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 #define HB_OT_SHAPE_COMPLEX_MAX_COMBINING_MARKS 32
  43 
  44 enum hb_ot_shape_zero_width_marks_type_t {
  45   HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
  46   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_EARLY,
  47   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE
  48 };
  49 
  50 
  51 /* Master OT shaper list */
  52 #define HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS \
  53   HB_COMPLEX_SHAPER_IMPLEMENT (default) /* should be first */ \
  54   HB_COMPLEX_SHAPER_IMPLEMENT (arabic) \
  55   HB_COMPLEX_SHAPER_IMPLEMENT (hangul) \
  56   HB_COMPLEX_SHAPER_IMPLEMENT (hebrew) \
  57   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar_old) \
  58   HB_COMPLEX_SHAPER_IMPLEMENT (indic) \
  59   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
  60   HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
  61   HB_COMPLEX_SHAPER_IMPLEMENT (tibetan) \
  62   HB_COMPLEX_SHAPER_IMPLEMENT (use) \
  63   /* ^--- Add new shapers here */
  64 
  65 
  66 struct hb_ot_complex_shaper_t
  67 {
  68   /* collect_features()
  69    * Called during shape_plan().
  70    * Shapers should use plan->map to add their features and callbacks.
  71    * May be nullptr.
  72    */
  73   void (*collect_features) (hb_ot_shape_planner_t *plan);
  74 
  75   /* override_features()
  76    * Called during shape_plan().
  77    * Shapers should use plan->map to override features and add callbacks after
  78    * common features are added.
  79    * May be nullptr.
  80    */
  81   void (*override_features) (hb_ot_shape_planner_t *plan);
  82 
  83 
  84   /* data_create()
  85    * Called at the end of shape_plan().
  86    * Whatever shapers return will be accessible through plan->data later.
  87    * If nullptr is returned, means a plan failure.
  88    */
  89   void *(*data_create) (const hb_ot_shape_plan_t *plan);
  90 
  91   /* data_destroy()
  92    * Called when the shape_plan is being destroyed.
  93    * plan->data is passed here for destruction.
  94    * If nullptr is returned, means a plan failure.
  95    * May be nullptr.
  96    */
  97   void (*data_destroy) (void *data);
  98 
  99 
 100   /* preprocess_text()
 101    * Called during shape().
 102    * Shapers can use to modify text before shaping starts.
 103    * May be nullptr.
 104    */
 105   void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
 106                            hb_buffer_t              *buffer,
 107                            hb_font_t                *font);
 108 
 109   /* postprocess_glyphs()
 110    * Called during shape().
 111    * Shapers can use to modify glyphs after shaping ends.
 112    * May be nullptr.
 113    */
 114   void (*postprocess_glyphs) (const hb_ot_shape_plan_t *plan,
 115                               hb_buffer_t              *buffer,
 116                               hb_font_t                *font);
 117 
 118 
 119   hb_ot_shape_normalization_mode_t normalization_preference;
 120 
 121   /* decompose()
 122    * Called during shape()'s normalization.
 123    * May be nullptr.
 124    */
 125   bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
 126                      hb_codepoint_t  ab,
 127                      hb_codepoint_t *a,
 128                      hb_codepoint_t *b);
 129 
 130   /* compose()
 131    * Called during shape()'s normalization.
 132    * May be nullptr.
 133    */
 134   bool (*compose) (const hb_ot_shape_normalize_context_t *c,
 135                    hb_codepoint_t  a,
 136                    hb_codepoint_t  b,
 137                    hb_codepoint_t *ab);
 138 
 139   /* setup_masks()
 140    * Called during shape().
 141    * Shapers should use map to get feature masks and set on buffer.
 142    * Shapers may NOT modify characters.
 143    * May be nullptr.
 144    */
 145   void (*setup_masks) (const hb_ot_shape_plan_t *plan,
 146                        hb_buffer_t              *buffer,
 147                        hb_font_t                *font);
 148 
 149   /* disable_otl()
 150    * Called during shape().
 151    * If set and returns true, GDEF/GSUB/GPOS of the font are ignored
 152    * and fallback operations used.
 153    * May be nullptr.
 154    */
 155   bool (*disable_otl) (const hb_ot_shape_plan_t *plan);
 156 
 157   /* reorder_marks()
 158    * Called during shape().
 159    * Shapers can use to modify ordering of combining marks.
 160    * May be nullptr.
 161    */
 162   void (*reorder_marks) (const hb_ot_shape_plan_t *plan,
 163                          hb_buffer_t              *buffer,
 164                          unsigned int              start,
 165                          unsigned int              end);
 166 
 167   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
 168 
 169   bool fallback_position;
 170 };
 171 
 172 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
 173 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
 174 #undef HB_COMPLEX_SHAPER_IMPLEMENT
 175 
 176 
 177 static inline const hb_ot_complex_shaper_t *
 178 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 179 {
 180   switch ((hb_tag_t) planner->props.script)
 181   {
 182     default:
 183       return &_hb_ot_complex_shaper_default;
 184 
 185 
 186     /* Unicode-1.1 additions */
 187     case HB_SCRIPT_ARABIC:
 188 
 189     /* Unicode-3.0 additions */
 190     case HB_SCRIPT_MONGOLIAN:
 191     case HB_SCRIPT_SYRIAC:
 192 
 193     /* Unicode-5.0 additions */
 194     case HB_SCRIPT_NKO:
 195     case HB_SCRIPT_PHAGS_PA:
 196 
 197     /* Unicode-6.0 additions */
 198     case HB_SCRIPT_MANDAIC:
 199 
 200     /* Unicode-7.0 additions */
 201     case HB_SCRIPT_MANICHAEAN:
 202     case HB_SCRIPT_PSALTER_PAHLAVI:
 203 
 204     /* Unicode-9.0 additions */
 205     case HB_SCRIPT_ADLAM:
 206 
 207       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
 208        * This is because we do fallback shaping for Arabic script (and not others).
 209        * But note that Arabic shaping is applicable only to horizontal layout; for
 210        * vertical text, just use the generic shaper instead. */
 211       if ((planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
 212            planner->props.script == HB_SCRIPT_ARABIC) &&
 213           HB_DIRECTION_IS_HORIZONTAL(planner->props.direction))
 214         return &_hb_ot_complex_shaper_arabic;
 215       else
 216         return &_hb_ot_complex_shaper_default;
 217 
 218 
 219     /* Unicode-1.1 additions */
 220     case HB_SCRIPT_THAI:
 221     case HB_SCRIPT_LAO:
 222 
 223       return &_hb_ot_complex_shaper_thai;
 224 
 225 
 226     /* Unicode-1.1 additions */
 227     case HB_SCRIPT_HANGUL:
 228 
 229       return &_hb_ot_complex_shaper_hangul;
 230 
 231 
 232     /* Unicode-2.0 additions */
 233     case HB_SCRIPT_TIBETAN:
 234 
 235       return &_hb_ot_complex_shaper_tibetan;
 236 
 237 
 238     /* Unicode-1.1 additions */
 239     case HB_SCRIPT_HEBREW:
 240 
 241       return &_hb_ot_complex_shaper_hebrew;
 242 
 243 
 244     /* ^--- Add new shapers here */
 245 
 246 #if 0
 247     /* Unicode-4.1 additions */
 248     case HB_SCRIPT_NEW_TAI_LUE:
 249 #endif
 250 
 251     /* Unicode-1.1 additions */
 252     case HB_SCRIPT_BENGALI:
 253     case HB_SCRIPT_DEVANAGARI:
 254     case HB_SCRIPT_GUJARATI:
 255     case HB_SCRIPT_GURMUKHI:
 256     case HB_SCRIPT_KANNADA:
 257     case HB_SCRIPT_MALAYALAM:
 258     case HB_SCRIPT_ORIYA:
 259     case HB_SCRIPT_TAMIL:
 260     case HB_SCRIPT_TELUGU:
 261 
 262     /* Unicode-3.0 additions */
 263     case HB_SCRIPT_SINHALA:
 264 
 265       /* If the designer designed the font for the 'DFLT' script,
 266        * (or we ended up arbitrarily pick 'latn'), use the default shaper.
 267        * Otherwise, use the specific shaper.
 268        * Note that for some simple scripts, there may not be *any*
 269        * GSUB/GPOS needed, so there may be no scripts found! */
 270       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T') ||
 271           planner->map.chosen_script[0] == HB_TAG ('l','a','t','n'))
 272         return &_hb_ot_complex_shaper_default;
 273       else
 274         return &_hb_ot_complex_shaper_indic;
 275 
 276     case HB_SCRIPT_KHMER:
 277       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
 278        * and as such won't shape properly via the Indic shaper;
 279        * however, they typically have 'liga' / 'clig' features that implement
 280        * the necessary "reordering" by means of ligature substitutions.
 281        * So we send such pref-less fonts through the generic shaper instead. */
 282       if (planner->map.found_script[0] &&
 283           hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
 284                                               planner->map.script_index[0],
 285                                               planner->map.language_index[0],
 286                                               HB_TAG ('p','r','e','f'),
 287                                               nullptr))
 288         return &_hb_ot_complex_shaper_indic;
 289       else
 290         return &_hb_ot_complex_shaper_default;
 291 
 292     case HB_SCRIPT_MYANMAR:
 293       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
 294         return &_hb_ot_complex_shaper_myanmar;
 295       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
 296         return &_hb_ot_complex_shaper_myanmar_old;
 297       else
 298         return &_hb_ot_complex_shaper_default;
 299 
 300 
 301     /* Unicode-2.0 additions */
 302     //case HB_SCRIPT_TIBETAN:
 303 
 304     /* Unicode-3.0 additions */
 305     //case HB_SCRIPT_MONGOLIAN:
 306     //case HB_SCRIPT_SINHALA:
 307 
 308     /* Unicode-3.2 additions */
 309     case HB_SCRIPT_BUHID:
 310     case HB_SCRIPT_HANUNOO:
 311     case HB_SCRIPT_TAGALOG:
 312     case HB_SCRIPT_TAGBANWA:
 313 
 314     /* Unicode-4.0 additions */
 315     case HB_SCRIPT_LIMBU:
 316     case HB_SCRIPT_TAI_LE:
 317 
 318     /* Unicode-4.1 additions */
 319     case HB_SCRIPT_BUGINESE:
 320     case HB_SCRIPT_KHAROSHTHI:
 321     case HB_SCRIPT_SYLOTI_NAGRI:
 322     case HB_SCRIPT_TIFINAGH:
 323 
 324     /* Unicode-5.0 additions */
 325     case HB_SCRIPT_BALINESE:
 326     //case HB_SCRIPT_NKO:
 327     //case HB_SCRIPT_PHAGS_PA:
 328 
 329     /* Unicode-5.1 additions */
 330     case HB_SCRIPT_CHAM:
 331     case HB_SCRIPT_KAYAH_LI:
 332     case HB_SCRIPT_LEPCHA:
 333     case HB_SCRIPT_REJANG:
 334     case HB_SCRIPT_SAURASHTRA:
 335     case HB_SCRIPT_SUNDANESE:
 336 
 337     /* Unicode-5.2 additions */
 338     case HB_SCRIPT_EGYPTIAN_HIEROGLYPHS:
 339     case HB_SCRIPT_JAVANESE:
 340     case HB_SCRIPT_KAITHI:
 341     case HB_SCRIPT_MEETEI_MAYEK:
 342     case HB_SCRIPT_TAI_THAM:
 343     case HB_SCRIPT_TAI_VIET:
 344 
 345     /* Unicode-6.0 additions */
 346     case HB_SCRIPT_BATAK:
 347     case HB_SCRIPT_BRAHMI:
 348     //case HB_SCRIPT_MANDAIC:
 349 
 350     /* Unicode-6.1 additions */
 351     case HB_SCRIPT_CHAKMA:
 352     case HB_SCRIPT_SHARADA:
 353     case HB_SCRIPT_TAKRI:
 354 
 355     /* Unicode-7.0 additions */
 356     case HB_SCRIPT_DUPLOYAN:
 357     case HB_SCRIPT_GRANTHA:
 358     case HB_SCRIPT_KHOJKI:
 359     case HB_SCRIPT_KHUDAWADI:
 360     case HB_SCRIPT_MAHAJANI:
 361     //case HB_SCRIPT_MANICHAEAN:
 362     case HB_SCRIPT_MODI:
 363     case HB_SCRIPT_PAHAWH_HMONG:
 364     //case HB_SCRIPT_PSALTER_PAHLAVI:
 365     case HB_SCRIPT_SIDDHAM:
 366     case HB_SCRIPT_TIRHUTA:
 367 
 368     /* Unicode-8.0 additions */
 369     case HB_SCRIPT_AHOM:
 370     //case HB_SCRIPT_MULTANI:
 371 
 372     /* Unicode-9.0 additions */
 373     case HB_SCRIPT_BHAIKSUKI:
 374     case HB_SCRIPT_MARCHEN:
 375     case HB_SCRIPT_NEWA:
 376 
 377     /* Unicode-10.0 additions */
 378     case HB_SCRIPT_MASARAM_GONDI:
 379     case HB_SCRIPT_SOYOMBO:
 380     case HB_SCRIPT_ZANABAZAR_SQUARE:
 381 
 382       /* If the designer designed the font for the 'DFLT' script,
 383        * (or we ended up arbitrarily pick 'latn'), use the default shaper.
 384        * Otherwise, use the specific shaper.
 385        * Note that for some simple scripts, there may not be *any*
 386        * GSUB/GPOS needed, so there may be no scripts found! */
 387       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T') ||
 388           planner->map.chosen_script[0] == HB_TAG ('l','a','t','n'))
 389         return &_hb_ot_complex_shaper_default;
 390       else
 391         return &_hb_ot_complex_shaper_use;
 392   }
 393 }
 394 
 395 
 396 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */