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_LAYOUT_H
  28 #define HB_OT_LAYOUT_H
  29
  30 #include "hb-common.h"
  31 #include "hb-buffer.h"
  32 #include "hb-font.h"
  33
  34 #include "hb-ot-tag.h"
  35
  36 HB_BEGIN_DECLS
  37
  38
  39 #define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
  40 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
  41 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
  42
  43 /*
  44  * GDEF
  45  */
  46
  47 hb_bool_t
  48 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  49
  50 /* Not that useful.  Provides list of attach points for a glyph that a
  51  * client may want to cache */
  52 unsigned int
  53 hb_ot_layout_get_attach_points (hb_face_t      *face,
  54                                 hb_codepoint_t  glyph,
  55                                 unsigned int    start_offset,
  56                                 unsigned int   *point_count /* IN/OUT */,
  57                                 unsigned int   *point_array /* OUT */);
  58
  59 /* Ligature caret positions */
  60 unsigned int
  61 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
  62                                   hb_direction_t  direction,
  63                                   hb_codepoint_t  glyph,
  64                                   unsigned int    start_offset,
  65                                   unsigned int   *caret_count /* IN/OUT */,
  66                                   hb_position_t  *caret_array /* OUT */);
  67
  68
  69 /*
  70  * GSUB/GPOS feature query and enumeration interface
  71  */
  72
  73 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            ((unsigned int) 0xFFFF)
  74 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           ((unsigned int) 0xFFFF)
  75 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     ((unsigned int) 0xFFFF)
  76
  77 unsigned int
  78 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
  79                                     hb_tag_t      table_tag,
  80                                     unsigned int  start_offset,
  81                                     unsigned int *script_count /* IN/OUT */,
  82                                     hb_tag_t     *script_tags /* OUT */);
  83
  84 hb_bool_t
  85 hb_ot_layout_table_find_script (hb_face_t    *face,
  86                                 hb_tag_t      table_tag,
  87                                 hb_tag_t      script_tag,
  88                                 unsigned int *script_index);
  89
  90 /* Like find_script, but takes zero-terminated array of scripts to test */
  91 hb_bool_t
  92 hb_ot_layout_table_choose_script (hb_face_t      *face,
  93                                   hb_tag_t        table_tag,
  94                                   const hb_tag_t *script_tags,
  95                                   unsigned int   *script_index,
  96                                   hb_tag_t       *chosen_script);
  97
  98 unsigned int
  99 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 100                                      hb_tag_t      table_tag,
 101                                      unsigned int  start_offset,
 102                                      unsigned int *feature_count /* IN/OUT */,
 103                                      hb_tag_t     *feature_tags /* OUT */);
 104
 105 unsigned int
 106 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 107                                        hb_tag_t      table_tag,
 108                                        unsigned int  script_index,
 109                                        unsigned int  start_offset,
 110                                        unsigned int *language_count /* IN/OUT */,
 111                                        hb_tag_t     *language_tags /* OUT */);
 112
 113 hb_bool_t
 114 hb_ot_layout_script_find_language (hb_face_t    *face,
 115                                    hb_tag_t      table_tag,
 116                                    unsigned int  script_index,
 117                                    hb_tag_t      language_tag,
 118                                    unsigned int *language_index);
 119
 120 hb_bool_t
 121 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 122                                                   hb_tag_t      table_tag,
 123                                                   unsigned int  script_index,
 124                                                   unsigned int  language_index,
 125                                                   unsigned int *feature_index);
 126
 127 unsigned int
 128 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 129                                            hb_tag_t      table_tag,
 130                                            unsigned int  script_index,
 131                                            unsigned int  language_index,
 132                                            unsigned int  start_offset,
 133                                            unsigned int *feature_count /* IN/OUT */,
 134                                            unsigned int *feature_indexes /* OUT */);
 135
 136 unsigned int
 137 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 138                                         hb_tag_t      table_tag,
 139                                         unsigned int  script_index,
 140                                         unsigned int  language_index,
 141                                         unsigned int  start_offset,
 142                                         unsigned int *feature_count /* IN/OUT */,
 143                                         hb_tag_t     *feature_tags /* OUT */);
 144
 145 hb_bool_t
 146 hb_ot_layout_language_find_feature (hb_face_t    *face,
 147                                     hb_tag_t      table_tag,
 148                                     unsigned int  script_index,
 149                                     unsigned int  language_index,
 150                                     hb_tag_t      feature_tag,
 151                                     unsigned int *feature_index);
 152
 153 unsigned int
 154 hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
 155                                          hb_tag_t      table_tag,
 156                                          unsigned int  feature_index,
 157                                          unsigned int  start_offset,
 158                                          unsigned int *lookup_count /* IN/OUT */,
 159                                          unsigned int *lookup_indexes /* OUT */);
 160
 161
 162 /*
 163  * GSUB
 164  */
 165
 166 hb_bool_t
 167 hb_ot_layout_has_substitution (hb_face_t *face);
 168
 169 /* Should be called before all the substitute_lookup's are done. */
 170 void
 171 hb_ot_layout_substitute_start (hb_buffer_t  *buffer);
 172
 173 hb_bool_t
 174 hb_ot_layout_substitute_lookup (hb_face_t    *face,
 175                                 hb_buffer_t  *buffer,
 176                                 unsigned int  lookup_index,
 177                                 hb_mask_t     mask);
 178
 179 /* Should be called after all the substitute_lookup's are done */
 180 void
 181 hb_ot_layout_substitute_finish (hb_buffer_t  *buffer);
 182
 183 /*
 184  * GPOS
 185  */
 186
 187 hb_bool_t
 188 hb_ot_layout_has_positioning (hb_face_t *face);
 189
 190 /* Should be called before all the position_lookup's are done.  Resets positions to zero. */
 191 void
 192 hb_ot_layout_position_start (hb_buffer_t  *buffer);
 193
 194 hb_bool_t
 195 hb_ot_layout_position_lookup (hb_font_t    *font,
 196                               hb_buffer_t  *buffer,
 197                               unsigned int  lookup_index,
 198                               hb_mask_t     mask);
 199
 200 /* Should be called after all the position_lookup's are done */
 201 void
 202 hb_ot_layout_position_finish (hb_buffer_t  *buffer);
 203
 204
 205 HB_END_DECLS
 206
 207 #endif /* HB_OT_LAYOUT_H */