Google Git Google Git
Sign in
flutter/third_party/harfbuzz/refs/heads/variable-glyph-experiment/./src/hb-ot-layout.h
blob: 22060ccf037e7c7ab72a0b9e1dba1d4f8d2d7c33 [file] [edit]
/*
* Copyright © 2007,2008,2009 Red Hat, 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): Behdad Esfahbod
*/
#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
#error "Include <hb-ot.h> instead."
#endif
#ifndef HB_OT_LAYOUT_H
#define HB_OT_LAYOUT_H
#include "hb.h"
#include "hb-ot-name.h"
HB_BEGIN_DECLS
/**
* HB_OT_TAG_BASE:
*
* OpenType [Baseline Table](https://docs.microsoft.com/en-us/typography/opentype/spec/base).
*/
#define HB_OT_TAG_BASE HB_TAG('B','A','S','E')
/**
* HB_OT_TAG_GDEF:
*
* OpenType [Glyph Definition Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gdef).
*/
#define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
/**
* HB_OT_TAG_GSUB:
*
* OpenType [Glyph Substitution Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gsub).
*/
#define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
/**
* HB_OT_TAG_GPOS:
*
* OpenType [Glyph Positioning Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gpos).
*/
#define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
/**
* HB_OT_TAG_JSTF:
*
* OpenType [Justification Table](https://docs.microsoft.com/en-us/typography/opentype/spec/jstf).
*/
#define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
/*
* Script & Language tags.
*/
/**
* HB_OT_TAG_DEFAULT_SCRIPT:
*
* OpenType script tag, `DFLT`, for features that are not script-specific.
*
*/
#define HB_OT_TAG_DEFAULT_SCRIPT HB_TAG ('D', 'F', 'L', 'T')
/**
* HB_OT_TAG_DEFAULT_LANGUAGE:
*
* OpenType language tag, `dflt`. Not a valid language tag, but some fonts
* mistakenly use it.
*/
#define HB_OT_TAG_DEFAULT_LANGUAGE HB_TAG ('d', 'f', 'l', 't')
/**
* HB_OT_MAX_TAGS_PER_SCRIPT:
*
* Maximum number of OpenType tags that can correspond to a give #hb_script_t.
*
* Since: 2.0.0
**/
#define HB_OT_MAX_TAGS_PER_SCRIPT 3u
/**
* HB_OT_MAX_TAGS_PER_LANGUAGE:
*
* Maximum number of OpenType tags that can correspond to a give #hb_language_t.
*
* Since: 2.0.0
**/
#define HB_OT_MAX_TAGS_PER_LANGUAGE 3u
HB_EXTERN void
hb_ot_tags_from_script_and_language (hb_script_t script,
hb_language_t language,
unsigned int *script_count /* IN/OUT */,
hb_tag_t *script_tags /* OUT */,
unsigned int *language_count /* IN/OUT */,
hb_tag_t *language_tags /* OUT */);
HB_EXTERN hb_script_t
hb_ot_tag_to_script (hb_tag_t tag);
HB_EXTERN hb_language_t
hb_ot_tag_to_language (hb_tag_t tag);
HB_EXTERN void
hb_ot_tags_to_script_and_language (hb_tag_t script_tag,
hb_tag_t language_tag,
hb_script_t *script /* OUT */,
hb_language_t *language /* OUT */);
/*
* GDEF
*/
HB_EXTERN hb_bool_t
hb_ot_layout_has_glyph_classes (hb_face_t *face);
/**
* hb_ot_layout_glyph_class_t:
* @HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED: Glyphs not matching the other classifications
* @HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH: Spacing, single characters, capable of accepting marks
* @HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE: Glyphs that represent ligation of multiple characters
* @HB_OT_LAYOUT_GLYPH_CLASS_MARK: Non-spacing, combining glyphs that represent marks
* @HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT: Spacing glyphs that represent part of a single character
*
* The GDEF classes defined for glyphs.
*
**/
typedef enum {
HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED = 0,
HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH = 1,
HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE = 2,
HB_OT_LAYOUT_GLYPH_CLASS_MARK = 3,
HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT = 4
} hb_ot_layout_glyph_class_t;
HB_EXTERN hb_ot_layout_glyph_class_t
hb_ot_layout_get_glyph_class (hb_face_t *face,
hb_codepoint_t glyph);
HB_EXTERN void
hb_ot_layout_get_glyphs_in_class (hb_face_t *face,
hb_ot_layout_glyph_class_t klass,
hb_set_t *glyphs /* OUT */);
/* Not that useful. Provides list of attach points for a glyph that a
* client may want to cache */
HB_EXTERN unsigned int
hb_ot_layout_get_attach_points (hb_face_t *face,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *point_count /* IN/OUT */,
unsigned int *point_array /* OUT */);
/* Ligature caret positions */
HB_EXTERN unsigned int
hb_ot_layout_get_ligature_carets (hb_font_t *font,
hb_direction_t direction,
hb_codepoint_t glyph,
unsigned int start_offset,
unsigned int *caret_count /* IN/OUT */,
hb_position_t *caret_array /* OUT */);
/*
* GSUB/GPOS feature query and enumeration interface
*/
/**
* HB_OT_LAYOUT_NO_SCRIPT_INDEX:
*
* Special value for script index indicating unsupported script.
*/
#define HB_OT_LAYOUT_NO_SCRIPT_INDEX 0xFFFFu
/**
* HB_OT_LAYOUT_NO_FEATURE_INDEX:
*
* Special value for feature index indicating unsupported feature.
*/
#define HB_OT_LAYOUT_NO_FEATURE_INDEX 0xFFFFu
/**
* HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX:
*
* Special value for language index indicating default or unsupported language.
*/
#define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX 0xFFFFu
/**
* HB_OT_LAYOUT_NO_VARIATIONS_INDEX:
*
* Special value for variations index indicating unsupported variation.
*/
#define HB_OT_LAYOUT_NO_VARIATIONS_INDEX 0xFFFFFFFFu
HB_EXTERN unsigned int
hb_ot_layout_table_get_script_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int start_offset,
unsigned int *script_count /* IN/OUT */,
hb_tag_t *script_tags /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_table_find_script (hb_face_t *face,
hb_tag_t table_tag,
hb_tag_t script_tag,
unsigned int *script_index /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_table_select_script (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_count,
const hb_tag_t *script_tags,
unsigned int *script_index /* OUT */,
hb_tag_t *chosen_script /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_table_get_feature_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
hb_tag_t *feature_tags /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_script_get_language_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int start_offset,
unsigned int *language_count /* IN/OUT */,
hb_tag_t *language_tags /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_script_select_language (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_count,
const hb_tag_t *language_tags,
unsigned int *language_index /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_script_select_language2 (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_count,
const hb_tag_t *language_tags,
unsigned int *language_index /* OUT */,
hb_tag_t *chosen_language /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_language_get_required_feature_index (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int *feature_index /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_language_get_required_feature (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int *feature_index /* OUT */,
hb_tag_t *feature_tag /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_language_get_feature_indexes (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
unsigned int *feature_indexes /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_language_get_feature_tags (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
unsigned int start_offset,
unsigned int *feature_count /* IN/OUT */,
hb_tag_t *feature_tags /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_language_find_feature (hb_face_t *face,
hb_tag_t table_tag,
unsigned int script_index,
unsigned int language_index,
hb_tag_t feature_tag,
unsigned int *feature_index /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_feature_get_lookups (hb_face_t *face,
hb_tag_t table_tag,
unsigned int feature_index,
