src/hb-ot-layout.h

   1 /*
   2  * Copyright (C) 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 #define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
  39 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
  40 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
  41
  42 /*
  43  * GDEF
  44  */
  45
  46 typedef enum {
  47   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED = 0x0000,
  48   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH   = 0x0002,
  49   HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE     = 0x0004,
  50   HB_OT_LAYOUT_GLYPH_CLASS_MARK         = 0x0008,
  51   HB_OT_LAYOUT_GLYPH_CLASS_COMPONENT    = 0x0010
  52 } hb_ot_layout_glyph_class_t;
  53
  54 /* XXX These should eventually be removed as we move synthesized glyph
  55  * classes in harfbuzz. */
  56
  57 hb_bool_t
  58 hb_ot_layout_has_glyph_classes (hb_face_t *face);
  59
  60 hb_ot_layout_glyph_class_t
  61 hb_ot_layout_get_glyph_class (hb_face_t      *face,
  62                               hb_codepoint_t  glyph);
  63
  64 void
  65 hb_ot_layout_set_glyph_class (hb_face_t                 *face,
  66                               hb_codepoint_t             glyph,
  67                               hb_ot_layout_glyph_class_t klass);
  68
  69 void
  70 hb_ot_layout_build_glyph_classes (hb_face_t      *face,
  71                                   hb_codepoint_t *glyphs,
  72                                   unsigned char  *klasses,
  73                                   uint16_t        count);
  74
  75 /* Not that useful.  Provides list of attach points for a glyph that a
  76  * client may want to cache */
  77 unsigned int
  78 hb_ot_layout_get_attach_points (hb_face_t      *face,
  79                                 hb_codepoint_t  glyph,
  80                                 unsigned int    start_offset,
  81                                 unsigned int   *point_count /* IN/OUT */,
  82                                 unsigned int   *point_array /* OUT */);
  83
  84 /* Ligature caret positions */
  85 unsigned int
  86 hb_ot_layout_get_lig_carets (hb_font_t      *font,
  87                              hb_face_t      *face,
  88                              hb_codepoint_t  glyph,
  89                              unsigned int    start_offset,
  90                              unsigned int   *caret_count /* IN/OUT */,
  91                              int            *caret_array /* OUT */);
  92
  93
  94 /*
  95  * GSUB/GPOS feature query and enumeration interface
  96  */
  97
  98 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX            ((unsigned int) 0xFFFF)
  99 #define HB_OT_LAYOUT_NO_FEATURE_INDEX           ((unsigned int) 0xFFFF)
 100 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX     ((unsigned int) 0xFFFF)
 101
 102 unsigned int
 103 hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 104                                     hb_tag_t      table_tag,
 105                                     unsigned int  start_offset,
 106                                     unsigned int *script_count /* IN/OUT */,
 107                                     hb_tag_t     *script_tags /* OUT */);
 108
 109 hb_bool_t
 110 hb_ot_layout_table_find_script (hb_face_t    *face,
 111                                 hb_tag_t      table_tag,
 112                                 hb_tag_t      script_tag,
 113                                 unsigned int *script_index);
 114
 115 /* Like find_script, but takes zero-terminated array of scripts to test */
 116 hb_bool_t
 117 hb_ot_layout_table_choose_script (hb_face_t      *face,
 118                                   hb_tag_t        table_tag,
 119                                   const hb_tag_t *script_tags,
 120                                   unsigned int   *script_index);
 121
 122 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 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_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_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 unsigned int
 152 hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 153                                            hb_tag_t      table_tag,
 154                                            unsigned int  script_index,
 155                                            unsigned int  language_index,
 156                                            unsigned int  start_offset,
 157                                            unsigned int *feature_count /* IN/OUT */,
 158                                            unsigned int *feature_indexes /* OUT */);
 159
 160 unsigned int
 161 hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 162                                         hb_tag_t      table_tag,
 163                                         unsigned int  script_index,
 164                                         unsigned int  language_index,
 165                                         unsigned int  start_offset,
 166                                         unsigned int *feature_count /* IN/OUT */,
 167                                         hb_tag_t     *feature_tags /* OUT */);
 168
 169 hb_bool_t
 170 hb_ot_layout_language_find_feature (hb_face_t    *face,
 171                                     hb_tag_t      table_tag,
 172                                     unsigned int  script_index,
 173                                     unsigned int  language_index,
 174                                     hb_tag_t      feature_tag,
 175                                     unsigned int *feature_index);
 176
 177 unsigned int
 178 hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
 179                                          hb_tag_t      table_tag,
 180                                          unsigned int  feature_index,
 181                                          unsigned int  start_offset,
 182                                          unsigned int *lookup_count /* IN/OUT */,
 183                                          unsigned int *lookup_indexes /* OUT */);
 184
 185
 186 /*
 187  * GSUB
 188  */
 189
 190 hb_bool_t
 191 hb_ot_layout_has_substitution (hb_face_t *face);
 192
 193 hb_bool_t
 194 hb_ot_layout_substitute_lookup (hb_face_t    *face,
 195                                 hb_buffer_t  *buffer,
 196                                 unsigned int  lookup_index,
 197                                 hb_mask_t     mask);
 198
 199 /*
 200  * GPOS
 201  */
 202
 203 hb_bool_t
 204 hb_ot_layout_has_positioning (hb_face_t *face);
 205
 206 hb_bool_t
 207 hb_ot_layout_position_lookup (hb_font_t    *font,
 208                               hb_face_t    *face,
 209                               hb_buffer_t  *buffer,
 210                               unsigned int  lookup_index,
 211                               hb_mask_t     mask);
 212
 213 /* Should be called after all the position_lookup's are done */
 214 void
 215 hb_ot_layout_position_finish (hb_font_t    *font,
 216                               hb_face_t    *face,
 217                               hb_buffer_t  *buffer);
 218
 219
 220 HB_END_DECLS
 221
 222 #endif /* HB_OT_LAYOUT_H */