score::gfx::TextureShare Class Reference

GPU-only triple-buffered texture sharing between two QRhi instances in different threads. More...

Detailed Description

GPU-only triple-buffered texture sharing between two QRhi instances in different threads.

Classes
struct	Impl

Public Member Functions
	TextureShare (const TextureShare &)=delete
TextureShare &	operator= (const TextureShare &)=delete
	TextureShare (TextureShare &&)=delete
TextureShare &	operator= (TextureShare &&)=delete
bool	setup (QRhi *producer, QRhi *consumer, QSize size, QRhiTexture::Format format=QRhiTexture::RGBA8)
	Initialize the texture sharing system (single-thread convenience method).
bool	setupProducer (QRhi *producer, QSize size, QRhiTexture::Format format=QRhiTexture::RGBA8)
	Initialize producer-side resources (call from producer thread).
bool	setupConsumer (QRhi *consumer)
	Initialize consumer-side resources (call from consumer thread).
void	resize (QSize newSize)
	Resize the shared textures.
void	cleanup ()
	Clean up all resources.
bool	isValid () const noexcept
QSize	size () const noexcept
QRhiTextureRenderTarget *	beginProducerFrame ()
	Begin a producer frame.
QRhiTexture *	currentProducerTexture ()
	Get the current producer texture.
void	endProducerFrame (QRhiCommandBuffer *cb)
	End a producer frame and submit GPU copy to shared buffer.
QRhiRenderPassDescriptor *	producerRenderPassDescriptor () const noexcept
	Get a render pass descriptor compatible with producer textures.
QRhiTexture *	acquireConsumerTexture (QRhiCommandBuffer *cb)
	Acquire a texture for consumption/display.
bool	hasNewFrame () const noexcept

Member Function Documentation

acquireConsumerTexture()

QRhiTexture * score::gfx::TextureShare::acquireConsumerTexture

(

QRhiCommandBuffer *

cb

)

Acquire a texture for consumption/display.

Parameters

cb	The command buffer for any required GPU synchronization/copy.

Returns

The most recently completed texture, or nullptr if none ready.

The texture remains valid until the next call to acquireConsumerTexture().

Must be called from the consumer thread.

beginProducerFrame()

QRhiTextureRenderTarget * score::gfx::TextureShare::beginProducerFrame

(

)

Begin a producer frame.

Returns

The render target to render to, or nullptr if not ready.

The returned render target is owned by TextureShare. Call endProducerFrame() when rendering is complete.

Must be called from the producer thread.

cleanup()

void score::gfx::TextureShare::cleanup

(

)

Clean up all resources.

Must be called before destroying the QRhi instances.

currentProducerTexture()

QRhiTexture * score::gfx::TextureShare::currentProducerTexture

(

)

Get the current producer texture.

Returns

The texture being rendered to, or nullptr if not in a frame.

Must be called after beginProducerFrame() and before endProducerFrame().

endProducerFrame()

void score::gfx::TextureShare::endProducerFrame

(

QRhiCommandBuffer *

cb

)

End a producer frame and submit GPU copy to shared buffer.

Parameters

cb	The command buffer to record the copy command into.

This records a GPU-to-GPU copy from the render target to the shared intermediate texture.

Must be called from the producer thread.

resize()

void score::gfx::TextureShare::resize

(

QSize

newSize

)

Resize the shared textures.

Must be called when both threads are synchronized.

setup()

bool score::gfx::TextureShare::setup	(	QRhi *	producer,
		QRhi *	consumer,
		QSize	size,
		QRhiTexture::Format	format = QRhiTexture::RGBA8
	)

Initialize the texture sharing system (single-thread convenience method).

Parameters

producer	The QRhi instance that will produce/render textures
consumer	The QRhi instance that will consume/display textures
size	The texture size
format	The texture format (default RGBA8)

Returns

true if setup succeeded

Both QRhi instances must use the same graphics backend.

WARNING: This method calls both QRhi instances from the calling thread. Per QRhi threading rules, each QRhi should only be used from the thread that created it. Use setupProducer() and setupConsumer() for correct multi-threaded operation.

setupConsumer()

bool score::gfx::TextureShare::setupConsumer

(

QRhi *

consumer

)

Initialize consumer-side resources (call from consumer thread).

Parameters

consumer

The QRhi instance that will consume/display textures

Returns

true if consumer setup succeeded

Must be called after setupProducer() has completed.

Thread Safety: Must be called from the consumer thread (the thread that created the consumer QRhi instance).

setupProducer()

bool score::gfx::TextureShare::setupProducer	(	QRhi *	producer,
		QSize	size,
		QRhiTexture::Format	format = QRhiTexture::RGBA8
	)

Initialize producer-side resources (call from producer thread).

Parameters

producer	The QRhi instance that will produce/render textures
size	The texture size
format	The texture format (default RGBA8)

Returns

true if producer setup succeeded

After this returns, call setupConsumer() from the consumer thread.

Thread Safety: Must be called from the producer thread (the thread that created the producer QRhi instance).

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

• TextureShare.hpp
• TextureShare.cpp