src/hb-ot-layout.h

   1 /*
   2  * Copyright © 2007,2008,2009  Red Hat, Inc.
   3  *
   4  *  This is part of HarfBuzz, a text shaping library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  *
  24  * Red Hat Author(s): Behdad Esfahbod
  25  */
  26
  27 #ifndef HB_OT_H_IN
  28 #error "Include <hb-ot.h> instead."
  29 #endif
  30
  31 #ifndef HB_OT_LAYOUT_H
  32 #define HB_OT_LAYOUT_H
  33
  34 #include "hb.h"
  35
  36 #include "hb-ot-name.h"
  37
  38 HB_BEGIN_DECLS
  39
  40
  41 #define HB_OT_TAG_BASE HB_TAG('B','A','S','E')
  42 #define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
  43 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
  44 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
  45 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
  46
  47
  48 /*
  49  * Script & Language tags.
  50  */
  51
  52 #define HB_OT_TAG_DEFAULT_SCRIPT        HB_TAG ('D', 'F', 'L', 'T')
  53 #define HB_OT_TAG_DEFAULT_LANGUAGE      HB_TAG ('d', 'f', 'l', 't')
  54
  55 /**
  56  * HB_OT_MAX_TAGS_PER_SCRIPT:
  57  *
  58  * Since: 2.0.0
  59  **/
  60 #define HB_OT_MAX_TAGS_PER_SCRIPT       3u
  61 /**
  62  * HB_OT_MAX_TAGS_PER_LANGUAGE:
  63  *
  64  * Since: 2.0.0
  65  **/
  66 #define HB_OT_MAX_TAGS_PER_LANGUAGE     3u
  67
  68 HB_EXTERN void
  69 hb_ot_tags_from_script_and_language (hb_script_t   script,
  70                                      hb_language_t language,
  71                                      unsigned int *script_count /* IN/OUT */,
  72                                      hb_tag_t     *script_tags /* OUT */,
  73                                      unsigned int *language_count /* IN/OUT */,
  74                                      hb_tag_t     *language_tags /* OUT */);
  75
  76 HB_EXTERN hb_script_t
  77 hb_ot_tag_to_script (hb_tag_t tag);
  78
  79 HB_EXTERN hb_language_t
  80 hb_ot_tag_to_language (hb_tag_t tag);
  81
  82 HB_EXTERN void
  83 hb_ot_tags_to_script_and_language (hb_tag_t       script_tag,
  84                                    hb_tag_t       language_tag,
  85                                    hb_script_t   *script /* OUT */,
  86                                    hb_language_t *language /* OUT */);
  87
  88
  89 /*
  90  * GDEF
  91  */
  92
  93 HB_EXTERN hb_bool_t
  94 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  95
  96 typedef enum {
  97   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED = 0,
  98   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH   = 1,
  99   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE     = 2,
 100   HB_OT_LAYOUT_GLYPH_CLASS_MARK         = 3,
 101   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT    = 4
 102 } hb_ot_layout_glyph_class_t;
 103
 104 HB_EXTERN hb_ot_layout_glyph_class_t
 105 hb_ot_layout_get_glyph_class (hb_face_t      *face,
 106                               hb_codepoint_t  glyph);
 107
 108 HB_EXTERN void
 109 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
 110                                   hb_ot_layout_glyph_class_t  klass,
 111                                   hb_set_t                   *glyphs /* OUT */);
 112
 113
 114 /* Not that useful.  Provides list of attach points for a glyph that a
 115  * client may want to cache */
 116 HB_EXTERN unsigned int
 117 hb_ot_layout_get_attach_points (hb_face_t      *face,
 118                                 hb_codepoint_t  glyph,
 119                                 unsigned int    start_offset,
 120                                 unsigned int   *point_count /* IN/OUT */,
 121                                 unsigned int   *point_array /* OUT */);
 122
 123 /* Ligature caret positions */
 124 HB_EXTERN unsigned int
 125 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
 126                                   hb_direction_t  direction,
 127                                   hb_codepoint_t  glyph,
 128                                   unsigned int    start_offset,
 129                                   unsigned int   *caret_count /* IN/OUT */,
 130                                   hb_position_t  *caret_array /* OUT */);
 131
 132
 133 /*
 134  * GSUB/GPOS feature query and enumeration interface
 135  */
 136
 137 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            0xFFFFu
 138 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           0xFFFFu
 139 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     0xFFFFu
 140 #define HB_OT_LAYOUT_NO_VARIATIONS_INDEX        0xFFFFFFFFu
 141
 142 HB_EXTERN unsigned int
 143 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 144                                     hb_tag_t      table_tag,
 145                                     unsigned int  start_offset,
 146                                     unsigned int *script_count /* IN/OUT */,
 147                                     hb_tag_t     *script_tags /* OUT */);
 148
 149 HB_EXTERN hb_bool_t
 150 hb_ot_layout_table_find_script (hb_face_t    *face,
 151                                 hb_tag_t      table_tag,
 152                                 hb_tag_t      script_tag,
 153                                 unsigned int *script_index);
 154
 155 HB_EXTERN hb_bool_t
 156 hb_ot_layout_table_select_script (hb_face_t      *face,
 157                                   hb_tag_t        table_tag,
 158                                   unsigned int    script_count,
 159                                   const hb_tag_t *script_tags,
 160                                   unsigned int   *script_index /* OUT */,
 161                                   hb_tag_t       *chosen_script /* OUT */);
 162
 163 HB_EXTERN unsigned int
 164 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 165                                      hb_tag_t      table_tag,
 166                                      unsigned int  start_offset,
 167                                      unsigned int *feature_count /* IN/OUT */,
 168                                      hb_tag_t     *feature_tags /* OUT */);
