HB_TAG()

#define HB_TAG(c1,c2,c3,c4) ((hb_tag_t)((((uint32_t)(c1)&0xFF)<<24)|(((uint32_t)(c2)&0xFF)<<16)|(((uint32_t)(c3)&0xFF)<<8)|((uint32_t)(c4)&0xFF)))

Constructs an hb_tag_t from four character literals.

HB_UNTAG()

#define HB_UNTAG(tag)   (uint8_t)(((tag)>>24)&0xFF), (uint8_t)(((tag)>>16)&0xFF), (uint8_t)(((tag)>>8)&0xFF), (uint8_t)((tag)&0xFF)

Extracts four character literals from an hb_tag_t.

Since: 0.6.0

hb_tag_from_string ()

hb_tag_t
hb_tag_from_string (const char *str,
                    int len);

Converts a string into an hb_tag_t. Valid tags are four characters. Shorter input strings will be padded with spaces. Longer input strings will be truncated.

Since: 0.9.2

hb_tag_to_string ()

void
hb_tag_to_string (hb_tag_t tag,
                  char *buf);

Converts an hb_tag_t to a string and returns it in buf . Strings will be four characters long.

Since: 0.9.5

hb_direction_from_string ()

hb_direction_t
hb_direction_from_string (const char *str,
                          int len);

Converts a string to an hb_direction_t.

Matching is loose and applies only to the first letter. For examples, "LTR" and "left-to-right" will both return HB_DIRECTION_LTR.

Unmatched strings will return HB_DIRECTION_INVALID.

Since: 0.9.2

hb_direction_to_string ()

const char *
hb_direction_to_string (hb_direction_t direction);

Converts an hb_direction_t to a string.

Since: 0.9.2

HB_DIRECTION_REVERSE()

#define HB_DIRECTION_REVERSE(dir) ((hb_direction_t) (((unsigned int) (dir)) ^ 1))

Reverses a text direction. Requires that the direction be valid.

HB_DIRECTION_IS_BACKWARD()

#define HB_DIRECTION_IS_BACKWARD(dir) ((((unsigned int) (dir)) & ~2U) == 5)

Tests whether a text direction moves backward (from right to left, or from bottom to top). Requires that the direction be valid.

HB_DIRECTION_IS_FORWARD()

#define HB_DIRECTION_IS_FORWARD(dir) ((((unsigned int) (dir)) & ~2U) == 4)

Tests whether a text direction moves forward (from left to right, or from top to bottom). Requires that the direction be valid.

HB_DIRECTION_IS_HORIZONTAL()

#define HB_DIRECTION_IS_HORIZONTAL(dir) ((((unsigned int) (dir)) & ~1U) == 4)

Tests whether a text direction is horizontal. Requires that the direction be valid.

HB_DIRECTION_IS_VALID()

#define HB_DIRECTION_IS_VALID(dir) ((((unsigned int) (dir)) & ~3U) == 4)

Tests whether a text direction is valid.

HB_DIRECTION_IS_VERTICAL()

#define HB_DIRECTION_IS_VERTICAL(dir) ((((unsigned int) (dir)) & ~1U) == 6)

Tests whether a text direction is vertical. Requires that the direction be valid.

hb_script_from_iso15924_tag ()

hb_script_t
hb_script_from_iso15924_tag (hb_tag_t tag);

Converts an ISO 15924 script tag to a corresponding hb_script_t.

Since: 0.9.2

hb_script_to_iso15924_tag ()

hb_tag_t
hb_script_to_iso15924_tag (hb_script_t script);

Converts an hb_script_t to a corresponding ISO 15924 script tag.

Since: 0.9.2

hb_script_from_string ()

hb_script_t
hb_script_from_string (const char *str,
                       int len);

Converts a string str representing an ISO 15924 script tag to a corresponding hb_script_t. Shorthand for hb_tag_from_string() then hb_script_from_iso15924_tag().

Since: 0.9.2

hb_script_get_horizontal_direction ()

hb_direction_t
hb_script_get_horizontal_direction (hb_script_t script);

Fetches the hb_direction_t of a script when it is set horizontally. All right-to-left scripts will return HB_DIRECTION_RTL. All left-to-right scripts will return HB_DIRECTION_LTR. Scripts that can be written either horizontally or vertically will return HB_DIRECTION_INVALID. Unknown scripts will return HB_DIRECTION_LTR.

Since: 0.9.2

hb_language_from_string ()

hb_language_t
hb_language_from_string (const char *str,
                         int len);

Converts str representing a BCP 47 language tag to the corresponding hb_language_t.

Since: 0.9.2

hb_language_to_string ()

const char *
hb_language_to_string (hb_language_t language);

Converts an hb_language_t to a string.

Since: 0.9.2

hb_language_get_default ()

hb_language_t
hb_language_get_default (void);

Fetch the default language from current locale.

Since: 0.9.2

hb_language_matches ()

hb_bool_t
hb_language_matches (hb_language_t language,
                     hb_language_t specific);

Check whether a second language tag is the same or a more specific version of the provided language tag. For example, "fa_IR.utf8" is a more specific tag for "fa" or for "fa_IR".

Since: 5.0.0

hb_feature_from_string ()

hb_bool_t
hb_feature_from_string (const char *str,
                        int len,
                        hb_feature_t *feature);

Parses a string into a hb_feature_t.

The format for specifying feature strings follows. All valid CSS font-feature-settings values other than 'normal' and the global values are also accepted, though not documented below. CSS string escapes are not supported.

The range indices refer to the positions between Unicode characters. The position before the first character is always 0.

The format is Python-esque. Here is how it all works:

Since: 0.9.5

hb_feature_to_string ()

void
hb_feature_to_string (hb_feature_t *feature,
                      char *buf,
                      unsigned int size);

Converts a hb_feature_t into a NULL-terminated string in the format understood by hb_feature_from_string(). The client in responsible for allocating big enough size for buf , 128 bytes is more than enough.

Since: 0.9.5

hb_variation_from_string ()

hb_bool_t
hb_variation_from_string (const char *str,
                          int len,
                          hb_variation_t *variation);

Parses a string into a hb_variation_t.

The format for specifying variation settings follows. All valid CSS font-variation-settings values other than 'normal' and 'inherited' are also accepted, though, not documented below.

The format is a tag, optionally followed by an equals sign, followed by a number. For example wght=500, or slnt=-7.5.

Since: 1.4.2

hb_variation_to_string ()

void
hb_variation_to_string (hb_variation_t *variation,
                        char *buf,
                        unsigned int size);

Converts an hb_variation_t into a NULL-terminated string in the format understood by hb_variation_from_string(). The client in responsible for allocating big enough size for buf , 128 bytes is more than enough.

Since: 1.4.2

hb_destroy_func_t ()

void
(*hb_destroy_func_t) (void *user_data);

A virtual method for destroy user-data callbacks.

hb_bool_t

typedef int hb_bool_t;

Data type for booleans.

hb_codepoint_t

typedef uint32_t hb_codepoint_t;

Data type for holding Unicode codepoints. Also used to hold glyph IDs.

HB_CODEPOINT_INVALID

#define HB_CODEPOINT_INVALID ((hb_codepoint_t) -1)

Unused hb_codepoint_t value.

Since: 8.0.0

enum hb_direction_t

The direction of a text segment or buffer.

A segment can also be tested for horizontal or vertical orientation (irrespective of specific direction) with HB_DIRECTION_IS_HORIZONTAL() or HB_DIRECTION_IS_VERTICAL().

hb_language_t

typedef const struct hb_language_impl_t *hb_language_t;

Data type for languages. Each hb_language_t corresponds to a BCP 47 language tag.

hb_feature_t

typedef struct {
  hb_tag_t      tag;
  uint32_t      value;
  unsigned int  start;
  unsigned int  end;
} hb_feature_t;

The hb_feature_t is the structure that holds information about requested feature application. The feature will be applied with the given value to all glyphs which are in clusters between start (inclusive) and end (exclusive). Setting start to HB_FEATURE_GLOBAL_START and end to HB_FEATURE_GLOBAL_END specifies that the feature always applies to the entire buffer.

hb_variation_t

typedef struct {
  hb_tag_t tag;
  float    value;
} hb_variation_t;

Data type for holding variation data. Registered OpenType variation-axis tags are listed in OpenType Axis Tag Registry.

Since: 1.4.2

hb_mask_t

typedef uint32_t hb_mask_t;

Data type for bitmasks.

hb_position_t

typedef int32_t hb_position_t;

Data type for holding a single coordinate value. Contour points and other multi-dimensional data are stored as tuples of hb_position_t's.

hb_tag_t

typedef uint32_t hb_tag_t;

Data type for tag identifiers. Tags are four byte integers, each byte representing a character.

Tags are used to identify tables, design-variation axes, scripts, languages, font features, and baselines with human-readable names.

enum hb_script_t

Data type for scripts. Each hb_script_t's value is an hb_tag_t corresponding to the four-letter values defined by ISO 15924.

See also the Script (sc) property of the Unicode Character Database.

hb_user_data_key_t

typedef struct {
} hb_user_data_key_t;

Data structure for holding user-data keys.

HB_TAG_NONE

#define HB_TAG_NONE HB_TAG(0,0,0,0)

Unset hb_tag_t.

HB_TAG_MAX

#define HB_TAG_MAX HB_TAG(0xff,0xff,0xff,0xff)

Maximum possible unsigned hb_tag_t.

Since: 0.9.26

HB_TAG_MAX_SIGNED

#define HB_TAG_MAX_SIGNED HB_TAG(0x7f,0xff,0xff,0xff)

Maximum possible signed hb_tag_t.

Since: 0.9.33

HB_LANGUAGE_INVALID

#define HB_LANGUAGE_INVALID ((hb_language_t) 0)

An unset hb_language_t.

Since: 0.6.0

HB_FEATURE_GLOBAL_END

#define HB_FEATURE_GLOBAL_END ((unsigned int) -1)

Special setting for hb_feature_t.end to apply the feature from to the end of the buffer.

Since: 2.0.0

HB_FEATURE_GLOBAL_START

#define HB_FEATURE_GLOBAL_START 0

Special setting for hb_feature_t.start to apply the feature from the start of the buffer.

Since: 2.0.0