#include <qrhimetal_p.h>

Inheritance diagram for QMetalRenderPassDescriptor:

Collaboration diagram for QMetalRenderPassDescriptor:

Public Member Functions
	QMetalRenderPassDescriptor (QRhiImplementation *rhi)
	~QMetalRenderPassDescriptor ()
void	destroy () override
	Releases (or requests deferred releasing of) the underlying native graphics resources.
bool	isCompatible (const QRhiRenderPassDescriptor *other) const override
QRhiRenderPassDescriptor *	newCompatibleRenderPassDescriptor () const override
QVector< quint32 >	serializedFormat () const override
void	updateSerializedFormat ()
Public Member Functions inherited from QRhiRenderPassDescriptor
QRhiResource::Type	resourceType () const override
virtual const QRhiNativeHandles *	nativeHandles ()
Public Member Functions inherited from QRhiResource
virtual	~QRhiResource ()
	Destructor.
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
int	colorAttachmentCount = 0
bool	hasDepthStencil = false
int	colorFormat [MAX_COLOR_ATTACHMENTS]
int	dsFormat
bool	hasShadingRateMap = false
QVector< quint32 >	serializedFormatData

Static Public Attributes
static const int	MAX_COLOR_ATTACHMENTS = 8

Additional Inherited Members
Public Types inherited from QRhiResource
enum	Type { Buffer , Texture , Sampler , RenderBuffer , RenderPassDescriptor , SwapChainRenderTarget , TextureRenderTarget , ShaderResourceBindings , GraphicsPipeline , SwapChain , ComputePipeline , CommandBuffer , ShadingRateMap }
	Specifies type of the resource. More...
Protected Member Functions inherited from QRhiRenderPassDescriptor
	QRhiRenderPassDescriptor (QRhiImplementation *rhi)
Protected Member Functions inherited from QRhiResource
	QRhiResource (QRhiImplementation *rhi)
Protected Attributes inherited from QRhiResource
QRhiImplementation *	m_rhi = nullptr
quint64	m_id
QByteArray	m_objectName

Detailed Description

Definition at line 123 of file qrhimetal_p.h.

Constructor & Destructor Documentation

◆ QMetalRenderPassDescriptor()

QMetalRenderPassDescriptor::QMetalRenderPassDescriptor ( QRhiImplementation * rhi )

Definition at line 4210 of file qrhimetal.mm.

References QMetalRenderPassDescriptor().

Referenced by QMetalRenderPassDescriptor().

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◆ ~QMetalRenderPassDescriptor()

QMetalRenderPassDescriptor::~QMetalRenderPassDescriptor ( )

Definition at line 4216 of file qrhimetal.mm.

References destroy().

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Member Function Documentation

◆ destroy()

void QMetalRenderPassDescriptor::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 4221 of file qrhimetal.mm.

Referenced by ~QMetalRenderPassDescriptor().

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◆ isCompatible()

bool QMetalRenderPassDescriptor::isCompatible ( const QRhiRenderPassDescriptor * other ) const

overridevirtual

Returns: true if the other QRhiRenderPassDescriptor is compatible with this one, meaning this and other can be used interchangebly in QRhiGraphicsPipeline::setRenderPassDescriptor().

The concept of the compatibility of renderpass descriptors is similar to the \l{QRhiShaderResourceBindings::isLayoutCompatible}{layout compatibility} of QRhiShaderResourceBindings instances. They allow better reuse of QRhiGraphicsPipeline instances: for example, a QRhiGraphicsPipeline instance cache is expected to use these functions to look for a matching pipeline, instead of just comparing pointers, thus allowing a different QRhiRenderPassDescriptor and QRhiShaderResourceBindings to be used in combination with the pipeline, as long as they are compatible.

The exact details of compatibility depend on the underlying graphics API. Two renderpass descriptors \l{QRhiTextureRenderTarget::newCompatibleRenderPassDescriptor()}{created} from the same QRhiTextureRenderTarget are always compatible.

Similarly to QRhiShaderResourceBindings, compatibility can also be tested without having two existing objects available. Extracting the opaque blob by calling serializedFormat() allows testing for compatibility by comparing the returned vector to another QRhiRenderPassDescriptor's serializedFormat(). This has benefits in certain situations, because it allows testing the compatibility of a QRhiRenderPassDescriptor with a QRhiGraphicsPipeline even when the QRhiRenderPassDescriptor the pipeline was originally built was is no longer available (but the data returned from its serializedFormat() still is).

See also: newCompatibleRenderPassDescriptor(), serializedFormat()

Implements QRhiRenderPassDescriptor.

Definition at line 4228 of file qrhimetal.mm.

References colorAttachmentCount, colorFormat, dsFormat, hasDepthStencil, and hasShadingRateMap.

◆ newCompatibleRenderPassDescriptor()

QRhiRenderPassDescriptor * QMetalRenderPassDescriptor::newCompatibleRenderPassDescriptor ( ) const

overridevirtual

Returns: a new QRhiRenderPassDescriptor that is \l{isCompatible()}{compatible} with this one.

This function allows cloning a QRhiRenderPassDescriptor. The returned object is ready to be used, and the ownership is transferred to the caller. Cloning a QRhiRenderPassDescriptor object can become useful in situations where the object is stored in data structures related to graphics pipelines (in order to allow creating new pipelines which in turn requires a renderpass descriptor object), and the lifetime of the renderpass descriptor created from a render target may be shorter than the pipelines. (for example, because the engine manages and destroys renderpasses together with the textures and render targets it was created from) In such a situation, it can be beneficial to store a cloned version in the data structures, and thus transferring ownership as well.

See also: isCompatible()

Implements QRhiRenderPassDescriptor.

Definition at line 4270 of file qrhimetal.mm.

References colorAttachmentCount, colorFormat, dsFormat, hasDepthStencil, hasShadingRateMap, and updateSerializedFormat().

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◆ serializedFormat()

QVector< quint32 > QMetalRenderPassDescriptor::serializedFormat ( ) const

overridevirtual

Returns: a vector of integers containing an opaque blob describing the data relevant for \l{isCompatible()}{compatibility}.

Given two QRhiRenderPassDescriptor objects rp1 and rp2, if the data returned from this function is identical, then {rp1->isCompatible(rp2)}, and vice versa hold true as well.

Note: The returned data is meant to be used for storing in memory and comparisons during the lifetime of the QRhi the object belongs to. It is not meant for storing on disk, reusing between processes, or using with multiple QRhi instances with potentially different backends.; Calling this function is expected to be a cheap operation since the backends are not supposed to calculate the data in this function, but rather return an already calculated series of data.

When creating reusable components as part of a library, where graphics pipelines are created and maintained while targeting a QRhiRenderTarget (be it a swapchain or a texture) managed by the client of the library, the components must be able to deal with a changing QRhiRenderPassDescriptor. For example, because the render target changes and so invalidates the previously QRhiRenderPassDescriptor (with regards to the new render target at least) due to having a potentially different color format and attachments now. Or because \l{QRhiShadingRateMap}{variable rate shading} is taken into use dynamically. A simple pattern that helps dealing with this is performing the following check on every frame, to recognize the case when the pipeline needs to be associated with a new QRhiRenderPassDescriptor, because something is different about the render target now, compared to earlier frames:

QRhiRenderPassDescriptor *rp = m_renderTarget->renderPassDescriptor();
if (m_pipeline && rp->serializedFormat() != m_renderPassFormat) {
    m_pipeline->setRenderPassDescriptor(rp);
    m_renderPassFormat = rp->serializedFormat();
    m_pipeline->create();
}
// remember to store m_renderPassFormat also when creating m_pipeline the first time