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 (thai) \
  63   HB_COMPLEX_SHAPER_IMPLEMENT (tibetan) \
  64   HB_COMPLEX_SHAPER_IMPLEMENT (use) \
  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        * But note that Arabic shaping is applicable only to horizontal layout; for
 184        * vertical text, just use the generic shaper instead. */
 185       if ((planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
 186            planner->props.script == HB_SCRIPT_ARABIC) &&
 187           HB_DIRECTION_IS_HORIZONTAL(planner->props.direction))
 188         return &_hb_ot_complex_shaper_arabic;
 189       else
 190         return &_hb_ot_complex_shaper_default;
 191 
 192 
 193     /* Unicode-1.1 additions */
 194     case HB_SCRIPT_THAI:
 195     case HB_SCRIPT_LAO:
 196 
 197       return &_hb_ot_complex_shaper_thai;
 198 
 199 
 200     /* Unicode-1.1 additions */
 201     case HB_SCRIPT_HANGUL:
 202 
 203       return &_hb_ot_complex_shaper_hangul;
 204 
 205 
 206     /* Unicode-2.0 additions */
 207     case HB_SCRIPT_TIBETAN:
 208 
 209       return &_hb_ot_complex_shaper_tibetan;
 210 
 211 
 212     /* Unicode-1.1 additions */
 213     case HB_SCRIPT_HEBREW:
 214 
 215       return &_hb_ot_complex_shaper_hebrew;
 216 
 217 
 218     /* ^--- Add new shapers here */
 219 
 220 #if 0
 221     /* Unicode-4.1 additions */
 222     case HB_SCRIPT_NEW_TAI_LUE:
 223 #endif
 224 
 225     /* Unicode-1.1 additions */
 226     case HB_SCRIPT_BENGALI:
 227     case HB_SCRIPT_DEVANAGARI:
 228     case HB_SCRIPT_GUJARATI:
 229     case HB_SCRIPT_GURMUKHI:
 230     case HB_SCRIPT_KANNADA:
 231     case HB_SCRIPT_MALAYALAM:
 232     case HB_SCRIPT_ORIYA:
 233     case HB_SCRIPT_TAMIL:
 234     case HB_SCRIPT_TELUGU:
 235 
 236     /* Unicode-3.0 additions */
 237     case HB_SCRIPT_SINHALA:
 238 
 239     /* Unicode-5.2 additions */
 240     case HB_SCRIPT_JAVANESE:
 241 
 242       /* If the designer designed the font for the 'DFLT' script,
 243        * use the default shaper.  Otherwise, use the specific shaper.
 244        * Note that for some simple scripts, there may not be *any*
 245        * GSUB/GPOS needed, so there may be no scripts found! */
 246       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 247         return &_hb_ot_complex_shaper_default;
 248       else
 249         return &_hb_ot_complex_shaper_indic;
 250 
 251     case HB_SCRIPT_KHMER:
 252       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
 253        * and as such won't shape properly via the Indic shaper;
 254        * however, they typically have 'liga' / 'clig' features that implement
 255        * the necessary "reordering" by means of ligature substitutions.
 256        * So we send such pref-less fonts through the generic shaper instead. */
 257       if (planner->map.found_script[0] &&
 258           hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
 259                                               planner->map.script_index[0],
 260                                               planner->map.language_index[0],
 261                                               HB_TAG ('p','r','e','f'),
 262                                               NULL))
 263         return &_hb_ot_complex_shaper_indic;
 264       else
 265         return &_hb_ot_complex_shaper_default;
 266 
 267     case HB_SCRIPT_MYANMAR:
 268       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
 269         return &_hb_ot_complex_shaper_myanmar;
 270       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
 271         return &_hb_ot_complex_shaper_myanmar_old;
 272       else
 273         return &_hb_ot_complex_shaper_default;
 274 
 275 
 276     /* Unicode-2.0 additions */
 277     //case HB_SCRIPT_TIBETAN:
 278 
 279     /* Unicode-3.0 additions */
 280     //case HB_SCRIPT_MONGOLIAN:
 281     //case HB_SCRIPT_SINHALA:
 282 
 283     /* Unicode-3.2 additions */
 284     case HB_SCRIPT_BUHID:
 285     case HB_SCRIPT_HANUNOO:
 286     case HB_SCRIPT_TAGALOG:
 287     case HB_SCRIPT_TAGBANWA:
 288 
 289     /* Unicode-4.0 additions */
 290     case HB_SCRIPT_LIMBU:
 291     case HB_SCRIPT_TAI_LE:
 292 
 293     /* Unicode-4.1 additions */
 294     case HB_SCRIPT_BUGINESE:
 295     case HB_SCRIPT_KHAROSHTHI:
 296     case HB_SCRIPT_SYLOTI_NAGRI:
 297     case HB_SCRIPT_TIFINAGH:
 298 
 299     /* Unicode-5.0 additions */
 300     case HB_SCRIPT_BALINESE:
 301     //case HB_SCRIPT_NKO:
 302     //case HB_SCRIPT_PHAGS_PA:
 303 
 304     /* Unicode-5.1 additions */
 305     case HB_SCRIPT_CHAM:
 306     case HB_SCRIPT_KAYAH_LI:
 307     case HB_SCRIPT_LEPCHA:
 308     case HB_SCRIPT_REJANG:
 309     case HB_SCRIPT_SAURASHTRA:
 310     case HB_SCRIPT_SUNDANESE:
 311 
 312     /* Unicode-5.2 additions */
 313     case HB_SCRIPT_EGYPTIAN_HIEROGLYPHS:
 314     //case HB_SCRIPT_JAVANESE:
 315     case HB_SCRIPT_KAITHI:
 316     case HB_SCRIPT_MEETEI_MAYEK:
 317     case HB_SCRIPT_TAI_THAM:
 318     case HB_SCRIPT_TAI_VIET:
 319 
 320     /* Unicode-6.0 additions */
 321     case HB_SCRIPT_BATAK:
 322     case HB_SCRIPT_BRAHMI:
 323     //case HB_SCRIPT_MANDAIC:
 324 
 325     /* Unicode-6.1 additions */
 326     case HB_SCRIPT_CHAKMA:
 327     case HB_SCRIPT_SHARADA:
 328     case HB_SCRIPT_TAKRI:
 329 
 330     /* Unicode-7.0 additions */
 331     case HB_SCRIPT_DUPLOYAN:
 332     case HB_SCRIPT_GRANTHA:
 333     case HB_SCRIPT_KHOJKI:
 334     case HB_SCRIPT_KHUDAWADI:
 335     case HB_SCRIPT_MAHAJANI:
 336     //case HB_SCRIPT_MANICHAEAN:
 337     case HB_SCRIPT_MODI:
 338     case HB_SCRIPT_PAHAWH_HMONG:
 339     //case HB_SCRIPT_PSALTER_PAHLAVI:
 340     case HB_SCRIPT_SIDDHAM:
 341     case HB_SCRIPT_TIRHUTA:
 342 
 343       /* If the designer designed the font for the 'DFLT' script,
 344        * use the default shaper.  Otherwise, use the specific shaper.
 345        * Note that for some simple scripts, there may not be *any*
 346        * GSUB/GPOS needed, so there may be no scripts found! */
 347       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 348         return &_hb_ot_complex_shaper_default;
 349       else
 350         return &_hb_ot_complex_shaper_use;
 351   }
 352 }
 353 
 354 
 355 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */