hb_paint_funcs_create ()

hb_paint_funcs_t *
hb_paint_funcs_create (void);

Creates a new hb_paint_funcs_t structure of paint functions.

The initial reference count of 1 should be released with hb_paint_funcs_destroy() when you are done using the hb_paint_funcs_t. This function never returns NULL. If memory cannot be allocated, a special singleton hb_paint_funcs_t object will be returned.

Returns value: (transfer full): the paint-functions structure

Since: 7.0.0

hb_paint_funcs_get_empty ()

hb_paint_funcs_t *
hb_paint_funcs_get_empty (void);

Fetches the singleton empty paint-functions structure.

Since: 7.0.0

hb_paint_funcs_reference ()

hb_paint_funcs_t *
hb_paint_funcs_reference (hb_paint_funcs_t *funcs);

Increases the reference count on a paint-functions structure.

This prevents funcs from being destroyed until a matching call to hb_paint_funcs_destroy() is made.

[skip]

Since: 7.0.0

hb_paint_funcs_destroy ()

void
hb_paint_funcs_destroy (hb_paint_funcs_t *funcs);

Decreases the reference count on a paint-functions structure.

When the reference count reaches zero, the structure is destroyed, freeing all memory.

[skip]

Since: 7.0.0

hb_paint_funcs_set_user_data ()

hb_bool_t
hb_paint_funcs_set_user_data (hb_paint_funcs_t *funcs,
                              hb_user_data_key_t *key,
                              void *data,
                              hb_destroy_func_t destroy,
                              hb_bool_t replace);

Attaches a user-data key/data pair to the specified paint-functions structure.

[skip]

Since: 7.0.0

hb_paint_funcs_get_user_data ()

void *
hb_paint_funcs_get_user_data (const hb_paint_funcs_t *funcs,
                              hb_user_data_key_t *key);

Fetches the user-data associated with the specified key, attached to the specified paint-functions structure.

[skip]

Since: 7.0.0

hb_paint_funcs_make_immutable ()

void
hb_paint_funcs_make_immutable (hb_paint_funcs_t *funcs);

Makes a paint-functions structure immutable.

After this call, all attempts to set one of the callbacks on funcs will fail.

Since: 7.0.0

hb_paint_funcs_is_immutable ()

hb_bool_t
hb_paint_funcs_is_immutable (hb_paint_funcs_t *funcs);

Tests whether a paint-functions structure is immutable.

Since: 7.0.0

hb_paint_push_transform_func_t ()

void
(*hb_paint_push_transform_func_t) (hb_paint_funcs_t *funcs,
                                   void *paint_data,
                                   float xx,
                                   float yx,
                                   float xy,
                                   float yy,
                                   float dx,
                                   float dy,
                                   void *user_data);

A virtual method for the hb_paint_funcs_t to apply a transform to subsequent paint calls.

This transform is applied after the current transform, and remains in effect until a matching call to the hb_paint_funcs_pop_transform_func_t vfunc.

Since: 7.0.0

hb_paint_funcs_set_push_transform_func ()

void
hb_paint_funcs_set_push_transform_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_transform_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-transform callback on the paint functions struct.

Since: 7.0.0

hb_paint_pop_transform_func_t ()

void
(*hb_paint_pop_transform_func_t) (hb_paint_funcs_t *funcs,
                                  void *paint_data,
                                  void *user_data);

A virtual method for the hb_paint_funcs_t to undo the effect of a prior call to the hb_paint_funcs_push_transform_func_t vfunc.

Since: 7.0.0

hb_paint_funcs_set_pop_transform_func ()

void
hb_paint_funcs_set_pop_transform_func (hb_paint_funcs_t *funcs,
                                       hb_paint_pop_transform_func_t func,
                                       void *user_data,
                                       hb_destroy_func_t destroy);

Sets the pop-transform callback on the paint functions struct.

Since: 7.0.0

hb_paint_color_glyph_func_t ()

hb_bool_t
(*hb_paint_color_glyph_func_t) (hb_paint_funcs_t *funcs,
                                void *paint_data,
                                hb_codepoint_t glyph,
                                hb_font_t *font,
                                void *user_data);

A virtual method for the hb_paint_funcs_t to render a color glyph by glyph index.

Since: 8.2.0

hb_paint_funcs_set_color_glyph_func ()

void
hb_paint_funcs_set_color_glyph_func (hb_paint_funcs_t *funcs,
                                     hb_paint_color_glyph_func_t func,
                                     void *user_data,
                                     hb_destroy_func_t destroy);

Sets the color-glyph callback on the paint functions struct.

Since: 8.2.0

hb_paint_push_clip_glyph_func_t ()

void
(*hb_paint_push_clip_glyph_func_t) (hb_paint_funcs_t *funcs,
                                    void *paint_data,
                                    hb_codepoint_t glyph,
                                    hb_font_t *font,
                                    void *user_data);

A virtual method for the hb_paint_funcs_t to clip subsequent paint calls to the outline of a glyph.

The coordinates of the glyph outline are expected in the current font scale (ie. the results of calling hb_font_draw_glyph() with font ). The outline is transformed by the current transform.

This clip is applied in addition to the current clip, and remains in effect until a matching call to the hb_paint_funcs_pop_clip_func_t vfunc.

Since: 7.0.0

hb_paint_funcs_set_push_clip_glyph_func ()

void
hb_paint_funcs_set_push_clip_glyph_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_clip_glyph_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-clip-glyph callback on the paint functions struct.

Since: 7.0.0

hb_paint_push_clip_rectangle_func_t ()

void
(*hb_paint_push_clip_rectangle_func_t)
                               (hb_paint_funcs_t *funcs,
                                void *paint_data,
                                float xmin,
                                float ymin,
                                float xmax,
                                float ymax,
                                void *user_data);

A virtual method for the hb_paint_funcs_t to clip subsequent paint calls to a rectangle.

The coordinates of the rectangle are interpreted according to the current transform.

This clip is applied in addition to the current clip, and remains in effect until a matching call to the hb_paint_funcs_pop_clip_func_t vfunc.

Since: 7.0.0

hb_paint_funcs_set_push_clip_rectangle_func ()

void
hb_paint_funcs_set_push_clip_rectangle_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_clip_rectangle_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-clip-rect callback on the paint functions struct.

Since: 7.0.0

hb_paint_push_clip_path_start_func_t ()

hb_draw_funcs_t *
(*hb_paint_push_clip_path_start_func_t)
                               (hb_paint_funcs_t *funcs,
                                void *paint_data,
                                void **draw_data,
                                void *user_data);

A virtual method for the hb_paint_funcs_t to begin clipping to an arbitrary path. The backend returns an hb_draw_funcs_t it owns (the caller must not free it) that the caller feeds the clip outline to via hb_draw_*() calls, plus a draw_data value to pass alongside those calls. Both are only valid until the matching hb_paint_push_clip_path_end_func_t call; no other paint calls should be made in between. The clip remains in effect until a later hb_paint_pop_clip_func_t call.

Since: 14.2.0

hb_paint_funcs_set_push_clip_path_start_func ()

void
hb_paint_funcs_set_push_clip_path_start_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_clip_path_start_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-clip-path-start callback on the paint functions struct.

Since: 14.2.0

hb_paint_push_clip_path_end_func_t ()

void
(*hb_paint_push_clip_path_end_func_t) (hb_paint_funcs_t *funcs,
                                       void *paint_data,
                                       void *user_data);

A virtual method for the hb_paint_funcs_t to close the clip path started by the hb_paint_push_clip_path_start_func_t vfunc. The emitted path is now active as a clip; subsequent paint ops are masked by it until a matching hb_paint_pop_clip_func_t call.

Since: 14.2.0

hb_paint_funcs_set_push_clip_path_end_func ()

void
hb_paint_funcs_set_push_clip_path_end_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_clip_path_end_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-clip-path-end callback on the paint functions struct.

Since: 14.2.0

hb_paint_pop_clip_func_t ()

void
(*hb_paint_pop_clip_func_t) (hb_paint_funcs_t *funcs,
                             void *paint_data,
                             void *user_data);

A virtual method for the hb_paint_funcs_t to undo the effect of a prior call to the hb_paint_funcs_push_clip_glyph_func_t, hb_paint_funcs_push_clip_rectangle_func_t, or hb_paint_funcs_push_clip_path_end_func_t vfuncs.

Since: 7.0.0

hb_paint_funcs_set_pop_clip_func ()

void
hb_paint_funcs_set_pop_clip_func (hb_paint_funcs_t *funcs,
                                  hb_paint_pop_clip_func_t func,
                                  void *user_data,
                                  hb_destroy_func_t destroy);

Sets the pop-clip callback on the paint functions struct.

Since: 7.0.0

hb_paint_color_func_t ()

void
(*hb_paint_color_func_t) (hb_paint_funcs_t *funcs,
                          void *paint_data,
                          hb_bool_t is_foreground,
                          hb_color_t color,
                          void *user_data);

A virtual method for the hb_paint_funcs_t to paint a color everywhere within the current clip.

When is_foreground is true, this color originates from the foreground-color sentinel in the font's color data. The color parameter still carries a fully resolved RGBA value (with any paint-tree alpha already applied), so backends that do not need to distinguish the foreground can simply use color directly.

Backends that defer foreground resolution (e.g. to honor a CSS currentColor or a runtime uniform) should substitute their own foreground RGB when is_foreground is true, but must combine the alpha from color with their foreground alpha, since it encodes additional modulation from the paint tree. For this mode to work correctly, the caller should pass a fully-opaque foreground color to hb_font_paint_glyph(), so that the alpha in color reflects only the paint-tree contribution.

Since: 7.0.0

hb_paint_funcs_set_color_func ()

void
hb_paint_funcs_set_color_func (hb_paint_funcs_t *funcs,
                               hb_paint_color_func_t func,
                               void *user_data,
                               hb_destroy_func_t destroy);

Sets the paint-color callback on the paint functions struct.

Since: 7.0.0

hb_paint_image_func_t ()

hb_bool_t
(*hb_paint_image_func_t) (hb_paint_funcs_t *funcs,
                          void *paint_data,
                          hb_blob_t *image,
                          unsigned int width,
                          unsigned int height,
                          hb_tag_t format,
                          float slant,
                          hb_glyph_extents_t *extents,
                          void *user_data);

A virtual method for the hb_paint_funcs_t to paint a glyph image.

This method is called for glyphs with image blobs in the CBDT, sbix or SVG tables. The format identifies the kind of data that is contained in image . Possible values include HB_PAINT_IMAGE_FORMAT_PNG, HB_PAINT_IMAGE_FORMAT_SVG and HB_PAINT_IMAGE_FORMAT_BGRA.

The image dimensions and glyph extents are provided if available, and should be used to size and position the image.

Since: 7.0.0

hb_paint_funcs_set_image_func ()

void
hb_paint_funcs_set_image_func (hb_paint_funcs_t *funcs,
                               hb_paint_image_func_t func,
                               void *user_data,
                               hb_destroy_func_t destroy);

Sets the paint-image callback on the paint functions struct.

Since: 7.0.0

hb_color_line_get_color_stops_func_t ()

unsigned int
(*hb_color_line_get_color_stops_func_t)
                               (hb_color_line_t *color_line,
                                void *color_line_data,
                                unsigned int start,
                                unsigned int *count,
                                hb_color_stop_t *color_stops,
                                void *user_data);

A virtual method for the hb_color_line_t to fetch color stops.

Since: 7.0.0

hb_color_line_get_color_stops ()

unsigned int
hb_color_line_get_color_stops (hb_color_line_t *color_line,
                               unsigned int start,
                               unsigned int *count,
                               hb_color_stop_t *color_stops);

Fetches a list of color stops from the given color line object.

Note that due to variations being applied, the returned color stops may be out of order. It is the callers responsibility to ensure that color stops are sorted by their offset before they are used.

Since: 7.0.0

hb_color_line_get_extend_func_t ()

hb_paint_extend_t
(*hb_color_line_get_extend_func_t) (hb_color_line_t *color_line,
                                    void *color_line_data,
                                    void *user_data);

A virtual method for the hb_color_line_t to fetches the extend mode.

Since: 7.0.0

hb_color_line_get_extend ()

hb_paint_extend_t
hb_color_line_get_extend (hb_color_line_t *color_line);

Fetches the extend mode of the color line object.

Since: 7.0.0

hb_paint_linear_gradient_func_t ()

void
(*hb_paint_linear_gradient_func_t) (hb_paint_funcs_t *funcs,
                                    void *paint_data,
                                    hb_color_line_t *color_line,
                                    float x0,
                                    float y0,
                                    float x1,
                                    float y1,
                                    float x2,
                                    float y2,
                                    void *user_data);

A virtual method for the hb_paint_funcs_t to paint a linear gradient everywhere within the current clip.

The color_line object contains information about the colors of the gradients. It is only valid for the duration of the callback, you cannot keep it around.

The coordinates of the points are interpreted according to the current transform.

See the OpenType spec COLR section for details on how the points define the direction of the gradient, and how to interpret the color_line .

Since: 7.0.0

hb_paint_funcs_set_linear_gradient_func ()

void
hb_paint_funcs_set_linear_gradient_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_linear_gradient_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the linear-gradient callback on the paint functions struct.

Since: 7.0.0

hb_paint_radial_gradient_func_t ()

void
(*hb_paint_radial_gradient_func_t) (hb_paint_funcs_t *funcs,
                                    void *paint_data,
                                    hb_color_line_t *color_line,
                                    float x0,
                                    float y0,
                                    float r0,
                                    float x1,
                                    float y1,
                                    float r1,
                                    void *user_data);

A virtual method for the hb_paint_funcs_t to paint a radial gradient everywhere within the current clip.

The color_line object contains information about the colors of the gradients. It is only valid for the duration of the callback, you cannot keep it around.

The coordinates of the points are interpreted according to the current transform.

See the OpenType spec COLR section for details on how the points define the direction of the gradient, and how to interpret the color_line .

Since: 7.0.0

hb_paint_funcs_set_radial_gradient_func ()

void
hb_paint_funcs_set_radial_gradient_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_radial_gradient_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the radial-gradient callback on the paint functions struct.

Since: 7.0.0

hb_paint_sweep_gradient_func_t ()

void
(*hb_paint_sweep_gradient_func_t) (hb_paint_funcs_t *funcs,
                                   void *paint_data,
                                   hb_color_line_t *color_line,
                                   float x0,
                                   float y0,
                                   float start_angle,
                                   float end_angle,
                                   void *user_data);

A virtual method for the hb_paint_funcs_t to paint a sweep gradient everywhere within the current clip.

The color_line object contains information about the colors of the gradients. It is only valid for the duration of the callback, you cannot keep it around.

The coordinates of the points are interpreted according to the current transform.

See the OpenType spec COLR section for details on how the points define the direction of the gradient, and how to interpret the color_line .

Since: 7.0.0

hb_paint_funcs_set_sweep_gradient_func ()

void
hb_paint_funcs_set_sweep_gradient_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_sweep_gradient_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the sweep-gradient callback on the paint functions struct.

Since: 7.0.0

hb_paint_push_group_func_t ()

void
(*hb_paint_push_group_func_t) (hb_paint_funcs_t *funcs,
                               void *paint_data,
                               void *user_data);

A virtual method for the hb_paint_funcs_t to use an intermediate surface for subsequent paint calls.

The drawing will be redirected to an intermediate surface until a matching call to the hb_paint_funcs_pop_group_func_t vfunc.

Since: 7.0.0

hb_paint_funcs_set_push_group_func ()

void
hb_paint_funcs_set_push_group_func (hb_paint_funcs_t *funcs,
                                    hb_paint_push_group_func_t func,
                                    void *user_data,
                                    hb_destroy_func_t destroy);

Sets the push-group callback on the paint functions struct.

Since: 7.0.0

hb_paint_push_group_for_func_t ()

void
(*hb_paint_push_group_for_func_t) (hb_paint_funcs_t *funcs,
                                   void *paint_data,
                                   hb_paint_composite_mode_t mode,
                                   void *user_data);

A virtual method for the hb_paint_funcs_t to use an intermediate surface for subsequent paint calls, with the compositing mode known in advance.

This is like hb_paint_push_group_func_t, but the compositing mode is provided at push time. By default this calls hb_paint_push_group_func_t.

Since: 14.2.0

hb_paint_funcs_set_push_group_for_func ()

void
hb_paint_funcs_set_push_group_for_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_push_group_for_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the push-group-for callback on the paint functions struct.

Since: 14.2.0

hb_paint_pop_group_func_t ()

void
(*hb_paint_pop_group_func_t) (hb_paint_funcs_t *funcs,
                              void *paint_data,
                              hb_paint_composite_mode_t mode,
                              void *user_data);

A virtual method for the hb_paint_funcs_t to undo the effect of a prior call to the hb_paint_funcs_push_group_func_t vfunc.

This call stops the redirection to the intermediate surface, and then composites it on the previous surface, using the compositing mode passed to this call.

Since: 7.0.0

hb_paint_funcs_set_pop_group_func ()

void
hb_paint_funcs_set_pop_group_func (hb_paint_funcs_t *funcs,
                                   hb_paint_pop_group_func_t func,
                                   void *user_data,
                                   hb_destroy_func_t destroy);

Sets the pop-group callback on the paint functions struct.

Since: 7.0.0

hb_paint_custom_palette_color_func_t ()

hb_bool_t
(*hb_paint_custom_palette_color_func_t)
                               (hb_paint_funcs_t *funcs,
                                void *paint_data,
                                unsigned int color_index,
                                hb_color_t *color,
                                void *user_data);

A virtual method for hb_paint_funcs_t to fetch a custom palette override color for color_index .

Custom palette colors override colors from the font's selected color palette. It is not necessary to override all palette entries; return false for entries that should be taken from the font palette.

This function might be called multiple times, but the custom palette is expected to remain unchanged for the duration of one hb_font_paint_glyph() call.

Since: 7.0.0

hb_paint_funcs_set_custom_palette_color_func ()

void
hb_paint_funcs_set_custom_palette_color_func
                               (hb_paint_funcs_t *funcs,
                                hb_paint_custom_palette_color_func_t func,
                                void *user_data,
                                hb_destroy_func_t destroy);

Sets the custom-palette-color callback on funcs .

Since: 7.0.0

hb_paint_push_transform ()

void
hb_paint_push_transform (hb_paint_funcs_t *funcs,
                         void *paint_data,
                         float xx,
                         float yx,
                         float xy,
                         float yy,
                         float dx,
                         float dy);

Perform a "push-transform" paint operation.

Since: 7.0.0

hb_paint_push_font_transform ()

void
hb_paint_push_font_transform (hb_paint_funcs_t *funcs,
                              void *paint_data,
                              const hb_font_t *font);

Push the transform reflecting the font's scale and slant settings onto the paint functions.

Since: 11.0.0

hb_paint_push_inverse_font_transform ()

void
hb_paint_push_inverse_font_transform (hb_paint_funcs_t *funcs,
                                      void *paint_data,
                                      const hb_font_t *font);

Push the inverse of the transform reflecting the font's scale and slant settings onto the paint functions.

Since: 11.0.0

hb_paint_pop_transform ()

void
hb_paint_pop_transform (hb_paint_funcs_t *funcs,
                        void *paint_data);

Perform a "pop-transform" paint operation.

Since: 7.0.0

hb_paint_color_glyph ()

hb_bool_t
hb_paint_color_glyph (hb_paint_funcs_t *funcs,
                      void *paint_data,
                      hb_codepoint_t glyph,
                      hb_font_t *font);

Perform a "color-glyph" paint operation.

Since: 8.2.0

hb_paint_push_clip_glyph ()

void
hb_paint_push_clip_glyph (hb_paint_funcs_t *funcs,
                          void *paint_data,
                          hb_codepoint_t glyph,
                          hb_font_t *font);

Perform a "push-clip-glyph" paint operation.

Since: 7.0.0

hb_paint_push_clip_rectangle ()

void
hb_paint_push_clip_rectangle (hb_paint_funcs_t *funcs,
                              void *paint_data,
                              float xmin,
                              float ymin,
                              float xmax,
                              float ymax);

Perform a "push-clip-rect" paint operation.

Since: 7.0.0

hb_paint_push_clip_path_start ()

hb_draw_funcs_t *
hb_paint_push_clip_path_start (hb_paint_funcs_t *funcs,
                               void *paint_data,
                               void **draw_data);

Begin clipping to an arbitrary path. Returns an hb_draw_funcs_t owned by the backend (the caller must not free it) that the caller uses to emit the clip outline via hb_draw_*() calls, using the returned draw_data as the draw data. The returned draw funcs and draw data are only valid until the matching hb_paint_push_clip_path_end() call; no other paint calls should be made between start and end except hb_draw_*() on the returned funcs. Finish the path with hb_paint_push_clip_path_end(); pop the clip later with hb_paint_pop_clip().

Usage:

hb_draw_funcs_t *df = hb_paint_push_clip_path_start (pf, pd, &dd);
hb_draw_move_to (df, dd, NULL, ...);
hb_draw_line_to (df, dd, NULL, ...);
...
hb_draw_close_path (df, dd, NULL);
hb_paint_push_clip_path_end (pf, pd);
/* paint ops here are clipped to the emitted path */
hb_paint_pop_clip (pf, pd);

Since: 14.2.0

hb_paint_push_clip_path_end ()

void
hb_paint_push_clip_path_end (hb_paint_funcs_t *funcs,
                             void *paint_data);

Signal that the arbitrary-clip path started by hb_paint_push_clip_path_start() is fully drawn. The accumulated path now acts as a clip on the paint context until a matching hb_paint_pop_clip() call.

Since: 14.2.0

hb_paint_pop_clip ()

void
hb_paint_pop_clip (hb_paint_funcs_t *funcs,
                   void *paint_data);

Perform a "pop-clip" paint operation.

Since: 7.0.0

hb_paint_color ()

void
hb_paint_color (hb_paint_funcs_t *funcs,
                void *paint_data,
                hb_bool_t is_foreground,
                hb_color_t color);

Perform a "color" paint operation.

Since: 7.0.0

hb_paint_image ()

void
hb_paint_image (hb_paint_funcs_t *funcs,
                void *paint_data,
                hb_blob_t *image,
                unsigned int width,
                unsigned int height,
                hb_tag_t format,
                float slant,
                hb_glyph_extents_t *extents);

Perform a "image" paint operation.

Since: 7.0.0

hb_paint_linear_gradient ()

void
hb_paint_linear_gradient (hb_paint_funcs_t *funcs,
                          void *paint_data,
                          hb_color_line_t *color_line,
                          float x0,
                          float y0,
                          float x1,
                          float y1,
                          float x2,
                          float y2);

Perform a "linear-gradient" paint operation.

Since: 7.0.0

hb_paint_radial_gradient ()

void
hb_paint_radial_gradient (hb_paint_funcs_t *funcs,
                          void *paint_data,
                          hb_color_line_t *color_line,
                          float x0,
                          float y0,
                          float r0,
                          float x1,
                          float y1,
                          float r1);

Perform a "radial-gradient" paint operation.

Since: 7.0.0

hb_paint_sweep_gradient ()

void
hb_paint_sweep_gradient (hb_paint_funcs_t *funcs,
                         void *paint_data,
                         hb_color_line_t *color_line,
                         float x0,
                         float y0,
                         float start_angle,
                         float end_angle);

Perform a "sweep-gradient" paint operation.

Since: 7.0.0

hb_paint_push_group ()

void
hb_paint_push_group (hb_paint_funcs_t *funcs,
                     void *paint_data);

Perform a "push-group" paint operation.

Since: 7.0.0

hb_paint_push_group_for ()

void
hb_paint_push_group_for (hb_paint_funcs_t *funcs,
                         void *paint_data,
                         hb_paint_composite_mode_t mode);

Perform a "push-group" paint operation, with the compositing mode known in advance. By default, this calls hb_paint_push_group().

Since: 14.2.0

hb_paint_pop_group ()

void
hb_paint_pop_group (hb_paint_funcs_t *funcs,
                    void *paint_data,
                    hb_paint_composite_mode_t mode);

Perform a "pop-group" paint operation.

Since: 7.0.0

hb_paint_custom_palette_color ()

hb_bool_t
hb_paint_custom_palette_color (hb_paint_funcs_t *funcs,
                               void *paint_data,
                               unsigned int color_index,
                               hb_color_t *color);

Gets the custom palette override color for color_index .

Since: 7.0.0

hb_paint_reduce_linear_anchors ()

void
hb_paint_reduce_linear_anchors (float x0,
                                float y0,
                                float x1,
                                float y1,
                                float x2,
                                float y2,
                                float *xx0,
                                float *yy0,
                                float *xx1,
                                float *yy1);

Reduces a COLRv1 linear gradient's 3-anchor spec (P0=color stop 0, P1=color stop 1, P2=rotation reference) to the 2-point axis (P0, P1') used by SVG / cairo / most software renderers. P1' is the foot of P1 on the line through P0 perpendicular to (P2 - P0); the resulting axis is the gradient's actual direction (perpendicular to the rotation line). Degenerate (P0 == P2) passes through unchanged.

Since: 14.2.0

hb_paint_normalize_color_line ()

void
hb_paint_normalize_color_line (hb_color_stop_t *stops,
                               unsigned int len,
                               float *min,
                               float *max);

Sorts stops by offset and rescales offsets into [0, 1] in place. Writes the original (min, max) to min / max so the caller can shift the gradient geometry (axis endpoints for linear, centers+radii for radial, start+end angles for sweep) to keep the rendered gradient visually unchanged after the rescale. Empty input is safe: both out-parameters set to 0.

Since: 14.2.0

hb_paint_sweep_gradient_tile_func_t ()

void
(*hb_paint_sweep_gradient_tile_func_t)
                               (float a0,
                                hb_color_t c0,
                                float a1,
                                hb_color_t c1,
                                void *user_data);

Callback invoked once per (a0, a1) sector of a sweep gradient tiling. See hb_paint_sweep_gradient_tiles().

Since: 14.2.0

hb_paint_sweep_gradient_tiles ()

void
hb_paint_sweep_gradient_tiles (hb_color_stop_t *stops,
                               unsigned int n_stops,
                               hb_paint_extend_t extend,
                               float start_angle,
                               float end_angle,
                               hb_paint_sweep_gradient_tile_func_t emit_patch,
                               void *user_data);

Iterates the full 0..2π sweep produced by a color-stop list, invoking emit_patch once per (start, end) angular segment. Handles HB_PAINT_EXTEND_PAD, HB_PAINT_EXTEND_REPEAT, and HB_PAINT_EXTEND_REFLECT. Stops must be pre-sorted by offset; use hb_paint_normalize_color_line() first if they aren't.

Since: 14.2.0

hb_paint_funcs_t

typedef struct hb_paint_funcs_t hb_paint_funcs_t;

Glyph paint callbacks.

The callbacks assume that the caller maintains a stack of current transforms, clips and intermediate surfaces, as evidenced by the pairs of push/pop callbacks. The push/pop calls will be properly nested, so it is fine to store the different kinds of object on a single stack.

Not all callbacks are required for all kinds of glyphs. For rendering COLRv0 or non-color outline glyphs, the gradient callbacks are not needed, and the composite callback only needs to handle simple alpha compositing (HB_PAINT_COMPOSITE_MODE_SRC_OVER).

The paint-image callback is only needed for glyphs with image blobs in the CBDT, sbix or SVG tables.

The custom-palette-color callback is only necessary if you want to override colors from the font palette with custom colors.

Since: 7.0.0

HB_PAINT_IMAGE_FORMAT_PNG

#define HB_PAINT_IMAGE_FORMAT_PNG HB_TAG('p','n','g',' ')

Tag identifying PNG images in hb_paint_image_func_t callbacks.

Since: 7.0.0

HB_PAINT_IMAGE_FORMAT_SVG

#define HB_PAINT_IMAGE_FORMAT_SVG HB_TAG('s','v','g',' ')

Tag identifying SVG images in hb_paint_image_func_t callbacks.

Since: 7.0.0

HB_PAINT_IMAGE_FORMAT_BGRA

#define HB_PAINT_IMAGE_FORMAT_BGRA HB_TAG('B','G','R','A')

Tag identifying raw pixel-data images in hb_paint_image_func_t callbacks. The data is in BGRA pre-multiplied sRGBA color-space format.

Since: 7.0.0

hb_color_line_t

typedef struct hb_color_line_t hb_color_line_t;

A struct containing color information for a gradient.

Since: 7.0.0

hb_color_stop_t

typedef struct {
  float offset;
  hb_bool_t is_foreground;
  hb_color_t color;
} hb_color_stop_t;

Information about a color stop on a color line.

Color lines typically have offsets ranging between 0 and 1, but that is not required.

The is_foreground and color fields have the same semantics as in hb_paint_color_func_t.

Note: despite color being unpremultiplied here, interpolation in gradients shall happen in premultiplied space. See the OpenType spec COLR section for details.

Since: 7.0.0

enum hb_paint_extend_t

The values of this enumeration determine how color values outside the minimum and maximum defined offset on a hb_color_line_t are determined.

See the OpenType spec COLR section for details.

Since: 7.0.0

enum hb_paint_composite_mode_t

The values of this enumeration describe the compositing modes that can be used when combining temporary redirected drawing with the backdrop.

See the OpenType spec COLR section for details.

Since: 7.0.0