#include <qrhivulkan_p.h>

Inheritance diagram for QVkBuffer:

Collaboration diagram for QVkBuffer:

Classes
struct	DynamicUpdate

struct	UsageState

Public Member Functions
	QVkBuffer (QRhiImplementation *rhi, Type type, UsageFlags usage, quint32 size)

	~QVkBuffer ()

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

bool	create () override
	Creates the corresponding native graphics resources.

QRhiBuffer::NativeBuffer	nativeBuffer () override

char *	beginFullDynamicBufferUpdateForCurrentFrame () override

void	endFullDynamicBufferUpdateForCurrentFrame () override
	To be called when the entire contents of the buffer data has been updated in the memory block returned from beginFullDynamicBufferUpdateForCurrentFrame().

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

Type	type () const

void	setType (Type t)
	Sets the buffer's type to t.

UsageFlags	usage () const

void	setUsage (UsageFlags u)
	Sets the buffer's usage flags to u.

quint32	size () const

void	setSize (quint32 sz)
	Sets the size of the buffer in bytes.

virtual bool	create ()=0
	Creates the corresponding native graphics resources.

virtual NativeBuffer	nativeBuffer ()

virtual char *	beginFullDynamicBufferUpdateForCurrentFrame ()

virtual void	endFullDynamicBufferUpdateForCurrentFrame ()
	To be called when the entire contents of the buffer data has been updated in the memory block returned from beginFullDynamicBufferUpdateForCurrentFrame().

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
VkBuffer	buffers [QVK_FRAMES_IN_FLIGHT]

QVkAlloc	allocations [QVK_FRAMES_IN_FLIGHT]

QVarLengthArray< DynamicUpdate, 16 >	pendingDynamicUpdates [QVK_FRAMES_IN_FLIGHT]

VkBuffer	stagingBuffers [QVK_FRAMES_IN_FLIGHT]

QVkAlloc	stagingAllocations [QVK_FRAMES_IN_FLIGHT]

UsageState	usageState [QVK_FRAMES_IN_FLIGHT]

int	lastActiveFrameSlot = -1

uint	generation = 0

Friends
class	QRhiVulkan

Additional Inherited Members
Public Types inherited from QRhiBuffer
enum	Type { Immutable , Static , Dynamic }
	Specifies storage type of buffer resource. More...

enum	UsageFlag { VertexBuffer = 1 << 0 , IndexBuffer = 1 << 1 , UniformBuffer = 1 << 2 , StorageBuffer = 1 << 3 }
	Flag values to specify how the buffer is going to be used. 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 QRhiBuffer
	QRhiBuffer (QRhiImplementation *rhi, Type type_, UsageFlags usage_, quint32 size_)
	\variable QRhiBuffer::NativeBuffer::objects

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

Protected Attributes inherited from QRhiBuffer
Type	m_type

UsageFlags	m_usage

quint32	m_size

Protected Attributes inherited from QRhiResource
QRhiImplementation *	m_rhi = nullptr

quint64	m_id

QByteArray	m_objectName

Detailed Description

Definition at line 39 of file qrhivulkan_p.h.

Constructor & Destructor Documentation

◆ QVkBuffer()

QVkBuffer::QVkBuffer	(	QRhiImplementation *	rhi,
		Type	type,
		UsageFlags	usage,
		quint32	size
	)

Definition at line 5796 of file qrhivulkan.cpp.

References allocations, i, QVK_FRAMES_IN_FLIGHT, stagingAllocations, and stagingBuffers.

◆ ~QVkBuffer()

QVkBuffer::~QVkBuffer ( )

Definition at line 5805 of file qrhivulkan.cpp.

References destroy().

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Member Function Documentation

◆ beginFullDynamicBufferUpdateForCurrentFrame()

char * QVkBuffer::beginFullDynamicBufferUpdateForCurrentFrame ( )

overridevirtual

Returns: a pointer to a memory block with the host visible buffer data.

This is a shortcut for medium-to-large dynamic uniform buffers that have their entire contents (or at least all regions that are read by the shaders in the current frame) changed {in every frame} and the QRhiResourceUpdateBatch-based update mechanism is seen too heavy due to the amount of data copying involved.

The call to this function must be eventually followed by a call to endFullDynamicUniformBufferUpdateForCurrentFrame(), before recording any render or compute pass that relies on this buffer.

Warning: Updating data via this method is not compatible with QRhiResourceUpdateBatch-based updates and readbacks. Unexpected behavior may occur when attempting to combine the two update models for the same buffer. Similarly, the data updated this direct way may not be visible to \l{QRhiResourceUpdateBatch::readBackBuffer()}{readBackBuffer operations}, depending on the backend.; When updating buffer data via this method, the update must be done in every frame, otherwise backends that perform double or triple buffering of resources may end up in unexpected behavior.; Partial updates are not possible with this approach since some backends may choose a strategy where the previous contents of the buffer is lost upon calling this function. Data must be written to all regions that are read by shaders in the frame currently being prepared.; This function can only be called when recording a frame, so between QRhi::beginFrame() and QRhi::endFrame().; This function can only be called on Dynamic buffers.

Reimplemented from QRhiBuffer.

Definition at line 5919 of file qrhivulkan.cpp.

References allocations, QRhiBuffer::Dynamic, QRhiBuffer::m_type, Q_ASSERT, QRHI_RES_RHI, qWarning, toVmaAllocation(), and toVmaAllocator().

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◆ create()

bool QVkBuffer::create ( )

overridevirtual

Creates the corresponding native graphics resources.

If there are already resources present due to an earlier create() with no corresponding destroy(), then destroy() is called implicitly first.

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

Implements QRhiBuffer.

Definition at line 5842 of file qrhivulkan.cpp.

References QVkBuffer::UsageState::access, allocation, allocations, destroy(), QRhiBuffer::Dynamic, generation, i, lastActiveFrameSlot, QRhiResource::m_objectName, QRhiBuffer::m_size, QRhiBuffer::m_type, QRhiBuffer::m_usage, QRHI_RES_RHI, QVK_FRAMES_IN_FLIGHT, qWarning, QVkBuffer::UsageState::stage, QRhiBuffer::StorageBuffer, toVkBufferUsage(), toVmaAllocator(), and usageState.

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◆ destroy()

void QVkBuffer::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 5810 of file qrhivulkan.cpp.

References allocations, QRhiVulkan::DeferredReleaseEntry::Buffer, e, i, lastActiveFrameSlot, pendingDynamicUpdates, QRHI_RES_RHI, QVK_FRAMES_IN_FLIGHT, stagingAllocations, and stagingBuffers.

Referenced by ~QVkBuffer(), and create().

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◆ endFullDynamicBufferUpdateForCurrentFrame()

void QVkBuffer::endFullDynamicBufferUpdateForCurrentFrame ( )

overridevirtual

To be called when the entire contents of the buffer data has been updated in the memory block returned from beginFullDynamicBufferUpdateForCurrentFrame().

Reimplemented from QRhiBuffer.

Definition at line 5940 of file qrhivulkan.cpp.

References allocations, QRhiBuffer::m_size, QRHI_RES_RHI, toVmaAllocation(), and toVmaAllocator().

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◆ nativeBuffer()

QRhiBuffer::NativeBuffer QVkBuffer::nativeBuffer ( )

overridevirtual

Returns: the underlying native resources for this buffer. The returned value will be empty if exposing the underlying native resources is not supported by the backend.

A QRhiBuffer may be backed by multiple native buffer objects, depending on the type() and the QRhi backend in use. When this is the case, all of them are returned in the objects array in the returned struct, with slotCount specifying the number of native buffer objects. While \l{QRhi::beginFrame()}{recording a frame}, QRhi::currentFrameSlot() can be used to determine which of the native buffers QRhi is using for operations that read or write from this QRhiBuffer within the frame being recorded.

In some cases a QRhiBuffer will not be backed by a native buffer object at all. In this case slotCount will be set to 0 and no valid native objects are returned. This is not an error, and is perfectly valid when a given backend does not use native buffers for QRhiBuffers with certain types or usages.

Note: Be aware that QRhi backends may employ various buffer update strategies. Unlike textures, where uploading image data always means recording a buffer-to-image (or similar) copy command on the command buffer, buffers, in particular Dynamic and UniformBuffer ones, can operate in many different ways. For example, a QRhiBuffer with usage type UniformBuffer may not even be backed by a native buffer object at all if uniform buffers are not used or supported by a given backend and graphics API. There are also differences to how data is written to the buffer and the type of backing memory used. For buffers backed by host visible memory, calling this function guarantees that pending host writes are executed for all the returned native buffers.