unsigned int start_offset,
unsigned int *lookup_count /* IN/OUT */,
unsigned int *lookup_indexes /* OUT */);
HB_EXTERN unsigned int
hb_ot_layout_table_get_lookup_count (hb_face_t *face,
hb_tag_t table_tag);
HB_EXTERN void
hb_ot_layout_collect_features (hb_face_t *face,
hb_tag_t table_tag,
const hb_tag_t *scripts,
const hb_tag_t *languages,
const hb_tag_t *features,
hb_set_t *feature_indexes /* OUT */);
HB_EXTERN void
hb_ot_layout_collect_features_map (hb_face_t *face,
hb_tag_t table_tag,
unsigned script_index,
unsigned language_index,
hb_map_t *feature_map /* OUT */);
HB_EXTERN void
hb_ot_layout_collect_lookups (hb_face_t *face,
hb_tag_t table_tag,
const hb_tag_t *scripts,
const hb_tag_t *languages,
const hb_tag_t *features,
hb_set_t *lookup_indexes /* OUT */);
HB_EXTERN void
hb_ot_layout_lookup_collect_glyphs (hb_face_t *face,
hb_tag_t table_tag,
unsigned int lookup_index,
hb_set_t *glyphs_before, /* OUT. May be NULL */
hb_set_t *glyphs_input, /* OUT. May be NULL */
hb_set_t *glyphs_after, /* OUT. May be NULL */
hb_set_t *glyphs_output /* OUT. May be NULL */);
/* Variations support */
HB_EXTERN hb_bool_t
hb_ot_layout_table_find_feature_variations (hb_face_t *face,
hb_tag_t table_tag,
const int *coords,
unsigned int num_coords,
unsigned int *variations_index /* out */);
HB_EXTERN unsigned int
hb_ot_layout_feature_with_variations_get_lookups (hb_face_t *face,
hb_tag_t table_tag,
unsigned int feature_index,
unsigned int variations_index,
unsigned int start_offset,
unsigned int *lookup_count /* IN/OUT */,
unsigned int *lookup_indexes /* OUT */);
/*
* GSUB
*/
HB_EXTERN hb_bool_t
hb_ot_layout_has_substitution (hb_face_t *face);
HB_EXTERN unsigned
hb_ot_layout_lookup_get_glyph_alternates (hb_face_t *face,
unsigned lookup_index,
hb_codepoint_t glyph,
unsigned start_offset,
unsigned *alternate_count /* IN/OUT */,
hb_codepoint_t *alternate_glyphs /* OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_lookup_collect_glyph_alternates (hb_face_t *face,
unsigned lookup_index,
hb_map_t *alternate_count /* IN/OUT */,
hb_map_t *alternate_glyphs /* IN/OUT */);
HB_EXTERN hb_bool_t
hb_ot_layout_lookup_would_substitute (hb_face_t *face,
unsigned int lookup_index,
const hb_codepoint_t *glyphs,
unsigned int glyphs_length,
hb_bool_t zero_context);
HB_EXTERN void
hb_ot_layout_lookup_substitute_closure (hb_face_t *face,
unsigned int lookup_index,
hb_set_t *glyphs
/*TODO , hb_bool_t inclusive */);
HB_EXTERN void
hb_ot_layout_lookups_substitute_closure (hb_face_t *face,
const hb_set_t *lookups,
hb_set_t *glyphs);
/*
* GPOS
*/
HB_EXTERN hb_bool_t
hb_ot_layout_has_positioning (hb_face_t *face);
/* Optical 'size' feature info. Returns true if found.
* https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */
HB_EXTERN hb_bool_t
hb_ot_layout_get_size_params (hb_face_t *face,
unsigned int *design_size, /* OUT. May be NULL */
unsigned int *subfamily_id, /* OUT. May be NULL */
hb_ot_name_id_t *subfamily_name_id, /* OUT. May be NULL */
unsigned int *range_start, /* OUT. May be NULL */
unsigned int *range_end /* OUT. May be NULL */);
HB_EXTERN hb_position_t
hb_ot_layout_lookup_get_optical_bound (hb_font_t *font,
unsigned lookup_index,
hb_direction_t direction,
hb_codepoint_t glyph);
/*
* GSUB/GPOS
*/
HB_EXTERN hb_bool_t
hb_ot_layout_feature_get_name_ids (hb_face_t *face,
hb_tag_t table_tag,
unsigned int feature_index,
hb_ot_name_id_t *label_id /* OUT. May be NULL */,
hb_ot_name_id_t *tooltip_id /* OUT. May be NULL */,
hb_ot_name_id_t *sample_id /* OUT. May be NULL */,
unsigned int *num_named_parameters /* OUT. May be NULL */,
hb_ot_name_id_t *first_param_id /* OUT. May be NULL */);
HB_EXTERN unsigned int
hb_ot_layout_feature_get_characters (hb_face_t *face,
hb_tag_t table_tag,
unsigned int feature_index,
unsigned int start_offset,
unsigned int *char_count /* IN/OUT. May be NULL */,
hb_codepoint_t *characters /* OUT. May be NULL */);
/*
* BASE
*/
HB_EXTERN hb_bool_t
hb_ot_layout_get_font_extents (hb_font_t *font,
hb_direction_t direction,
hb_tag_t script_tag,
hb_tag_t language_tag,
hb_font_extents_t *extents);
HB_EXTERN hb_bool_t
hb_ot_layout_get_font_extents2 (hb_font_t *font,
hb_direction_t direction,
hb_script_t script,
hb_language_t language,
hb_font_extents_t *extents);
/**
* hb_ot_layout_baseline_tag_t:
* @HB_OT_LAYOUT_BASELINE_TAG_ROMAN: The baseline used by alphabetic scripts such as Latin, Cyrillic and Greek.
