#include <FontCache.h>

Inheritance diagram for FSlateFontCache:

Public Member Functions
SLATECORE_API	FSlateFontCache (TSharedRef< ISlateFontAtlasFactory > InFontAtlasFactory, ESlateTextureAtlasThreadId InOwningThread)

virtual SLATECORE_API	~FSlateFontCache ()

virtual SLATECORE_API int32	GetNumAtlasPages () const override

virtual SLATECORE_API FSlateShaderResource *	GetAtlasPageResource (const int32 InIndex) const override

virtual SLATECORE_API bool	IsAtlasPageResourceAlphaOnly (const int32 InIndex) const override

SLATECORE_API FShapedGlyphSequenceRef	ShapeBidirectionalText (const FString &InText, const FSlateFontInfo &InFontInfo, const float InFontScale, const TextBiDi::ETextDirection InBaseDirection, const ETextShapingMethod InTextShapingMethod) const

SLATECORE_API FShapedGlyphSequenceRef	ShapeBidirectionalText (const TCHAR *InText, const int32 InTextStart, const int32 InTextLen, const FSlateFontInfo &InFontInfo, const float InFontScale, const TextBiDi::ETextDirection InBaseDirection, const ETextShapingMethod InTextShapingMethod) const

SLATECORE_API FShapedGlyphSequenceRef	ShapeUnidirectionalText (const FString &InText, const FSlateFontInfo &InFontInfo, const float InFontScale, const TextBiDi::ETextDirection InTextDirection, const ETextShapingMethod InTextShapingMethod) const

SLATECORE_API FShapedGlyphSequenceRef	ShapeUnidirectionalText (const TCHAR *InText, const int32 InTextStart, const int32 InTextLen, const FSlateFontInfo &InFontInfo, const float InFontScale, const TextBiDi::ETextDirection InTextDirection, const ETextShapingMethod InTextShapingMethod) const

SLATECORE_API FShapedGlyphSequenceRef	ShapeOverflowEllipsisText (const FSlateFontInfo &InFontInfo, const float InFontScale)

SLATECORE_API class FCharacterList &	GetCharacterList (const FSlateFontInfo &InFontInfo, float FontScale, const FFontOutlineSettings &InOutlineSettings=FFontOutlineSettings::NoOutline)

SLATECORE_API FShapedGlyphFontAtlasData	GetShapedGlyphFontAtlasData (const FShapedGlyphEntry &InShapedGlyph, const FFontOutlineSettings &InOutlineSettings)

SLATECORE_API FSdfGlyphFontAtlasData	GetSdfGlyphFontAtlasData (const FShapedGlyphEntry &InShapedGlyph, const FFontOutlineSettings &InOutlineSettings)

SLATECORE_API FShapedGlyphSequenceRef	GetOverflowEllipsisText (const FSlateFontInfo &InFontInfo, const float InFontScale)

SLATECORE_API void	FlushObject (const UObject *const InObject)

SLATECORE_API void	FlushCompositeFont (const FCompositeFont &InCompositeFont)

SLATECORE_API bool	ConditionalFlushCache ()

SLATECORE_API void	UpdateCache ()

SLATECORE_API void	ReleaseResources ()

FOnReleaseFontResources &	OnReleaseResources ()

ISlateFontTexture *	GetFontTexture (uint32 Index)

SLATECORE_API const FFontData &	GetDefaultFontData (const FSlateFontInfo &InFontInfo) const

SLATECORE_API const FFontData &	GetFontDataForCodepoint (const FSlateFontInfo &InFontInfo, const UTF32CHAR InCodepoint, float &OutScalingFactor) const

SLATECORE_API bool	HasLoadedFontForCodepoint (const FSlateFontInfo &InFontInfo, const UTF32CHAR InCodepoint) const

SLATECORE_API uint16	GetMaxCharacterHeight (const FSlateFontInfo &InFontInfo, float FontScale) const

SLATECORE_API int16	GetBaseline (const FSlateFontInfo &InFontInfo, float FontScale) const

SLATECORE_API void	GetUnderlineMetrics (const FSlateFontInfo &InFontInfo, const float FontScale, int16 &OutUnderlinePos, int16 &OutUnderlineThickness) const

SLATECORE_API void	GetStrikeMetrics (const FSlateFontInfo &InFontInfo, const float FontScale, int16 &OutStrikeLinePos, int16 &OutStrikeLineThickness) const

SLATECORE_API int8	GetKerning (const FFontData &InFontData, const float InSize, TCHAR First, TCHAR Second, float Scale) const

SLATECORE_API bool	HasKerning (const FFontData &InFontData) const

SLATECORE_API bool	CanLoadCodepoint (const FFontData &InFontData, const UTF32CHAR InCodepoint, EFontFallback MaxFallbackLevel=EFontFallback::FF_NoFallback) const

SLATECORE_API const TSet< FName > &	GetFontAttributes (const FFontData &InFontData) const

SLATECORE_API TArray< FString >	GetAvailableFontSubFaces (FFontFaceDataConstRef InMemory) const

SLATECORE_API TArray< FString >	GetAvailableFontSubFaces (const FString &InFilename) const

SLATECORE_API void	RequestFlushCache (const FString &FlushReason)

SLATECORE_API void	FlushData ()

SLATECORE_API SIZE_T	GetFontDataAssetResidentMemory (const UObject *FontDataAsset) const

Public Member Functions inherited from ISlateAtlasProvider
virtual	~ISlateAtlasProvider ()

Public Member Functions inherited from FSlateFlushableAtlasCache
	FSlateFlushableAtlasCache (const FAtlasFlushParams *InFlushParams)

virtual	~FSlateFlushableAtlasCache ()

void	ResetFlushCounters ()

void	UpdateFlushCounters (int32 NumGrayscale, int32 NumColor, int32 NumMsdf, int32 NumNonAtlased)

Detailed Description

Font caching implementation Caches characters into textures as needed

Constructor & Destructor Documentation

◆ FSlateFontCache()

FSlateFontCache::FSlateFontCache	(	TSharedRef< ISlateFontAtlasFactory >	InFontAtlasFactory,
		ESlateTextureAtlasThreadId	InOwningThread
	)

Constructor

Parameters

InTextureSize	The size of the atlas texture
InFontAlas	Platform specific font atlas resource

◆ ~FSlateFontCache()

FSlateFontCache::~FSlateFontCache ( )

virtual

Member Function Documentation

◆ CanLoadCodepoint()

bool FSlateFontCache::CanLoadCodepoint	(	const FFontData &	InFontData,
		const UTF32CHAR	InCodepoint,
		EFontFallback	MaxFallbackLevel = `EFontFallback::FF_NoFallback`
	)		const

Whether or not the specified character, within the specified font, can be loaded with the specified maximum font fallback level

Parameters

InFontData	Information about the font to load
InCodepoint	The codepoint being loaded
MaxFallbackLevel	The maximum fallback level to try for the font

Returns: Whether or not the character can be loaded

◆ ConditionalFlushCache()

bool FSlateFontCache::ConditionalFlushCache ( )

Flush the cache if needed

◆ FlushCompositeFont()

void FSlateFontCache::FlushCompositeFont ( const FCompositeFont & InCompositeFont )

Flush the given composite font out of the cache

◆ FlushData()

void FSlateFontCache::FlushData ( )

Clears just the cached font data, but leaves the atlases alone

◆ FlushObject()

void FSlateFontCache::FlushObject ( const UObject *const InObject )

Flush the given object out of the cache

◆ GetAtlasPageResource()

FSlateShaderResource * FSlateFontCache::GetAtlasPageResource ( const int32 InIndex ) const

overridevirtual

Get the page resource for the given index (verify with GetNumAtlasPages)

Implements ISlateAtlasProvider.

◆ GetAvailableFontSubFaces() [1/2]

TArray< FString > FSlateFontCache::GetAvailableFontSubFaces ( const FString & InFilename ) const

◆ GetAvailableFontSubFaces() [2/2]

TArray< FString > FSlateFontCache::GetAvailableFontSubFaces ( FFontFaceDataConstRef InMemory ) const

Get the available sub-face data from the given font. Typically there will only be one face unless this is a TTC/OTC font. The index of the returned entry can be passed as InFaceIndex to the FFreeTypeFace constructor.

◆ GetBaseline()

int16 FSlateFontCache::GetBaseline	(	const FSlateFontInfo &	InFontInfo,
		float	FontScale
	)		const

Returns the baseline for the specified font.

Parameters

InFontInfo	A descriptor of the font to get character size for
FontScale	The scale to apply to the font

Returns: The offset from the bottom of the max character height to the baseline.

◆ GetCharacterList()

FCharacterList & FSlateFontCache::GetCharacterList	(	const FSlateFontInfo &	InFontInfo,
		float	FontScale,
		const FFontOutlineSettings &	InOutlineSettings = `FFontOutlineSettings::NoOutline`
	)

Gets information for how to draw all non-shaped characters in the specified string. Caches characters as they are found

Parameters

InFontInfo	Information about the font that the string is drawn with
FontScale	The scale to apply to the font
OutCharacterEntries	Populated array of character entries. Indices of characters in Text match indices in this array

◆ GetDefaultFontData()

const FFontData & FSlateFontCache::GetDefaultFontData ( const FSlateFontInfo & InFontInfo ) const

Returns the font to use from the default typeface

Parameters

InFontInfo A descriptor of the font to get the default typeface for

Returns: The raw font data

◆ GetFontAttributes()

const TSet< FName > & FSlateFontCache::GetFontAttributes ( const FFontData & InFontData ) const

Returns the font attributes for the specified font.

Parameters

InFontData The font to get attributes for

Returns: The font attributes for the specified font.

◆ GetFontDataAssetResidentMemory()

SIZE_T FSlateFontCache::GetFontDataAssetResidentMemory ( const UObject * FontDataAsset ) const

Gets the allocated font face data for a font data asset

◆ GetFontDataForCodepoint()

const FFontData & FSlateFontCache::GetFontDataForCodepoint	(	const FSlateFontInfo &	InFontInfo,
		const UTF32CHAR	InCodepoint,
		float &	OutScalingFactor
	)		const

Returns the font to use from the typeface associated with the given codepoint

Parameters

InFontInfo	A descriptor of the font to get the typeface for
InCodepoint	The codepoint to get the typeface associated with
OutScalingFactor	The scaling factor applied to characters rendered with the given font

Returns: The raw font data

◆ GetFontTexture()

ISlateFontTexture * FSlateFontCache::GetFontTexture ( uint32 Index )

inline

Get the texture resource for a font atlas at a given index

Parameters

Index The index of the texture

Returns: Handle to the texture resource

◆ GetKerning()

int8 FSlateFontCache::GetKerning	(	const FFontData &	InFontData,
		const float	InSize,
		TCHAR	First,
		TCHAR	Second,
		float	Scale
	)		const

Calculates the kerning amount for a pair of characters

Parameters

InFontData	The font that used to draw the string with the first and second characters
InSize	The size of the font to draw
First	The first character in the pair
Second	The second character in the pair

Returns: The kerning amount, 0 if no kerning

◆ GetMaxCharacterHeight()

uint16 FSlateFontCache::GetMaxCharacterHeight	(	const FSlateFontInfo &	InFontInfo,
		float	FontScale
	)		const

Returns the height of the largest character in the font.

Parameters

InFontInfo	A descriptor of the font to get character size for
FontScale	The scale to apply to the font

Returns: The largest character height

◆ GetNumAtlasPages()

int32 FSlateFontCache::GetNumAtlasPages ( ) const

overridevirtual

ISlateAtlasProvider

Implements ISlateAtlasProvider.

◆ GetOverflowEllipsisText()

FShapedGlyphSequenceRef FSlateFontCache::GetOverflowEllipsisText	(	const FSlateFontInfo &	InFontInfo,
		const float	InFontScale
	)

Gets the overflow glyph sequence for a given font. The overflow sequence is used to replace characters that are clipped

◆ GetSdfGlyphFontAtlasData()

FSdfGlyphFontAtlasData FSlateFontCache::GetSdfGlyphFontAtlasData	(	const FShapedGlyphEntry &	InShapedGlyph,
		const FFontOutlineSettings &	InOutlineSettings
	)

Get the atlas information and the scaled metrics of a given shaped sdf glyph. This information will be cached if required.

