FSlateSdfGenerator Class Reference

#include <SlateSdfGenerator.h>

Inheritance diagram for FSlateSdfGenerator:

Classes
struct	FRequestDescriptor
struct	FRequestOutputInfo

Public Types
enum class	ERequestResponse {   SUCCESS = 0 , SDF_UNAVAILABLE , BUSY , PLACEHOLDER_ONLY ,   BAD_REQUEST }
enum class	ESdfType { Simple , Perpendicular , MultichannelAndSimple }
using	Ptr = TUniquePtr< FSlateSdfGenerator >
using	FForEachRequestDoneCallback = TFunctionRef< void(const FRequestDescriptor, TArray< uint8 >)>

Public Member Functions
virtual	~FSlateSdfGenerator ()
virtual ERequestResponse	Spawn (const FRequestDescriptor &InRequest, FRequestOutputInfo &OutCharInfo)=0
virtual ERequestResponse	SpawnWithPlaceholder (const FRequestDescriptor &InRequest, FRequestOutputInfo &OutCharInfo, TArray< uint8 > &OutRawPixels)=0
virtual ERequestResponse	Respawn (const FRequestDescriptor &InRequest, const FRequestOutputInfo &InCharInfo)=0
virtual ERequestResponse	MakePlaceholder (const FRequestDescriptor &InRequest, FRequestOutputInfo &OutCharInfo, TArray< uint8 > &OutRawPixels)=0
virtual void	Update (const FForEachRequestDoneCallback &InEnumerator)=0
virtual void	Flush ()=0

Static Public Member Functions
static Ptr	create ()

Protected Member Functions
	FSlateSdfGenerator ()

Detailed Description

Generates multi-channel signed distance fields for font glyphs.

Member Typedef Documentation

FForEachRequestDoneCallback

using FSlateSdfGenerator::FForEachRequestDoneCallback = TFunctionRef<void(const FRequestDescriptor, TArray<uint8>)>

Callback function for the finished tasks.

Ptr

using FSlateSdfGenerator::Ptr = TUniquePtr<FSlateSdfGenerator>

A unique pointer to a FSlateSdfGenerator object.

Member Enumeration Documentation

ERequestResponse

enum class FSlateSdfGenerator::ERequestResponse

strong

Generator's response to caller's request.

Enumerator
SUCCESS	Task spawned successfully (and placeholder generated if requested)
SDF_UNAVAILABLE	Glyph is available in the face but the SDF generation was not possible/successful
BUSY	Task not spawned due to task pool being full (try again later)
PLACEHOLDER_ONLY	Task not spawned but placeholder and output info generated (respawn later)
BAD_REQUEST	Task not spawned because the request data was not valid

ESdfType

enum class FSlateSdfGenerator::ESdfType

strong

Type of requested signed distance field.

Enumerator
Simple	Simple single-channel signed distance field based on true Euclidean distance (1 channel/pixel)
Perpendicular	Single-channel signed distance field based on the perpendicular distance metric, which is always orthogonal to an edge, and produces mitered rather than rounded outlines (1 channel/pixel)
MultichannelAndSimple	Multi-channel signed distance field with simple (true) signed distance field in additional channel (4 channels/pixel, also known as MTSDF)

Constructor & Destructor Documentation

~FSlateSdfGenerator()

FSlateSdfGenerator::~FSlateSdfGenerator ( )

virtual

FSlateSdfGenerator()

FSlateSdfGenerator::FSlateSdfGenerator ( )

protected

Member Function Documentation

create()

FSlateSdfGenerator::Ptr FSlateSdfGenerator::create ( )

static

Creates an instance of FSlateSdfGenerator.

Flush()

virtual void FSlateSdfGenerator::Flush ( )

pure virtual

Flushes all started tasks.

Implemented in FSlateSdfGeneratorImpl.

MakePlaceholder()

virtual ERequestResponse FSlateSdfGenerator::MakePlaceholder ( const FRequestDescriptor &  InRequest, FRequestOutputInfo &  OutCharInfo, TArray< uint8 > &  OutRawPixels  )

pure virtual

Only generates a placeholder-quality signed distance field immediately into OutRawPixels without spawning.

Implemented in FSlateSdfGeneratorImpl.

Respawn()

virtual ERequestResponse FSlateSdfGenerator::Respawn ( const FRequestDescriptor &  InRequest, const FRequestOutputInfo &  InCharInfo  )

pure virtual

Attempts to start generating again if previous attempt failed but produced a placeholder, whose FRequestOutputInfo must match.

Implemented in FSlateSdfGeneratorImpl.

Spawn()

virtual ERequestResponse FSlateSdfGenerator::Spawn ( const FRequestDescriptor &  InRequest, FRequestOutputInfo &  OutCharInfo  )

pure virtual

Starts generating a distance field for the requested glyph.

Implemented in FSlateSdfGeneratorImpl.

SpawnWithPlaceholder()

virtual ERequestResponse FSlateSdfGenerator::SpawnWithPlaceholder ( const FRequestDescriptor &  InRequest, FRequestOutputInfo &  OutCharInfo, TArray< uint8 > &  OutRawPixels  )

pure virtual

Starts generating a distance field and immediately provides an approximate distance field placeholder.

Implemented in FSlateSdfGeneratorImpl.

Update()

virtual void FSlateSdfGenerator::Update ( const FForEachRequestDoneCallback &  InEnumerator )

pure virtual

Checks for finished tasks and processes each of them by calling InEnumerator.

Implemented in FSlateSdfGeneratorImpl.

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

• Engine/Source/Runtime/SlateCore/Private/Fonts/SlateSdfGenerator.h
• Engine/Source/Runtime/SlateCore/Private/Fonts/SlateSdfGenerator.cpp