* In vertical writing mode, the alphabetic baseline for characters rotated 90 degrees clockwise.
* (This would not apply to alphabetic characters that remain upright in vertical writing mode, since these
* characters are not rotated.)
* @HB_OT_LAYOUT_BASELINE_TAG_HANGING: The hanging baseline. In horizontal direction, this is the horizontal
* line from which syllables seem, to hang in Tibetan and other similar scripts. In vertical writing mode,
* for Tibetan (or some other similar script) characters rotated 90 degrees clockwise.
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT: Ideographic character face bottom or left edge,
* if the direction is horizontal or vertical, respectively.
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT: Ideographic character face top or right edge,
* if the direction is horizontal or vertical, respectively.
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_CENTRAL: The center of the ideographic character face. Since: 4.0.0
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT: Ideographic em-box bottom or left edge,
* if the direction is horizontal or vertical, respectively.
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT: Ideographic em-box top or right edge baseline,
* @HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_CENTRAL: The center of the ideographic em-box. Since: 4.0.0
* if the direction is horizontal or vertical, respectively.
* @HB_OT_LAYOUT_BASELINE_TAG_MATH: The baseline about which mathematical characters are centered.
* In vertical writing mode when mathematical characters rotated 90 degrees clockwise, are centered.
*
* Baseline tags from [Baseline Tags](https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags) registry.
*
* Since: 2.6.0
*/
typedef enum {
HB_OT_LAYOUT_BASELINE_TAG_ROMAN = HB_TAG ('r','o','m','n'),
HB_OT_LAYOUT_BASELINE_TAG_HANGING = HB_TAG ('h','a','n','g'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT = HB_TAG ('i','c','f','b'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT = HB_TAG ('i','c','f','t'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_CENTRAL = HB_TAG ('I','c','f','c'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT = HB_TAG ('i','d','e','o'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT = HB_TAG ('i','d','t','p'),
HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_CENTRAL = HB_TAG ('I','d','c','e'),
HB_OT_LAYOUT_BASELINE_TAG_MATH = HB_TAG ('m','a','t','h'),
/*< private >*/
_HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
} hb_ot_layout_baseline_tag_t;
HB_EXTERN hb_ot_layout_baseline_tag_t
hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script);
HB_EXTERN hb_bool_t
hb_ot_layout_get_baseline (hb_font_t *font,
hb_ot_layout_baseline_tag_t baseline_tag,
hb_direction_t direction,
hb_tag_t script_tag,
hb_tag_t language_tag,
hb_position_t *coord /* OUT. May be NULL. */);
HB_EXTERN hb_bool_t
hb_ot_layout_get_baseline2 (hb_font_t *font,
hb_ot_layout_baseline_tag_t baseline_tag,
hb_direction_t direction,
hb_script_t script,
hb_language_t language,
hb_position_t *coord /* OUT. May be NULL. */);
HB_EXTERN void
hb_ot_layout_get_baseline_with_fallback (hb_font_t *font,
hb_ot_layout_baseline_tag_t baseline_tag,
hb_direction_t direction,
hb_tag_t script_tag,
hb_tag_t language_tag,
hb_position_t *coord /* OUT */);
HB_EXTERN void
hb_ot_layout_get_baseline_with_fallback2 (hb_font_t *font,
hb_ot_layout_baseline_tag_t baseline_tag,
hb_direction_t direction,
hb_script_t script,
hb_language_t language,
hb_position_t *coord /* OUT */);
HB_END_DECLS
#endif /* HB_OT_LAYOUT_H */