMaterial::vivanteMapping(), src_gui_opengl_qopenglfunctions::wrapper0(), src_gui_opengl_qopenglfunctions::wrapper1(), and src_gui_opengl_qopengldebug::SnippetWrapper::wrapper1().

defaultFramebufferObject()

GLuint QOpenGLContext::defaultFramebufferObject

(

)

const

Call this to get the default framebuffer object for the current surface.

On some platforms (for instance, iOS) the default framebuffer object depends on the surface being rendered to, and might be different from 0. Thus, instead of calling glBindFramebuffer(0), you should call glBindFramebuffer(ctx->defaultFramebufferObject()) if you want your application to work across different Qt platforms.

If you use the glBindFramebuffer() in QOpenGLFunctions you do not have to worry about this, as it automatically binds the current context's defaultFramebufferObject() when 0 is passed.

Note

Widgets that render via framebuffer objects, like QOpenGLWidget and QQuickWidget, will override the value returned from this function when painting is active, because at that time the correct "default" framebuffer is the widget's associated backing framebuffer, not the platform-specific one belonging to the top-level window's surface. This ensures the expected behavior for this function and other classes relying on it (for example, QOpenGLFramebufferObject::bindDefault() or QOpenGLFramebufferObject::release()).

See also

QOpenGLFramebufferObject

Definition at line 619 of file qopenglcontext.cpp.

References d, and isValid().

Referenced by QOpenGLWindowPrivate::beginPaint(), QOpenGLWindowPrivate::endPaint(), and QOpenGLFramebufferObject::release().

Here is the call graph for this function:

Here is the caller graph for this function:

doneCurrent()

void QOpenGLContext::doneCurrent

(

)

Convenience function for calling makeCurrent with a 0 surface.

This results in no context being current in the current thread.

See also

makeCurrent(), currentContext()

Definition at line 743 of file qopenglcontext.cpp.

References currentContext(), d, isValid(), and QOpenGLContextPrivate::setCurrentContext().

Referenced by QGuiGLThreadContext::~QGuiGLThreadContext(), QOpenGLDebugLoggerPrivate::_q_contextAboutToBeDestroyed(), WaylandEglClientBufferIntegrationPrivate::handleEglstreamTexture(), WaylandEglStreamClientBufferIntegrationPrivate::handleEglstreamTexture(), WaylandEglStreamClientBufferIntegrationPrivate::initEglStream(), makeCurrent(), src_gui_opengl_qopenglfunctions::MyGLWindow::paintGL(), and QGLXContext::queryDummyContext().

Here is the call graph for this function:

Here is the caller graph for this function:

extensions()

QSet< QByteArray > QOpenGLContext::extensions

(

)

const

Returns the set of OpenGL extensions supported by this context.

The context or a sharing context must be current.

See also

hasExtension()

Definition at line 571 of file qopenglcontext.cpp.

References d, and matcher.

Referenced by hasExtension().

Here is the caller graph for this function:

extraFunctions()

QOpenGLExtraFunctions * QOpenGLContext::extraFunctions

(

)

const

Get the QOpenGLExtraFunctions instance for this context.

QOpenGLContext offers this as a convenient way to access QOpenGLExtraFunctions without having to manage it manually.

The context or a sharing context must be current.

The returned QOpenGLExtraFunctions instance is ready to be used and it does not need initializeOpenGLFunctions() to be called.

Note

QOpenGLExtraFunctions contains functionality that is not guaranteed to be available at runtime. Runtime availability depends on the platform, graphics driver, and the OpenGL version requested by the application.

See also

QOpenGLFunctions, QOpenGLExtraFunctions

Definition at line 559 of file qopenglcontext.cpp.

References functions().

Here is the call graph for this function:

format()

QSurfaceFormat QOpenGLContext::format

(

)

const

Returns the format of the underlying platform context, if create() has been called.

Otherwise, returns the requested format.

The requested and the actual format may differ. Requesting a given OpenGL version does not mean the resulting context will target exactly the requested version. It is only guaranteed that the version/profile/options combination for the created context is compatible with the request, as long as the driver is able to provide such a context.

For example, requesting an OpenGL version 3.x core profile context may result in an OpenGL 4.x core profile context. Similarly, a request for OpenGL 2.1 may result in an OpenGL 3.0 context with deprecated functions enabled. Finally, depending on the driver, unsupported versions may result in either a context creation failure or in a context for the highest supported version.

