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