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_GDEF_EARLY,
  45   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE
  46 };
  47 
  48 
  49 /* Master OT shaper list */
  50 #define HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS \
  51   HB_COMPLEX_SHAPER_IMPLEMENT (default) /* should be first */ \
  52   HB_COMPLEX_SHAPER_IMPLEMENT (arabic) \
  53   HB_COMPLEX_SHAPER_IMPLEMENT (hangul) \
  54   HB_COMPLEX_SHAPER_IMPLEMENT (hebrew) \
  55   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar_old) \
  56   HB_COMPLEX_SHAPER_IMPLEMENT (indic) \
  57   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
  58   HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
  59   HB_COMPLEX_SHAPER_IMPLEMENT (tibetan) \
  60   HB_COMPLEX_SHAPER_IMPLEMENT (use) \
  61   /* ^--- Add new shapers here */
  62 
  63 
  64 struct hb_ot_complex_shaper_t
  65 {
  66   char name[8];
  67 
  68   /* collect_features()
  69    * Called during shape_plan().
  70    * Shapers should use plan->map to add their features and callbacks.
  71    * May be NULL.
  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 NULL.
  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 NULL 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 NULL is returned, means a plan failure.
  95    * May be NULL.
  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 NULL.
 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 NULL.
 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 NULL.
 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 NULL.
 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 NULL.
 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 NULL.
 154    */
 155   bool (*disable_otl) (const hb_ot_shape_plan_t *plan);
 156 
 157   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
 158 
 159   bool fallback_position;
 160 };
 161 
 162 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
 163 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
 164 #undef HB_COMPLEX_SHAPER_IMPLEMENT
 165 
 166 
 167 static inline const hb_ot_complex_shaper_t *
 168 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 169 {
 170   switch ((hb_tag_t) planner->props.script)
 171   {
 172     default:
 173       return &_hb_ot_complex_shaper_default;
 174 
 175 
 176     /* Unicode-1.1 additions */
 177     case HB_SCRIPT_ARABIC:
 178 
 179     /* Unicode-3.0 additions */
 180     case HB_SCRIPT_MONGOLIAN:
 181     case HB_SCRIPT_SYRIAC:
 182 
 183     /* Unicode-5.0 additions */
 184     case HB_SCRIPT_NKO:
 185     case HB_SCRIPT_PHAGS_PA:
 186 
 187     /* Unicode-6.0 additions */
 188     case HB_SCRIPT_MANDAIC:
 189 
 190     /* Unicode-7.0 additions */
 191     case HB_SCRIPT_MANICHAEAN:
 192     case HB_SCRIPT_PSALTER_PAHLAVI:
 193 
 194       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
 195        * This is because we do fallback shaping for Arabic script (and not others).
 196        * But note that Arabic shaping is applicable only to horizontal layout; for
 197        * vertical text, just use the generic shaper instead. */
 198       if ((planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
 199            planner->props.script == HB_SCRIPT_ARABIC) &&
 200           HB_DIRECTION_IS_HORIZONTAL(planner->props.direction))
 201         return &_hb_ot_complex_shaper_arabic;
 202       else
 203         return &_hb_ot_complex_shaper_default;
 204 
 205 
 206     /* Unicode-1.1 additions */
 207     case HB_SCRIPT_THAI:
 208     case HB_SCRIPT_LAO:
 209 
 210       return &_hb_ot_complex_shaper_thai;
 211 
 212 
 213     /* Unicode-1.1 additions */
 214     case HB_SCRIPT_HANGUL:
 215 
 216       return &_hb_ot_complex_shaper_hangul;
 217 
 218 
 219     /* Unicode-2.0 additions */
 220     case HB_SCRIPT_TIBETAN:
 221 
 222       return &_hb_ot_complex_shaper_tibetan;
 223 
 224 
 225     /* Unicode-1.1 additions */
 226     case HB_SCRIPT_HEBREW:
 227 
 228       return &_hb_ot_complex_shaper_hebrew;
 229 
 230 
 231     /* ^--- Add new shapers here */
 232 
 233 #if 0
 234     /* Unicode-4.1 additions */
 235     case HB_SCRIPT_NEW_TAI_LUE:
 236 #endif
 237 
 238     /* Unicode-1.1 additions */
 239     case HB_SCRIPT_BENGALI:
 240     case HB_SCRIPT_DEVANAGARI:
 241     case HB_SCRIPT_GUJARATI:
 242     case HB_SCRIPT_GURMUKHI:
 243     case HB_SCRIPT_KANNADA:
 244     case HB_SCRIPT_MALAYALAM:
 245     case HB_SCRIPT_ORIYA:
 246     case HB_SCRIPT_TAMIL:
 247     case HB_SCRIPT_TELUGU:
 248 
 249     /* Unicode-3.0 additions */
 250     case HB_SCRIPT_SINHALA:
 251 
 252       /* If the designer designed the font for the 'DFLT' script,
 253        * use the default shaper.  Otherwise, use the specific shaper.
