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Functions
cairo_font_face_t * | hb_cairo_font_face_create_for_font () |
hb_font_t * | hb_cairo_font_face_get_font () |
cairo_font_face_t * | hb_cairo_font_face_create_for_face () |
hb_face_t * | hb_cairo_font_face_get_face () |
hb_font_t * | (*hb_cairo_font_init_func_t) () |
void | hb_cairo_font_face_set_font_init_func () |
hb_font_t * | hb_cairo_scaled_font_get_font () |
void | hb_cairo_font_face_set_scale_factor () |
unsigned int | hb_cairo_font_face_get_scale_factor () |
void | hb_cairo_glyphs_from_buffer () |
Description
Functions for using HarfBuzz with the cairo library.
HarfBuzz supports using cairo for rendering.
Functions
hb_cairo_font_face_create_for_font ()
cairo_font_face_t *
hb_cairo_font_face_create_for_font (hb_font_t *font
);
Creates a cairo_font_face_t for rendering text according
to font
.
Note that the scale of font
does not affect the rendering,
but the variations and slant that are set on font
do.
Since: 7.0.0
hb_cairo_font_face_get_font ()
hb_font_t *
hb_cairo_font_face_get_font (cairo_font_face_t *font_face
);
Gets the hb_font_t that font_face
was created from.
Since: 7.0.0
hb_cairo_font_face_create_for_face ()
cairo_font_face_t *
hb_cairo_font_face_create_for_face (hb_face_t *face
);
Creates a cairo_font_face_t for rendering text according
to face
.
Since: 7.0.0
hb_cairo_font_face_get_face ()
hb_face_t *
hb_cairo_font_face_get_face (cairo_font_face_t *font_face
);
Gets the hb_face_t associated with font_face
.
Since: 7.0.0
hb_cairo_font_init_func_t ()
hb_font_t * (*hb_cairo_font_init_func_t) (hb_font_t *font
,cairo_scaled_font_t *scaled_font
,void *user_data
);
The type of a virtual method to be called when a cairo
face created using hb_cairo_font_face_create_for_face()
creates an hb_font_t for a cairo_scaled_font_t.
Parameters
font |
The hb_font_t being created |
|
scaled_font |
The respective cairo_scaled_font_t |
|
user_data |
User data accompanying this method |
Since: 7.0.0
hb_cairo_font_face_set_font_init_func ()
void hb_cairo_font_face_set_font_init_func (cairo_font_face_t *font_face
,hb_cairo_font_init_func_t func
,void *user_data
,hb_destroy_func_t destroy
);
Set the virtual method to be called when a cairo
face created using hb_cairo_font_face_create_for_face()
creates an hb_font_t for a cairo_scaled_font_t.
Parameters
font_face |
a cairo_font_face_t |
|
func |
The virtual method to use |
|
user_data |
user data accompanying the method |
|
destroy |
function to call when |
Since: 7.0.0
hb_cairo_scaled_font_get_font ()
hb_font_t *
hb_cairo_scaled_font_get_font (cairo_scaled_font_t *scaled_font
);
Gets the hb_font_t associated with scaled_font
.
Since: 7.0.0
hb_cairo_font_face_set_scale_factor ()
void hb_cairo_font_face_set_scale_factor (cairo_font_face_t *font_face
,unsigned int scale_factor
);
Sets the scale factor of the font_face
. Default scale
factor is zero.
When a cairo_font_face_t is created from a hb_face_t using
hb_cairo_font_face_create_for_face()
, such face will create
hb_font_t objects during scaled-font creation. The scale
factor defines how the scale set on such hb_font_t objects
relates to the font-matrix (as such font size) of the cairo
scaled-font.
If the scale-factor is zero (default), then the scale of the hb_font_t object will be left at default, which is the UPEM value of the respective hb_face_t.
If the scale-factor is set to non-zero, then the X and Y scale
of the hb_font_t object will be respectively set to the
scale_factor
times the xx and yy elements of the scale-matrix
of the cairo scaled-font being created.
When using the hb_cairo_glyphs_from_buffer()
API to convert the
HarfBuzz glyph buffer that resulted from shaping with such a hb_font_t,
if the scale-factor was non-zero, you can pass it directly to
that API as both X and Y scale factors.
If the scale-factor was zero however, or the cairo face was
created using the alternative constructor
hb_cairo_font_face_create_for_font()
, you need to calculate the
correct X/Y scale-factors to pass to hb_cairo_glyphs_from_buffer()
by dividing the hb_font_t X/Y scale-factors by the
cairo scaled-font's scale-matrix XX/YY components respectively
and use those values. Or if you know that relationship offhand
(because you set the scale of the hb_font_t yourself), use
the conversion rate involved.
Since: 7.0.0
hb_cairo_font_face_get_scale_factor ()
unsigned int
hb_cairo_font_face_get_scale_factor (cairo_font_face_t *font_face
);
Gets the scale factor set on the font_face
. Defaults to zero.
See hb_cairo_font_face_set_scale_factor()
for details.
Since: 7.0.0
hb_cairo_glyphs_from_buffer ()
void hb_cairo_glyphs_from_buffer (hb_buffer_t *buffer
,hb_bool_t utf8_clusters
,double x_scale_factor
,double y_scale_factor
,double x
,double y
,const char *utf8
,int utf8_len
,cairo_glyph_t **glyphs
,unsigned int *num_glyphs
,cairo_text_cluster_t **clusters
,unsigned int *num_clusters
,cairo_text_cluster_flags_t *cluster_flags
);
Extracts information from buffer
in a form that can be
passed to cairo_show_text_glyphs()
or cairo_show_glyphs()
.
This API is modeled after cairo_scaled_font_text_to_glyphs()
and
cairo_user_scaled_font_text_to_glyphs_func_t.
The num_glyphs
argument should be preset to the number of glyph entries available
in the glyphs
buffer. If the glyphs
buffer is NULL
, the value of
num_glyphs
must be zero. If the provided glyph array is too short for
the conversion (or for convenience), a new glyph array may be allocated
using cairo_glyph_allocate()
and placed in glyphs
. Upon return,
num_glyphs
should contain the number of generated glyphs. If the value
glyphs
points at has changed after the call, the caller will free the
allocated glyph array using cairo_glyph_free()
. The caller will also free
the original value of glyphs
, so this function shouldn't do so.
If clusters
is not NULL
, then num_clusters
and cluster_flags
should not be either, and utf8
must be provided, and cluster
mapping will be computed. The semantics of how
cluster array allocation works is similar to the glyph array. That is,
if clusters
initially points to a non-NULL
value, that array may be used
as a cluster buffer, and num_clusters
points to the number of cluster
entries available there. If the provided cluster array is too short for
the conversion (or for convenience), a new cluster array may be allocated
using cairo_text_cluster_allocate()
and placed in clusters
. In this case,
the original value of clusters
will still be freed by the caller. Upon
return, num_clusters
will contain the number of generated clusters.
If the value clusters
points at has changed after the call, the caller
will free the allocated cluster array using cairo_text_cluster_free()
.
See hb_cairo_font_face_set_scale_factor()
for the details of
the scale_factor
argument.
The returned glyphs
vector actually has @num_glyphs + 1
entries in
it and the x,y values of the extra entry at the end add up the advance
x,y of all the glyphs in the buffer
.
Parameters
buffer |
a hb_buffer_t containing glyphs |
|
utf8_clusters |
|
|
x_scale_factor |
scale factor to divide hb_position_t Y values by |
|
y_scale_factor |
scale factor to divide hb_position_t X values by |
|
x |
X position to place first glyph |
|
y |
Y position to place first glyph |
|
utf8 |
the text that was shaped in |
[nullable] |
utf8_len |
the length of |
|
glyphs |
return location for an array of cairo_glyph_t. |
[out] |
num_glyphs |
return location for the length of |
[inout] |
clusters |
return location for an array of cluster positions. |
[out][nullable] |
num_clusters |
return location for the length of |
[inout][nullable] |
cluster_flags |
return location for cluster flags. |
[out][nullable] |
Since: 7.0.0