FMaterialKeyGeneratorContext | Unreal Engine 5.5 Documentation

References


Module	Engine
Header	/Engine/Source/Runtime/Engine/Public/MaterialKeyGeneratorContext.h
Include	#include "MaterialKeyGeneratorContext.h"

Syntax

class FMaterialKeyGeneratorContext

Remarks

Output class passed to RecordAndEmit functions for material shader data. It receives function calls that either save/load variables to compact binary or emits those variables to an FShaderKeyGenerator to construct the key. It is written to by the function RecordOrEmitMaterialShaderMapKey and its helper functions, to create the shadermap's DDC key, to hash the Material's cook dependencies for incremental cooks, and to save/load the inputs for those cook dependencies to cook metadata, with a single function definition that lists all the relevant variables. This reduces the amount of boilerplate that has to be written and maintained for each variable that can affect the DDC key and cook dependencies.

The Context additionally holds flags for which portion of data should be included in its output; these flags are set differently by the calling function depending on whether we are saving a DDC key or material dependencies, and on what kind of DDC key we are saving.

The Context additionally holds some common arguments - ShaderPlatform and ShaderFormat - that are provided to the functions from the calling functions.

Variables

	Type	Name	Description
	FShaderKeyGenerator	KeyGen
	TArray< FCbObjectView, TInlineAllocator< 2 > >	ObjectStack
	FCbWriter *	Writer

Constructors

	Type	Name	Description
		FMaterialKeyGeneratorContext ( TUniqueFunction< void(const void*Data, uint64 Size)>&& HashFunction, EShaderPlatform InShaderPlatform )	Construct a Context that is emitting variables into a binary-formatted shader DDC key or into a material dependencies hash function.
		FMaterialKeyGeneratorContext ( FString& InResultString, EShaderPlatform InShaderPlatform )	Construct a Context that is emitting variables into a text-formatted shader DDC key.
		FMaterialKeyGeneratorContext ( FCbWriter& InWriter, EShaderPlatform InShaderPlatform )	Construct a Context that is saving data to compact binary.
		FMaterialKeyGeneratorContext ( FCbObjectView LoadRoot, EShaderPlatform InShaderPlatform )	Construct a Context that is loading data from compact binary.

Destructors

	Type	Name	Description
		~FMaterialKeyGeneratorContext ()

Functions

Type	Name	Description
void	AddFlags ( EMaterialKeyInclude Flags )	Inline implementations.
void	Emit ( T&& Data )	When emitting, append the given Data to the ShaderKeyGenerator, using operator<<.
void	EmitBoolInt ( bool Data )	When emitting, call the ShaderKeyGenerator's AppendBoolInt.
void	EmitDebugText ( FStringView Data )	When emitting, call the ShaderKeyGenerator's AppendDebugText.
void	EmitFunc ( TFunctionRef< void(FShaderKeyGenerator&)> Callback )	When emitting, call Callback with the ShaderKeyGenerator.
void	EmitSeparator ()	When emitting, call the ShaderKeyGenerator's AppendSeparator.
EMaterialKeyInclude	GetFlags ()	Return the list of include flags.
FShaderKeyGenerator *	GetKeyGenIfEmitting ()	When emitting, return pointer to the ShaderKeyGenerator. In all other modes, returns nullptr.
FShaderKeyGenerator &	GetKeyGenIfEmittingChecked ()	Must only be called when emitting; fails assertion if not.
EMode	GetMode ()	Return the mode the Context is operating in.
FName	GetShaderFormat ()	The ShaderFormat that corresponds to the ShaderPlatform provided by the caller.
EShaderPlatform	GetShaderPlatform ()	The ShaderPlatform provided by the caller.
bool	HasAllFlags ( EMaterialKeyInclude Flags )	Report whether all requested flags are included.
bool	HasLoadError ()	When loading, report whether any Record function reported an error.
bool	IsEmitting ()	True iff the Context is in emit mode - creating DDC key or hashing material dependencies.
bool	IsLoading ()	True iff the Context is loading from compact binary.
bool	IsRecording ()	True iff the Context is in either IsSaving or IsLoading mode.
bool	IsSaving ()	True iff the Context is saving to compact binary.
void	PostLoad ( TFunctionRef< void()> Action )	When loading, execute the given function. In all other modes, this function is a noop.
void	Record ( FUtf8StringView Name, T&& Data )	When saving or loading, save the given Data with the given name.
void	RecordAndEmit ( FUtf8StringView Name, T&& Data )	Output function used by all three modes.
void	RecordObjectEnd ()	When saving or loading, end the object scope started by the last call to RecordObjectStart, and return to the parent object scope.
void	RecordObjectStart ( FUtf8StringView Name )	When saving or loading, start a new object scope with the given name.
void	RemoveFlags ( EMaterialKeyInclude Flags )	Remove include flags.
void	SetFlags ( EMaterialKeyInclude Flags, bool bIncluded )	Add or remove include flags, depending on the value of bIncluded.