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-tag.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  * GDEF
  50  */
  51
  52 HB_EXTERN hb_bool_t
  53 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  54
  55 typedef enum {
  56   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED = 0,
  57   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH   = 1,
  58   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE     = 2,
  59   HB_OT_LAYOUT_GLYPH_CLASS_MARK         = 3,
  60   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT    = 4
  61 } hb_ot_layout_glyph_class_t;
  62
  63 HB_EXTERN hb_ot_layout_glyph_class_t
  64 hb_ot_layout_get_glyph_class (hb_face_t      *face,
  65                               hb_codepoint_t  glyph);
  66
  67 HB_EXTERN void
  68 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
  69                                   hb_ot_layout_glyph_class_t  klass,
  70                                   hb_set_t                   *glyphs /* OUT */);
  71
  72
  73 /* Not that useful.  Provides list of attach points for a glyph that a
  74  * client may want to cache */
  75 HB_EXTERN unsigned int
  76 hb_ot_layout_get_attach_points (hb_face_t      *face,
  77                                 hb_codepoint_t  glyph,
  78                                 unsigned int    start_offset,
  79                                 unsigned int   *point_count /* IN/OUT */,
  80                                 unsigned int   *point_array /* OUT */);
  81
  82 /* Ligature caret positions */
  83 HB_EXTERN unsigned int
  84 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
  85                                   hb_direction_t  direction,
  86                                   hb_codepoint_t  glyph,
  87                                   unsigned int    start_offset,
  88                                   unsigned int   *caret_count /* IN/OUT */,
  89                                   hb_position_t  *caret_array /* OUT */);
  90
  91
  92 /*
  93  * GSUB/GPOS feature query and enumeration interface
  94  */
  95
  96 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            0xFFFFu
  97 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           0xFFFFu
  98 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     0xFFFFu
  99 #define HB_OT_LAYOUT_NO_VARIATIONS_INDEX        0xFFFFFFFFu
 100
 101 HB_EXTERN unsigned int
 102 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 103                                     hb_tag_t      table_tag,
 104                                     unsigned int  start_offset,
 105                                     unsigned int *script_count /* IN/OUT */,
 106                                     hb_tag_t     *script_tags /* OUT */);
 107
 108 HB_EXTERN hb_bool_t
 109 hb_ot_layout_table_find_script (hb_face_t    *face,
 110                                 hb_tag_t      table_tag,
 111                                 hb_tag_t      script_tag,
 112                                 unsigned int *script_index);
 113
 114 /* Like find_script, but takes zero-terminated array of scripts to test */
 115 HB_EXTERN hb_bool_t
 116 hb_ot_layout_table_choose_script (hb_face_t      *face,
 117                                   hb_tag_t        table_tag,
 118                                   const hb_tag_t *script_tags,
 119                                   unsigned int   *script_index,
 120                                   hb_tag_t       *chosen_script);
 121
 122 HB_EXTERN unsigned int
 123 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 124                                      hb_tag_t      table_tag,
 125                                      unsigned int  start_offset,
 126                                      unsigned int *feature_count /* IN/OUT */,
 127                                      hb_tag_t     *feature_tags /* OUT */);
 128
 129 HB_EXTERN unsigned int
 130 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 131                                        hb_tag_t      table_tag,
 132                                        unsigned int  script_index,
 133                                        unsigned int  start_offset,
 134                                        unsigned int *language_count /* IN/OUT */,
 135                                        hb_tag_t     *language_tags /* OUT */);
 136
 137 HB_EXTERN hb_bool_t
 138 hb_ot_layout_script_find_language (hb_face_t    *face,
 139                                    hb_tag_t      table_tag,
 140                                    unsigned int  script_index,
 141                                    hb_tag_t      language_tag,
 142                                    unsigned int *language_index);
 143
 144 HB_EXTERN hb_bool_t
 145 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 146                                                   hb_tag_t      table_tag,
 147                                                   unsigned int  script_index,
 148                                                   unsigned int  language_index,
 149                                                   unsigned int *feature_index);
 150
 151 HB_EXTERN hb_bool_t
 152 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
 153                                             hb_tag_t      table_tag,
 154                                             unsigned int  script_index,
 155                                             unsigned int  language_index,
 156                                             unsigned int *feature_index,
 157                                             hb_tag_t     *feature_tag);
 158
 159 HB_EXTERN unsigned int
 160 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 161                                            hb_tag_t      table_tag,
 162                                            unsigned int  script_index,
 163                                            unsigned int  language_index,
 164                                            unsigned int  start_offset,
 165                                            unsigned int *feature_count /* IN/OUT */,
 166                                            unsigned int *feature_indexes /* OUT */);
 167
 168 HB_EXTERN unsigned int
 169 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 170                                         hb_tag_t      table_tag,
 171                                         unsigned int  script_index,
 172                                         unsigned int  language_index,
 173                                         unsigned int  start_offset,
 174                                         unsigned int *feature_count /* IN/OUT */,
 175                                         hb_tag_t     *feature_tags /* OUT */);
 176
 177 HB_EXTERN hb_bool_t
 178 hb_ot_layout_language_find_feature (hb_face_t    *face,
 179                                     hb_tag_t      table_tag,
 180                                     unsigned int  script_index,
 181                                     unsigned int  language_index,
 182                                     hb_tag_t      feature_tag,
 183                                     unsigned int *feature_index);
 184
 185 HB_EXTERN unsigned int
 186 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
 187                                   hb_tag_t      table_tag,
 188                                   unsigned int  feature_index,
 189                                   unsigned int  start_offset,
 190                                   unsigned int *lookup_count /* IN/OUT */,
 191                                   unsigned int *lookup_indexes /* OUT */);
 192
 193 HB_EXTERN unsigned int
 194 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
 195                                      hb_tag_t      table_tag);
 196
 197
 198 HB_EXTERN void
 199 hb_ot_layout_collect_lookups (hb_face_t      *face,
 200                               hb_tag_t        table_tag,
 201                               const hb_tag_t *scripts,
 202                               const hb_tag_t *languages,
 203                               const hb_tag_t *features,
 204                               hb_set_t       *lookup_indexes /* OUT */);
 205
 206 HB_EXTERN void
 207 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
 208                                     hb_tag_t      table_tag,
 209                                     unsigned int  lookup_index,
 210                                     hb_set_t     *glyphs_before, /* OUT. May be NULL */
 211                                     hb_set_t     *glyphs_input,  /* OUT. May be NULL */
 212                                     hb_set_t     *glyphs_after,  /* OUT. May be NULL */
 213                                     hb_set_t     *glyphs_output  /* OUT. May be NULL */);
 214
 215 #ifdef HB_NOT_IMPLEMENTED
 216 typedef struct
 217 {
 218   const hb_codepoint_t *before,
 219   unsigned int          before_length,
 220   const hb_codepoint_t *input,
 221   unsigned int          input_length,
 222   const hb_codepoint_t *after,
 223   unsigned int          after_length,
 224 } hb_ot_layout_glyph_sequence_t;
 225
 226 typedef hb_bool_t
 227 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
 228                                        hb_tag_t      table_tag,
 229                                        unsigned int  lookup_index,
 230                                        const hb_ot_layout_glyph_sequence_t *sequence,
 231                                        void         *user_data);
 232
 233 HB_EXTERN void
 234 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
 235                                          hb_tag_t      table_tag,
