FTexturePagePool Class Reference

#include <TexturePagePool.h>

Public Member Functions
	FTexturePagePool ()
	~FTexturePagePool ()
void	Initialize (uint32 InNumPages)
FCriticalSection &	GetLock ()
uint32	GetNumPages () const
uint32	GetNumLockedPages () const
uint32	GetNumMappedPages () const
uint32	GetNumAllocatedPages () const
void	EvictAllPages (FVirtualTextureSystem *System)
void	EvictPages (FVirtualTextureSystem *System, const FVirtualTextureProducerHandle &ProducerHandle)
void	EvictPages (FVirtualTextureSystem *System, FVirtualTextureProducerHandle const &ProducerHandle, FVTProducerDescription const &Desc, FIntRect const &TextureRegion, uint32 MaxLevelToEvict, uint32 MinFrameToKeepMapped, EVTInvalidatePriority InvalidatePriority, TSet< union FVirtualTextureLocalTileRequest > &OutDirtyMapped)
void	UnmapAllPagesForSpace (FVirtualTextureSystem *System, uint8 SpaceID, uint32 vAddress, uint32 Width, uint32 Height, uint32 MaxLevel)
void	RemapPages (FVirtualTextureSystem *System, uint8 SpaceID, FVirtualTexturePhysicalSpace *PhysicalSpace, FVirtualTextureProducerHandle const &ProducerHandleOld, uint32 OldVirtualAddress, FVirtualTextureProducerHandle const &ProducerHandleNew, uint32 NewVirtualAddress, int32 vLevelBias, uint32 Frame)
void	GetAllLockedPages (FVirtualTextureSystem *System, TSet< union FVirtualTextureLocalTile > &OutPages)
FVirtualTextureLocalTile	GetLocalTileFromPhysicalAddress (uint16 pAddress)
uint8	GetLocalLevelForAddress (uint16 pAddress) const
bool	AnyFreeAvailable (uint32 Frame, uint32 FreeThreshold) const
uint32	FindPageAddress (const FVirtualTextureProducerHandle &ProducerHandle, uint8 GroupIndex, uint32 Local_vAddress, uint8 Local_vLevel) const
uint32	FindNearestPageAddress (const FVirtualTextureProducerHandle &ProducerHandle, uint8 GroupIndex, uint32 Local_vAddress, uint8 Local_vLevel, uint8 MaxLevel) const
uint32	FindNearestPageLevel (const FVirtualTextureProducerHandle &ProducerHandle, uint8 GroupIndex, uint32 Local_vAddress, uint8 Local_vLevel) const
uint32	Alloc (FVirtualTextureSystem *System, uint32 Frame, const FVirtualTextureProducerHandle &ProducerHandle, uint8 GroupIndex, uint32 Local_vAddress, uint8 Local_vLevel, bool bLock)
void	Free (FVirtualTextureSystem *System, uint16 pAddress)
void	Lock (uint16 pAddress)
void	Unlock (uint32 Frame, uint16 pAddress)
void	UpdateUsage (uint32 Frame, uint16 pAddress)
uint32	GetNumVisiblePages (uint32 Frame) const
void	CollectProducerCounts (TMap< uint32, FUintVector2 > &OutProducerCountMap) const
void	MapPage (FVirtualTextureSpace *Space, FVirtualTexturePhysicalSpace *PhysicalSpace, uint8 PageTableLayerIndex, uint8 MaxLevel, uint8 vLogSize, uint32 vAddress, uint8 Local_vLevel, uint16 pAddress)

Detailed Description

Manages a pool of texture pages, backed by a large GPU texture atlas. Pages can be allocated for a particular virtual texture, and mapped into any number of virtual pages tables. FTexturePagePool tracks the VT that owns the allocation for each page, and maintains a list of page table mappings for each allocated page. In order to maintain page table mappings, this class works closely with FTexturePageMap, which tracks mappings for a single layer of a given page table

Constructor & Destructor Documentation

FTexturePagePool()

FTexturePagePool::FTexturePagePool

(

)

~FTexturePagePool()

FTexturePagePool::~FTexturePagePool

(

)

Member Function Documentation

Alloc()

uint32 FTexturePagePool::Alloc	(	FVirtualTextureSystem *	System,
		uint32	Frame,
		const FVirtualTextureProducerHandle &	ProducerHandle,
		uint8	GroupIndex,
		uint32	Local_vAddress,
		uint8	Local_vLevel,
		bool	bLock
	)

Allocate a physical address This allocation will be owned by the given VT producer, and if successful, may be mapped into virtual page tables Assuming the pool is full, the returned physical address will first be unmapped from anything that was previously using it

Parameters

Frame	The current frame, used to manage LRU allocations
ProducerHandle	Handle of the VT producer requesting this page
GroupIndex	Physical group in the producer
Local_vAddress	Virtual address relative to the given producer
Local_vLevel	Mip level in the producer
bLock	Should the allocation be locked; locked allocations will never be evicted

AnyFreeAvailable()

bool FTexturePagePool::AnyFreeAvailable	(	uint32	Frame,
		uint32	FreeThreshold
	)		const

Check if there are any free pages available at the moment.

CollectProducerCounts()

void FTexturePagePool::CollectProducerCounts

(

TMap< uint32, FUintVector2 > &

OutProducerCountMap

)

const

Returns a map between producer handle and a uint2 containing number of tiles and number of locked tils that the producer uses in the pool.

EvictAllPages()

void FTexturePagePool::EvictAllPages

(

FVirtualTextureSystem *

System

)

Reset the page pool. This can be used to flush any caches. Mainly useful for debug and testing purposes.

EvictPages() [1/2]

void FTexturePagePool::EvictPages	(	FVirtualTextureSystem *	System,
		const FVirtualTextureProducerHandle &	ProducerHandle
	)

Unmap/remove any pages that were allocated by the given producer

EvictPages() [2/2]

void FTexturePagePool::EvictPages	(	FVirtualTextureSystem *	System,
		FVirtualTextureProducerHandle const &	ProducerHandle,
		FVTProducerDescription const &	Desc,
		FIntRect const &	TextureRegion,
		uint32	MaxLevelToEvict,
		uint32	MinFrameToKeepMapped,
		EVTInvalidatePriority	InvalidatePriority,
		TSet< union FVirtualTextureLocalTileRequest > &	OutDirtyMapped
	)

Unmap/remove any pages that were allocated by the given producer and are inside the TextureRegion. Outputs the locked pages that can't be unmapped to the OutLocked array.

FindNearestPageAddress()

uint32 FTexturePagePool::FindNearestPageAddress	(	const FVirtualTextureProducerHandle &	ProducerHandle,
		uint8	GroupIndex,
		uint32	Local_vAddress,
		uint8	Local_vLevel,
		uint8	MaxLevel
	)		const

Find the physical address of the allocated page that's closest to the given page, or ~0 if not found

FindNearestPageLevel()

uint32 FTexturePagePool::FindNearestPageLevel	(	const FVirtualTextureProducerHandle &	ProducerHandle,
		uint8	GroupIndex,
		uint32	Local_vAddress,
		uint8	Local_vLevel
	)		const

Find the level of the allocated page that's closest to the given page, or ~0 if not found

FindPageAddress()

uint32 FTexturePagePool::FindPageAddress	(	const FVirtualTextureProducerHandle &	ProducerHandle,
		uint8	GroupIndex,
		uint32	Local_vAddress,
		uint8	Local_vLevel
	)		const

Find physical address of the page allocated for the given VT address, or ~0 if not allocated

Free()

void FTexturePagePool::Free	(	FVirtualTextureSystem *	System,
		uint16	pAddress
	)

Marks the given physical address as free, will be unlocked if needed, moved to top of LRU list, no longer associated with any producer

GetAllLockedPages()

void FTexturePagePool::GetAllLockedPages	(	FVirtualTextureSystem *	System,
		TSet< union FVirtualTextureLocalTile > &	OutPages
	)

Get descriptions of the locked pages in this pool

GetLocalLevelForAddress()

uint8 FTexturePagePool::GetLocalLevelForAddress ( uint16  pAddress ) const

inline

Get the local vLevel of the page allocated at the given physical address

GetLocalTileFromPhysicalAddress()

FVirtualTextureLocalTile FTexturePagePool::GetLocalTileFromPhysicalAddress

(

uint16

pAddress

)

GetLock()

FCriticalSection & FTexturePagePool::GetLock ( )

inline

GetNumAllocatedPages()

uint32 FTexturePagePool::GetNumAllocatedPages ( ) const

inline

GetNumLockedPages()

uint32 FTexturePagePool::GetNumLockedPages ( ) const

inline

GetNumMappedPages()

uint32 FTexturePagePool::GetNumMappedPages ( ) const

inline

GetNumPages()

uint32 FTexturePagePool::GetNumPages ( ) const

inline

GetNumVisiblePages()

uint32 FTexturePagePool::GetNumVisiblePages

(

uint32

Frame

)

const

Returns the number of pages marked as used since a given frame.

Initialize()

void FTexturePagePool::Initialize

(

uint32

InNumPages

)

Lock()

void FTexturePagePool::Lock

(

uint16

pAddress

)

Mark a physical address as locked, so it will not be evicted.

MapPage()

void FTexturePagePool::MapPage	(	FVirtualTextureSpace *	Space,
		FVirtualTexturePhysicalSpace *	PhysicalSpace,
		uint8	PageTableLayerIndex,
		uint8	MaxLevel,
		uint8	vLogSize,
		uint32	vAddress,
		uint8	Local_vLevel,
		uint16	pAddress
	)

Map the physical address to a specific virtual address.

RemapPages()

void FTexturePagePool::RemapPages	(	FVirtualTextureSystem *	System,
		uint8	SpaceID,
		FVirtualTexturePhysicalSpace *	PhysicalSpace,
		FVirtualTextureProducerHandle const &	ProducerHandleOld,
		uint32	OldVirtualAddress,
		FVirtualTextureProducerHandle const &	ProducerHandleNew,
		uint32	NewVirtualAddress,
		int32	vLevelBias,
		uint32	Frame
	)

Remap physical pages from one producer to another.

Unlock()

void FTexturePagePool::Unlock	(	uint32	Frame,
		uint16	pAddress
	)

Unlock the given physical address

UnmapAllPagesForSpace()

void FTexturePagePool::UnmapAllPagesForSpace	(	FVirtualTextureSystem *	System,
		uint8	SpaceID,
		uint32	vAddress,
		uint32	Width,
		uint32	Height,
		uint32	MaxLevel
	)

Unmap all pages from the given address range in a space. Pages will remain resident in the pool, but no longer by mapped to any page table.

UpdateUsage()

void FTexturePagePool::UpdateUsage	(	uint32	Frame,
		uint16	pAddress
	)

Marks the given physical address as used on this frame. This means it's guaranteed not to be evicted later on this frame, and less likely to be evicted on future frames (LRU pages are evicted first)

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

• Engine/Source/Runtime/Renderer/Private/VT/TexturePagePool.h
• Engine/Source/Runtime/Renderer/Private/VT/TexturePagePool.cpp