Font_FTFont Class Reference

Wrapper over FreeType font. Notice that this class uses internal buffers for loaded glyphs and it is absolutely UNSAFE to load/read glyph from concurrent threads! More...

#include <Font_FTFont.hxx>

Inheritance diagram for Font_FTFont:

Public Member Functions
	Font_FTFont (const occ::handle< Font_FTLibrary > &theFTLib=occ::handle< Font_FTLibrary >())
	Create uninitialized instance.
	~Font_FTFont () override
	Destructor.
bool	IsValid () const
const Image_PixMap &	GlyphImage () const
bool	Init (const TCollection_AsciiString &theFontPath, const Font_FTFontParams &theParams, const int theFaceId=0)
	Initialize the font from the given file path.
bool	Init (const occ::handle< NCollection_Buffer > &theData, const TCollection_AsciiString &theFileName, const Font_FTFontParams &theParams, const int theFaceId=0)
	Initialize the font from the given file path or memory buffer.
bool	FindAndInit (const TCollection_AsciiString &theFontName, Font_FontAspect theFontAspect, const Font_FTFontParams &theParams, Font_StrictLevel theStrictLevel=Font_StrictLevel_Any)
	Find (using Font_FontMgr) and initialize the font from the given name.
bool	ToUseUnicodeSubsetFallback () const
	Return flag to use fallback fonts in case if used font does not include symbols from specific Unicode subset; TRUE by default.
void	SetUseUnicodeSubsetFallback (bool theToFallback)
	Set if fallback fonts should be used in case if used font does not include symbols from specific Unicode subset.
bool	IsSingleStrokeFont () const
	Return TRUE if this is single-stroke (one-line) font, FALSE by default. Such fonts define single-line glyphs instead of closed contours, so that they are rendered incorrectly by normal software.
void	SetSingleStrokeFont (bool theIsSingleLine)
	Set if this font should be rendered as single-stroke (one-line).
bool	ToSynthesizeItalic () const
	Return TRUE if italic style should be synthesized; FALSE by default.
virtual void	Release ()
	Release currently loaded font.
bool	RenderGlyph (const char32_t theChar)
	Render specified glyph into internal buffer (bitmap).
unsigned int	GlyphMaxSizeX (bool theToIncludeFallback=false) const
unsigned int	GlyphMaxSizeY (bool theToIncludeFallback=false) const
float	Ascender () const
float	Descender () const
float	LineSpacing () const
unsigned int	PointSize () const
	Configured point size.
float	WidthScaling () const
	Return glyph scaling along X-axis.
void	SetWidthScaling (const float theScaleFactor)
	Setup glyph scaling along X-axis. By default glyphs are not scaled (scaling factor = 1.0).
bool	HasSymbol (char32_t theUChar) const
	Return TRUE if font contains specified symbol (excluding fallback list).
float	AdvanceX (char32_t theUCharNext) const
	Compute horizontal advance to the next character with kerning applied when applicable. Assuming text rendered horizontally.
float	AdvanceX (char32_t theUChar, char32_t theUCharNext)
	Compute horizontal advance to the next character with kerning applied when applicable. Assuming text rendered horizontally.
float	AdvanceY (char32_t theUCharNext) const
	Compute vertical advance to the next character with kerning applied when applicable. Assuming text rendered vertically.
float	AdvanceY (char32_t theUChar, char32_t theUCharNext)
	Compute vertical advance to the next character with kerning applied when applicable. Assuming text rendered vertically.
int	GlyphsNumber (bool theToIncludeFallback=false) const
	Return glyphs number in this font.
void	GlyphRect (Font_Rect &theRect) const
	Retrieve glyph bitmap rectangle.
Font_Rect	BoundingBox (const NCollection_String &theString, const Graphic3d_HorizontalTextAlignment theAlignX, const Graphic3d_VerticalTextAlignment theAlignY)
	Computes bounding box of the given text using plain-text formatter (Font_TextFormatter). Note that bounding box takes into account the text alignment options. Its corners are relative to the text alignment anchor point, their coordinates can be negative.
const FT_Outline *	renderGlyphOutline (const char32_t theChar)
	Computes outline contour for the symbol.
parameters bool	Init (const NCollection_String &theFontPath, unsigned int thePointSize, unsigned int theResolution)
	Initialize the font.
parameters bool	Init (const NCollection_String &theFontName, Font_FontAspect theFontAspect, unsigned int thePointSize, unsigned int theResolution)
	Initialize the font.
Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor.
	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing.
Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter.
virtual	~Standard_Transient ()=default
	Destructor must be virtual.
virtual const opencascade::handle< Standard_Type > &	DynamicType () const
	Returns a type descriptor about this object.
bool	IsInstance (const opencascade::handle< Standard_Type > &theType) const
	Returns a true value if this is an instance of Type.
bool	IsInstance (const char *const theTypeName) const
	Returns a true value if this is an instance of TypeName.
bool	IsKind (const opencascade::handle< Standard_Type > &theType) const
	Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
bool	IsKind (const char *const theTypeName) const
	Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism.
Standard_Transient *	This () const
	Returns non-const pointer to this object (like const_cast). For protection against creating handle to objects allocated in stack or call from constructor, it will raise exception Standard_ProgramError if reference counter is zero.
int	GetRefCount () const noexcept
	Get the reference counter of this object.
void	IncrementRefCounter () noexcept
	Increments the reference counter of this object. Uses relaxed memory ordering since incrementing only requires atomicity, not synchronization with other memory operations.
int	DecrementRefCounter () noexcept
	Decrements the reference counter of this object; returns the decremented value. Uses release ordering for the decrement to ensure all writes to the object are visible before the count reaches zero. An acquire fence is added only when the count reaches zero, ensuring proper synchronization before deletion. This is more efficient than using acq_rel for every decrement.
virtual void	Delete () const
	Memory deallocator for transient classes.

Static Public Member Functions
static occ::handle< Font_FTFont >	FindAndCreate (const TCollection_AsciiString &theFontName, const Font_FontAspect theFontAspect, const Font_FTFontParams &theParams, const Font_StrictLevel theStrictLevel=Font_StrictLevel_Any)
	Find the font Initialize the font.
static bool	IsCharFromCJK (char32_t theUChar)
	Return TRUE if specified character is within subset of modern CJK characters.
static bool	IsCharFromHiragana (char32_t theUChar)
	Return TRUE if specified character is within subset of Hiragana (Japanese).
static bool	IsCharFromKatakana (char32_t theUChar)
	Return TRUE if specified character is within subset of Katakana (Japanese).
static bool	IsCharFromKorean (char32_t theUChar)
	Return TRUE if specified character is within subset of modern Korean characters (Hangul).
static bool	IsCharFromArabic (char32_t theUChar)
	Return TRUE if specified character is within subset of Arabic characters.
static bool	IsCharRightToLeft (char32_t theUChar)
	Return TRUE if specified character should be displayed in Right-to-Left order.
static Font_UnicodeSubset	CharSubset (char32_t theUChar)
	Determine Unicode subset for specified character.
static constexpr const char *	get_type_name ()
	Returns a type descriptor about this object.
static const opencascade::handle< Standard_Type > &	get_type_descriptor ()
	Returns type descriptor of Standard_Transient class.

Protected Member Functions
template<typename theInput_t>
int32_t	toFTPoints (const theInput_t thePointSize) const
	Convert value to 26.6 fixed-point format for FT library API.
template<typename theReturn_t, typename theFTUnits_t>
theReturn_t	fromFTPoints (const theFTUnits_t theFTUnits) const
	Convert value from 26.6 fixed-point format for FT library API.
bool	loadGlyph (const char32_t theUChar)
	Load glyph without rendering it.
bool	getKerning (FT_Vector &theKern, char32_t theUCharCurr, char32_t theUCharNext) const
	Wrapper for FT_Get_Kerning - retrieve kerning values.
bool	findAndInitFallback (Font_UnicodeSubset theSubset)
	Initialize fallback font.
void	setLoadFlag (int32_t theFlag, bool theToEnable)
	Enable/disable load flag.

Protected Attributes
occ::handle< Font_FTLibrary >	myFTLib
	handle to the FT library object
occ::handle< NCollection_Buffer >	myBuffer
	memory buffer
occ::handle< Font_FTFont >	myFallbackFaces [Font_UnicodeSubset_NB]
	fallback fonts
FT_Face	myFTFace
	FT face object.
FT_Face	myActiveFTFace
	active FT face object (the main of fallback)
TCollection_AsciiString	myFontPath
	font path
Font_FTFontParams	myFontParams
	font initialization parameters
Font_FontAspect	myFontAspect
	font initialization aspect
float	myWidthScaling
	scale glyphs along X-axis
int32_t	myLoadFlags
	default load flags
Image_PixMap	myGlyphImg
	cached glyph plane
char32_t	myUChar
	currently loaded unicode character
bool	myToUseUnicodeSubsetFallback
	use default fallback fonts for extended Unicode sub-sets (Korean, CJK, etc.)

