Texture font. More...

#include <OpenGl_Font.hxx>

Inheritance diagram for OpenGl_Font:

[legend]

Data Structures
struct	RectI

struct	Tile
	Simple structure stores tile rectangle. More...

Public Member Functions
	OpenGl_Font (const occ::handle< Font_FTFont > &theFont, const TCollection_AsciiString &theKey="")
	Main constructor.

	~OpenGl_Font () override
	Destroy object.

void	Release (OpenGl_Context *theCtx) override
	Destroy object - will release GPU memory if any.

size_t	EstimatedDataSize () const override
	Returns estimated GPU memory usage.

const TCollection_AsciiString &	ResourceKey () const

const occ::handle< Font_FTFont > &	FTFont () const

bool	IsValid () const

bool	WasInitialized () const
	Notice that this method doesn't return initialization success state. Use IsValid() instead.

bool	Init (const occ::handle< OpenGl_Context > &theCtx)
	Initialize GL resources. FreeType font instance should be already initialized!

float	Ascender () const

float	Descender () const

bool	RenderGlyph (const occ::handle< OpenGl_Context > &theCtx, const char32_t theUChar, Tile &theGlyph)
	Render glyph to texture if not already.

const occ::handle< OpenGl_Texture > &	Texture () const

Public Member Functions inherited from OpenGl_Resource
	OpenGl_Resource ()
	Empty constructor.

	~OpenGl_Resource () override
	Destructor. Inheritors should call Clean (NULL) within it.

virtual void	DumpJson (Standard_OStream &theOStream, int theDepth=-1) const
	Dumps the content of me into the stream.

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.

Protected Member Functions
bool	renderGlyph (const occ::handle< OpenGl_Context > &theCtx, const char32_t theChar)
	Render new glyph to the texture.

bool	createTexture (const occ::handle< OpenGl_Context > &theCtx)
	Allocate new texture.

Protected Attributes
TCollection_AsciiString	myKey
	key of shared resource

occ::handle< Font_FTFont >	myFont
	FreeType font instance.

float	myAscender
	ascender provided my FT font

float	myDescender
	descender provided my FT font

int	myTileSizeY
	tile height

int	myLastTileId
	id of last tile

RectI	myLastTilePx

int	myTextureFormat
	texture format

NCollection_DynamicArray< occ::handle< OpenGl_Texture > >	myTextures
	array of textures

NCollection_DynamicArray< Tile >	myTiles
	array of loaded tiles

NCollection_DataMap< char32_t, int >	myGlyphMap

Additional Inherited Members
Public Types inherited from Standard_Transient
typedef void	base_type
	Returns a type descriptor about this object.

Static Public Member Functions inherited from Standard_Transient
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.

Detailed Description

Texture font.

Constructor & Destructor Documentation

◆ OpenGl_Font()

OpenGl_Font::OpenGl_Font	(	const occ::handle< Font_FTFont > &	theFont,
		const TCollection_AsciiString &	theKey = "" )

Main constructor.

◆ ~OpenGl_Font()

OpenGl_Font::~OpenGl_Font ( )

override

Destroy object.

Member Function Documentation

◆ Ascender()

float OpenGl_Font::Ascender ( ) const

inline

Returns: vertical distance from the horizontal baseline to the highest character coordinate

◆ createTexture()

bool OpenGl_Font::createTexture ( const occ::handle< OpenGl_Context > & theCtx )

protected

Allocate new texture.

◆ Descender()

float OpenGl_Font::Descender ( ) const

inline

Returns: vertical distance from the horizontal baseline to the lowest character coordinate

◆ EstimatedDataSize()

size_t OpenGl_Font::EstimatedDataSize ( ) const

overridevirtual

Returns estimated GPU memory usage.

Implements OpenGl_Resource.

◆ FTFont()

const occ::handle< Font_FTFont > & OpenGl_Font::FTFont ( ) const

inline

Returns: FreeType font instance specified on construction.

◆ Init()

bool OpenGl_Font::Init ( const occ::handle< OpenGl_Context > & theCtx )

Initialize GL resources. FreeType font instance should be already initialized!

◆ IsValid()

bool OpenGl_Font::IsValid ( ) const

inline

Returns: true if font was loaded successfully.

◆ Release()

void OpenGl_Font::Release ( OpenGl_Context * theCtx )

overridevirtual

Destroy object - will release GPU memory if any.

Implements OpenGl_Resource.

◆ renderGlyph()

bool OpenGl_Font::renderGlyph	(	const occ::handle< OpenGl_Context > &	theCtx,
		const char32_t	theChar )

protected

Render new glyph to the texture.

◆ RenderGlyph()

bool OpenGl_Font::RenderGlyph	(	const occ::handle< OpenGl_Context > &	theCtx,
		const char32_t	theUChar,
		Tile &	theGlyph )

Render glyph to texture if not already.

Parameters

theCtx	active context
theUChar	unicode symbol to render
theGlyph	computed glyph position rectangle, texture ID and UV coordinates

◆ ResourceKey()

const TCollection_AsciiString & OpenGl_Font::ResourceKey ( ) const

inline

Returns: key of shared resource

◆ Texture()

const occ::handle< OpenGl_Texture > & OpenGl_Font::Texture ( ) const

inline

Returns: first texture.

◆ WasInitialized()

bool OpenGl_Font::WasInitialized ( ) const

inline

Notice that this method doesn't return initialization success state. Use IsValid() instead.

Returns: true if initialization was already called.

Field Documentation

◆ myAscender

float OpenGl_Font::myAscender

protected

ascender provided my FT font

◆ myDescender

float OpenGl_Font::myDescender

protected

descender provided my FT font

◆ myFont

occ::handle<Font_FTFont> OpenGl_Font::myFont

protected

FreeType font instance.

◆ myGlyphMap

NCollection_DataMap<char32_t, int> OpenGl_Font::myGlyphMap

protected

◆ myKey

TCollection_AsciiString OpenGl_Font::myKey

protected

key of shared resource

◆ myLastTileId

int OpenGl_Font::myLastTileId

protected

id of last tile

◆ myLastTilePx

RectI OpenGl_Font::myLastTilePx

protected

◆ myTextureFormat

int OpenGl_Font::myTextureFormat

protected

texture format

◆ myTextures

NCollection_DynamicArray<occ::handle<OpenGl_Texture> > OpenGl_Font::myTextures

protected

array of textures

◆ myTiles

NCollection_DynamicArray<Tile> OpenGl_Font::myTiles

protected

array of loaded tiles

◆ myTileSizeY

int OpenGl_Font::myTileSizeY

protected

tile height

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

OpenGl_Font.hxx

Data Structures

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ OpenGl_Font()

◆ ~OpenGl_Font()

Member Function Documentation

◆ Ascender()

◆ createTexture()

◆ Descender()

◆ EstimatedDataSize()

◆ FTFont()

◆ Init()

◆ IsValid()

◆ Release()

◆ renderGlyph()

◆ RenderGlyph()

◆ ResourceKey()

◆ Texture()

◆ WasInitialized()

Field Documentation

◆ myAscender

◆ myDescender

◆ myFont

◆ myGlyphMap

◆ myKey

◆ myLastTileId

◆ myLastTilePx

◆ myTextureFormat

◆ myTextures

◆ myTiles

◆ myTileSizeY