harfbuzz/src/hb-buffer.h

572 lines
18 KiB
C

/*
* Copyright © 1998-2004 David Turner and Werner Lemberg
* Copyright © 2004,2007,2009 Red Hat, Inc.
* Copyright © 2011,2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Owen Taylor, Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_H_IN
#error "Include <hb.h> instead."
#endif
#ifndef HB_BUFFER_H
#define HB_BUFFER_H
#include "hb-common.h"
#include "hb-unicode.h"
#include "hb-font.h"
HB_BEGIN_DECLS
/**
* hb_glyph_info_t:
* @codepoint: either a Unicode code point (before shaping) or a glyph index
* (after shaping).
* @cluster: the index of the character in the original text that corresponds
* to this #hb_glyph_info_t, or whatever the client passes to
* hb_buffer_add(). More than one #hb_glyph_info_t can have the same
* @cluster value, if they resulted from the same character (e.g. one
* to many glyph substitution), and when more than one character gets
* merged in the same glyph (e.g. many to one glyph substitution) the
* #hb_glyph_info_t will have the smallest cluster value of them.
* By default some characters are merged into the same cluster
* (e.g. combining marks have the same cluster as their bases)
* even if they are separate glyphs, hb_buffer_set_cluster_level()
* allow selecting more fine-grained cluster handling.
*
* The #hb_glyph_info_t is the structure that holds information about the
* glyphs and their relation to input text.
*/
typedef struct hb_glyph_info_t
{
hb_codepoint_t codepoint;
/*< private >*/
hb_mask_t mask;
/*< public >*/
uint32_t cluster;
/*< private >*/
hb_var_int_t var1;
hb_var_int_t var2;
} hb_glyph_info_t;
/**
* hb_glyph_flags_t:
* @HB_GLYPH_FLAG_UNSAFE_TO_BREAK: Indicates that if input text is broken at the
* beginning of the cluster this glyph is part of,
* then both sides need to be re-shaped, as the
* result might be different. On the flip side,
* it means that when this flag is not present,
* then it's safe to break the glyph-run at the
* beginning of this cluster, and the two sides
* represent the exact same result one would get
* if breaking input text at the beginning of
* this cluster and shaping the two sides
* separately. This can be used to optimize
* paragraph layout, by avoiding re-shaping
* of each line after line-breaking, or limiting
* the reshaping to a small piece around the
* breaking point only.
*/
typedef enum { /*< flags >*/
HB_GLYPH_FLAG_UNSAFE_TO_BREAK = 0x00000001,
HB_GLYPH_FLAG_DEFINED = 0x00000001 /*< skip >*/ /* OR of all defined flags */
} hb_glyph_flags_t;
HB_EXTERN hb_glyph_flags_t
hb_glyph_info_get_glyph_flags (const hb_glyph_info_t *info);
#define hb_glyph_info_get_glyph_flags(info) \
((hb_glyph_flags_t) ((unsigned int) (info)->mask & HB_GLYPH_FLAG_DEFINED))
/**
* hb_glyph_position_t:
* @x_advance: how much the line advances after drawing this glyph when setting
* text in horizontal direction.
* @y_advance: how much the line advances after drawing this glyph when setting
* text in vertical direction.
* @x_offset: how much the glyph moves on the X-axis before drawing it, this
* should not affect how much the line advances.
* @y_offset: how much the glyph moves on the Y-axis before drawing it, this
* should not affect how much the line advances.
*
* The #hb_glyph_position_t is the structure that holds the positions of the
* glyph in both horizontal and vertical directions. All positions in
* #hb_glyph_position_t are relative to the current point.
*
*/
typedef struct hb_glyph_position_t {
hb_position_t x_advance;
hb_position_t y_advance;
hb_position_t x_offset;
hb_position_t y_offset;
/*< private >*/
hb_var_int_t var;
} hb_glyph_position_t;
/**
* hb_segment_properties_t:
* @direction: the #hb_direction_t of the buffer, see hb_buffer_set_direction().
* @script: the #hb_script_t of the buffer, see hb_buffer_set_script().
* @language: the #hb_language_t of the buffer, see hb_buffer_set_language().
*
* The structure that holds various text properties of an #hb_buffer_t. Can be
* set and retrieved using hb_buffer_set_segment_properties() and
* hb_buffer_get_segment_properties(), respectively.