Additional Inherited Members
typedef void	base_type
	Returns a type descriptor about this object.

Detailed Description

Wrapper over FreeType font. Notice that this class uses internal buffers for loaded glyphs and it is absolutely UNSAFE to load/read glyph from concurrent threads!

Constructor & Destructor Documentation

Font_FTFont()

Font_FTFont::Font_FTFont

(

const occ::handle< Font_FTLibrary > &

theFTLib = occ::handle< Font_FTLibrary >()

)

Create uninitialized instance.

~Font_FTFont()

Font_FTFont::~Font_FTFont ( )

override

Destructor.

Member Function Documentation

AdvanceX() [1/2]

float Font_FTFont::AdvanceX	(	char32_t	theUChar,
		char32_t	theUCharNext )

Compute horizontal advance to the next character with kerning applied when applicable. Assuming text rendered horizontally.

Parameters

theUChar	the character to be loaded as current one
theUCharNext	the next character to compute advance from current one

AdvanceX() [2/2]

float Font_FTFont::AdvanceX

(

char32_t

theUCharNext

)

const

Compute horizontal advance to the next character with kerning applied when applicable. Assuming text rendered horizontally.

Parameters

theUCharNext

the next character to compute advance from current one

AdvanceY() [1/2]

float Font_FTFont::AdvanceY	(	char32_t	theUChar,
		char32_t	theUCharNext )

Compute vertical advance to the next character with kerning applied when applicable. Assuming text rendered vertically.

Parameters

theUChar	the character to be loaded as current one
theUCharNext	the next character to compute advance from current one

AdvanceY() [2/2]

float Font_FTFont::AdvanceY

(

char32_t

theUCharNext

)

const

Compute vertical advance to the next character with kerning applied when applicable. Assuming text rendered vertically.

Parameters

theUCharNext

the next character to compute advance from current one

Ascender()

float Font_FTFont::Ascender

(

)

const

Returns

vertical distance from the horizontal baseline to the highest character coordinate.

BoundingBox()

Font_Rect Font_FTFont::BoundingBox	(	const NCollection_String &	theString,
		const Graphic3d_HorizontalTextAlignment	theAlignX,
		const Graphic3d_VerticalTextAlignment	theAlignY )

Computes bounding box of the given text using plain-text formatter (Font_TextFormatter). Note that bounding box takes into account the text alignment options. Its corners are relative to the text alignment anchor point, their coordinates can be negative.

CharSubset()

Font_UnicodeSubset Font_FTFont::CharSubset ( char32_t theUChar )

inlinestatic

Determine Unicode subset for specified character.

Descender()

float Font_FTFont::Descender

(

)

const

Returns

vertical distance from the horizontal baseline to the lowest character coordinate.

FindAndCreate()

occ::handle< Font_FTFont > Font_FTFont::FindAndCreate ( const TCollection_AsciiString & theFontName, const Font_FontAspect theFontAspect, const Font_FTFontParams & theParams, const Font_StrictLevel theStrictLevel = Font_StrictLevel_Any )

static

Find the font Initialize the font.

Parameters

theFontName	the font name
theFontAspect	the font style
theParams	initialization parameters
theStrictLevel	search strict level for using aliases and fallback

Returns

true on success

FindAndInit()

bool Font_FTFont::FindAndInit	(	const TCollection_AsciiString &	theFontName,
		Font_FontAspect	theFontAspect,
		const Font_FTFontParams &	theParams,
		Font_StrictLevel	theStrictLevel = Font_StrictLevel_Any )

Find (using Font_FontMgr) and initialize the font from the given name.

Parameters

theFontName	the font name
theFontAspect	the font style
theParams	initialization parameters
theStrictLevel	search strict level for using aliases and fallback

Returns

true on success

findAndInitFallback()

bool Font_FTFont::findAndInitFallback ( Font_UnicodeSubset theSubset )

protected

Initialize fallback font.

fromFTPoints()

template<typename theReturn_t, typename theFTUnits_t>

theReturn_t Font_FTFont::fromFTPoints ( const theFTUnits_t theFTUnits ) const

inlineprotected

Convert value from 26.6 fixed-point format for FT library API.

getKerning()

bool Font_FTFont::getKerning ( FT_Vector & theKern, char32_t theUCharCurr, char32_t theUCharNext ) const

protected

Wrapper for FT_Get_Kerning - retrieve kerning values.