 169
 170 HB_EXTERN unsigned int
 171 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 172                                        hb_tag_t      table_tag,
 173                                        unsigned int  script_index,
 174                                        unsigned int  start_offset,
 175                                        unsigned int *language_count /* IN/OUT */,
 176                                        hb_tag_t     *language_tags /* OUT */);
 177
 178 HB_EXTERN hb_bool_t
 179 hb_ot_layout_script_select_language (hb_face_t      *face,
 180                                      hb_tag_t        table_tag,
 181                                      unsigned int    script_index,
 182                                      unsigned int    language_count,
 183                                      const hb_tag_t *language_tags,
 184                                      unsigned int   *language_index /* OUT */);
 185
 186 HB_EXTERN hb_bool_t
 187 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 188                                                   hb_tag_t      table_tag,
 189                                                   unsigned int  script_index,
 190                                                   unsigned int  language_index,
 191                                                   unsigned int *feature_index);
 192
 193 HB_EXTERN hb_bool_t
 194 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
 195                                             hb_tag_t      table_tag,
 196                                             unsigned int  script_index,
 197                                             unsigned int  language_index,
 198                                             unsigned int *feature_index,
 199                                             hb_tag_t     *feature_tag);
 200
 201 HB_EXTERN unsigned int
 202 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 203                                            hb_tag_t      table_tag,
 204                                            unsigned int  script_index,
 205                                            unsigned int  language_index,
 206                                            unsigned int  start_offset,
 207                                            unsigned int *feature_count /* IN/OUT */,
 208                                            unsigned int *feature_indexes /* OUT */);
 209
 210 HB_EXTERN unsigned int
 211 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 212                                         hb_tag_t      table_tag,
 213                                         unsigned int  script_index,
 214                                         unsigned int  language_index,
 215                                         unsigned int  start_offset,
 216                                         unsigned int *feature_count /* IN/OUT */,
 217                                         hb_tag_t     *feature_tags /* OUT */);
 218
 219 HB_EXTERN hb_bool_t
 220 hb_ot_layout_language_find_feature (hb_face_t    *face,
 221                                     hb_tag_t      table_tag,
 222                                     unsigned int  script_index,
 223                                     unsigned int  language_index,
 224                                     hb_tag_t      feature_tag,
 225                                     unsigned int *feature_index);
 226
 227 HB_EXTERN unsigned int
 228 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
 229                                   hb_tag_t      table_tag,
 230                                   unsigned int  feature_index,
 231                                   unsigned int  start_offset,
 232                                   unsigned int *lookup_count /* IN/OUT */,
 233                                   unsigned int *lookup_indexes /* OUT */);
 234
 235 HB_EXTERN unsigned int
 236 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
 237                                      hb_tag_t      table_tag);
 238
 239 HB_EXTERN void
 240 hb_ot_layout_collect_features (hb_face_t      *face,
 241                                hb_tag_t        table_tag,
 242                                const hb_tag_t *scripts,
 243                                const hb_tag_t *languages,
 244                                const hb_tag_t *features,
 245                                hb_set_t       *feature_indexes /* OUT */);
 246
 247 HB_EXTERN void
 248 hb_ot_layout_collect_lookups (hb_face_t      *face,
 249                               hb_tag_t        table_tag,
 250                               const hb_tag_t *scripts,
 251                               const hb_tag_t *languages,
 252                               const hb_tag_t *features,
 253                               hb_set_t       *lookup_indexes /* OUT */);
 254
 255 HB_EXTERN void
 256 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
 257                                     hb_tag_t      table_tag,
 258                                     unsigned int  lookup_index,
 259                                     hb_set_t     *glyphs_before, /* OUT.  May be NULL */
 260                                     hb_set_t     *glyphs_input,  /* OUT.  May be NULL */
 261                                     hb_set_t     *glyphs_after,  /* OUT.  May be NULL */
 262                                     hb_set_t     *glyphs_output  /* OUT.  May be NULL */);
 263
 264 #ifdef HB_NOT_IMPLEMENTED
 265 typedef struct
 266 {
 267   const hb_codepoint_t *before,
 268   unsigned int          before_length,
 269   const hb_codepoint_t *input,
 270   unsigned int          input_length,
 271   const hb_codepoint_t *after,
 272   unsigned int          after_length,
 273 } hb_ot_layout_glyph_sequence_t;
 274
 275 typedef hb_bool_t
 276 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
 277                                        hb_tag_t      table_tag,
 278                                        unsigned int  lookup_index,
 279                                        const hb_ot_layout_glyph_sequence_t *sequence,
 280                                        void         *user_data);
 281
 282 HB_EXTERN void
 283 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
 284                                          hb_tag_t      table_tag,
 285                                          unsigned int  lookup_index,
 286                                          hb_ot_layout_glyph_sequence_func_t callback,
 287                                          void         *user_data);
 288 #endif
 289
 290 /* Variations support */
 291
 292 HB_EXTERN hb_bool_t
 293 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
 294                                             hb_tag_t      table_tag,
 295                                             const int    *coords,
 296                                             unsigned int  num_coords,
 297                                             unsigned int *variations_index /* out */);
 298
 299 HB_EXTERN unsigned int
 300 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
 301                                                   hb_tag_t      table_tag,
 302                                                   unsigned int  feature_index,
 303                                                   unsigned int  variations_index,
 304                                                   unsigned int  start_offset,
 305                                                   unsigned int *lookup_count /* IN/OUT */,
 306                                                   unsigned int *lookup_indexes /* OUT */);
 307
 308
 309 /*
 310  * GSUB
 311  */
 312
 313 HB_EXTERN hb_bool_t
 314 hb_ot_layout_has_substitution (hb_face_t *face);
 315
 316 HB_EXTERN hb_bool_t
 317 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
 318                                       unsigned int          lookup_index,
 319                                       const hb_codepoint_t *glyphs,
 320                                       unsigned int          glyphs_length,
 321                                       hb_bool_t             zero_context);
 322
 323 HB_EXTERN void
 324 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
 325                                         unsigned int  lookup_index,
 326                                         hb_set_t     *glyphs
 327                                         /*TODO , hb_bool_t  inclusive */);
 328
 329 HB_EXTERN void
 330 hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
 331                                          const hb_set_t *lookups,
 332                                          hb_set_t       *glyphs);
 333
 334
 335 #ifdef HB_NOT_IMPLEMENTED
 336 /* Note: You better have GDEF when using this API, or marks won't do much. */
 337 HB_EXTERN hb_bool_t
 338 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
 339                                 unsigned int          lookup_index,
 340                                 const hb_ot_layout_glyph_sequence_t *sequence,
 341                                 unsigned int          out_size,
 342                                 hb_codepoint_t       *glyphs_out,   /* OUT */
 343                                 unsigned int         *clusters_out, /* OUT */
 344                                 unsigned int         *out_length    /* OUT */);
 345 #endif
 346
 347
 348 /*
 349  * GPOS
 350  */
 351
 352 HB_EXTERN hb_bool_t
 353 hb_ot_layout_has_positioning (hb_face_t *face);
 354
 355 #ifdef HB_NOT_IMPLEMENTED
 356 /* Note: You better have GDEF when using this API, or marks won't do much. */
 357 HB_EXTERN hb_bool_t
 358 Xhb_ot_layout_lookup_position (hb_font_t            *font,
 359                               unsigned int          lookup_index,
 360                               const hb_ot_layout_glyph_sequence_t *sequence,
 361                               hb_glyph_position_t  *positions /* IN / OUT */);
 362 #endif
 363
 364 /* Optical 'size' feature info.  Returns true if found.
 365  * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */
 366 HB_EXTERN hb_bool_t
 367 hb_ot_layout_get_size_params (hb_face_t       *face,
 368                               unsigned int    *design_size,       /* OUT.  May be NULL */
 369                               unsigned int    *subfamily_id,      /* OUT.  May be NULL */
 370                               hb_ot_name_id_t *subfamily_name_id, /* OUT.  May be NULL */
 371                               unsigned int    *range_start,       /* OUT.  May be NULL */
 372                               unsigned int    *range_end          /* OUT.  May be NULL */);
 373
 374
 375 HB_EXTERN hb_bool_t
 376 hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
 377                                    hb_tag_t         table_tag,
 378                                    unsigned int     feature_index,
 379                                    hb_ot_name_id_t *label_id             /* OUT.  May be NULL */,
 380                                    hb_ot_name_id_t *tooltip_id           /* OUT.  May be NULL */,
 381                                    hb_ot_name_id_t *sample_id            /* OUT.  May be NULL */,
 382                                    unsigned int    *num_named_parameters /* OUT.  May be NULL */,
 383                                    hb_ot_name_id_t *first_param_id       /* OUT.  May be NULL */);
 384
 385
 386 HB_EXTERN unsigned int
 387 hb_ot_layout_feature_get_characters (hb_face_t      *face,
 388                                      hb_tag_t        table_tag,
 389                                      unsigned int    feature_index,
 390                                      unsigned int    start_offset,
 391                                      unsigned int   *char_count    /* IN/OUT.  May be NULL */,
 392                                      hb_codepoint_t *characters    /* OUT.     May be NULL */);
 393
 394 HB_END_DECLS
 395
 396 #endif /* HB_OT_LAYOUT_H */