*/
typedef struct hb_segment_properties_t {
hb_direction_t direction;
hb_script_t script;
hb_language_t language;
/*< private >*/
void *reserved1;
void *reserved2;
} hb_segment_properties_t;
#define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
HB_SCRIPT_INVALID, \
HB_LANGUAGE_INVALID, \
(void *) 0, \
(void *) 0}
HB_EXTERN hb_bool_t
hb_segment_properties_equal (const hb_segment_properties_t *a,
const hb_segment_properties_t *b);
HB_EXTERN unsigned int
hb_segment_properties_hash (const hb_segment_properties_t *p);
/**
* hb_buffer_t:
*
* The main structure holding the input text and its properties before shaping,
* and output glyphs and their information after shaping.
*/
typedef struct hb_buffer_t hb_buffer_t;
HB_EXTERN hb_buffer_t *
hb_buffer_create (void);
HB_EXTERN hb_buffer_t *
hb_buffer_get_empty (void);
HB_EXTERN hb_buffer_t *
hb_buffer_reference (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_destroy (hb_buffer_t *buffer);
HB_EXTERN hb_bool_t
hb_buffer_set_user_data (hb_buffer_t *buffer,
hb_user_data_key_t *key,
void * data,
hb_destroy_func_t destroy,
hb_bool_t replace);
HB_EXTERN void *
hb_buffer_get_user_data (hb_buffer_t *buffer,
hb_user_data_key_t *key);
/**
* hb_buffer_content_type_t:
* @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
* @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
* @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
*/
typedef enum {
HB_BUFFER_CONTENT_TYPE_INVALID = 0,
HB_BUFFER_CONTENT_TYPE_UNICODE,
HB_BUFFER_CONTENT_TYPE_GLYPHS
} hb_buffer_content_type_t;
HB_EXTERN void
hb_buffer_set_content_type (hb_buffer_t *buffer,
hb_buffer_content_type_t content_type);
HB_EXTERN hb_buffer_content_type_t
hb_buffer_get_content_type (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_set_unicode_funcs (hb_buffer_t *buffer,
hb_unicode_funcs_t *unicode_funcs);
HB_EXTERN hb_unicode_funcs_t *
hb_buffer_get_unicode_funcs (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_set_direction (hb_buffer_t *buffer,
hb_direction_t direction);
HB_EXTERN hb_direction_t
hb_buffer_get_direction (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_set_script (hb_buffer_t *buffer,
hb_script_t script);
HB_EXTERN hb_script_t
hb_buffer_get_script (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_set_language (hb_buffer_t *buffer,
hb_language_t language);
HB_EXTERN hb_language_t
hb_buffer_get_language (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_set_segment_properties (hb_buffer_t *buffer,
const hb_segment_properties_t *props);
HB_EXTERN void
hb_buffer_get_segment_properties (hb_buffer_t *buffer,
hb_segment_properties_t *props);
HB_EXTERN void
hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
/**
* hb_buffer_flags_t:
* @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
* @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
* of text paragraph can be applied to this buffer. Should usually
* be set, unless you are passing to the buffer only part
* of the text without the full context.
* @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
* paragraph can be applied to this buffer, similar to
* @HB_BUFFER_FLAG_BOT.
* @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
* flag indication that character with Default_Ignorable
* Unicode property should use the corresponding glyph
* from the font, instead of hiding them (done by
* replacing them with the space glyph and zeroing the
* advance width.) This flag takes precedence over
* @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES.
* @HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES:
* flag indication that character with Default_Ignorable
* Unicode property should be removed from glyph string
* instead of hiding them (done by replacing them with the
* space glyph and zeroing the advance width.)
* @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES takes
* precedence over this flag. Since: 1.8.0
*
* Since: 0.9.20
*/
typedef enum { /*< flags >*/
HB_BUFFER_FLAG_DEFAULT = 0x00000000u,
HB_BUFFER_FLAG_BOT = 0x00000001u, /* Beginning-of-text */
HB_BUFFER_FLAG_EOT = 0x00000002u, /* End-of-text */
HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES = 0x00000004u,
HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES = 0x00000008u
} hb_buffer_flags_t;
HB_EXTERN void
hb_buffer_set_flags (hb_buffer_t *buffer,
hb_buffer_flags_t flags);
HB_EXTERN hb_buffer_flags_t
hb_buffer_get_flags (hb_buffer_t *buffer);
/**
* hb_buffer_cluster_level_t:
* @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES: Return cluster values grouped by graphemes into
* monotone order.
* @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS: Return cluster values grouped into monotone order.
* @HB_BUFFER_CLUSTER_LEVEL_CHARACTERS: Don't group cluster values.
* @HB_BUFFER_CLUSTER_LEVEL_DEFAULT: Default cluster level,
* equal to @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES.
*
* Since: 0.9.42
*/
typedef enum {
HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES = 0,
HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS = 1,
HB_BUFFER_CLUSTER_LEVEL_CHARACTERS = 2,
HB_BUFFER_CLUSTER_LEVEL_DEFAULT = HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES
} hb_buffer_cluster_level_t;
HB_EXTERN void
hb_buffer_set_cluster_level (hb_buffer_t *buffer,
hb_buffer_cluster_level_t cluster_level);
HB_EXTERN hb_buffer_cluster_level_t
hb_buffer_get_cluster_level (hb_buffer_t *buffer);
/**
* HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT:
*
* The default code point for replacing invalid characters in a given encoding.
* Set to U+FFFD REPLACEMENT CHARACTER.
*
* Since: 0.9.31
*/
#define HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT 0xFFFDu
HB_EXTERN void
hb_buffer_set_replacement_codepoint (hb_buffer_t *buffer,
hb_codepoint_t replacement);
HB_EXTERN hb_codepoint_t
hb_buffer_get_replacement_codepoint (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_reset (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_clear_contents (hb_buffer_t *buffer);
HB_EXTERN hb_bool_t
hb_buffer_pre_allocate (hb_buffer_t *buffer,
unsigned int size);
HB_EXTERN hb_bool_t
hb_buffer_allocation_successful (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_reverse (hb_buffer_t *buffer);
HB_EXTERN void
hb_buffer_reverse_range (hb_buffer_t *buffer,
unsigned int start, unsigned int end);
HB_EXTERN void
hb_buffer_reverse_clusters (hb_buffer_t *buffer);
/* Filling the buffer in */
HB_EXTERN void
hb_buffer_add (hb_buffer_t *buffer,
hb_codepoint_t codepoint,
unsigned int cluster);
HB_EXTERN void
hb_buffer_add_utf8 (hb_buffer_t *buffer,
const char *text,
int text_length,
unsigned int item_offset,
int item_length);
HB_EXTERN void
hb_buffer_add_utf16 (hb_buffer_t *buffer,
const uint16_t *text,
int text_length,
unsigned int item_offset,
int item_length);
HB_EXTERN void
hb_buffer_add_utf32 (hb_buffer_t *buffer,
const uint32_t *text,
int text_length,
unsigned int item_offset,
int item_length);
HB_EXTERN void
hb_buffer_add_latin1 (hb_buffer_t *buffer,
const uint8_t *text,
int text_length,
unsigned int item_offset,
int item_length);
HB_EXTERN void
hb_buffer_add_codepoints (hb_buffer_t *buffer,
const hb_codepoint_t *text,
int text_length,
unsigned int item_offset,
int item_length);
HB_EXTERN void
hb_buffer_append (hb_buffer_t *buffer,
hb_buffer_t *source,
unsigned int start,
unsigned int end);
HB_EXTERN hb_bool_t
hb_buffer_set_length (hb_buffer_t *buffer,
unsigned int length);
HB_EXTERN unsigned int
hb_buffer_get_length (hb_buffer_t *buffer);
/* Getting glyphs out of the buffer */
HB_EXTERN hb_glyph_info_t *
hb_buffer_get_glyph_infos (hb_buffer_t *buffer,
unsigned int *length);
HB_EXTERN hb_glyph_position_t *
hb_buffer_get_glyph_positions (hb_buffer_t *buffer,
unsigned int *length);
HB_EXTERN void
hb_buffer_normalize_glyphs (hb_buffer_t *buffer);
/*
* Serialize
*/
/**
* hb_buffer_serialize_flags_t:
* @HB_BUFFER_SERIALIZE_FLAG_DEFAULT: serialize glyph names, clusters and positions.
* @HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS: do not serialize glyph cluster.
* @HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS: do not serialize glyph position information.
* @HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES: do no serialize glyph name.
* @HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS: serialize glyph extents.
* @HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS: serialize glyph flags. Since: 1.5.0
* @HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES: do not serialize glyph advances,
* glyph offsets will reflect absolute glyph positions. Since: 1.8.0
*
* Flags that control what glyph information are serialized in hb_buffer_serialize_glyphs().
*
* Since: 0.9.20
*/
typedef enum { /*< flags >*/
HB_BUFFER_SERIALIZE_FLAG_DEFAULT = 0x00000000u,
HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS = 0x00000001u,
HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS = 0x00000002u,
HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES = 0x00000004u,
HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS = 0x00000008u,
HB_BUFFER_SERIALIZE_FLAG_GLYPH_FLAGS = 0x00000010u,
HB_BUFFER_SERIALIZE_FLAG_NO_ADVANCES = 0x00000020u
} hb_buffer_serialize_flags_t;
/**
* hb_buffer_serialize_format_t:
* @HB_BUFFER_SERIALIZE_FORMAT_TEXT: a human-readable, plain text format.
* @HB_BUFFER_SERIALIZE_FORMAT_JSON: a machine-readable JSON format.
* @HB_BUFFER_SERIALIZE_FORMAT_INVALID: invalid format.
*
* The buffer serialization and de-serialization format used in
* hb_buffer_serialize_glyphs() and hb_buffer_deserialize_glyphs().
*
* Since: 0.9.2
*/
typedef enum {
HB_BUFFER_SERIALIZE_FORMAT_TEXT = HB_TAG('T','E','X','T'),
HB_BUFFER_SERIALIZE_FORMAT_JSON = HB_TAG('J','S','O','N'),
HB_BUFFER_SERIALIZE_FORMAT_INVALID = HB_TAG_NONE
} hb_buffer_serialize_format_t;
HB_EXTERN hb_buffer_serialize_format_t
hb_buffer_serialize_format_from_string (const char *str, int len);
HB_EXTERN const char *
hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format);
HB_EXTERN const char **
hb_buffer_serialize_list_formats (void);
HB_EXTERN unsigned int
hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
unsigned int start,
unsigned int end,
char *buf,
unsigned int buf_size,
unsigned int *buf_consumed,
hb_font_t *font,
hb_buffer_serialize_format_t format,
hb_buffer_serialize_flags_t flags);
HB_EXTERN hb_bool_t
hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
const char *buf,
int buf_len,
const char **end_ptr,
hb_font_t *font,
hb_buffer_serialize_format_t format);
/*
* Compare buffers
*/
typedef enum { /*< flags >*/
HB_BUFFER_DIFF_FLAG_EQUAL = 0x0000,
/* Buffers with different content_type cannot be meaningfully compared
* in any further detail. */
HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH = 0x0001,
/* For buffers with differing length, the per-glyph comparison is not
* attempted, though we do still scan reference for dottedcircle / .notdef
* glyphs. */
HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH = 0x0002,
/* We want to know if dottedcircle / .notdef glyphs are present in the
* reference, as we may not care so much about other differences in this
* case. */
HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT = 0x0004,
HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT = 0x0008,
/* If the buffers have the same length, we compare them glyph-by-glyph
* and report which aspect(s) of the glyph info/position are different. */
HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH = 0x0010,
HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH = 0x0020,
HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH = 0x0040,
HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH = 0x0080
} hb_buffer_diff_flags_t;
/* Compare the contents of two buffers, report types of differences. */
HB_EXTERN hb_buffer_diff_flags_t
hb_buffer_diff (hb_buffer_t *buffer,
hb_buffer_t *reference,
hb_codepoint_t dottedcircle_glyph,
unsigned int position_fuzz);
/*
* Debugging.
*/
typedef hb_bool_t (*hb_buffer_message_func_t) (hb_buffer_t *buffer,
hb_font_t *font,
const char *message,
void *user_data);
HB_EXTERN void
hb_buffer_set_message_func (hb_buffer_t *buffer,
hb_buffer_message_func_t func,
void *user_data, hb_destroy_func_t destroy);
HB_END_DECLS
#endif /* HB_BUFFER_H */