#include <qrhivulkan_p.h>

Inheritance diagram for QVkSwapChain:

Collaboration diagram for QVkSwapChain:

Classes
struct	FrameResources

struct	ImageResources

Public Member Functions
	QVkSwapChain (QRhiImplementation *rhi)

	~QVkSwapChain ()

void	destroy () override
	Releases (or requests deferred releasing of) the underlying native graphics resources.

QRhiCommandBuffer *	currentFrameCommandBuffer () override

QRhiRenderTarget *	currentFrameRenderTarget () override

QSize	surfacePixelSize () override

bool	isFormatSupported (Format f) override

QRhiRenderPassDescriptor *	newCompatibleRenderPassDescriptor () override

bool	createOrResize () override
	Creates the swapchain if not already done and resizes the swapchain buffers to match the current size of the targeted surface.

bool	ensureSurface ()

Public Member Functions inherited from QRhiSwapChain
QRhiResource::Type	resourceType () const override

QWindow *	window () const

void	setWindow (QWindow *window)
	Sets the window.

QRhiSwapChainProxyData	proxyData () const

void	setProxyData (const QRhiSwapChainProxyData &d)
	Sets the proxy data d.

Flags	flags () const

void	setFlags (Flags f)
	Sets the flags f.

Format	format () const

void	setFormat (Format f)
	Sets the format f.

QRhiRenderBuffer *	depthStencil () const

void	setDepthStencil (QRhiRenderBuffer *ds)
	Sets the renderbuffer ds for use as a depth-stencil buffer.

int	sampleCount () const

void	setSampleCount (int samples)
	Sets the sample count.

QRhiRenderPassDescriptor *	renderPassDescriptor () const

void	setRenderPassDescriptor (QRhiRenderPassDescriptor *desc)
	Associates with the QRhiRenderPassDescriptor desc.

QSize	currentPixelSize () const

virtual QRhiCommandBuffer *	currentFrameCommandBuffer ()=0

virtual QRhiRenderTarget *	currentFrameRenderTarget ()=0

virtual QRhiRenderTarget *	currentFrameRenderTarget (StereoTargetBuffer targetBuffer)

virtual QSize	surfacePixelSize ()=0

virtual bool	isFormatSupported (Format f)=0

virtual QRhiRenderPassDescriptor *	newCompatibleRenderPassDescriptor ()=0

virtual bool	createOrResize ()=0
	Creates the swapchain if not already done and resizes the swapchain buffers to match the current size of the targeted surface.

virtual QRhiSwapChainHdrInfo	hdrInfo ()
	\variable QRhiSwapChainHdrInfo::isHardCodedDefaults

Public Member Functions inherited from QRhiResource
virtual	~QRhiResource ()
	Destructor.

virtual Type	resourceType () const =0

virtual void	destroy ()=0
	Releases (or requests deferred releasing of) the underlying native graphics resources.

void	deleteLater ()
	When called without a frame being recorded, this function is equivalent to deleting the object.

QByteArray	name () const

void	setName (const QByteArray &name)
	Sets a name for the object.

quint64	globalResourceId () const

QRhi *	rhi () const

Public Attributes
QWindow *	window = nullptr

QSize	pixelSize

bool	supportsReadback = false

VkSwapchainKHR	sc = VK_NULL_HANDLE

int	bufferCount = 0

VkSurfaceKHR	surface = VK_NULL_HANDLE

VkSurfaceKHR	lastConnectedSurface = VK_NULL_HANDLE

VkFormat	colorFormat = VK_FORMAT_B8G8R8A8_UNORM

VkColorSpaceKHR	colorSpace = VK_COLOR_SPACE_SRGB_NONLINEAR_KHR

QVkRenderBuffer *	ds = nullptr

VkSampleCountFlagBits	samples = VK_SAMPLE_COUNT_1_BIT

QVarLengthArray< VkPresentModeKHR, 8 >	supportedPresentationModes

VkDeviceMemory	msaaImageMem = VK_NULL_HANDLE

QVkSwapChainRenderTarget	rtWrapper

QVkCommandBuffer	cbWrapper

QVarLengthArray< ImageResources, EXPECTED_MAX_BUFFER_COUNT >	imageRes

struct QVkSwapChain::FrameResources	frameRes [QVK_FRAMES_IN_FLIGHT]

