OpenGl_Font Class Reference

Texture font. More...

#include <OpenGl_Font.hxx>

Inheritance diagram for OpenGl_Font:

Data Structures
struct	RectI
struct	Tile
	Simple structure stores tile rectangle. More...

Public Member Functions
	OpenGl_Font (const Handle< Font_FTFont > &theFont, const TCollection_AsciiString &theKey="")
	Main constructor. More...
virtual	~OpenGl_Font ()
	Destroy object. More...
virtual void	Release (OpenGl_Context *theCtx)
	Destroy object - will release GPU memory if any. More...
const TCollection_AsciiString &	ResourceKey () const
const Handle< Font_FTFont > &	FTFont () const
bool	IsValid () const
bool	WasInitialized () const
	Notice that this method doesn't return initialization success state. Use IsValid() instead. More...
bool	Init (const Handle< OpenGl_Context > &theCtx)
	Initialize GL resources. FreeType font instance should be already initialized! More...
float	AdvanceX (const Standard_Utf32Char theUChar, const Standard_Utf32Char theUCharNext)
	Compute advance to the next character with kerning applied when applicable. Assuming text rendered horizontally. More...
float	Ascender () const
float	Descender () const
float	LineSpacing () const
void	RenderGlyph (const Handle< OpenGl_Context > &theCtx, const Standard_Utf32Char theUChar, const Standard_Utf32Char theUCharNext, Tile &theGlyph, OpenGl_Vec2 &thePen)
	Compute glyph rectangle at specified pen position (on baseline) and render it to texture if not already. More...
Public Member Functions inherited from OpenGl_Resource
	OpenGl_Resource ()
	Empty constructor. More...
virtual	~OpenGl_Resource ()
	Destructor. Inheritors should call Clean (NULL) within it. More...
Public Member Functions inherited from Standard_Transient
	Standard_Transient ()
	Empty constructor. More...
	Standard_Transient (const Standard_Transient &)
	Copy constructor – does nothing. More...
Standard_Transient &	operator= (const Standard_Transient &)
	Assignment operator, needed to avoid copying reference counter. More...
virtual	~Standard_Transient ()
	Destructor must be virtual. More...
virtual void	Delete () const
	Memory deallocator for transient classes. More...
virtual const Handle_Standard_Type &	DynamicType () const
	Returns a type information object about this object. More...
Standard_Boolean	IsInstance (const Handle_Standard_Type &theType) const
	Returns a true value if this is an instance of Type. More...
Standard_Boolean	IsInstance (const Standard_CString theTypeName) const
	Returns a true value if this is an instance of TypeName. More...
Standard_Boolean	IsKind (const 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. More...
Standard_Boolean	IsKind (const Standard_CString 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. More...
virtual Handle_Standard_Transient	This () const
	Returns a Handle which references this object. Must never be called to objects created in stack. More...
Standard_Integer	GetRefCount () const
	Get the reference counter of this object. More...

Protected Member Functions
bool	renderGlyph (const Handle< OpenGl_Context > &theCtx, const Standard_Utf32Char theChar)
	Render new glyph to the texture. More...
bool	createTexture (const Handle< OpenGl_Context > &theCtx)
	Allocate new texture. More...

Protected Attributes
TCollection_AsciiString	myKey
	key of shared resource More...
Handle< Font_FTFont >	myFont
	FreeType font instance. More...
Standard_ShortReal	myAscender
	ascender provided my FT font More...
Standard_ShortReal	myDescender
	descender provided my FT font More...
Standard_ShortReal	myLineSpacing
	line spacing provided my FT font More...
Standard_Integer	myTileSizeX
	tile width More...
Standard_Integer	myTileSizeY
	tile height More...
Standard_Integer	myLastTileId
	id of last tile More...
RectI	myLastTilePx
Standard_Integer	myTextureFormat
	texture format More...
NCollection_Vector< Handle < OpenGl_Texture > >	myTextures
	array of textures More...
NCollection_Vector< Tile >	myTiles
	array of loaded tiles More...
NCollection_DataMap < Standard_Utf32Char, Standard_Integer >	myGlyphMap

Detailed Description

Texture font.

Constructor & Destructor Documentation

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

Main constructor.

virtual OpenGl_Font::~OpenGl_Font ( )

virtual

Destroy object.

Member Function Documentation

float OpenGl_Font::AdvanceX ( const Standard_Utf32Char  theUChar, const Standard_Utf32Char  theUCharNext  )

inline

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

float OpenGl_Font::Ascender ( ) const

inline

Returns

vertical distance from the horizontal baseline to the highest character coordinate

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

protected

Allocate new texture.

float OpenGl_Font::Descender ( ) const

inline

Returns

vertical distance from the horizontal baseline to the lowest character coordinate

const Handle< Font_FTFont >& OpenGl_Font::FTFont ( ) const

inline

Returns

FreeType font instance specified on construction.

bool OpenGl_Font::Init

(

const Handle< OpenGl_Context > &

theCtx

)

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

bool OpenGl_Font::IsValid ( ) const

inline

Returns

true if font was loaded successfully.

float OpenGl_Font::LineSpacing ( ) const

inline

Returns

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

virtual void OpenGl_Font::Release ( OpenGl_Context *  theCtx )

virtual

Destroy object - will release GPU memory if any.

Implements OpenGl_Resource.

void OpenGl_Font::RenderGlyph	(	const Handle< OpenGl_Context > &	theCtx,
		const Standard_Utf32Char	theUChar,
		const Standard_Utf32Char	theUCharNext,
		Tile &	theGlyph,
		OpenGl_Vec2 &	thePen
	)

Compute glyph rectangle at specified pen position (on baseline) and render it to texture if not already.

Parameters

theCtx	active context
theUChar	unicode symbol to render
theUCharNext	next symbol to compute advance with kerning when available
theGlyph	computed glyph position rectangle, texture ID and UV coordinates
thePen	pen position on baseline to place new glyph

bool OpenGl_Font::renderGlyph ( const Handle< OpenGl_Context > &  theCtx, const Standard_Utf32Char  theChar  )

protected

Render new glyph to the texture.

const TCollection_AsciiString& OpenGl_Font::ResourceKey ( ) const

inline

Returns

key of shared resource

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

Standard_ShortReal OpenGl_Font::myAscender

protected

ascender provided my FT font

Standard_ShortReal OpenGl_Font::myDescender

protected

descender provided my FT font

Handle< Font_FTFont > OpenGl_Font::myFont

protected

FreeType font instance.

NCollection_DataMap<Standard_Utf32Char, Standard_Integer> OpenGl_Font::myGlyphMap

protected

TCollection_AsciiString OpenGl_Font::myKey

protected

key of shared resource

Standard_Integer OpenGl_Font::myLastTileId

protected

id of last tile

RectI OpenGl_Font::myLastTilePx

protected

Standard_ShortReal OpenGl_Font::myLineSpacing

protected

line spacing provided my FT font

Standard_Integer OpenGl_Font::myTextureFormat

protected

texture format

NCollection_Vector<Handle< OpenGl_Texture > > OpenGl_Font::myTextures

protected

array of textures

NCollection_Vector<Tile> OpenGl_Font::myTiles

protected

array of loaded tiles

Standard_Integer OpenGl_Font::myTileSizeX

protected

tile width

Standard_Integer OpenGl_Font::myTileSizeY

protected

tile height

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

• OpenGl_Font.hxx