◆ GetShapedGlyphFontAtlasData()

FShapedGlyphFontAtlasData FSlateFontCache::GetShapedGlyphFontAtlasData	(	const FShapedGlyphEntry &	InShapedGlyph,
		const FFontOutlineSettings &	InOutlineSettings
	)

Get the atlas information for the given shaped glyph. This information will be cached if required

◆ GetStrikeMetrics()

void FSlateFontCache::GetStrikeMetrics	(	const FSlateFontInfo &	InFontInfo,
		const float	FontScale,
		int16 &	OutStrikeLinePos,
		int16 &	OutStrikeLineThickness
	)		const

Get the strike metrics for the specified font.

Parameters

InFontInfo	A descriptor of the font to get character size for
FontScale	The scale to apply to the font
OutStrikeLinePos	The offset from the baseline to the center of the strike bar
OutStrikeLineThickness	The thickness of the strike bar

◆ GetUnderlineMetrics()

void FSlateFontCache::GetUnderlineMetrics	(	const FSlateFontInfo &	InFontInfo,
		const float	FontScale,
		int16 &	OutUnderlinePos,
		int16 &	OutUnderlineThickness
	)		const

Get the underline metrics for the specified font.

Parameters

InFontInfo	A descriptor of the font to get character size for
FontScale	The scale to apply to the font
OutUnderlinePos	The offset from the baseline to the center of the underline bar
OutUnderlineThickness	The thickness of the underline bar

◆ HasKerning()

bool FSlateFontCache::HasKerning ( const FFontData & InFontData ) const

Returns: Whether or not the font used has kerning information

◆ HasLoadedFontForCodepoint()

bool FSlateFontCache::HasLoadedFontForCodepoint	(	const FSlateFontInfo &	InFontInfo,
		const UTF32CHAR	InCodepoint
	)		const

Returns true if the font to use from the typeface associated with the given codepoint is already loaded

Parameters

InFontInfo	A descriptor of the font to get the typeface for
InCodepoint	The codepoint to get the typeface associated with

Returns: FontData is already loaded

◆ IsAtlasPageResourceAlphaOnly()

bool FSlateFontCache::IsAtlasPageResourceAlphaOnly ( const int32 InIndex ) const

overridevirtual

Does the page resources for the given index only contain alpha information? This affects how the atlas visualizer will sample them (verify with GetNumAtlasPages)

Implements ISlateAtlasProvider.

◆ OnReleaseResources()

FOnReleaseFontResources & FSlateFontCache::OnReleaseResources ( )

inline

Event called after releasing the rendering resources in ReleaseResources

◆ ReleaseResources()

void FSlateFontCache::ReleaseResources ( )

Releases rendering resources

◆ RequestFlushCache()

void FSlateFontCache::RequestFlushCache ( const FString & FlushReason )

virtual

Issues a request to clear all cached data from the cache

Implements FSlateFlushableAtlasCache.

◆ ShapeBidirectionalText() [1/2]

FShapedGlyphSequenceRef FSlateFontCache::ShapeBidirectionalText	(	const FString &	InText,
		const FSlateFontInfo &	InFontInfo,
		const float	InFontScale,
		const TextBiDi::ETextDirection	InBaseDirection,
		const ETextShapingMethod	InTextShapingMethod
	)		const

Performs text shaping on the given string using the given font info. Returns you the shaped text sequence to use for text rendering via FSlateDrawElement::MakeShapedText. When using the version which takes a start point and length, the text outside of the given range won't be shaped, but will provide context information to allow the shaping to function correctly. ShapeBidirectionalText is used when you have text that may contain a mixture of LTR and RTL text runs.

Parameters

InText	The string to shape
InTextStart	The start position of the text to shape
InTextLen	The length of the text to shape
InFontInfo	Information about the font that the string is drawn with
InFontScale	The scale to apply to the font
InBaseDirection	The overall reading direction of the text (see TextBiDi::ComputeBaseDirection). This will affect where some characters (such as brackets and quotes) are placed within the resultant shaped text
InTextShapingMethod	The text shaping method to use

◆ ShapeBidirectionalText() [2/2]

FShapedGlyphSequenceRef FSlateFontCache::ShapeBidirectionalText	(	const TCHAR *	InText,
		const int32	InTextStart,
		const int32	InTextLen,
		const FSlateFontInfo &	InFontInfo,
		const float	InFontScale,
		const TextBiDi::ETextDirection	InBaseDirection,
		const ETextShapingMethod	InTextShapingMethod
	)		const

◆ ShapeOverflowEllipsisText()

FShapedGlyphSequenceRef FSlateFontCache::ShapeOverflowEllipsisText	(	const FSlateFontInfo &	InFontInfo,
		const float	InFontScale
	)

Performs text shaping on the overflow glyph sequence for a given font. The overflow sequence is used to replace characters that are clipped

◆ ShapeUnidirectionalText() [1/2]

FShapedGlyphSequenceRef FSlateFontCache::ShapeUnidirectionalText	(	const FString &	InText,
		const FSlateFontInfo &	InFontInfo,
		const float	InFontScale,
		const TextBiDi::ETextDirection	InTextDirection,
		const ETextShapingMethod	InTextShapingMethod
	)		const

Performs text shaping on the given range of the string using the given font info. Returns you the shaped text sequence to use for text rendering via FSlateDrawElement::MakeShapedText. When using the version which takes a start point and length, the text outside of the given range won't be shaped, but will provide context information to allow the shaping to function correctly. ShapeUnidirectionalText is used when you have text that all reads in the same direction (either LTR or RTL).

Parameters

InText	The string containing the sub-string to shape
InTextStart	The start position of the text to shape
InTextLen	The length of the text to shape
InFontInfo	Information about the font that the string is drawn with
InFontScale	The scale to apply to the font
InTextDirection	The reading direction of the text to shape (valid values are LeftToRight or RightToLeft)
InTextShapingMethod	The text shaping method to use

◆ ShapeUnidirectionalText() [2/2]

FShapedGlyphSequenceRef FSlateFontCache::ShapeUnidirectionalText	(	const TCHAR *	InText,
		const int32	InTextStart,
		const int32	InTextLen,
		const FSlateFontInfo &	InFontInfo,
		const float	InFontScale,
		const TextBiDi::ETextDirection	InTextDirection,
		const ETextShapingMethod	InTextShapingMethod
	)		const

◆ UpdateCache()

void FSlateFontCache::UpdateCache ( )

Updates the texture used for rendering

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

Engine/Source/Runtime/SlateCore/Public/Fonts/FontCache.h
Engine/Source/Runtime/SlateCore/Private/Fonts/FontCache.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ FSlateFontCache()

◆ ~FSlateFontCache()

Member Function Documentation

◆ CanLoadCodepoint()

◆ ConditionalFlushCache()

◆ FlushCompositeFont()

◆ FlushData()

◆ FlushObject()

◆ GetAtlasPageResource()

◆ GetAvailableFontSubFaces() [1/2]

◆ GetAvailableFontSubFaces() [2/2]

◆ GetBaseline()

◆ GetCharacterList()

◆ GetDefaultFontData()

◆ GetFontAttributes()

◆ GetFontDataAssetResidentMemory()

◆ GetFontDataForCodepoint()

◆ GetFontTexture()

◆ GetKerning()

◆ GetMaxCharacterHeight()

◆ GetNumAtlasPages()

◆ GetOverflowEllipsisText()

◆ GetSdfGlyphFontAtlasData()

◆ GetShapedGlyphFontAtlasData()

◆ GetStrikeMetrics()

◆ GetUnderlineMetrics()

◆ HasKerning()

◆ HasLoadedFontForCodepoint()

◆ IsAtlasPageResourceAlphaOnly()

◆ OnReleaseResources()

◆ ReleaseResources()

◆ RequestFlushCache()

◆ ShapeBidirectionalText() [1/2]

◆ ShapeBidirectionalText() [2/2]

◆ ShapeOverflowEllipsisText()

◆ ShapeUnidirectionalText() [1/2]

◆ ShapeUnidirectionalText() [2/2]

◆ UpdateCache()