FreeType Fonts

FreeType Fonts — Font support for FreeType

Synopsis




cairo_font_face_t* cairo_ft_font_face_create_for_ft_face
                                            (FT_Face face,
                                             int load_flags);
cairo_font_face_t* cairo_ft_font_face_create_for_pattern
                                            (FcPattern *pattern);
void        cairo_ft_font_options_substitute
                                            (const cairo_font_options_t *options,
                                             FcPattern *pattern);
FT_Face     cairo_ft_scaled_font_lock_face  (cairo_scaled_font_t *scaled_font);
void        cairo_ft_scaled_font_unlock_face
                                            (cairo_scaled_font_t *scaled_font);

Description

Details

cairo_ft_font_face_create_for_ft_face ()

cairo_font_face_t* cairo_ft_font_face_create_for_ft_face
                                            (FT_Face face,
                                             int load_flags);

Creates a new font face for the FreeType font backend from a pre-opened FreeType face. This font can then be used with cairo_set_font_face() or cairo_font_create(). The cairo_scaled_font_t returned from cairo_font_create() is also for the FreeType backend and can be used with functions such as cairo_ft_font_lock_face().

`face` :	A FreeType face object, already opened. This must be kept around until the face's ref_count drops to zero and it is freed. Since the face may be referenced internally to Cairo, the best way to determine when it is safe to free the face is to pass a cairo_destroy_func_t to `cairo_font_face_set_user_data()`
`load_flags` :	flags to pass to FT_Load_Glyph when loading glyphs from the font. These flags are OR'ed together with the flags derived from the cairo_font_options_t passed to `cairo_scaled_font_create()`, so only a few values such as `FT_LOAD_VERTICAL_LAYOUT`, and `FT_LOAD_FORCE_AUTOHINT` are useful. You should not pass any of the flags affecting the load target, such as `FT_LOAD_TARGET_LIGHT`.
Returns :	a newly created cairo_font_face_t. Free with `cairo_font_face_destroy()` when you are done using it.

cairo_ft_font_face_create_for_pattern ()

cairo_font_face_t* cairo_ft_font_face_create_for_pattern
                                            (FcPattern *pattern);

Creates a new font face for the FreeType font backend based on a fontconfig pattern. This font can then be used with cairo_set_font_face() or cairo_font_create(). The cairo_scaled_font_t returned from cairo_font_create() is also for the FreeType backend and can be used with functions such as cairo_ft_font_lock_face().

Font rendering options are representated both here and when you call cairo_scaled_font_create(). Font options that have a representation in a FcPattern must be passed in here; to modify FcPattern appropriately to reflect the options in a cairo_font_options_t, call cairo_ft_font_options_substitute().

`pattern` :	A fully resolved fontconfig pattern. A pattern can be resolved, by, among other things, calling `FcConfigSubstitute()`, `FcDefaultSubstitute()`, then `FcFontMatch()`. Cairo will call `FcPatternReference()` on this pattern, so you should not further modify the pattern, but you can release your reference to the pattern with `FcPatternDestroy()` if you no longer need to access it.
Returns :	a newly created cairo_font_face_t. Free with `cairo_font_face_destroy()` when you are done using it.

cairo_ft_font_options_substitute ()

void        cairo_ft_font_options_substitute
                                            (const cairo_font_options_t *options,
                                             FcPattern *pattern);

Add options to a FcPattern based on a cairo_font_options_t font options object. Options that are already in the pattern, are not overriden, so you should call this function after calling FcConfigSubstitute() (the user's settings should override options based on the surface type), but before calling FcDefaultSubstitute().

`options` :	a cairo_font_options_t object
`pattern` :	an existing FcPattern

cairo_ft_scaled_font_lock_face ()

FT_Face     cairo_ft_scaled_font_lock_face  (cairo_scaled_font_t *scaled_font);

cairo_ft_font_lock_face() gets the FT_Face object from a FreeType backend font and scales it appropriately for the font. You must release the face with cairo_ft_font_unlock_face() when you are done using it. Since the FT_Face object can be shared between multiple cairo_scaled_font_t objects, you must not lock any other font objects until you unlock this one. A count is kept of the number of times cairo_ft_font_lock_face() is called. cairo_ft_font_unlock_face() must be called the same number of times.

You must be careful when using this function in a library or in a threaded application, because other threads may lock faces that share the same FT_Face object. For this reason, you must call cairo_ft_lock() before locking any face objects, and cairo_ft_unlock() after you are done. (These functions are not yet implemented, so this function cannot be currently safely used in a threaded application.)

`scaled_font` :	A cairo_scaled_font_t from the FreeType font backend. Such an object can be created by calling `cairo_scaled_font_create()` on a FreeType backend font face (see `cairo_ft_font_face_create_for_pattern()`, `cairo_ft_font_face_create_for_face()`).
Returns :	The FT_Face object for `font`, scaled appropriately, or `NULL` if `scaled_font` is in an error state (see `cairo_scaled_font_status()`) or there is insufficient memory.

cairo_ft_scaled_font_unlock_face ()

void        cairo_ft_scaled_font_unlock_face
                                            (cairo_scaled_font_t *scaled_font);

Releases a face obtained with cairo_ft_scaled_font_lock_face().

scaled_font : A cairo_scaled_font_t from the FreeType font backend. Such an object can be created by calling cairo_scaled_font_create() on a FreeType backend font face (see cairo_ft_font_face_create_for_pattern(), cairo_ft_font_face_create_for_ft_face()).