A backing store implementation for OpenGL. More...

#include <qopenglcompositorbackingstore_p.h>

Inheritance diagram for QOpenGLCompositorBackingStore:

Collaboration diagram for QOpenGLCompositorBackingStore:

Public Member Functions
	QOpenGLCompositorBackingStore (QWindow *window)

	~QOpenGLCompositorBackingStore ()

QPaintDevice *	paintDevice () override
	Implement this function to return the appropriate paint device.

void	beginPaint (const QRegion &region) override
	This function is called before painting onto the surface begins, with the region in which the painting will occur.

void	flush (QWindow *window, const QRegion &region, const QPoint &offset) override
	Flushes the given region from the specified window.

void	resize (const QSize &size, const QRegion &staticContents) override

QImage	toImage () const override
	Implemented in subclasses to return the content of the backingstore as a QImage.

FlushResult	rhiFlush (QWindow window, qreal sourceDevicePixelRatio, const QRegion &region, const QPoint &offset, QPlatformTextureList textures, bool translucentBackground) override
	Flushes the given region from the specified window, and compositing it with the specified textures list.

const QPlatformTextureList *	textures () const

void	notifyComposited ()

Public Member Functions inherited from QPlatformBackingStore
	QPlatformBackingStore (QWindow *window)
	Constructs an empty surface for the given top-level window.

virtual	~QPlatformBackingStore ()
	Destroys this surface.

QWindow *	window () const
	Returns a pointer to the top-level window associated with this surface.

QBackingStore *	backingStore () const
	Returns a pointer to the backing store associated with this surface.

virtual QRhiTexture *	toTexture (QRhiResourceUpdateBatch resourceUpdates, const QRegion &dirtyRegion, TextureFlags flags) const
	May be reimplemented in subclasses to return the content of the backingstore as an QRhiTexture.

virtual QPlatformGraphicsBuffer *	graphicsBuffer () const
	Accessor for a backingstores graphics buffer abstraction.

virtual bool	scroll (const QRegion &area, int dx, int dy)
	Scrolls the given area dx pixels to the right and dy downward; both dx and dy may be negative.

virtual void	endPaint ()
	This function is called after painting onto the surface has ended.

void	setRhiConfig (const QPlatformBackingStoreRhiConfig &config)

QRhi *	rhi () const

void	surfaceAboutToBeDestroyed ()

void	graphicsDeviceReportedLost ()

Additional Inherited Members
Public Types inherited from QPlatformBackingStore
enum	FlushResult { FlushSuccess , FlushFailed , FlushFailedDueToLostDevice }

enum	TextureFlag { TextureSwizzle = 0x01 , TextureFlip = 0x02 , TexturePremultiplied = 0x04 }

Detailed Description

A backing store implementation for OpenGL.

Since: 5.4

This implementation uploads raster-rendered widget windows into textures. It is meant to be used with QOpenGLCompositor that composites the textures onto a single native window using OpenGL. This means that multiple top-level widgets are supported without creating actual native windows for each of them.

Note: It is important to call notifyComposited() from the corresponding platform window's endCompositing() callback (inherited from QOpenGLCompositorWindow).; When implementing QOpenGLCompositorWindow::textures() for windows of type RasterSurface or RasterGLSurface, simply return the list provided by this class' textures().

Definition at line 31 of file qopenglcompositorbackingstore_p.h.

Constructor & Destructor Documentation

◆ QOpenGLCompositorBackingStore()

QOpenGLCompositorBackingStore::QOpenGLCompositorBackingStore ( QWindow * window )

Definition at line 42 of file qopenglcompositorbackingstore.cpp.

◆ ~QOpenGLCompositorBackingStore()

QOpenGLCompositorBackingStore::~QOpenGLCompositorBackingStore ( )

Definition at line 54 of file qopenglcompositorbackingstore.cpp.

References QRhi::makeThreadLocalNativeContextCurrent().

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Member Function Documentation

◆ beginPaint()

void QOpenGLCompositorBackingStore::beginPaint ( const QRegion & )

overridevirtual

This function is called before painting onto the surface begins, with the region in which the painting will occur.

See also: endPaint(), paintDevice()

Reimplemented from QPlatformBackingStore.

Definition at line 234 of file qopenglcompositorbackingstore.cpp.

References QPainter::CompositionMode_Source, QImage::hasAlphaChannel(), and Qt::transparent.

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◆ flush()

void QOpenGLCompositorBackingStore::flush	(	QWindow *	window,
		const QRegion &	region,
		const QPoint &	offset )

overridevirtual

Flushes the given region from the specified window.

Note: region is relative to the window which may not be top-level in case window corresponds to a native child widget. offset is the position of the native child relative to the top-level window.

Unlike rhiFlush(), this function's default implementation does nothing. It is expected that subclasses provide a platform-specific (non-QRhi-based) implementation, if applicable on the given platform.

See also: rhiFlush()

Reimplemented from QPlatformBackingStore.

Definition at line 137 of file qopenglcompositorbackingstore.cpp.

References QPlatformTextureList::appendTexture(), QPlatformTextureList::clear(), compositor, QOpenGLCompositor::instance(), QPlatformBackingStoreRhiConfig::OpenGL, Q_ASSERT, Q_UNUSED, QPlatformBackingStore::rhi(), QOpenGLCompositorWindow::setBackingStore(), QPlatformBackingStore::setRhiConfig(), and QPlatformBackingStore::window().

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◆ notifyComposited()

void QOpenGLCompositorBackingStore::notifyComposited ( )

Definition at line 225 of file qopenglcompositorbackingstore.cpp.

References QPlatformTextureList::lock().

Referenced by QEglFSWindow::endCompositing().

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◆ paintDevice()

QPaintDevice * QOpenGLCompositorBackingStore::paintDevice ( )

overridevirtual

Implement this function to return the appropriate paint device.

Implements QPlatformBackingStore.

Definition at line 67 of file qopenglcompositorbackingstore.cpp.

◆ resize()

void QOpenGLCompositorBackingStore::resize	(	const QSize &	size,
		const QRegion &	staticContents )

overridevirtual

Implements QPlatformBackingStore.

Definition at line 246 of file qopenglcompositorbackingstore.cpp.

References compositor, QImage::Format_RGBA8888, QOpenGLCompositor::instance(), and Q_UNUSED.

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◆ rhiFlush()

QPlatformBackingStore::FlushResult QOpenGLCompositorBackingStore::rhiFlush	(	QWindow *	window,
		qreal	sourceDevicePixelRatio,
		const QRegion &	region,
		const QPoint &	offset,
		QPlatformTextureList *	textures,
		bool	translucentBackground )

overridevirtual

Flushes the given region from the specified window, and compositing it with the specified textures list.

The default implementation retrieves the contents using toTexture() and composes using QRhi with OpenGL, Metal, Vulkan, or Direct 3D underneath. May be reimplemented in subclasses if customization is desired.

Note: region is relative to the window which may not be top-level in case window corresponds to a native child widget. offset is the position of the native child relative to the top-level window.

See also: flush()

Reimplemented from QPlatformBackingStore.

Definition at line 173 of file qopenglcompositorbackingstore.cpp.

References QPlatformTextureList::appendTexture(), QPlatformTextureList::clear(), compositor, QPlatformBackingStore::FlushFailed, QPlatformBackingStore::FlushSuccess, QWindowPrivate::get(), i, QOpenGLCompositor::instance(), QPlatformBackingStoreRhiConfig::OpenGL, Q_ASSERT, Q_UNUSED, QPlatformBackingStore::rhi(), QPlatformBackingStore::setRhiConfig(), textures(), and QPlatformBackingStore::window().

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◆ textures()

const QPlatformTextureList * QOpenGLCompositorBackingStore::textures ( ) const

inline

Definition at line 53 of file qopenglcompositorbackingstore_p.h.

Referenced by rhiFlush(), and QEglFSWindow::textures().

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◆ toImage()

QImage QOpenGLCompositorBackingStore::toImage ( ) const

overridevirtual

Implemented in subclasses to return the content of the backingstore as a QImage.

If composition via a 3D graphics API is supported, either this function or toTexture() must be implemented.

The returned image is only valid until the next operation (resize, paint, scroll, or flush) on the backingstore. The caller must not store the return value between calls, but instead call this function before each use, or make an explicit copy.