QGLOffscreen Class Reference

Inheritance diagram for QGLOffscreen:

Public Slots
void	cleanupGLContextRefs (const QGLContext *context)
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...

Public Functions
void	begin ()
void	bind ()
QGLContext *	context () const
QSize	drawableSize () const
void	end ()
void	initialize ()
bool	isBound () const
bool	isValid () const
QSize	offscreenSize () const
GLuint	offscreenTexture () const
	QGLOffscreen ()
void	release ()
void	setDevice (QPaintDevice *pdev)
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) 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. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
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. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...

Static Public Functions
static bool	isSupported ()
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)

Properties
bool	activated
bool	bound
QGLContext *	ctx
QGLPaintDevice *	device
bool	drawable_fbo
bool	initialized
QSize	last_failed_size
int	mask_dim
QGLFramebufferObject *	offscreen

Additional Inherited Members
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
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 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

Definition at line 235 of file qpaintengine_opengl.cpp.

Constructors and Destructors

QGLOffscreen()

QGLOffscreen::QGLOffscreen ( )

inline

Definition at line 239 of file qpaintengine_opengl.cpp.

        : QObject(),
          offscreen(0),
          ctx(0),
          mask_dim(0),
          activated(false),
          bound(false)
    {
        connect(QGLSignalProxy::instance(),
                SIGNAL(aboutToDestroyContext(const QGLContext*)),
                SLOT(cleanupGLContextRefs(const QGLContext*)));
    }

Functions

begin()

void QGLOffscreen::begin

(

)

Definition at line 316 of file qpaintengine_opengl.cpp.

{
#ifndef QT_OPENGL_ES
    initialized = false;

    if (activated)
        initialize();
#endif
}

bind()

void QGLOffscreen::bind ( )

inline

Definition at line 397 of file qpaintengine_opengl.cpp.

Referenced by QGLTrapezoidMaskGenerator::drawMask(), and QGLEllipseMaskGenerator::drawMask().

{
#ifndef QT_OPENGL_ES
    Q_ASSERT(initialized);

    if (!offscreen || bound)
        return;

    DEBUG_ONCE qDebug() << "QGLOffscreen: binding offscreen";
    offscreen->bind();

    bound = true;

    glViewport(0, 0, offscreenSize().width(), offscreenSize().height());

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, offscreenSize().width(), offscreenSize().height(), 0, -999999, 999999);
    glMatrixMode(GL_MODELVIEW);
#endif
}

cleanupGLContextRefs

void QGLOffscreen::cleanupGLContextRefs ( const QGLContext *  context )

inlineslot

Definition at line 276 of file qpaintengine_opengl.cpp.

                                                         {
        if (context == ctx) {
            delete offscreen;
            ctx = 0;
            offscreen = 0;
            mask_dim = 0;
        }
    }

context()

QGLContext * QGLOffscreen::context ( ) const

inline

Definition at line 474 of file qpaintengine_opengl.cpp.

Referenced by QGLTrapezoidMaskGenerator::drawMask(), and QGLEllipseMaskGenerator::drawMask().

{
    return ctx;
}

drawableSize()

QSize QGLOffscreen::drawableSize ( ) const

inline

Definition at line 459 of file qpaintengine_opengl.cpp.

Referenced by QGLEllipseMaskGenerator::drawMask(), and QGLTrapezoidMaskGenerator::screenRect().

{
    return device->size();
}

end()

void QGLOffscreen::end

(

)

Definition at line 369 of file qpaintengine_opengl.cpp.

{
    if (bound)
        release();
#ifdef DEBUG_DISPLAY_MASK_TEXTURE
    glReadBuffer(GL_BACK);
    glDrawBuffer(GL_BACK);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glColor4f(1, 1, 1, 1);
    glDisable(GL_DEPTH_TEST);
    glBlendFunc(GL_ONE, GL_ZERO);
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, offscreen->texture());

    glBegin(GL_QUADS);
    glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 0.0);
    glTexCoord2f(1.0, 1.0); glVertex2f(drawable.size().width(), 0.0);
    glTexCoord2f(1.0, 0.0); glVertex2f(drawable.size().width(), drawable.size().height());
    glTexCoord2f(0.0, 0.0); glVertex2f(0.0, drawable.size().height());
    glEnd();

    glBindTexture(GL_TEXTURE_2D, 0);
    glDisable(GL_TEXTURE_2D);
#endif
}

initialize()

void QGLOffscreen::initialize ( )

inline

Definition at line 326 of file qpaintengine_opengl.cpp.

