A ScaledFont is a font scaled to a particular size and device resolution. More...

#include <cairomm/scaledfont.h>

Inheritance diagram for Cairo::ScaledFont:

Public Types
typedef cairo_scaled_font_t	cobject
	The underlying C cairo object type. More...

Public Member Functions
cobject *	cobj ()
	Provides acces to the underlying C cairo object. More...

const cobject *	cobj () const
	Provides acces to the underlying C cairo object. More...

	ScaledFont (cobject *cobj, bool has_reference=false)
	Create a C++ wrapper object from the C instance. More...

	ScaledFont (const ScaledFont &)=delete

ScaledFont &	operator= (const ScaledFont &)=delete

virtual	~ScaledFont ()

void	get_extents (FontExtents & extents) const
	Gets the metrics for a ScaledFont. More...

void	get_text_extents (const std::string & utf8, TextExtents & extents) const
	Gets the extents for a string of text. More...

void	get_glyph_extents (const std::vector< Glyph > & glyphs, TextExtents & extents)
	Gets the extents for an array of glyphs. More...

RefPtr< FontFace >	get_font_face () const
	The FontFace with which this ScaledFont was created. More...

void	get_font_options (FontOptions & options) const
	Gets the FontOptions with which the ScaledFont was created. More...

void	get_font_matrix (Matrix & font_matrix) const
	Gets the font matrix with which the ScaledFont was created. More...

void	get_ctm (Matrix & ctm) const
	Gets the CTM with which the ScaledFont was created. More...

FontType	get_type () const
	Gets the type of scaled Font. More...

void	text_to_glyphs (double x, double y, const std::string & utf8, std::vector< Glyph > & glyphs, std::vector< TextCluster > & clusters, TextClusterFlags & cluster_flags)

void	get_scale_matrix (Matrix & scale_matrix) const
	Stores the scale matrix of this scaled font into matrix. More...

Static Public Member Functions
static RefPtr< ScaledFont >	create (const RefPtr< FontFace > & font_face, const Matrix & font_matrix, const Matrix & ctm, const FontOptions & options=FontOptions())
	Creates a ScaledFont object from a font face and matrices that describe the size of the font and the environment in which it will be used. More...

Protected Member Functions
	ScaledFont (const RefPtr< FontFace > & font_face, const Matrix & font_matrix, const Matrix & ctm, const FontOptions & options=FontOptions())

Protected Attributes
cobject *	m_cobject
	The underlying C cairo object that is wrapped by this ScaledFont. More...

Detailed Description

A ScaledFont is a font scaled to a particular size and device resolution.

It is most useful for low-level font usage where a library or application wants to cache a reference to a scaled font to speed up the computation of metrics.

Member Typedef Documentation

◆ cobject

typedef cairo_scaled_font_t Cairo::ScaledFont::cobject

The underlying C cairo object type.

Constructor & Destructor Documentation

◆ ScaledFont() [1/3]

Cairo::ScaledFont::ScaledFont	(	cobject *	cobj,
		bool	has_reference = `false`
	)

explicit

Create a C++ wrapper object from the C instance.

This C++ object should then be given to a RefPtr.

◆ ScaledFont() [2/3]

Cairo::ScaledFont::ScaledFont ( const ScaledFont & )

delete

◆ ~ScaledFont()

virtual Cairo::ScaledFont::~ScaledFont ( )

virtual

◆ ScaledFont() [3/3]

Cairo::ScaledFont::ScaledFont	(	const RefPtr< FontFace > &	font_face,
		const Matrix &	font_matrix,
		const Matrix &	ctm,
		const FontOptions &	options = `FontOptions()`
	)

protected

Member Function Documentation

◆ cobj() [1/2]

cobject* Cairo::ScaledFont::cobj ( )

inline

Provides acces to the underlying C cairo object.

◆ cobj() [2/2]

const cobject* Cairo::ScaledFont::cobj ( ) const

inline

Provides acces to the underlying C cairo object.

◆ create()

static RefPtr<ScaledFont> Cairo::ScaledFont::create	(	const RefPtr< FontFace > &	font_face,
		const Matrix &	font_matrix,
		const Matrix &	ctm,
		const FontOptions &	options = `FontOptions()`
	)

static

Creates a ScaledFont object from a font face and matrices that describe the size of the font and the environment in which it will be used.

Parameters

font_face	A font face.
font_matrix	font space to user space transformation matrix for the font. In the simplest case of a N point font, this matrix is just a scale by N, but it can also be used to shear the font or stretch it unequally along the two axes. See Context::set_font_matrix().
ctm	user to device transformation matrix with which the font will be used.
options	options to use when getting metrics for the font and rendering with it.

◆ get_ctm()

void Cairo::ScaledFont::get_ctm ( Matrix & ctm ) const

Gets the CTM with which the ScaledFont was created.

Since: 1.2

◆ get_extents()

void Cairo::ScaledFont::get_extents ( FontExtents & extents ) const

Gets the metrics for a ScaledFont.

Since: 1.8

◆ get_font_face()

RefPtr<FontFace> Cairo::ScaledFont::get_font_face ( ) const

The FontFace with which this ScaledFont was created.

Since: 1.2

◆ get_font_matrix()

void Cairo::ScaledFont::get_font_matrix ( Matrix & font_matrix ) const

Gets the font matrix with which the ScaledFont was created.

Since: 1.2

◆ get_font_options()

void Cairo::ScaledFont::get_font_options ( FontOptions & options ) const

Gets the FontOptions with which the ScaledFont was created.

Since: 1.2

◆ get_glyph_extents()

void Cairo::ScaledFont::get_glyph_extents	(	const std::vector< Glyph > &	glyphs,
		TextExtents &	extents
	)

Gets the extents for an array of glyphs.

The extents describe a user-space rectangle that encloses the "inked" portion of the glyphs, (as they would be drawn by Context::show_glyphs() if the cairo graphics state were set to the same font_face, font_matrix, ctm, and font_options as the ScaledFont object). Additionally, the x_advance and y_advance values indicate the amount by which the current point would be advanced by Context::show_glyphs().

Note that whitespace glyphs do not contribute to the size of the rectangle (extents.width and extents.height).

Parameters

glyphs	A vector of glyphs to calculate the extents of.
extents	Returns the extents for the array of glyphs.

Since: 1.8

◆ get_scale_matrix()

void Cairo::ScaledFont::get_scale_matrix ( Matrix & scale_matrix ) const

Stores the scale matrix of this scaled font into matrix.

The scale matrix is product of the font matrix and the ctm associated with the scaled font, and hence is the matrix mapping from font space to device space.

Parameters

scale_matrix return value for the matrix.

Since: 1.8

◆ get_text_extents()

void Cairo::ScaledFont::get_text_extents	(	const std::string &	utf8,
		TextExtents &	extents
	)		const

Gets the extents for a string of text.

The extents describe a user-space rectangle that encloses the "inked" portion of the text drawn at the origin (0,0) (as it would be drawn by Context::show_text() if the cairo graphics state were set to the same font_face, font_matrix, ctm, and font_options as the ScaledFont object). Additionally, the x_advance and y_advance values indicate the amount by which the current point would be advanced by Context::show_text().

Note that whitespace characters do not directly contribute to the size of the rectangle (extents.width and extents.height). They do contribute indirectly by changing the position of non-whitespace characters. In particular, trailing whitespace characters are likely to not affect the size of the rectangle, though they will affect the x_advance and y_advance values.

Parameters

utf8	a string of text, encoded in UTF-8.
extents	Returns the extents of the given string.

Since: 1.8

◆ get_type()

FontType Cairo::ScaledFont::get_type ( ) const

Gets the type of scaled Font.

Since: 1.2

◆ operator=()

ScaledFont& Cairo::ScaledFont::operator= ( const ScaledFont & )

delete

◆ text_to_glyphs()

void Cairo::ScaledFont::text_to_glyphs	(	double	x,
		double	y,
		const std::string &	utf8,
		std::vector< Glyph > &	glyphs,
		std::vector< TextCluster > &	clusters,
		TextClusterFlags &	cluster_flags
	)

Parameters

x	X position to place first glyph.
y	Y position to place first glyph.
utf8	a string of text encoded in UTF-8.
glyphs	pointer to array of glyphs to fill.
clusters	pointer to array of cluster mapping information to fill. @cluster_flags cluster mapping flags

Converts UTF-8 text to an array of glyphs, with cluster mapping, that can be used to render later.

For details of how (clusters and cluster_flags map input UTF-8 text to the output glyphs see Context::show_text_glyphs().

The output values can be readily passed to Context::show_text_glyphs() Context::show_glyphs(), or related functions, assuming that the exact same scaled font is used for the operation.

Since: 1.8

Member Data Documentation

◆ m_cobject

cobject* Cairo::ScaledFont::m_cobject

protected

The underlying C cairo object that is wrapped by this ScaledFont.

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

cairomm/scaledfont.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ cobject

Constructor & Destructor Documentation

◆ ScaledFont() [1/3]

◆ ScaledFont() [2/3]

◆ ~ScaledFont()

◆ ScaledFont() [3/3]

Member Function Documentation

◆ cobj() [1/2]

◆ cobj() [2/2]

◆ create()

◆ get_ctm()

◆ get_extents()

◆ get_font_face()

◆ get_font_matrix()

◆ get_font_options()

◆ get_glyph_extents()

◆ get_scale_matrix()

◆ get_text_extents()

◆ get_type()

◆ operator=()

◆ text_to_glyphs()

Member Data Documentation

◆ m_cobject