third_party/harfbuzz-ng/src/hb-ot-shape-complex-private.hh

   1 /*
   2  * Copyright © 2010,2011,2012  Google, 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  * Google Author(s): Behdad Esfahbod
  25  */
  26
  27 #ifndef HB_OT_SHAPE_COMPLEX_PRIVATE_HH
  28 #define HB_OT_SHAPE_COMPLEX_PRIVATE_HH
  29
  30 #include "hb-private.hh"
  31
  32 #include "hb-ot-shape-private.hh"
  33 #include "hb-ot-shape-normalize-private.hh"
  34
  35
  36
  37 /* buffer var allocations, used by complex shapers */
  38 #define complex_var_u8_0()      var2.u8[2]
  39 #define complex_var_u8_1()      var2.u8[3]
  40
  41
  42 enum hb_ot_shape_zero_width_marks_type_t {
  43   HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
  44 //  HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_EARLY,
  45   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
  46   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
  47   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
  48
  49   HB_OT_SHAPE_ZERO_WIDTH_MARKS_DEFAULT = HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE
  50 };
  51
  52
  53 /* Master OT shaper list */
  54 #define HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS \
  55   HB_COMPLEX_SHAPER_IMPLEMENT (default) /* should be first */ \
  56   HB_COMPLEX_SHAPER_IMPLEMENT (arabic) \
  57   HB_COMPLEX_SHAPER_IMPLEMENT (hangul) \
  58   HB_COMPLEX_SHAPER_IMPLEMENT (hebrew) \
  59   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar_old) \
  60   HB_COMPLEX_SHAPER_IMPLEMENT (indic) \
  61   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
  62   HB_COMPLEX_SHAPER_IMPLEMENT (sea) \
  63   HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
  64   HB_COMPLEX_SHAPER_IMPLEMENT (tibetan) \
  65   /* ^--- Add new shapers here */
  66
  67
  68 struct hb_ot_complex_shaper_t
  69 {
  70   char name[8];
  71
  72   /* collect_features()
  73    * Called during shape_plan().
  74    * Shapers should use plan->map to add their features and callbacks.
  75    * May be NULL.
  76    */
  77   void (*collect_features) (hb_ot_shape_planner_t *plan);
  78
  79   /* override_features()
  80    * Called during shape_plan().
  81    * Shapers should use plan->map to override features and add callbacks after
  82    * common features are added.
  83    * May be NULL.
  84    */
  85   void (*override_features) (hb_ot_shape_planner_t *plan);
  86
  87
  88   /* data_create()
  89    * Called at the end of shape_plan().
  90    * Whatever shapers return will be accessible through plan->data later.
  91    * If NULL is returned, means a plan failure.
  92    */
  93   void *(*data_create) (const hb_ot_shape_plan_t *plan);
  94
  95   /* data_destroy()
  96    * Called when the shape_plan is being destroyed.
  97    * plan->data is passed here for destruction.
  98    * If NULL is returned, means a plan failure.
  99    * May be NULL.
 100    */
 101   void (*data_destroy) (void *data);
 102
 103
 104   /* preprocess_text()
 105    * Called during shape().
 106    * Shapers can use to modify text before shaping starts.
 107    * May be NULL.
 108    */
 109   void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
 110                            hb_buffer_t              *buffer,
 111                            hb_font_t                *font);
 112
 113
 114   hb_ot_shape_normalization_mode_t normalization_preference;
 115
 116   /* decompose()
 117    * Called during shape()'s normalization.
 118    * May be NULL.
 119    */
 120   bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
 121                      hb_codepoint_t  ab,
 122                      hb_codepoint_t *a,
 123                      hb_codepoint_t *b);
 124
 125   /* compose()
 126    * Called during shape()'s normalization.
 127    * May be NULL.
 128    */
 129   bool (*compose) (const hb_ot_shape_normalize_context_t *c,
 130                    hb_codepoint_t  a,
 131                    hb_codepoint_t  b,
 132                    hb_codepoint_t *ab);
 133
 134   /* setup_masks()
 135    * Called during shape().
 136    * Shapers should use map to get feature masks and set on buffer.
 137    * Shapers may NOT modify characters.
 138    * May be NULL.
 139    */
 140   void (*setup_masks) (const hb_ot_shape_plan_t *plan,
 141                        hb_buffer_t              *buffer,
 142                        hb_font_t                *font);
 143
 144   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
 145
 146   bool fallback_position;
 147 };
 148
 149 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
 150 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
 151 #undef HB_COMPLEX_SHAPER_IMPLEMENT
 152
 153
 154 static inline const hb_ot_complex_shaper_t *
 155 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 156 {
 157   switch ((hb_tag_t) planner->props.script)
 158   {
 159     default:
 160       return &_hb_ot_complex_shaper_default;
 161
 162
 163     /* Unicode-1.1 additions */
 164     case HB_SCRIPT_ARABIC:
 165
 166     /* Unicode-3.0 additions */
 167     case HB_SCRIPT_MONGOLIAN:
 168     case HB_SCRIPT_SYRIAC:
 169
 170     /* Unicode-5.0 additions */
 171     case HB_SCRIPT_NKO:
 172     case HB_SCRIPT_PHAGS_PA:
 173
 174     /* Unicode-6.0 additions */
 175     case HB_SCRIPT_MANDAIC:
 176
 177     /* Unicode-7.0 additions */
 178     case HB_SCRIPT_MANICHAEAN:
 179     case HB_SCRIPT_PSALTER_PAHLAVI:
 180
 181       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
 182        * This is because we do fallback shaping for Arabic script (and not others). */
 183       if (planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
 184           planner->props.script == HB_SCRIPT_ARABIC)
 185         return &_hb_ot_complex_shaper_arabic;
 186       else
 187         return &_hb_ot_complex_shaper_default;
 188
 189
 190     /* Unicode-1.1 additions */
 191     case HB_SCRIPT_THAI:
 192     case HB_SCRIPT_LAO:
 193
 194       return &_hb_ot_complex_shaper_thai;
 195
 196
 197     /* Unicode-1.1 additions */
 198     case HB_SCRIPT_HANGUL:
 199
 200       return &_hb_ot_complex_shaper_hangul;
 201
 202
 203     /* Unicode-2.0 additions */
 204     case HB_SCRIPT_TIBETAN:
 205
 206       return &_hb_ot_complex_shaper_tibetan;
 207
 208
 209     /* Unicode-1.1 additions */
 210     case HB_SCRIPT_HEBREW:
 211
 212       return &_hb_ot_complex_shaper_hebrew;
 213
 214
 215     /* ^--- Add new shapers here */
 216
 217
 218 #if 0
 219     /* Note:
 220      *
 221      * These disabled scripts are listed in ucd/IndicSyllabicCategory.txt, but according
 222      * to Martin Hosken and Jonathan Kew do not require complex shaping.
 223      *
 224      * TODO We should automate figuring out which scripts do not need complex shaping
 225      *
 226      * TODO We currently keep data for these scripts in our indic table.  Need to fix the
 227      * generator to not do that.
 228      */
 229
 230
 231     /* Simple? */
 232
 233     /* Unicode-3.2 additions */
 234     case HB_SCRIPT_BUHID:
 235     case HB_SCRIPT_HANUNOO:
 236
 237     /* Unicode-5.1 additions */
 238     case HB_SCRIPT_SAURASHTRA:
 239
 240     /* Unicode-6.0 additions */
 241     case HB_SCRIPT_BATAK:
 242     case HB_SCRIPT_BRAHMI:
 243
 244
 245     /* Simple */
 246
 247     /* Unicode-1.1 additions */
 248     /* These have their own shaper now. */
 249     case HB_SCRIPT_LAO:
 250     case HB_SCRIPT_THAI:
 251
 252     /* Unicode-3.2 additions */
 253     case HB_SCRIPT_TAGALOG:
 254     case HB_SCRIPT_TAGBANWA:
 255
 256     /* Unicode-4.0 additions */
 257     case HB_SCRIPT_LIMBU:
 258     case HB_SCRIPT_TAI_LE:
 259
 260     /* Unicode-4.1 additions */
 261     case HB_SCRIPT_KHAROSHTHI:
 262     case HB_SCRIPT_NEW_TAI_LUE:
 263     case HB_SCRIPT_SYLOTI_NAGRI:
 264
 265     /* Unicode-5.1 additions */
 266     case HB_SCRIPT_KAYAH_LI:
 267
 268     /* Unicode-5.2 additions */
 269     case HB_SCRIPT_TAI_VIET:
 270
 271
 272 #endif
 273
 274     /* Unicode-1.1 additions */
 275     case HB_SCRIPT_BENGALI:
 276     case HB_SCRIPT_DEVANAGARI:
 277     case HB_SCRIPT_GUJARATI:
 278     case HB_SCRIPT_GURMUKHI:
 279     case HB_SCRIPT_KANNADA:
 280     case HB_SCRIPT_MALAYALAM:
 281     case HB_SCRIPT_ORIYA:
 282     case HB_SCRIPT_TAMIL:
 283     case HB_SCRIPT_TELUGU:
 284
 285     /* Unicode-3.0 additions */
 286     case HB_SCRIPT_SINHALA:
 287
 288     /* Unicode-5.0 additions */
 289     case HB_SCRIPT_BALINESE:
 290
 291     /* Unicode-5.1 additions */
 292     case HB_SCRIPT_LEPCHA:
 293     case HB_SCRIPT_REJANG:
 294     case HB_SCRIPT_SUNDANESE:
 295
 296     /* Unicode-5.2 additions */
 297     case HB_SCRIPT_JAVANESE:
 298     case HB_SCRIPT_KAITHI:
 299     case HB_SCRIPT_MEETEI_MAYEK:
 300
 301     /* Unicode-6.0 additions */
 302
 303     /* Unicode-6.1 additions */
 304     case HB_SCRIPT_CHAKMA:
 305     case HB_SCRIPT_SHARADA:
 306     case HB_SCRIPT_TAKRI:
 307
 308       /* If the designer designed the font for the 'DFLT' script,
 309        * use the default shaper.  Otherwise, use the Indic shaper.
 310        * Note that for some simple scripts, there may not be *any*
 311        * GSUB/GPOS needed, so there may be no scripts found! */
 312       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 313         return &_hb_ot_complex_shaper_default;
 314       else
 315         return &_hb_ot_complex_shaper_indic;
 316
 317     case HB_SCRIPT_KHMER:
 318       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
 319        * and as such won't shape properly via the Indic shaper;
 320        * however, they typically have 'liga' / 'clig' features that implement
 321        * the necessary "reordering" by means of ligature substitutions.
 322        * So we send such pref-less fonts through the generic shaper instead. */
 323       if (planner->map.found_script[0] &&
 324           hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
 325                                               planner->map.script_index[0],
 326                                               planner->map.language_index[0],
 327                                               HB_TAG ('p','r','e','f'),
 328                                               NULL))
 329         return &_hb_ot_complex_shaper_indic;
 330       else
 331         return &_hb_ot_complex_shaper_default;
 332
 333     case HB_SCRIPT_MYANMAR:
 334       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
 335         return &_hb_ot_complex_shaper_myanmar;
 336       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
 337         return &_hb_ot_complex_shaper_myanmar_old;
 338       else
 339         return &_hb_ot_complex_shaper_default;
 340
 341     /* Unicode-4.1 additions */
 342     case HB_SCRIPT_BUGINESE:
 343
 344     /* Unicode-5.1 additions */
 345     case HB_SCRIPT_CHAM:
 346
 347     /* Unicode-5.2 additions */
 348     case HB_SCRIPT_TAI_THAM:
 349
 350       /* If the designer designed the font for the 'DFLT' script,
 351        * use the default shaper.  Otherwise, use the Indic shaper.
 352        * Note that for some simple scripts, there may not be *any*
 353        * GSUB/GPOS needed, so there may be no scripts found! */
 354       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 355         return &_hb_ot_complex_shaper_default;
 356       else
 357         return &_hb_ot_complex_shaper_sea;
 358   }
 359 }
 360
 361
 362 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */