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.
Public Types | |
typedef cairo_scaled_font_t | cobject |
The underlying C cairo object type. | |
Public Member Functions | |
const cobject * | cobj () const |
Provides acces to the underlying C cairo object. | |
cobject * | cobj () |
Provides acces to the underlying C cairo object. | |
void | extents (FontExtents &extents) const |
Gets the metrics for a ScaledFont. | |
void | get_ctm (Matrix &ctm) const |
Gets the CTM with which the ScaledFont was created. | |
RefPtr< FontFace > | get_font_face () const |
The FontFace with which this ScaledFont was created. | |
void | get_font_matrix (Matrix &font_matrix) const |
Gets the font matrix with which the ScaledFont was created. | |
void | get_font_options (FontOptions &options) const |
Gets the FontOptions with which the ScaledFont was created. | |
FontType | get_type () const |
Gets the type of scaled Font. | |
void | glyph_extents (const std::vector< Glyph > &glyphs, TextExtents &extents) |
Gets the extents for an array of glyphs. | |
ScaledFont (cobject *cobj, bool has_reference=false) | |
Createa C++ wrapper object from the C instance. | |
void | text_extents (const std::string &utf8, TextExtents &extents) const |
Gets the extents for a string of text. | |
Static Public Member Functions | |
static RefPtr< ScaledFont > | create (FontFace &font_face, const Matrix &font_matrix, const Matrix &ctm, const FontOptions &options) |
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. | |
Protected Attributes | |
cobject * | m_cobject |
The underlying C cairo object that is wrapped by this ScaledFont. |
typedef cairo_scaled_font_t Cairo::ScaledFont::cobject |
The underlying C cairo object type.
Cairo::ScaledFont::ScaledFont | ( | cobject * | cobj, | |
bool | has_reference = false | |||
) | [explicit] |
Createa C++ wrapper object from the C instance.
This C++ object should then be given to a RefPtr.
const cobject* Cairo::ScaledFont::cobj | ( | ) | const [inline] |
Provides acces to the underlying C cairo object.
cobject* Cairo::ScaledFont::cobj | ( | ) | [inline] |
Provides acces to the underlying C cairo object.
static RefPtr<ScaledFont> Cairo::ScaledFont::create | ( | FontFace & | font_face, | |
const Matrix & | font_matrix, | |||
const Matrix & | ctm, | |||
const FontOptions & | options | |||
) | [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.
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. |
void Cairo::ScaledFont::extents | ( | FontExtents & | extents | ) | const |
Gets the metrics for a ScaledFont.
void Cairo::ScaledFont::get_ctm | ( | Matrix & | ctm | ) | const |
void Cairo::ScaledFont::get_font_matrix | ( | Matrix & | font_matrix | ) | const |
void Cairo::ScaledFont::get_font_options | ( | FontOptions & | options | ) | const |
FontType Cairo::ScaledFont::get_type | ( | ) | const |
Gets the type of scaled Font.
void Cairo::ScaledFont::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).
glyphs | A vector of glyphs to calculate the extents of | |
extents | Returns the extents for the array of glyphs |
void Cairo::ScaledFont::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.
utf8 | a string of text, encoded in UTF-8 | |
extents | Returns the extents of the given string |
cobject* Cairo::ScaledFont::m_cobject [protected] |
The underlying C cairo object that is wrapped by this ScaledFont.