src/hb-ot-layout.h - third_party/harfbuzz - Git at Google

 /*
  * 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_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_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 */);

 #ifdef HB_NOT_IMPLEMENTED
 typedef struct
 {
   const hb_codepoint_t *before,
   unsigned int          before_length,
   const hb_codepoint_t *input,
   unsigned int          input_length,
   const hb_codepoint_t *after,
   unsigned int          after_length,
 } hb_ot_layout_glyph_sequence_t;

 typedef hb_bool_t
 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
 				       hb_tag_t      table_tag,
 				       unsigned int  lookup_index,
 				       const hb_ot_layout_glyph_sequence_t *sequence,
 				       void         *user_data);

 HB_EXTERN void
 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
 					 hb_tag_t      table_tag,
 					 unsigned int  lookup_index,
 					 hb_ot_layout_glyph_sequence_func_t callback,
 					 void         *user_data);
 #endif

 /* 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_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);


 #ifdef HB_NOT_IMPLEMENTED
 /* Note: You better have GDEF when using this API, or marks won't do much. */
 HB_EXTERN hb_bool_t
 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
 				unsigned int          lookup_index,
 				const hb_ot_layout_glyph_sequence_t *sequence,
 				unsigned int          out_size,
 				hb_codepoint_t       *glyphs_out,   /* OUT */
 				unsigned int         *clusters_out, /* OUT */
 				unsigned int         *out_length    /* OUT */);
 #endif


 /*
  * GPOS
  */

 HB_EXTERN hb_bool_t
 hb_ot_layout_has_positioning (hb_face_t *face);

 #ifdef HB_NOT_IMPLEMENTED
 /* Note: You better have GDEF when using this API, or marks won't do much. */
 HB_EXTERN hb_bool_t
 Xhb_ot_layout_lookup_position (hb_font_t            *font,
 			      unsigned int          lookup_index,
 			      const hb_ot_layout_glyph_sequence_t *sequence,
 			      hb_glyph_position_t  *positions /* IN / OUT */);
 #endif

 /* 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_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_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_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,
  * 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_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_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_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_END_DECLS

 #endif /* HB_OT_LAYOUT_H */
	/*
	* 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_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_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 */);

	#ifdef HB_NOT_IMPLEMENTED
	typedef struct
	{
	const hb_codepoint_t *before,
	unsigned int before_length,
	const hb_codepoint_t *input,
	unsigned int input_length,
	const hb_codepoint_t *after,
	unsigned int after_length,
	} hb_ot_layout_glyph_sequence_t;

	typedef hb_bool_t
	(hb_ot_layout_glyph_sequence_func_t) (hb_font_t font,
	hb_tag_t table_tag,
	unsigned int lookup_index,
	const hb_ot_layout_glyph_sequence_t *sequence,
	void *user_data);

	HB_EXTERN void
	Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t *face,
	hb_tag_t table_tag,
	unsigned int lookup_index,
	hb_ot_layout_glyph_sequence_func_t callback,
	void *user_data);
	#endif

	/* 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_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);


	#ifdef HB_NOT_IMPLEMENTED
	/* Note: You better have GDEF when using this API, or marks won't do much. */
	HB_EXTERN hb_bool_t
	Xhb_ot_layout_lookup_substitute (hb_font_t *font,
	unsigned int lookup_index,
	const hb_ot_layout_glyph_sequence_t *sequence,
	unsigned int out_size,
	hb_codepoint_t glyphs_out, / OUT */
	unsigned int clusters_out, / OUT */
	unsigned int out_length / OUT */);
	#endif


	/*
	* GPOS
	*/

	HB_EXTERN hb_bool_t
	hb_ot_layout_has_positioning (hb_face_t *face);

	#ifdef HB_NOT_IMPLEMENTED
	/* Note: You better have GDEF when using this API, or marks won't do much. */
	HB_EXTERN hb_bool_t
	Xhb_ot_layout_lookup_position (hb_font_t *font,
	unsigned int lookup_index,
	const hb_ot_layout_glyph_sequence_t *sequence,
	hb_glyph_position_t positions / IN / OUT */);
	#endif

	/* 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_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_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_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,
	* 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_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_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_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_END_DECLS

	#endif /* HB_OT_LAYOUT_H */