quint32	currentImageIndex = 0

quint32	currentFrameSlot = 0

int	frameCount = 0

Static Public Attributes
static const quint32	EXPECTED_MAX_BUFFER_COUNT = 4

Friends
class	QRhiVulkan

Additional Inherited Members
Public Types inherited from QRhiSwapChain
enum	Flag { SurfaceHasPreMulAlpha = 1 << 0 , SurfaceHasNonPreMulAlpha = 1 << 1 , sRGB = 1 << 2 , UsedAsTransferSource = 1 << 3 , NoVSync = 1 << 4 , MinimalBufferCount = 1 << 5 }
	Flag values to describe swapchain properties. More...

enum	Format { SDR , HDRExtendedSrgbLinear , HDR10 }
	Describes the swapchain format. More...

enum	StereoTargetBuffer { LeftBuffer , RightBuffer }
	Selects the backbuffer to use with a stereoscopic swapchain. More...

Public Types inherited from QRhiResource
enum	Type { Buffer , Texture , Sampler , RenderBuffer , RenderPassDescriptor , SwapChainRenderTarget , TextureRenderTarget , ShaderResourceBindings , GraphicsPipeline , SwapChain , ComputePipeline , CommandBuffer }
	Specifies type of the resource. More...

Protected Member Functions inherited from QRhiSwapChain
	QRhiSwapChain (QRhiImplementation *rhi)

Protected Member Functions inherited from QRhiResource
	QRhiResource (QRhiImplementation *rhi)

Protected Attributes inherited from QRhiSwapChain
QWindow *	m_window = nullptr

Flags	m_flags

Format	m_format = SDR

QRhiRenderBuffer *	m_depthStencil = nullptr

int	m_sampleCount = 1

QRhiRenderPassDescriptor *	m_renderPassDesc = nullptr

QSize	m_currentPixelSize

QRhiSwapChainProxyData	m_proxyData

Protected Attributes inherited from QRhiResource
QRhiImplementation *	m_rhi = nullptr

quint64	m_id

QByteArray	m_objectName

Detailed Description

Definition at line 567 of file qrhivulkan_p.h.

Constructor & Destructor Documentation

◆ QVkSwapChain()

QVkSwapChain::QVkSwapChain ( QRhiImplementation * rhi )

Definition at line 7446 of file qrhivulkan.cpp.

◆ ~QVkSwapChain()

QVkSwapChain::~QVkSwapChain ( )

Definition at line 7453 of file qrhivulkan.cpp.

References destroy().

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Member Function Documentation

◆ createOrResize()

bool QVkSwapChain::createOrResize ( )

overridevirtual

Creates the swapchain if not already done and resizes the swapchain buffers to match the current size of the targeted surface.

Call this whenever the size of the target surface is different than before.

Note: call destroy() only when the swapchain needs to be released completely, typically upon QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed. To perform resizing, just call createOrResize().

Returns: true when successful, false when a graphics operation failed. Regardless of the return value, calling destroy() is always safe.

Implements QRhiSwapChain.

Definition at line 7649 of file qrhivulkan.cpp.

References bufferCount, QVkRenderTargetData::colorAttCount, QRhiRenderBuffer::create(), QVkSwapChainRenderTarget::d, destroy(), QVkRenderTargetData::dpr, ds, QVkRenderTargetData::dsAttCount, QRhiRenderBuffer::flags(), frameCount, QSize::height(), i, imageRes, QVkRenderBuffer::imageView, QRhiSwapChain::m_currentPixelSize, QRhiSwapChain::m_depthStencil, QRhiSwapChain::m_renderPassDesc, QRhiSwapChain::m_sampleCount, QRhiSwapChain::m_window, QRhiRenderBuffer::pixelSize(), QVkRenderTargetData::pixelSize, pixelSize, Q_ASSERT, QRHI_RES, QRHI_RES_RHI, qWarning, QVkRenderTargetData::resolveAttCount, QVkRenderPassDescriptor::rp, QVkRenderTargetData::rp, rtWrapper, QRhiRenderBuffer::sampleCount(), QVkRenderTargetData::sampleCount, samples, QRhiRenderBuffer::setPixelSize(), QRhiRenderTarget::setRenderPassDescriptor(), surfacePixelSize(), QRhiRenderBuffer::UsedWithSwapChainOnly, QSize::width(), and window.

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◆ currentFrameCommandBuffer()

QRhiCommandBuffer * QVkSwapChain::currentFrameCommandBuffer ( )

overridevirtual

Returns: a command buffer on which rendering commands and resource updates can be recorded within a \l{QRhi::beginFrame()}{beginFrame} - \l{QRhi::endFrame()}{endFrame} block, assuming beginFrame() was called with this swapchain.

Note: The returned object is valid also after endFrame(), up until the next beginFrame(), but the returned command buffer should not be used to record any commands then. Rather, it can be used to query data collected during the frame (or previous frames), for example by calling \l{QRhiCommandBuffer::lastCompletedGpuTime()}{lastCompletedGpuTime()}.; The value must not be cached and reused between frames. The caller should not hold on to the returned object once \l{QRhi::beginFrame()}{beginFrame()} is called again. Instead, the command buffer object should be queried again by calling this function.

Implements QRhiSwapChain.

Definition at line 7481 of file qrhivulkan.cpp.

References cbWrapper.

◆ currentFrameRenderTarget()

QRhiRenderTarget * QVkSwapChain::currentFrameRenderTarget ( )

overridevirtual

Returns: a render target that can used with beginPass() in order to render the swapchain's current backbuffer. Only valid within a QRhi::beginFrame() - QRhi::endFrame() block where beginFrame() was called with this swapchain.

Note: the value must not be cached and reused between frames

Implements QRhiSwapChain.

Definition at line 7486 of file qrhivulkan.cpp.

References rtWrapper.

◆ destroy()

void QVkSwapChain::destroy ( )

overridevirtual

Releases (or requests deferred releasing of) the underlying native graphics resources.

Safe to call multiple times, subsequent invocations will be a no-op then.

Once destroy() is called, the QRhiResource instance can be reused, by calling create() again. That will then result in creating new native graphics resources underneath.

Note: Resources referenced by commands for the current frame should not be released until the frame is submitted by QRhi::endFrame().

The QRhiResource destructor also performs the same task, so calling this function is not necessary before deleting a QRhiResource.

See also: deleteLater()

Implements QRhiResource.

Definition at line 7458 of file qrhivulkan.cpp.

References frame, frameRes, i, lastConnectedSurface, QRHI_RES_RHI, QVK_FRAMES_IN_FLIGHT, sc, and surface.

Referenced by ~QVkSwapChain(), and createOrResize().

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◆ ensureSurface()

bool QVkSwapChain::ensureSurface ( )

Definition at line 7592 of file qrhivulkan.cpp.

References colorSpace, QVarLengthArray< T, Prealloc >::data(), hdrFormatMatchesVkSurfaceFormat(), i, isSrgbFormat(), QRhiSwapChain::m_flags, QRhiSwapChain::m_format, QRhiSwapChain::m_sampleCount, QRhiSwapChain::m_window, ok, Q_ASSERT, QRHI_RES_RHI, qWarning, QVarLengthArray< T, Prealloc >::resize(), QRhiSwapChain::SDR, QRhiSwapChain::sRGB, supportedPresentationModes, and surface.

Referenced by newCompatibleRenderPassDescriptor(), and surfacePixelSize().

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◆ isFormatSupported()

bool QVkSwapChain::isFormatSupported ( Format f )

overridevirtual

Returns: true if the given swapchain format f is supported. SDR is always supported.

Note: Can be called independently of createOrResize(), but window() must already be set. Calling without the window set may lead to unexpected results depending on the backend and platform (most likely false for any HDR format), because HDR format support is usually tied to the output (screen) to which the swapchain's associated window belongs at any given time. If the result is true for a HDR format, then creating the swapchain with that format is expected to succeed as long as the window is not moved to another screen in the meantime.

The main use of this function is to call it before the first createOrResize() after the window is already set. This allow the QRhi backends to perform platform or windowing system specific queries to determine if the window (and the screen it is on) is capable of true HDR output with the specified format.

When the format is reported as supported, call setFormat() to set the requested format and call createOrResize(). Be aware of the consequences however: successfully requesting a HDR format will involve having to deal with a different color space, possibly doing white level correction for non-HDR-aware content, adjusting tonemapping methods, adjusting offscreen render target settings, etc.

See also: setFormat()

Implements QRhiSwapChain.

Definition at line 7524 of file qrhivulkan.cpp.

References hdrFormatMatchesVkSurfaceFormat(), i, QRhiSwapChain::m_window, QRHI_RES_RHI, qWarning, and QRhiSwapChain::SDR.

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◆ newCompatibleRenderPassDescriptor()

QRhiRenderPassDescriptor * QVkSwapChain::newCompatibleRenderPassDescriptor ( )

overridevirtual

Returns: a new QRhiRenderPassDescriptor that is compatible with this swapchain.

The returned value is used in two ways: it can be passed to setRenderPassDescriptor() and QRhiGraphicsPipeline::setRenderPassDescriptor(). A render pass descriptor describes the attachments (color, depth/stencil) and the load/store behavior that can be affected by flags(). A QRhiGraphicsPipeline can only be used in combination with a swapchain that has a \l{QRhiRenderPassDescriptor::isCompatible()}{compatible} QRhiRenderPassDescriptor set.

See also: createOrResize()

Implements QRhiSwapChain.

Definition at line 7552 of file qrhivulkan.cpp.

References ensureSurface(), QRhiSwapChain::m_depthStencil, QRhiResource::m_rhi, QVkRenderPassDescriptor::ownsRp, QRHI_RES_RHI, and QVkRenderPassDescriptor::updateSerializedFormat().

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◆ surfacePixelSize()

QSize QVkSwapChain::surfacePixelSize ( )

overridevirtual

Returns: The size of the window's associated surface or layer.

Warning: Do not assume this is the same as {QWindow::size() * QWindow::devicePixelRatio()}. With some graphics APIs and windowing system interfaces (for example, Vulkan) there is a theoretical possibility for a surface to assume a size different from the associated window. To support these cases, {rendering logic must always base size-derived calculations (such as, viewports) on the size reported from QRhiSwapChain, and never on the size queried from QWindow}.

Note: {Can also be called before createOrResize(), if at least window() is already set. This in combination with currentPixelSize() allows to detect when a swapchain needs to be resized.} However, watch out for the fact that the size of the underlying native object (surface, layer, or similar) is "live", so whenever this function is called, it returns the latest value reported by the underlying implementation, without any atomicity guarantee. Therefore, using this function to determine pixel sizes for graphics resources that are used in a frame is strongly discouraged. Rely on currentPixelSize() instead which returns a size that is atomic and will not change between createOrResize() invocations.; For depth-stencil buffers used in combination with the swapchain's color buffers, it is strongly recommended to rely on the automatic sizing and rebuilding behavior provided by the QRhiRenderBuffer:UsedWithSwapChainOnly flag. Avoid querying the surface size via this function just to get a size that can be passed to QRhiRenderBuffer::setPixelSize() as that would suffer from the lack of atomicity as described above.