GlyphImage()

const Image_PixMap & Font_FTFont::GlyphImage ( ) const

inline

Returns

image plane for currently rendered glyph

GlyphMaxSizeX()

unsigned int Font_FTFont::GlyphMaxSizeX

(

bool

theToIncludeFallback = false

)

const

Returns

maximal glyph width in pixels (rendered to bitmap).

GlyphMaxSizeY()

unsigned int Font_FTFont::GlyphMaxSizeY

(

bool

theToIncludeFallback = false

)

const

Returns

maximal glyph height in pixels (rendered to bitmap).

GlyphRect()

void Font_FTFont::GlyphRect

(

Font_Rect &

theRect

)

const

Retrieve glyph bitmap rectangle.

GlyphsNumber()

int Font_FTFont::GlyphsNumber

(

bool

theToIncludeFallback = false

)

const

Return glyphs number in this font.

Parameters

theToIncludeFallback

if TRUE then the number will include fallback list

HasSymbol()

bool Font_FTFont::HasSymbol

(

char32_t

theUChar

)

const

Return TRUE if font contains specified symbol (excluding fallback list).

Init() [1/4]

parameters bool Font_FTFont::Init ( const NCollection_String & theFontName, Font_FontAspect theFontAspect, unsigned int thePointSize, unsigned int theResolution )

inline

Initialize the font.

Parameters

theFontName	the font name
theFontAspect	the font style
thePointSize	the face size in points (1/72 inch)
theResolution	the resolution of the target device in dpi

Returns

true on success

Deprecated

("Deprecated method, Font_FTFontParams should be used for passing "

Init() [2/4]

parameters bool Font_FTFont::Init ( const NCollection_String & theFontPath, unsigned int thePointSize, unsigned int theResolution )

inline

Initialize the font.

Parameters

theFontPath	path to the font
thePointSize	the face size in points (1/72 inch)
theResolution	the resolution of the target device in dpi

Returns

true on success

Deprecated

("Deprecated method, Font_FTFontParams should be used for passing "

Init() [3/4]

bool Font_FTFont::Init	(	const occ::handle< NCollection_Buffer > &	theData,
		const TCollection_AsciiString &	theFileName,
		const Font_FTFontParams &	theParams,
		const int	theFaceId = 0 )

Initialize the font from the given file path or memory buffer.

Parameters

theData	memory to read from, should NOT be freed after initialization! when NULL, function will attempt to open theFileName file
theFileName	optional path to the font
theParams	initialization parameters
theFaceId	face id within the file (0 by default)

Returns

true on success

Init() [4/4]

bool Font_FTFont::Init ( const TCollection_AsciiString & theFontPath, const Font_FTFontParams & theParams, const int theFaceId = 0 )

inline

Initialize the font from the given file path.

Parameters

theFontPath	path to the font
theParams	initialization parameters
theFaceId	face id within the file (0 by default)

Returns

true on success

IsCharFromArabic()

bool Font_FTFont::IsCharFromArabic ( char32_t theUChar )

inlinestatic

Return TRUE if specified character is within subset of Arabic characters.

IsCharFromCJK()

bool Font_FTFont::IsCharFromCJK ( char32_t theUChar )

inlinestatic

Return TRUE if specified character is within subset of modern CJK characters.

IsCharFromHiragana()

bool Font_FTFont::IsCharFromHiragana ( char32_t theUChar )

inlinestatic

Return TRUE if specified character is within subset of Hiragana (Japanese).

IsCharFromKatakana()

bool Font_FTFont::IsCharFromKatakana ( char32_t theUChar )

inlinestatic

Return TRUE if specified character is within subset of Katakana (Japanese).

IsCharFromKorean()

bool Font_FTFont::IsCharFromKorean ( char32_t theUChar )

inlinestatic

Return TRUE if specified character is within subset of modern Korean characters (Hangul).

IsCharRightToLeft()

bool Font_FTFont::IsCharRightToLeft ( char32_t theUChar )

inlinestatic

Return TRUE if specified character should be displayed in Right-to-Left order.

IsSingleStrokeFont()

bool Font_FTFont::IsSingleStrokeFont ( ) const

inline

Return TRUE if this is single-stroke (one-line) font, FALSE by default. Such fonts define single-line glyphs instead of closed contours, so that they are rendered incorrectly by normal software.

IsValid()

bool Font_FTFont::IsValid ( ) const

inline

Returns

true if font is loaded

LineSpacing()

float Font_FTFont::LineSpacing

(

)

const

Returns

default line spacing (the baseline-to-baseline distance).

loadGlyph()

bool Font_FTFont::loadGlyph ( const char32_t theUChar )

protected

Load glyph without rendering it.

PointSize()

unsigned int Font_FTFont::PointSize ( ) const

inline

Configured point size.

Release()

virtual void Font_FTFont::Release ( )

virtual

Release currently loaded font.

RenderGlyph()

bool Font_FTFont::RenderGlyph

(

const char32_t

theChar

)

Render specified glyph into internal buffer (bitmap).

renderGlyphOutline()

const FT_Outline * Font_FTFont::renderGlyphOutline

(

const char32_t

theChar

)

Computes outline contour for the symbol.

Parameters

[in]	theUChar	the character to be loaded as current one
[out]	theOutline	outline contour

Returns

true on success

setLoadFlag()

void Font_FTFont::setLoadFlag ( int32_t theFlag, bool theToEnable )

inlineprotected

Enable/disable load flag.

SetSingleStrokeFont()

void Font_FTFont::SetSingleStrokeFont ( bool theIsSingleLine )

inline

Set if this font should be rendered as single-stroke (one-line).

SetUseUnicodeSubsetFallback()

void Font_FTFont::SetUseUnicodeSubsetFallback ( bool theToFallback )

inline

Set if fallback fonts should be used in case if used font does not include symbols from specific Unicode subset.

SetWidthScaling()

void Font_FTFont::SetWidthScaling ( const float theScaleFactor )

inline

Setup glyph scaling along X-axis. By default glyphs are not scaled (scaling factor = 1.0).

toFTPoints()

template<typename theInput_t>

int32_t Font_FTFont::toFTPoints ( const theInput_t thePointSize ) const

inlineprotected

Convert value to 26.6 fixed-point format for FT library API.

ToSynthesizeItalic()

bool Font_FTFont::ToSynthesizeItalic ( ) const

inline

Return TRUE if italic style should be synthesized; FALSE by default.

ToUseUnicodeSubsetFallback()

bool Font_FTFont::ToUseUnicodeSubsetFallback ( ) const

inline

Return flag to use fallback fonts in case if used font does not include symbols from specific Unicode subset; TRUE by default.

See also

Font_FontMgr::ToUseUnicodeSubsetFallback()

WidthScaling()

float Font_FTFont::WidthScaling ( ) const

inline

Return glyph scaling along X-axis.

Field Documentation

myActiveFTFace

FT_Face Font_FTFont::myActiveFTFace

protected

active FT face object (the main of fallback)

myBuffer

occ::handle<NCollection_Buffer> Font_FTFont::myBuffer

protected

memory buffer

myFallbackFaces

occ::handle<Font_FTFont> Font_FTFont::myFallbackFaces[Font_UnicodeSubset_NB]

protected

fallback fonts

myFontAspect

Font_FontAspect Font_FTFont::myFontAspect

protected

font initialization aspect

myFontParams

Font_FTFontParams Font_FTFont::myFontParams

protected

font initialization parameters

myFontPath

TCollection_AsciiString Font_FTFont::myFontPath

protected

font path

myFTFace

FT_Face Font_FTFont::myFTFace

protected

FT face object.

myFTLib

occ::handle<Font_FTLibrary> Font_FTFont::myFTLib

protected

handle to the FT library object

myGlyphImg

Image_PixMap Font_FTFont::myGlyphImg

protected

cached glyph plane

myLoadFlags

int32_t Font_FTFont::myLoadFlags

protected

default load flags

myToUseUnicodeSubsetFallback

bool Font_FTFont::myToUseUnicodeSubsetFallback

protected

use default fallback fonts for extended Unicode sub-sets (Korean, CJK, etc.)

myUChar

char32_t Font_FTFont::myUChar

protected

currently loaded unicode character

myWidthScaling

float Font_FTFont::myWidthScaling

protected

scale glyphs along X-axis

---

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

• Font_FTFont.hxx