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_GDEF HB_TAG('G','D','E','F')
  42 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
  43 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
  44 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
  45
  46
  47 /*
  48  * GDEF
  49  */
  50
  51 HB_EXTERN hb_bool_t
  52 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  53
  54 typedef enum {
  55   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED = 0,
  56   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH   = 1,
  57   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE     = 2,
  58   HB_OT_LAYOUT_GLYPH_CLASS_MARK         = 3,
  59   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT    = 4
  60 } hb_ot_layout_glyph_class_t;
  61
  62 HB_EXTERN hb_ot_layout_glyph_class_t
  63 hb_ot_layout_get_glyph_class (hb_face_t      *face,
  64                               hb_codepoint_t  glyph);
  65
  66 HB_EXTERN void
  67 hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
  68                                   hb_ot_layout_glyph_class_t  klass,
  69                                   hb_set_t                   *glyphs /* OUT */);
  70
  71
  72 /* Not that useful.  Provides list of attach points for a glyph that a
  73  * client may want to cache */
  74 HB_EXTERN unsigned int
  75 hb_ot_layout_get_attach_points (hb_face_t      *face,
  76                                 hb_codepoint_t  glyph,
  77                                 unsigned int    start_offset,
  78                                 unsigned int   *point_count /* IN/OUT */,
  79                                 unsigned int   *point_array /* OUT */);
  80
  81 /* Ligature caret positions */
  82 HB_EXTERN unsigned int
  83 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
  84                                   hb_direction_t  direction,
  85                                   hb_codepoint_t  glyph,
  86                                   unsigned int    start_offset,
  87                                   unsigned int   *caret_count /* IN/OUT */,
  88                                   hb_position_t  *caret_array /* OUT */);
  89
  90
  91 /*
  92  * GSUB/GPOS feature query and enumeration interface
  93  */
  94
  95 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            0xFFFFu
  96 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           0xFFFFu
  97 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     0xFFFFu
  98 #define HB_OT_LAYOUT_NO_VARIATIONS_INDEX        0xFFFFFFFFu
  99
 100 HB_EXTERN unsigned int
 101 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 102                                     hb_tag_t      table_tag,
 103                                     unsigned int  start_offset,
 104                                     unsigned int *script_count /* IN/OUT */,
 105                                     hb_tag_t     *script_tags /* OUT */);
 106
 107 HB_EXTERN hb_bool_t
 108 hb_ot_layout_table_find_script (hb_face_t    *face,
 109                                 hb_tag_t      table_tag,
 110                                 hb_tag_t      script_tag,
 111                                 unsigned int *script_index);
 112
 113 /* Like find_script, but takes zero-terminated array of scripts to test */
 114 HB_EXTERN hb_bool_t
 115 hb_ot_layout_table_choose_script (hb_face_t      *face,
 116                                   hb_tag_t        table_tag,
 117                                   const hb_tag_t *script_tags,
 118                                   unsigned int   *script_index,
 119                                   hb_tag_t       *chosen_script);
 120
 121 HB_EXTERN unsigned int
 122 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 123                                      hb_tag_t      table_tag,
 124                                      unsigned int  start_offset,
 125                                      unsigned int *feature_count /* IN/OUT */,
 126                                      hb_tag_t     *feature_tags /* OUT */);
 127
 128 HB_EXTERN unsigned int
 129 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 130                                        hb_tag_t      table_tag,
 131                                        unsigned int  script_index,
 132                                        unsigned int  start_offset,
 133                                        unsigned int *language_count /* IN/OUT */,
 134                                        hb_tag_t     *language_tags /* OUT */);
 135
 136 HB_EXTERN hb_bool_t
 137 hb_ot_layout_script_find_language (hb_face_t    *face,
 138                                    hb_tag_t      table_tag,
 139                                    unsigned int  script_index,
 140                                    hb_tag_t      language_tag,
 141                                    unsigned int *language_index);
 142
 143 HB_EXTERN hb_bool_t
 144 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 145                                                   hb_tag_t      table_tag,
 146                                                   unsigned int  script_index,
 147                                                   unsigned int  language_index,
 148                                                   unsigned int *feature_index);
 149
 150 HB_EXTERN hb_bool_t
 151 hb_ot_layout_language_get_required_feature (hb_face_t    *face,
 152                                             hb_tag_t      table_tag,
 153                                             unsigned int  script_index,
 154                                             unsigned int  language_index,
 155                                             unsigned int *feature_index,
 156                                             hb_tag_t     *feature_tag);
 157
 158 HB_EXTERN unsigned int
 159 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 160                                            hb_tag_t      table_tag,
 161                                            unsigned int  script_index,
 162                                            unsigned int  language_index,
 163                                            unsigned int  start_offset,
 164                                            unsigned int *feature_count /* IN/OUT */,
 165                                            unsigned int *feature_indexes /* OUT */);
 166
 167 HB_EXTERN unsigned int
 168 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 169                                         hb_tag_t      table_tag,
 170                                         unsigned int  script_index,
 171                                         unsigned int  language_index,
 172                                         unsigned int  start_offset,
 173                                         unsigned int *feature_count /* IN/OUT */,
 174                                         hb_tag_t     *feature_tags /* OUT */);
 175
 176 HB_EXTERN hb_bool_t
 177 hb_ot_layout_language_find_feature (hb_face_t    *face,
 178                                     hb_tag_t      table_tag,
 179                                     unsigned int  script_index,
 180                                     unsigned int  language_index,
 181                                     hb_tag_t      feature_tag,
 182                                     unsigned int *feature_index);
 183
 184 HB_EXTERN unsigned int
 185 hb_ot_layout_feature_get_lookups (hb_face_t    *face,
 186                                   hb_tag_t      table_tag,
 187                                   unsigned int  feature_index,
 188                                   unsigned int  start_offset,
 189                                   unsigned int *lookup_count /* IN/OUT */,
 190                                   unsigned int *lookup_indexes /* OUT */);
 191
 192 HB_EXTERN unsigned int
 193 hb_ot_layout_table_get_lookup_count (hb_face_t    *face,
 194                                      hb_tag_t      table_tag);
 195
 196
 197 HB_EXTERN void
 198 hb_ot_layout_collect_lookups (hb_face_t      *face,
 199                               hb_tag_t        table_tag,
 200                               const hb_tag_t *scripts,
 201                               const hb_tag_t *languages,
 202                               const hb_tag_t *features,
 203                               hb_set_t       *lookup_indexes /* OUT */);
 204
 205 HB_EXTERN void
 206 hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
 207                                     hb_tag_t      table_tag,
 208                                     unsigned int  lookup_index,
 209                                     hb_set_t     *glyphs_before, /* OUT. May be NULL */
 210                                     hb_set_t     *glyphs_input,  /* OUT. May be NULL */
 211                                     hb_set_t     *glyphs_after,  /* OUT. May be NULL */
 212                                     hb_set_t     *glyphs_output  /* OUT. May be NULL */);
 213
 214 #ifdef HB_NOT_IMPLEMENTED
 215 typedef struct
 216 {
 217   const hb_codepoint_t *before,
 218   unsigned int          before_length,
 219   const hb_codepoint_t *input,
 220   unsigned int          input_length,
 221   const hb_codepoint_t *after,
 222   unsigned int          after_length,
 223 } hb_ot_layout_glyph_sequence_t;
 224
 225 typedef hb_bool_t
 226 (*hb_ot_layout_glyph_sequence_func_t) (hb_font_t    *font,
 227                                        hb_tag_t      table_tag,
 228                                        unsigned int  lookup_index,
 229                                        const hb_ot_layout_glyph_sequence_t *sequence,
 230                                        void         *user_data);
 231
 232 HB_EXTERN void
 233 Xhb_ot_layout_lookup_enumerate_sequences (hb_face_t    *face,
 234                                          hb_tag_t      table_tag,
 235                                          unsigned int  lookup_index,
 236                                          hb_ot_layout_glyph_sequence_func_t callback,
 237                                          void         *user_data);
 238 #endif
 239
 240 /* Variations support */
 241
 242 HB_EXTERN hb_bool_t
 243 hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
 244                                             hb_tag_t      table_tag,
 245                                             const int    *coords,
 246                                             unsigned int  num_coords,
 247                                             unsigned int *variations_index /* out */);
 248
 249 HB_EXTERN unsigned int
 250 hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
 251                                                   hb_tag_t      table_tag,
 252                                                   unsigned int  feature_index,
 253                                                   unsigned int  variations_index,
 254                                                   unsigned int  start_offset,
 255                                                   unsigned int *lookup_count /* IN/OUT */,
 256                                                   unsigned int *lookup_indexes /* OUT */);
 257
 258
 259 /*
 260  * GSUB
 261  */
 262
 263 HB_EXTERN hb_bool_t
 264 hb_ot_layout_has_substitution (hb_face_t *face);
 265
 266 HB_EXTERN hb_bool_t
 267 hb_ot_layout_lookup_would_substitute (hb_face_t            *face,
 268                                       unsigned int          lookup_index,
 269                                       const hb_codepoint_t *glyphs,
 270                                       unsigned int          glyphs_length,
 271                                       hb_bool_t             zero_context);
 272
 273 HB_EXTERN void
 274 hb_ot_layout_lookup_substitute_closure (hb_face_t    *face,
 275                                         unsigned int  lookup_index,
 276                                         hb_set_t     *glyphs
 277                                         /*TODO , hb_bool_t  inclusive */);
 278
 279 #ifdef HB_NOT_IMPLEMENTED
 280 /* Note: You better have GDEF when using this API, or marks won't do much. */
 281 HB_EXTERN hb_bool_t
 282 Xhb_ot_layout_lookup_substitute (hb_font_t            *font,
 283                                 unsigned int          lookup_index,
 284                                 const hb_ot_layout_glyph_sequence_t *sequence,
 285                                 unsigned int          out_size,
 286                                 hb_codepoint_t       *glyphs_out,   /* OUT */
 287                                 unsigned int         *clusters_out, /* OUT */
 288                                 unsigned int         *out_length    /* OUT */);
 289 #endif
 290
 291
 292 /*
 293  * GPOS
 294  */
 295
 296 HB_EXTERN hb_bool_t
 297 hb_ot_layout_has_positioning (hb_face_t *face);
 298
 299 #ifdef HB_NOT_IMPLEMENTED
 300 /* Note: You better have GDEF when using this API, or marks won't do much. */
 301 HB_EXTERN hb_bool_t
 302 Xhb_ot_layout_lookup_position (hb_font_t            *font,
 303                               unsigned int          lookup_index,
 304                               const hb_ot_layout_glyph_sequence_t *sequence,
 305                               hb_glyph_position_t  *positions /* IN / OUT */);
 306 #endif
 307
 308 /* Optical 'size' feature info.  Returns true if found.
 309  * http://www.microsoft.com/typography/otspec/features_pt.htm#size */
 310 HB_EXTERN hb_bool_t
 311 hb_ot_layout_get_size_params (hb_face_t    *face,
 312                               unsigned int *design_size,       /* OUT.  May be NULL */
 313                               unsigned int *subfamily_id,      /* OUT.  May be NULL */
 314                               unsigned int *subfamily_name_id, /* OUT.  May be NULL */
 315                               unsigned int *range_start,       /* OUT.  May be NULL */
 316                               unsigned int *range_end          /* OUT.  May be NULL */);
 317
 318
 319 HB_END_DECLS
 320
 321 #endif /* HB_OT_LAYOUT_H */