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      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 */
    397