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  * GDEF
  47  */
  48
  49 hb_bool_t
  50 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  51
  52 /* Not that useful.  Provides list of attach points for a glyph that a
  53  * client may want to cache */
  54 unsigned int
  55 hb_ot_layout_get_attach_points (hb_face_t      *face,
  56                                 hb_codepoint_t  glyph,
  57                                 unsigned int    start_offset,
  58                                 unsigned int   *point_count /* IN/OUT */,
  59                                 unsigned int   *point_array /* OUT */);
  60
  61 /* Ligature caret positions */
  62 unsigned int
  63 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
  64                                   hb_direction_t  direction,
  65                                   hb_codepoint_t  glyph,
  66                                   unsigned int    start_offset,
  67                                   unsigned int   *caret_count /* IN/OUT */,
  68                                   hb_position_t  *caret_array /* OUT */);
  69
  70
  71 /*
  72  * GSUB/GPOS feature query and enumeration interface
  73  */
  74
  75 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            ((unsigned int) 0xFFFF)
  76 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           ((unsigned int) 0xFFFF)
  77 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     ((unsigned int) 0xFFFF)
  78
  79 unsigned int
  80 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
  81                                     hb_tag_t      table_tag,
  82                                     unsigned int  start_offset,
  83                                     unsigned int *script_count /* IN/OUT */,
  84                                     hb_tag_t     *script_tags /* OUT */);
  85
  86 hb_bool_t
  87 hb_ot_layout_table_find_script (hb_face_t    *face,
  88                                 hb_tag_t      table_tag,
  89                                 hb_tag_t      script_tag,
  90                                 unsigned int *script_index);
  91
  92 /* Like find_script, but takes zero-terminated array of scripts to test */
  93 hb_bool_t
  94 hb_ot_layout_table_choose_script (hb_face_t      *face,
  95                                   hb_tag_t        table_tag,
  96                                   const hb_tag_t *script_tags,
  97                                   unsigned int   *script_index,
  98                                   hb_tag_t       *chosen_script);
  99
 100 unsigned int
 101 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 102                                      hb_tag_t      table_tag,
 103                                      unsigned int  start_offset,
 104                                      unsigned int *feature_count /* IN/OUT */,
 105                                      hb_tag_t     *feature_tags /* OUT */);
 106
 107 unsigned int
 108 hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 109                                        hb_tag_t      table_tag,
 110                                        unsigned int  script_index,
 111                                        unsigned int  start_offset,
 112                                        unsigned int *language_count /* IN/OUT */,
 113                                        hb_tag_t     *language_tags /* OUT */);
 114
 115 hb_bool_t
 116 hb_ot_layout_script_find_language (hb_face_t    *face,
 117                                    hb_tag_t      table_tag,
 118                                    unsigned int  script_index,
 119                                    hb_tag_t      language_tag,
 120                                    unsigned int *language_index);
 121
 122 hb_bool_t
 123 hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 124                                                   hb_tag_t      table_tag,
 125                                                   unsigned int  script_index,
 126                                                   unsigned int  language_index,
 127                                                   unsigned int *feature_index);
 128
 129 unsigned int
 130 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 131                                            hb_tag_t      table_tag,
 132                                            unsigned int  script_index,
 133                                            unsigned int  language_index,
 134                                            unsigned int  start_offset,
 135                                            unsigned int *feature_count /* IN/OUT */,
 136                                            unsigned int *feature_indexes /* OUT */);
 137
 138 unsigned int
 139 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 140                                         hb_tag_t      table_tag,
 141                                         unsigned int  script_index,
 142                                         unsigned int  language_index,
 143                                         unsigned int  start_offset,
 144                                         unsigned int *feature_count /* IN/OUT */,
 145                                         hb_tag_t     *feature_tags /* OUT */);
 146
 147 hb_bool_t
 148 hb_ot_layout_language_find_feature (hb_face_t    *face,
 149                                     hb_tag_t      table_tag,
 150                                     unsigned int  script_index,
 151                                     unsigned int  language_index,
 152                                     hb_tag_t      feature_tag,
 153                                     unsigned int *feature_index);
 154
 155 unsigned int
 156 hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
 157                                          hb_tag_t      table_tag,
 158                                          unsigned int  feature_index,
 159                                          unsigned int  start_offset,
 160                                          unsigned int *lookup_count /* IN/OUT */,
 161                                          unsigned int *lookup_indexes /* OUT */);
 162
 163
 164 /*
 165  * GSUB
 166  */
 167
 168 hb_bool_t
 169 hb_ot_layout_has_substitution (hb_face_t *face);
 170
 171 /* Should be called before all the substitute_lookup's are done. */
 172 void
 173 hb_ot_layout_substitute_start (hb_buffer_t  *buffer);
 174
 175 hb_bool_t
 176 hb_ot_layout_substitute_lookup (hb_face_t    *face,
 177                                 hb_buffer_t  *buffer,
 178                                 unsigned int  lookup_index,
 179                                 hb_mask_t     mask);
 180
 181 /* Should be called after all the substitute_lookup's are done */
 182 void
 183 hb_ot_layout_substitute_finish (hb_buffer_t  *buffer);
 184
 185
 186 void
 187 hb_ot_layout_substitute_closure_lookup (hb_face_t    *face,
 188                                         hb_set_t     *glyphs,
 189                                         unsigned int  lookup_index);
 190
 191 /*
 192  * GPOS
 193  */
 194
 195 hb_bool_t
 196 hb_ot_layout_has_positioning (hb_face_t *face);
 197
 198 /* Should be called before all the position_lookup's are done.  Resets positions to zero. */
 199 void
 200 hb_ot_layout_position_start (hb_buffer_t  *buffer);
 201
 202 hb_bool_t
 203 hb_ot_layout_position_lookup (hb_font_t    *font,
 204                               hb_buffer_t  *buffer,
 205                               unsigned int  lookup_index,
 206                               hb_mask_t     mask);
 207
 208 /* Should be called after all the position_lookup's are done */
 209 void
 210 hb_ot_layout_position_finish (hb_buffer_t  *buffer);
 211
 212
 213 HB_END_DECLS
 214
 215 #endif /* HB_OT_LAYOUT_H */