 236                                          unsigned int  lookup_index,
 237                                          hb_ot_layout_glyph_sequence_func_t callback,
 238                                          void         *user_data);
 239 #endif
 240
 241 /* Variations support */
 242
 243 HB_EXTERN hb_bool_t
 244 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
 245                                             hb_tag_t      table_tag,
 246                                             const int    *coords,
 247                                             unsigned int  num_coords,
 248                                             unsigned int *variations_index /* out */);
 249
 250 HB_EXTERN unsigned int
 251 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
 252                                                   hb_tag_t      table_tag,
 253                                                   unsigned int  feature_index,
 254                                                   unsigned int  variations_index,
 255                                                   unsigned int  start_offset,
 256                                                   unsigned int *lookup_count /* IN/OUT */,
 257                                                   unsigned int *lookup_indexes /* OUT */);
 258
 259
 260 /*
 261  * GSUB
 262  */
 263
 264 HB_EXTERN hb_bool_t
 265 hb_ot_layout_has_substitution (hb_face_t *face);
 266
 267 HB_EXTERN hb_bool_t
 268 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
 269                                       unsigned int          lookup_index,
 270                                       const hb_codepoint_t *glyphs,
 271                                       unsigned int          glyphs_length,
 272                                       hb_bool_t             zero_context);
 273
 274 HB_EXTERN void
 275 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
 276                                         unsigned int  lookup_index,
 277                                         hb_set_t     *glyphs
 278                                         /*TODO , hb_bool_t  inclusive */);
 279
 280 HB_EXTERN void
 281 hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
 282                                          const hb_set_t *lookups,
 283                                          hb_set_t       *glyphs);
 284
 285
 286 #ifdef HB_NOT_IMPLEMENTED
 287 /* Note: You better have GDEF when using this API, or marks won't do much. */
 288 HB_EXTERN hb_bool_t
 289 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
 290                                 unsigned int          lookup_index,
 291                                 const hb_ot_layout_glyph_sequence_t *sequence,
 292                                 unsigned int          out_size,
 293                                 hb_codepoint_t       *glyphs_out,   /* OUT */
 294                                 unsigned int         *clusters_out, /* OUT */
 295                                 unsigned int         *out_length    /* OUT */);
 296 #endif
 297
 298
 299 /*
 300  * GPOS
 301  */
 302
 303 HB_EXTERN hb_bool_t
 304 hb_ot_layout_has_positioning (hb_face_t *face);
 305
 306 #ifdef HB_NOT_IMPLEMENTED
 307 /* Note: You better have GDEF when using this API, or marks won't do much. */
 308 HB_EXTERN hb_bool_t
 309 Xhb_ot_layout_lookup_position (hb_font_t            *font,
 310                               unsigned int          lookup_index,
 311                               const hb_ot_layout_glyph_sequence_t *sequence,
 312                               hb_glyph_position_t  *positions /* IN / OUT */);
 313 #endif
 314
 315 /* Optical 'size' feature info.  Returns true if found.
 316  * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#size */
 317 HB_EXTERN hb_bool_t
 318 hb_ot_layout_get_size_params (hb_face_t    *face,
 319                               unsigned int *design_size,       /* OUT.  May be NULL */
 320                               unsigned int *subfamily_id,      /* OUT.  May be NULL */
 321                               unsigned int *subfamily_name_id, /* OUT.  May be NULL */
 322                               unsigned int *range_start,       /* OUT.  May be NULL */
 323                               unsigned int *range_end          /* OUT.  May be NULL */);
 324
 325
 326 /*
 327  * BASE
 328  */
 329 #if 0
 330
 331 #define HB_OT_TAG_BASE_HANG HB_TAG('h','a','n','g')
 332 #define HB_OT_TAG_BASE_ICFB HB_TAG('i','c','f','b')
 333 #define HB_OT_TAG_BASE_ICFT HB_TAG('i','c','f','t')
 334 #define HB_OT_TAG_BASE_IDEO HB_TAG('i','d','e','o')
 335 #define HB_OT_TAG_BASE_IDTB HB_TAG('i','d','t','b')
 336 #define HB_OT_TAG_BASE_MATH HB_TAG('m','a','t','h')
 337 #define HB_OT_TAG_BASE_ROMN HB_TAG('r','o','m','n')
 338
 339 #endif
 340
 341
 342 HB_END_DECLS
 343
 344 #endif /* HB_OT_LAYOUT_H */