{
#ifndef QT_OPENGL_ES
    if (initialized)
        return;

    activated = true;
    initialized = true;

    int dim = qMax(2048, static_cast<int>(qt_next_power_of_two(qMax(device->size().width(), device->size().height()))));

    bool shared_context = QGLContext::areSharing(device->context(), ctx);
    bool would_fail = last_failed_size.isValid() &&
                      (device->size().width() >= last_failed_size.width() ||
                       device->size().height() >= last_failed_size.height());
    bool needs_refresh = dim > mask_dim || !shared_context;

    if (needs_refresh && !would_fail) {
        DEBUG_ONCE qDebug() << "QGLOffscreen::initialize(): creating offscreen of size" << dim;
        delete offscreen;
        offscreen = new QGLFramebufferObject(dim, dim, GLenum(GL_TEXTURE_2D));
        mask_dim = dim;

        if (!offscreen->isValid()) {
            qWarning("QGLOffscreen: Invalid offscreen fbo (size %dx%d)", mask_dim, mask_dim);
            delete offscreen;
            offscreen = 0;
            mask_dim = 0;
            last_failed_size = device->size();
        }
    }

    qt_mask_texture_cache()->setOffscreenSize(offscreenSize());
    qt_mask_texture_cache()->setDrawableSize(device->size());
    ctx = device->context();
#endif
}

isBound()

bool QGLOffscreen::isBound ( ) const

inline

Definition at line 454 of file qpaintengine_opengl.cpp.

{
    return bound;
}

isSupported()

bool QGLOffscreen::isSupported ( )

static

Definition at line 479 of file qpaintengine_opengl.cpp.

Referenced by QOpenGLPaintEngine::updateRenderHints().

{
    return (QGLExtensions::glExtensions() & QGLExtensions::FramebufferObject); // for fbo
}

isValid()

bool QGLOffscreen::isValid ( ) const

inline

Definition at line 364 of file qpaintengine_opengl.cpp.

{
    return offscreen;
}

offscreenSize()

QSize QGLOffscreen::offscreenSize ( ) const

inline

Definition at line 464 of file qpaintengine_opengl.cpp.

Referenced by QOpenGLPaintEnginePrivate::drawItem(), QGLTrapezoidMaskGenerator::drawMask(), QGLEllipseMaskGenerator::drawMask(), and QOpenGLPaintEnginePrivate::updateFragmentProgramData().

{
    return QSize(mask_dim, mask_dim);
}

offscreenTexture()

GLuint QGLOffscreen::offscreenTexture ( ) const

inline

Definition at line 469 of file qpaintengine_opengl.cpp.

Referenced by QOpenGLPaintEnginePrivate::composite().

{
    return offscreen ? offscreen->texture() : 0;
}

release()

void QGLOffscreen::release ( )

inline

Definition at line 419 of file qpaintengine_opengl.cpp.

Referenced by QOpenGLPaintEnginePrivate::flushDrawQueue().

{
#ifndef QT_OPENGL_ES
    if (!offscreen || !bound)
        return;

#ifdef Q_WS_X11
    // workaround for bug in nvidia driver versions 9x.xx
    if (qt_nvidiaFboNeedsFinish)
        glFinish();
#endif

    DEBUG_ONCE_STR("QGLOffscreen: releasing offscreen");

    if (drawable_fbo)
        device->ensureActiveTarget(); //###
    else
        offscreen->release();

    QSize sz(device->size());
    glViewport(0, 0, sz.width(), sz.height());

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
#ifndef QT_OPENGL_ES
    glOrtho(0, sz.width(), sz.height(), 0, -999999, 999999);
#else
    glOrthof(0, sz.width(), sz.height(), 0, -999999, 999999);
#endif
    glMatrixMode(GL_MODELVIEW);

    bound = false;
#endif
}

setDevice()

void QGLOffscreen::setDevice ( QPaintDevice *  pdev )

inline

Definition at line 303 of file qpaintengine_opengl.cpp.

{
    if (pdev->devType() == QInternal::OpenGL)
        device = static_cast<QGLPaintDevice*>(pdev);
    else
        device = QGLPaintDevice::getDevice(pdev);

    if (!device)
        return;

    drawable_fbo = (pdev->devType() == QInternal::FramebufferObject);
}

Properties

activated

bool QGLOffscreen::activated

private

Definition at line 297 of file qpaintengine_opengl.cpp.

bound

bool QGLOffscreen::bound

private

Definition at line 300 of file qpaintengine_opengl.cpp.

ctx

QGLContext* QGLOffscreen::ctx

private

Definition at line 289 of file qpaintengine_opengl.cpp.

device

QGLPaintDevice* QGLOffscreen::device

private

Definition at line 286 of file qpaintengine_opengl.cpp.

drawable_fbo

bool QGLOffscreen::drawable_fbo

private

Definition at line 295 of file qpaintengine_opengl.cpp.

initialized

bool QGLOffscreen::initialized

private

Definition at line 298 of file qpaintengine_opengl.cpp.

last_failed_size

QSize QGLOffscreen::last_failed_size

private

Definition at line 293 of file qpaintengine_opengl.cpp.

mask_dim

int QGLOffscreen::mask_dim

private

Definition at line 292 of file qpaintengine_opengl.cpp.

offscreen

QGLFramebufferObject* QGLOffscreen::offscreen

private

Definition at line 288 of file qpaintengine_opengl.cpp.

---

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

• /src/opengl/qpaintengine_opengl.cpp