AZ::RHI::IndirectBufferWriter Class Reference

#include <IndirectBufferWriter.h>

Inherits AZ::RHI::Object.

Public Member Functions
	AZ_CLASS_ALLOCATOR (IndirectBufferWriter, AZ::SystemAllocator, 0)
	AZ_RTTI (IndirectBufferWriter, "{096CBDFF-AB05-4E8D-9EC1-04F12CFCD85D}")
Ptr< DeviceIndirectBufferWriter >	GetDeviceIndirectBufferWriter (int deviceIndex) const
	Returns the device-specific DeviceIndirectBufferWriter for the given index.
ResultCode	Init (Buffer &buffer, size_t byteOffset, uint32_t byteStride, uint32_t maxCommandSequences, const IndirectBufferSignature &signature)
ResultCode	Init (const AZStd::unordered_map< int, void * > &memoryPtrs, uint32_t byteStride, uint32_t maxCommandSequences, const IndirectBufferSignature &signature)
IndirectBufferWriter *	SetVertexView (uint32_t slot, const StreamBufferView &view)
IndirectBufferWriter *	SetIndexView (const IndexBufferView &view)
IndirectBufferWriter *	Draw (const DrawLinear &arguments, const RHI::DrawInstanceArguments &drawInstanceArgs)
IndirectBufferWriter *	DrawIndexed (const DrawIndexed &arguments, const RHI::DrawInstanceArguments &drawInstanceArgs)
IndirectBufferWriter *	Dispatch (const DispatchDirect &arguments)
IndirectBufferWriter *	SetRootConstants (const uint8_t *data, uint32_t byteSize)
bool	NextSequence ()
bool	Seek (const uint32_t sequenceIndex)
void	Flush ()
	Flush changes into the destination buffer. Only valid when using a buffer.
bool	IsInitialized () const
uint32_t	GetCurrentSequenceIndex () const
void	Shutdown () override
Public Member Functions inherited from AZ::RHI::Object
	AZ_RTTI (Object, "{E43378F1-2331-4173-94B8-990ED20E6003}")
void	SetName (const Name &name)
	Sets the name of the object.
const Name &	GetName () const
	Returns the name set on the object by SetName.
uint32_t	use_count ()
	Returns the current use count of the object.

Additional Inherited Members
Protected Member Functions inherited from AZ::RHI::Object
void	add_ref () const
void	release () const
Protected Attributes inherited from AZ::RHI::Object
AZStd::atomic_int	m_useCount = 0

Detailed Description

IndirectBufferWriter is a helper class to write indirect commands to a buffer or a memory location in a platform independent way. Different APIs may have different layouts for the arguments of an indirect command. This class provides a secure and simple way to write the commands without worrying about API differences.

It also provides basic checks, like trying to write more commands than allowed, or writing commands that are not specified in the layout.

Member Function Documentation

Dispatch()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::Dispatch

(

const DispatchDirect &

arguments

)

Writes a dispatch command into the current sequence.

Parameters

arguments

The dispatch arguments that will be written.

Returns

A pointer to the IndirectBufferWriter object (this).

Draw()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::Draw	(	const DrawLinear &	arguments,
		const RHI::DrawInstanceArguments &	drawInstanceArgs
	)

Writes a draw command into the current sequence.

Parameters

arguments

The draw arguments that will be written.

Returns

A pointer to the IndirectBufferWriter object (this).

DrawIndexed()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::DrawIndexed	(	const DrawIndexed &	arguments,
		const RHI::DrawInstanceArguments &	drawInstanceArgs
	)

Writes a draw indexed command into the current sequence.

Parameters

arguments

The draw indexed arguments that will be written.

Returns

A pointer to the IndirectBufferWriter object (this).

Init() [1/2]

ResultCode AZ::RHI::IndirectBufferWriter::Init	(	Buffer &	buffer,
		size_t	byteOffset,
		uint32_t	byteStride,
		uint32_t	maxCommandSequences,
		const IndirectBufferSignature &	signature
	)

Initialize the IndirectBufferWriter to write commands into a buffer.

Parameters

buffer	The buffer where to write the commands. Any previous values for the specified range will be overwritten. The buffer must be big enough to contain the max number of sequences.
byteOffset	The offset into the buffer.
byteStride	The stride between command sequences. Must be larger than the stride calculated from the signature.
maxCommandSequences	The max number of sequences that the IndirectBufferWriter can write.
signature	Signature of the indirect buffer.

Returns

A result code denoting the status of the call. If successful, the IndirectBufferWriter is considered initialized and is able to service write requests. If failure, the IndirectBufferWriter remains uninitialized.

Init() [2/2]

ResultCode AZ::RHI::IndirectBufferWriter::Init	(	const AZStd::unordered_map< int, void * > &	memoryPtrs,
		uint32_t	byteStride,
		uint32_t	maxCommandSequences,
		const IndirectBufferSignature &	signature
	)

Initialize the IndirectBufferWriter to write commands into a memory location.

Parameters

memoryPtr	The memory location where the commands will be written. Must not be null.
byteStride	The stride between command sequences. Must be larger than the stride calculated from the signature.
maxCommandSequences	The max number of sequences that the IndirectBufferWriter can write.
signature	Signature of the indirect buffer.

Returns

A result code denoting the status of the call. If successful, the IndirectBufferWriter is considered initialized and is able to service write requests. If failure, the IndirectBufferWriter remains uninitialized.

NextSequence()

bool AZ::RHI::IndirectBufferWriter::NextSequence

(

)

Advance the current sequence index by 1.

Returns

True if the sequence index was increased correctly. False otherwise.

Seek()

bool AZ::RHI::IndirectBufferWriter::Seek

(

const uint32_t

sequenceIndex

)

Move the current sequence index to a specified position.

Parameters

sequenceIndex

The index where the sequence index will be moved. Must be less than maxCommandSequences.

Returns

True if the sequence index was updated correctly. False otherwise and the current sequence index is not modified.

SetIndexView()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::SetIndexView

(

const IndexBufferView &

view

)

Writes an index buffer view command into the current sequence.

Parameters

view	The IndexBufferView that will be set.

Returns

A pointer to the IndirectBufferWriter object (this).

SetRootConstants()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::SetRootConstants	(	const uint8_t *	data,
		uint32_t	byteSize
	)

Writes an inline constants command into the current sequence. This command will set the values of all inline constants of the Pipeline.

Parameters

data	A pointer to the data that contains the values that will be written.
byteSize	The size of the data that will be written.

Returns

A pointer to the IndirectBufferWriter object (this).

SetVertexView()

IndirectBufferWriter * AZ::RHI::IndirectBufferWriter::SetVertexView	(	uint32_t	slot,
		const StreamBufferView &	view
	)

Writes a vertex buffer view command into the current sequence.

Parameters

slot	The stream buffer slot that the view will set.
view	The StreamBufferView that will be set.

Returns

A pointer to the IndirectBufferWriter object (this).

Shutdown()

void AZ::RHI::IndirectBufferWriter::Shutdown ( )

overridevirtual

Shuts down the object. Derived classes can make this public if it fits with their lifecycle model (i.e. if they use an explicit Init / Shutdown). By default, it is private in order to maintain consistency with a simpler RAII lifecycle.

Reimplemented from AZ::RHI::Object.

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

• Gems/Atom/RHI/Code/Include/Atom/RHI/IndirectBufferWriter.h