Similar differences are possible in the buffer sizes, for example, the resulting context may have a larger depth buffer than requested. This is perfectly normal.

Definition at line 847 of file qopenglcontext.cpp.

References d.

Referenced by QWindowsGLContext::QWindowsGLContext(), QOpenGLDebugLoggerPrivate::_q_contextAboutToBeDestroyed(), QOpenGLTextureBlitter::create(), QOpenGLTimerQueryPrivate::create(), QOpenGLTimeMonitorPrivate::create(), QOpenGLVertexArrayObjectPrivate::destroy(), WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), QOpenGLTextureBlitterPrivate::ensureProgram(), QOpenGL2PaintEngineExPrivate::fill(), QOpenGLWidgetPrivate::initialize(), QCocoaGLContext::initialize(), isOpenGLES(), and setFormat().

Here is the caller graph for this function:

functions()

QOpenGLFunctions * QOpenGLContext::functions

(

)

const

Get the QOpenGLFunctions instance for this context.

QOpenGLContext offers this as a convenient way to access QOpenGLFunctions without having to manage it manually.

The context or a sharing context must be current.

The returned QOpenGLFunctions instance is ready to be used and it does not need initializeOpenGLFunctions() to be called.

Definition at line 534 of file qopenglcontext.cpp.

References currentContext(), and d.

Referenced by QtWaylandClient::DecorationsBlitter::DecorationsBlitter(), QOpenGLWidgetPrivate::beginCompose(), QOpenGLWindowPrivate::beginPaint(), QOpenGLFramebufferObject::bindDefault(), QOpenGLWindowPrivate::endPaint(), extraFunctions(), makeCurrent(), QOpenGLWidgetPrivate::recreateFbos(), and swapBuffers().

Here is the call graph for this function:

Here is the caller graph for this function:

getProcAddress() [1/2]

QFunctionPointer QOpenGLContext::getProcAddress

(

const char *

procName

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since

5.8

Definition at line 820 of file qopenglcontext.cpp.

References d.

getProcAddress() [2/2]

QFunctionPointer QOpenGLContext::getProcAddress

(

const QByteArray &

procName

)

const

Resolves the function pointer to an OpenGL extension function, identified by procName.

Returns \nullptr if no such function can be found.

Definition at line 811 of file qopenglcontext.cpp.

Referenced by VulkanWrapperPrivate::VulkanWrapperPrivate().

Here is the caller graph for this function:

globalShareContext()

QOpenGLContext * QOpenGLContext::globalShareContext ( )

static

Since

5.5

Returns the application-wide shared OpenGL context, if present. Otherwise, returns \nullptr.

This is useful if you need to upload OpenGL objects (buffers, textures, etc.) before creating or showing a QOpenGLWidget or QQuickWidget.

Note

You must set the Qt::AA_ShareOpenGLContexts flag on QGuiApplication before creating the QGuiApplication object, otherwise Qt may not create a global shared context.

Warning

Do not attempt to make the context returned by this function current on any surface. Instead, you can create a new context which shares with the global one, and then make the new context current.

See also

Qt::AA_ShareOpenGLContexts, setShareContext(), makeCurrent()

Definition at line 972 of file qopenglcontext.cpp.

References Q_ASSERT, qGuiApp, and qt_gl_global_share_context().

Referenced by CurrentContext::CurrentContext(), WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), and QSurfaceFormat::setDefaultFormat().

Here is the call graph for this function:

Here is the caller graph for this function:

handle()

QPlatformOpenGLContext * QOpenGLContext::handle

(

)

const

Returns the underlying platform context.

Definition at line 249 of file qopenglcontext.cpp.

References d.

Referenced by QEGLPlatformContext::createFrom(), and QXcbGlxIntegration::createOpenGLContext().

Here is the caller graph for this function:

hasExtension()

bool QOpenGLContext::hasExtension

(

const QByteArray &

extension

)

const

Returns true if this OpenGL context supports the specified OpenGL extension, false otherwise.

The context or a sharing context must be current.

See also

extensions()

Definition at line 590 of file qopenglcontext.cpp.

References QSet< T >::contains(), extension(), and extensions().

Referenced by QOpenGLTimerQueryPrivate::create(), and QOpenGLTimeMonitorPrivate::create().

Here is the call graph for this function:

Here is the caller graph for this function:

isOpenGLES()

bool QOpenGLContext::isOpenGLES

(

)

const

Returns true if the context is an OpenGL ES context.

If the context has not yet been created, the result is based on the requested format set via setFormat().

See also

create(), format(), setFormat()

Since

5.3

Definition at line 933 of file qopenglcontext.cpp.

References format(), QSurfaceFormat::OpenGLES, and QSurfaceFormat::renderableType().

Referenced by QOpenGLTimerQueryPrivate::create().

Here is the call graph for this function:

Here is the caller graph for this function:

isValid()

bool QOpenGLContext::isValid

(

)

const

Returns if this context is valid, i.e.

has been successfully created.

On some platforms the return value of false for a context that was successfully created previously indicates that the OpenGL context was lost.

The typical way to handle context loss scenarios in applications is to check via this function whenever makeCurrent() fails and returns false. If this function then returns false, recreate the underlying native OpenGL context by calling create(), call makeCurrent() again and then reinitialize all OpenGL resources.

On some platforms context loss situations is not something that can avoided. On others however, they may need to be opted-in to. This can be done by enabling \l{QSurfaceFormat::ResetNotification}{ResetNotification} in the QSurfaceFormat. This will lead to setting {RESET_NOTIFICATION_STRATEGY_EXT} to {LOSE_CONTEXT_ON_RESET_EXT} in the underlying native OpenGL context. QOpenGLContext will then monitor the status via {glGetGraphicsResetStatusEXT()} in every makeCurrent().

See also

create()

Definition at line 517 of file qopenglcontext.cpp.

References d.

Referenced by create(), defaultFramebufferObject(), doneCurrent(), makeCurrent(), and swapBuffers().

Here is the caller graph for this function:

makeCurrent()

bool QOpenGLContext::makeCurrent

(

QSurface *

surface

)

Makes the context current in the current thread, against the given surface.

Returns true if successful; otherwise returns false. The latter may happen if the surface is not exposed, or the graphics hardware is not available due to e.g. the application being suspended.

If surface is \nullptr this is equivalent to calling doneCurrent().

Avoid calling this function from a different thread than the one the QOpenGLContext instance lives in. If you wish to use QOpenGLContext from a different thread you should first make sure it's not current in the current thread, by calling doneCurrent() if necessary. Then call moveToThread(otherThread) before using it in the other thread.

By default Qt employs a check that enforces the above condition on the thread affinity. It is still possible to disable this check by setting the {Qt::AA_DontCheckOpenGLContextThreadAffinity} application attribute. Be sure to understand the consequences of using QObjects from outside the thread they live in, as explained in the \l{QObject::Thread Affinity}{QObject thread affinity} documentation.

See also

functions(), doneCurrent(), Qt::AA_DontCheckOpenGLContextThreadAffinity

Definition at line 657 of file qopenglcontext.cpp.

References Qt::AA_DontCheckOpenGLContextThreadAffinity, QThread::currentThread(), d, doneCurrent(), functions(), QOpenGLFunctions::glGetString(), QByteArray::isEmpty(), isValid(), Q_UNLIKELY, qApp, QByteArrayLiteral, qFatal, qgetenv(), qstrcmp(), qstrncmp(), qWarning, QOpenGLContextPrivate::setCurrentContext(), QSurface::supportsOpenGL(), surface(), QSurface::surfaceHandle(), QObject::thread(), and QOpenGLContextPrivate::toggleMakeCurrentTracker().

Referenced by QOpenGLDebugLoggerPrivate::_q_contextAboutToBeDestroyed(), QMinimalEglBackingStore::beginPaint(), QOpenGLWindowPrivate::beginPaint(), QOpenGLVertexArrayObjectPrivate::destroy(), WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), QOpenGLCompositor::grabToFrameBufferObject(), QOpenGLWindowPrivate::initialize(), QOpenGLWidgetPrivate::initialize(), src_gui_opengl_qopenglfunctions::MyGLWindow::initializeGL(), src_gui_opengl_qopenglfunctions::MyGLWindow::paintGL(), QGLXContext::queryDummyContext(), and QOpenGLWidgetPrivate::recreateFbos().

Here is the call graph for this function:

Here is the caller graph for this function:

openGLModuleType()

QOpenGLContext::OpenGLModuleType QOpenGLContext::openGLModuleType ( )

static

Returns the underlying OpenGL implementation type.

On platforms where the OpenGL implementation is not dynamically loaded, the return value is determined during compile time and never changes.

Note

A desktop OpenGL implementation may be capable of creating ES-compatible contexts too. Therefore in most cases it is more appropriate to check QSurfaceFormat::renderableType() or use the convenience function isOpenGLES().

This function requires that the QGuiApplication instance is already created.

Since

5.3

Definition at line 911 of file qopenglcontext.cpp.

References QGuiApplicationPrivate::instance(), LibGL, LibGLES, Q_ASSERT, and qGuiApp.

Referenced by QGLXContext::QGLXContext(), QGLXContext::QGLXContext(), QOpenGLFramebufferObjectFormatPrivate::QOpenGLFramebufferObjectFormatPrivate(), QEglConfigChooser::chooseConfig(), QQuick3D::idealSurfaceFormat(), isSoftwareGl(), q_glFormatFromConfig(), renderToKTXFile(), and QWindowsContext::shouldHaveNonClientDpiScaling().

Here is the call graph for this function:

Here is the caller graph for this function:

screen()

QScreen * QOpenGLContext::screen

(

)

const

Returns the screen the context was created for.

Definition at line 879 of file qopenglcontext.cpp.

References d.

Referenced by QRhiGles2::create(), QOpenGLWidgetPrivate::initialize(), and setScreen().

Here is the caller graph for this function:

setFormat()

void QOpenGLContext::setFormat

(

const QSurfaceFormat &

format

)

Sets the format the OpenGL context should be compatible with.

You need to call create() before it takes effect.

When the format is not explicitly set via this function, the format returned by QSurfaceFormat::defaultFormat() will be used. This means that when having multiple contexts, individual calls to this function can be replaced by one single call to QSurfaceFormat::setDefaultFormat() before creating the first context.

Definition at line 292 of file qopenglcontext.cpp.

References d, and format().

Referenced by QMinimalEglBackingStore::QMinimalEglBackingStore(), QRhiGles2::create(), QOpenGLWindowPrivate::initialize(), QOpenGLWidgetPrivate::initialize(), Q_TRACE_INSTRUMENT(), and QEglFSWindow::setBackingStore().

Here is the call graph for this function:

Here is the caller graph for this function:

setScreen()

void QOpenGLContext::setScreen

(

QScreen *

screen

)

Sets the screen the OpenGL context should be valid for.

You need to call create() before it takes effect.

Definition at line 312 of file qopenglcontext.cpp.

References QObject::connect(), d, QObject::destroyed(), disconnect(), QGuiApplication::primaryScreen, screen(), SIGNAL, and SLOT.

Referenced by QMinimalEglBackingStore::QMinimalEglBackingStore(), QOpenGLContext(), QOpenGLWidgetPrivate::initialize(), and QEglFSWindow::setBackingStore().

Here is the call graph for this function:

Here is the caller graph for this function:

setShareContext()

void QOpenGLContext::setShareContext

(

QOpenGLContext *

shareContext

)

Makes this context share textures, shaders, and other OpenGL resources with shareContext.

You need to call create() before it takes effect.

Definition at line 302 of file qopenglcontext.cpp.

References d, and shareContext().

Referenced by WaylandEglClientBufferIntegrationPrivate::ensureContext(), WaylandEglStreamClientBufferIntegrationPrivate::ensureContext(), QOpenGLWindowPrivate::initialize(), QOpenGLWidgetPrivate::initialize(), and QEglFSWindow::setBackingStore().

Here is the call graph for this function:

Here is the caller graph for this function:

shareContext()

QOpenGLContext * QOpenGLContext::shareContext

(

)

const

Returns the share context this context was created with.

If the underlying platform was not able to support the requested sharing, this will return 0.

Definition at line 870 of file qopenglcontext.cpp.

References d.

Referenced by QRhiGles2::QRhiGles2(), QWasmOpenGLContext::isSharing(), QWasmOpenGLContext::makeCurrent(), and setShareContext().

Here is the caller graph for this function:

shareGroup()

QOpenGLContextGroup * QOpenGLContext::shareGroup

(

)

const

Returns the share group this context belongs to.

Definition at line 858 of file qopenglcontext.cpp.

References d.

Referenced by QOpenGLContextPrivate::adopt(), areSharing(), QOpenGLFramebufferObject::bind(), QOpenGLContextGroup::currentContextGroup(), QOpenGLSharedResource::free(), QOpenGLFramebufferObject::release(), QOpenGLFramebufferObject::setAttachment(), and QOpenGLFramebufferObject::takeTexture().

Here is the caller graph for this function:

shareHandle()

QPlatformOpenGLContext * QOpenGLContext::shareHandle

(

)

const

Returns the underlying platform context with which this context is sharing.

Definition at line 261 of file qopenglcontext.cpp.

References d.

Referenced by QWindowsGLContext::QWindowsGLContext(), and QWindowsGLContext::isSharing().

Here is the caller graph for this function:

supportsThreadedOpenGL()

bool QOpenGLContext::supportsThreadedOpenGL ( )

static

Returns true if the platform supports OpenGL rendering outside the main (gui) thread.

The value is controlled by the platform plugin in use and may also depend on the graphics drivers.

Since

5.5

Definition at line 947 of file qopenglcontext.cpp.

References QGuiApplicationPrivate::instance(), Q_ASSERT, qGuiApp, and QPlatformIntegration::ThreadedOpenGL.

Here is the call graph for this function:

surface()

QSurface * QOpenGLContext::surface

(

)

const

Returns the surface the context has been made current with.

This is the surface passed as an argument to makeCurrent().

Definition at line 763 of file qopenglcontext.cpp.

References d.

Referenced by QOpenGLDebugLoggerPrivate::_q_contextAboutToBeDestroyed(), makeCurrent(), and swapBuffers().

Here is the caller graph for this function:

swapBuffers()

void QOpenGLContext::swapBuffers

(

QSurface *

surface

)

Swap the back and front buffers of surface.

Call this to finish a frame of OpenGL rendering, and make sure to call makeCurrent() again before issuing any further OpenGL commands, for example as part of a new frame.

Definition at line 777 of file qopenglcontext.cpp.

References d, QSurface::format(), functions(), QOpenGLFunctions::glFlush(), isValid(), qWarning, QSurfaceFormat::SingleBuffer, QSurface::supportsOpenGL(), surface(), QSurface::surfaceHandle(), and QOpenGLContextPrivate::toggleMakeCurrentTracker().

Referenced by QOpenGLWindowPrivate::flush(), QMinimalEglBackingStore::flush(), and src_gui_opengl_qopenglfunctions::MyGLWindow::paintGL().

Here is the call graph for this function:

Here is the caller graph for this function:

Friends And Related Symbol Documentation

QAbstractOpenGLFunctionsPrivate

friend class QAbstractOpenGLFunctionsPrivate

friend

Definition at line 138 of file qopenglcontext.h.

QOpenGL2PaintEngineEx

friend class QOpenGL2PaintEngineEx

friend

Definition at line 134 of file qopenglcontext.h.

QOpenGL2PaintEngineExPrivate

friend class QOpenGL2PaintEngineExPrivate

friend

Definition at line 135 of file qopenglcontext.h.

QOpenGLContextResourceBase

friend class QOpenGLContextResourceBase

friend

Definition at line 127 of file qopenglcontext.h.

QOpenGLEngineShaderManager

friend class QOpenGLEngineShaderManager

friend

Definition at line 131 of file qopenglcontext.h.

QOpenGLFramebufferObject

friend class QOpenGLFramebufferObject

friend

Definition at line 132 of file qopenglcontext.h.

QOpenGLFramebufferObjectPrivate

friend class QOpenGLFramebufferObjectPrivate

friend

Definition at line 133 of file qopenglcontext.h.

QOpenGLGlyphTexture

friend class QOpenGLGlyphTexture

friend

Definition at line 129 of file qopenglcontext.h.

QOpenGLPaintDevice

friend class QOpenGLPaintDevice

friend

Definition at line 128 of file qopenglcontext.h.

QOpenGLTextureGlyphCache

friend class QOpenGLTextureGlyphCache

friend

Definition at line 130 of file qopenglcontext.h.

QOpenGLTexturePrivate

friend class QOpenGLTexturePrivate

friend

Definition at line 139 of file qopenglcontext.h.

QSGDistanceFieldGlyphCache

friend class QSGDistanceFieldGlyphCache

friend

Definition at line 136 of file qopenglcontext.h.

QWidgetPrivate

friend class QWidgetPrivate

friend

Definition at line 137 of file qopenglcontext.h.

---

The documentation for this class was generated from the following files:

• qtbase/src/gui/kernel/qopenglcontext.h (05fc3aef53348fb58be6308076e000825b704e58)
• qtbase/src/gui/kernel/qopenglcontext.cpp (d139642aefde2d00683cf29f3875ccfae6c66779)