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hb-ot-color

hb-ot-color — OpenType Color Fonts

Functions

Types and Values

Object Hierarchy

    GFlags
    ╰── hb_ot_color_palette_flags_t

Includes

#include <hb-ot.h>

Description

Functions for fetching color-font information from OpenType font faces.

HarfBuzz supports COLR/CPAL, sbix, CBDT, and SVG color fonts.

Functions

HB_COLOR()

#define HB_COLOR(b,g,r,a) ((hb_color_t) HB_TAG ((b),(g),(r),(a)))

hb_color_get_alpha ()

uint8_t
hb_color_get_alpha (hb_color_t color);

Returns

Alpha channel value of the given color

Since: 2.1.0


hb_color_get_blue ()

uint8_t
hb_color_get_blue (hb_color_t color);

Returns

Blue channel value of the given color

Since: 2.1.0


hb_color_get_green ()

uint8_t
hb_color_get_green (hb_color_t color);

Returns

Green channel value of the given color

Since: 2.1.0


hb_color_get_red ()

uint8_t
hb_color_get_red (hb_color_t color);

Returns

Red channel value of the given color

Since: 2.1.0


hb_ot_color_glyph_get_layers ()

unsigned int
hb_ot_color_glyph_get_layers (hb_face_t *face,
                              hb_codepoint_t glyph,
                              unsigned int start_offset,
                              unsigned int *layer_count,
                              hb_ot_color_layer_t *layers);

Fetches a list of all color layers for the specified glyph index in the specified face. The list returned will begin at the offset provided.

Parameters

face

hb_face_t to work upon

 

glyph

The glyph index to query

 

start_offset

offset of the first layer to retrieve

 

layer_count

Input = the maximum number of layers to return; Output = the actual number of layers returned (may be zero).

[inout][optional]

layers

The array of layers found.

[out][array length=layer_count][nullable]

Returns

Total number of layers available for the glyph index queried

Since: 2.1.0


hb_ot_color_glyph_reference_png ()

hb_blob_t *
hb_ot_color_glyph_reference_png (hb_font_t *font,
                                 hb_codepoint_t glyph);

Fetches the PNG image for a glyph. This function takes a font object, not a face object, as input. To get an optimally sized PNG blob, the UPEM value must be set on the font object. If UPEM is unset, the blob returned will be the largest PNG available.

Parameters

font

hb_font_t to work upon

 

glyph

a glyph index

 

Returns

An hb_blob_t containing the PNG image for the glyph, if available.

[transfer full]

Since: 2.1.0


hb_ot_color_glyph_reference_svg ()

hb_blob_t *
hb_ot_color_glyph_reference_svg (hb_face_t *face,
                                 hb_codepoint_t glyph);

Fetches the SVG document for a glyph. The blob may be either plain text or gzip-encoded.

Parameters

face

hb_face_t to work upon

 

glyph

a svg glyph index

 

Returns

An hb_blob_t containing the SVG document of the glyph, if available.

[transfer full]

Since: 2.1.0


hb_ot_color_has_layers ()

hb_bool_t
hb_ot_color_has_layers (hb_face_t *face);

Tests whether a face includes any COLR color layers.

Parameters

face

hb_face_t to work upon

 

Returns

true if data found, false otherwise

Since: 2.1.0


hb_ot_color_has_palettes ()

hb_bool_t
hb_ot_color_has_palettes (hb_face_t *face);

Tests whether a face includes a CPAL color-palette table.

Parameters

face

hb_face_t to work upon

 

Returns

true if data found, false otherwise

Since: 2.1.0


hb_ot_color_has_png ()

hb_bool_t
hb_ot_color_has_png (hb_face_t *face);

Tests whether a face has PNG glyph images (either in CBDT or sbix tables).

Parameters

face

hb_face_t to work upon

 

Returns

true if data found, false otherwise

Since: 2.1.0


hb_ot_color_has_svg ()

hb_bool_t
hb_ot_color_has_svg (hb_face_t *face);

Tests whether a face includes any SVG glyph images.

Parameters

face

hb_face_t to work upon.

 

Returns

true if data found, false otherwise.

Since: 2.1.0


hb_ot_color_palette_color_get_name_id ()

hb_ot_name_id_t
hb_ot_color_palette_color_get_name_id (hb_face_t *face,
                                       unsigned int color_index);

Fetches the name table Name ID that provides display names for the specificed color in a face's CPAL color palette.

Display names can be generic (e.g., "Background") or specific (e.g., "Eye color").

Parameters

face

hb_face_t to work upon

 

color_index

The index of the color

 

Returns

the Name ID found for the color.

Since: 2.1.0


hb_ot_color_palette_get_colors ()

unsigned int
hb_ot_color_palette_get_colors (hb_face_t *face,
                                unsigned int palette_index,
                                unsigned int start_offset,
                                unsigned int *color_count,
                                hb_color_t *colors);

Fetches a list of the colors in a color palette.

After calling this function, colors will be filled with the palette colors. If colors is NULL, the function will just return the number of total colors without storing any actual colors; this can be used for allocating a buffer of suitable size before calling hb_ot_color_palette_get_colors() a second time.

Parameters

face

hb_face_t to work upon

 

palette_index

the index of the color palette to query

 

start_offset

offset of the first color to retrieve

 

color_count

Input = the maximum number of colors to return; Output = the actual number of colors returned (may be zero).

[inout][optional]

colors

The array of hb_color_t records found.

[out][array length=color_count][nullable]

Returns

the total number of colors in the palette

Since: 2.1.0


hb_ot_color_palette_get_count ()

unsigned int
hb_ot_color_palette_get_count (hb_face_t *face);

Fetches the number of color palettes in a face.

Parameters

face

hb_face_t to work upon

 

Returns

the number of palettes found

Since: 2.1.0


hb_ot_color_palette_get_flags ()

hb_ot_color_palette_flags_t
hb_ot_color_palette_get_flags (hb_face_t *face,
                               unsigned int palette_index);

Fetches the flags defined for a color palette.

Parameters

face

hb_face_t to work upon

 

palette_index

The index of the color palette

 

Returns

the hb_ot_color_palette_flags_t of the requested color palette

Since: 2.1.0


hb_ot_color_palette_get_name_id ()

hb_ot_name_id_t
hb_ot_color_palette_get_name_id (hb_face_t *face,
                                 unsigned int palette_index);

Fetches the name table Name ID that provides display names for a CPAL color palette.

Palette display names can be generic (e.g., "Default") or provide specific, themed names (e.g., "Spring", "Summer", "Fall", and "Winter").

Parameters

face

hb_face_t to work upon

 

palette_index

The index of the color palette

 

Returns

the Named ID found for the palette. If the requested palette has no name the result is HB_OT_NAME_ID_INVALID.

Since: 2.1.0

Types and Values

hb_color_t

typedef uint32_t hb_color_t;

Data type for holding color values.

Since: 2.1.0


enum hb_ot_color_palette_flags_t

Members

HB_OT_COLOR_PALETTE_FLAG_DEFAULT

Default indicating that there is nothing special to note about a color palette.

 

HB_OT_COLOR_PALETTE_FLAG_USABLE_WITH_LIGHT_BACKGROUND

Flag indicating that the color palette is appropriate to use when displaying the font on a light background such as white.

 

HB_OT_COLOR_PALETTE_FLAG_USABLE_WITH_DARK_BACKGROUND

Flag indicating that the color palette is appropriate to use when displaying the font on a dark background such as black.

 

Since: 2.1.0