 254        * Note that for some simple scripts, there may not be *any*
 255        * GSUB/GPOS needed, so there may be no scripts found! */
 256       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 257         return &_hb_ot_complex_shaper_default;
 258       else
 259         return &_hb_ot_complex_shaper_indic;
 260 
 261     case HB_SCRIPT_KHMER:
 262       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
 263        * and as such won't shape properly via the Indic shaper;
 264        * however, they typically have 'liga' / 'clig' features that implement
 265        * the necessary "reordering" by means of ligature substitutions.
 266        * So we send such pref-less fonts through the generic shaper instead. */
 267       if (planner->map.found_script[0] &&
 268           hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
 269                                               planner->map.script_index[0],
 270                                               planner->map.language_index[0],
 271                                               HB_TAG ('p','r','e','f'),
 272                                               NULL))
 273         return &_hb_ot_complex_shaper_indic;
 274       else
 275         return &_hb_ot_complex_shaper_default;
 276 
 277     case HB_SCRIPT_MYANMAR:
 278       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
 279         return &_hb_ot_complex_shaper_myanmar;
 280       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
 281         return &_hb_ot_complex_shaper_myanmar_old;
 282       else
 283         return &_hb_ot_complex_shaper_default;
 284 
 285 
 286     /* Unicode-2.0 additions */
 287     //case HB_SCRIPT_TIBETAN:
 288 
 289     /* Unicode-3.0 additions */
 290     //case HB_SCRIPT_MONGOLIAN:
 291     //case HB_SCRIPT_SINHALA:
 292 
 293     /* Unicode-3.2 additions */
 294     case HB_SCRIPT_BUHID:
 295     case HB_SCRIPT_HANUNOO:
 296     case HB_SCRIPT_TAGALOG:
 297     case HB_SCRIPT_TAGBANWA:
 298 
 299     /* Unicode-4.0 additions */
 300     case HB_SCRIPT_LIMBU:
 301     case HB_SCRIPT_TAI_LE:
 302 
 303     /* Unicode-4.1 additions */
 304     case HB_SCRIPT_BUGINESE:
 305     case HB_SCRIPT_KHAROSHTHI:
 306     case HB_SCRIPT_SYLOTI_NAGRI:
 307     case HB_SCRIPT_TIFINAGH:
 308 
 309     /* Unicode-5.0 additions */
 310     case HB_SCRIPT_BALINESE:
 311     //case HB_SCRIPT_NKO:
 312     //case HB_SCRIPT_PHAGS_PA:
 313 
 314     /* Unicode-5.1 additions */
 315     case HB_SCRIPT_CHAM:
 316     case HB_SCRIPT_KAYAH_LI:
 317     case HB_SCRIPT_LEPCHA:
 318     case HB_SCRIPT_REJANG:
 319     case HB_SCRIPT_SAURASHTRA:
 320     case HB_SCRIPT_SUNDANESE:
 321 
 322     /* Unicode-5.2 additions */
 323     case HB_SCRIPT_EGYPTIAN_HIEROGLYPHS:
 324     case HB_SCRIPT_JAVANESE:
 325     case HB_SCRIPT_KAITHI:
 326     case HB_SCRIPT_MEETEI_MAYEK:
 327     case HB_SCRIPT_TAI_THAM:
 328     case HB_SCRIPT_TAI_VIET:
 329 
 330     /* Unicode-6.0 additions */
 331     case HB_SCRIPT_BATAK:
 332     case HB_SCRIPT_BRAHMI:
 333     //case HB_SCRIPT_MANDAIC:
 334 
 335     /* Unicode-6.1 additions */
 336     case HB_SCRIPT_CHAKMA:
 337     case HB_SCRIPT_SHARADA:
 338     case HB_SCRIPT_TAKRI:
 339 
 340     /* Unicode-7.0 additions */
 341     case HB_SCRIPT_DUPLOYAN:
 342     case HB_SCRIPT_GRANTHA:
 343     case HB_SCRIPT_KHOJKI:
 344     case HB_SCRIPT_KHUDAWADI:
 345     case HB_SCRIPT_MAHAJANI:
 346     //case HB_SCRIPT_MANICHAEAN:
 347     case HB_SCRIPT_MODI:
 348     case HB_SCRIPT_PAHAWH_HMONG:
 349     //case HB_SCRIPT_PSALTER_PAHLAVI:
 350     case HB_SCRIPT_SIDDHAM:
 351     case HB_SCRIPT_TIRHUTA:
 352 
 353     /* Unicode-8.0 additions */
 354     case HB_SCRIPT_AHOM:
 355     //case HB_SCRIPT_MULTANI:
 356 
 357     /* Unicode-9.0 additions */
 358     case HB_SCRIPT_BHAIKSUKI:
 359     case HB_SCRIPT_MARCHEN:
 360     case HB_SCRIPT_NEWA:
 361 
 362       /* If the designer designed the font for the 'DFLT' script,
 363        * use the default shaper.  Otherwise, use the specific shaper.
 364        * Note that for some simple scripts, there may not be *any*
 365        * GSUB/GPOS needed, so there may be no scripts found! */
 366       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 367         return &_hb_ot_complex_shaper_default;
 368       else
 369         return &_hb_ot_complex_shaper_use;
 370   }
 371 }
 372 
 373 
 374 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */