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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 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   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
    150 
    151   bool fallback_position;
    152 };
    153 
    154 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
    155 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
    156 #undef HB_COMPLEX_SHAPER_IMPLEMENT
    157 
    158 
    159 static inline const hb_ot_complex_shaper_t *
    160 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
    161 {
    162   switch ((hb_tag_t) planner->props.script)
    163   {
    164     default:
    165       return &_hb_ot_complex_shaper_default;
    166 
    167 
    168     /* Unicode-1.1 additions */
    169     case HB_SCRIPT_ARABIC:
    170 
    171     /* Unicode-3.0 additions */
    172     case HB_SCRIPT_MONGOLIAN:
    173     case HB_SCRIPT_SYRIAC:
    174 
    175     /* Unicode-5.0 additions */
    176     case HB_SCRIPT_NKO:
    177     case HB_SCRIPT_PHAGS_PA:
    178 
    179     /* Unicode-6.0 additions */
    180     case HB_SCRIPT_MANDAIC:
    181 
    182     /* Unicode-7.0 additions */
    183     case HB_SCRIPT_MANICHAEAN:
    184     case HB_SCRIPT_PSALTER_PAHLAVI:
    185 
    186       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
    187        * This is because we do fallback shaping for Arabic script (and not others).
    188        * But note that Arabic shaping is applicable only to horizontal layout; for
    189        * vertical text, just use the generic shaper instead. */
    190       if ((planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
    191 	   planner->props.script == HB_SCRIPT_ARABIC) &&
    192 	  HB_DIRECTION_IS_HORIZONTAL(planner->props.direction))
    193 	return &_hb_ot_complex_shaper_arabic;
    194       else
    195 	return &_hb_ot_complex_shaper_default;
    196 
    197 
    198     /* Unicode-1.1 additions */
    199     case HB_SCRIPT_THAI:
    200     case HB_SCRIPT_LAO:
    201 
    202       return &_hb_ot_complex_shaper_thai;
    203 
    204 
    205     /* Unicode-1.1 additions */
    206     case HB_SCRIPT_HANGUL:
    207 
    208       return &_hb_ot_complex_shaper_hangul;
    209 
    210 
    211     /* Unicode-2.0 additions */
    212     case HB_SCRIPT_TIBETAN:
    213 
    214       return &_hb_ot_complex_shaper_tibetan;
    215 
    216 
    217     /* Unicode-1.1 additions */
    218     case HB_SCRIPT_HEBREW:
    219 
    220       return &_hb_ot_complex_shaper_hebrew;
    221 
    222 
    223     /* ^--- Add new shapers here */
    224 
    225 #if 0
    226     /* Unicode-4.1 additions */
    227     case HB_SCRIPT_NEW_TAI_LUE:
    228 #endif
    229 
    230     /* Unicode-1.1 additions */
    231     case HB_SCRIPT_BENGALI:
    232     case HB_SCRIPT_DEVANAGARI:
    233     case HB_SCRIPT_GUJARATI:
    234     case HB_SCRIPT_GURMUKHI:
    235     case HB_SCRIPT_KANNADA:
    236     case HB_SCRIPT_MALAYALAM:
    237     case HB_SCRIPT_ORIYA:
    238     case HB_SCRIPT_TAMIL:
    239     case HB_SCRIPT_TELUGU:
    240 
    241     /* Unicode-3.0 additions */
    242     case HB_SCRIPT_SINHALA:
    243 
    244     /* Unicode-5.2 additions */
    245     case HB_SCRIPT_JAVANESE:
    246 
    247       /* If the designer designed the font for the 'DFLT' script,
    248        * use the default shaper.  Otherwise, use the specific shaper.
    249        * Note that for some simple scripts, there may not be *any*
    250        * GSUB/GPOS needed, so there may be no scripts found! */
    251       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
    252 	return &_hb_ot_complex_shaper_default;
    253       else
    254 	return &_hb_ot_complex_shaper_indic;
    255 
    256     case HB_SCRIPT_KHMER:
    257       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
    258        * and as such won't shape properly via the Indic shaper;
    259        * however, they typically have 'liga' / 'clig' features that implement
    260        * the necessary "reordering" by means of ligature substitutions.
    261        * So we send such pref-less fonts through the generic shaper instead. */
    262       if (planner->map.found_script[0] &&
    263 	  hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
    264 					      planner->map.script_index[0],
    265 					      planner->map.language_index[0],
    266 					      HB_TAG ('p','r','e','f'),
    267 					      NULL))
    268 	return &_hb_ot_complex_shaper_indic;
    269       else
    270 	return &_hb_ot_complex_shaper_default;
    271 
    272     case HB_SCRIPT_MYANMAR:
    273       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
    274 	return &_hb_ot_complex_shaper_myanmar;
    275       else if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','r'))
    276 	return &_hb_ot_complex_shaper_myanmar_old;
    277       else
    278 	return &_hb_ot_complex_shaper_default;
    279 
    280 
    281     /* Unicode-2.0 additions */
    282     //case HB_SCRIPT_TIBETAN:
    283 
    284     /* Unicode-3.0 additions */
    285     //case HB_SCRIPT_MONGOLIAN:
    286     //case HB_SCRIPT_SINHALA:
    287 
    288     /* Unicode-3.2 additions */
    289     case HB_SCRIPT_BUHID:
    290     case HB_SCRIPT_HANUNOO:
    291     case HB_SCRIPT_TAGALOG:
    292     case HB_SCRIPT_TAGBANWA:
    293 
    294     /* Unicode-4.0 additions */
    295     case HB_SCRIPT_LIMBU:
    296     case HB_SCRIPT_TAI_LE:
    297 
    298     /* Unicode-4.1 additions */
    299     case HB_SCRIPT_BUGINESE:
    300     case HB_SCRIPT_KHAROSHTHI:
    301     case HB_SCRIPT_SYLOTI_NAGRI:
    302     case HB_SCRIPT_TIFINAGH:
    303 
    304     /* Unicode-5.0 additions */
    305     case HB_SCRIPT_BALINESE:
    306     //case HB_SCRIPT_NKO:
    307     //case HB_SCRIPT_PHAGS_PA:
    308 
    309     /* Unicode-5.1 additions */
    310     case HB_SCRIPT_CHAM:
    311     case HB_SCRIPT_KAYAH_LI:
    312     case HB_SCRIPT_LEPCHA:
    313     case HB_SCRIPT_REJANG:
    314     case HB_SCRIPT_SAURASHTRA:
    315     case HB_SCRIPT_SUNDANESE:
    316 
    317     /* Unicode-5.2 additions */
    318     case HB_SCRIPT_EGYPTIAN_HIEROGLYPHS:
    319     //case HB_SCRIPT_JAVANESE:
    320     case HB_SCRIPT_KAITHI:
    321     case HB_SCRIPT_MEETEI_MAYEK:
    322     case HB_SCRIPT_TAI_THAM:
    323     case HB_SCRIPT_TAI_VIET:
    324 
    325     /* Unicode-6.0 additions */
    326     case HB_SCRIPT_BATAK:
    327     case HB_SCRIPT_BRAHMI:
    328     //case HB_SCRIPT_MANDAIC:
    329 
    330     /* Unicode-6.1 additions */
    331     case HB_SCRIPT_CHAKMA:
    332     case HB_SCRIPT_SHARADA:
    333     case HB_SCRIPT_TAKRI:
    334 
    335     /* Unicode-7.0 additions */
    336     case HB_SCRIPT_DUPLOYAN:
    337     case HB_SCRIPT_GRANTHA:
    338     case HB_SCRIPT_KHOJKI:
    339     case HB_SCRIPT_KHUDAWADI:
    340     case HB_SCRIPT_MAHAJANI:
    341     //case HB_SCRIPT_MANICHAEAN:
    342     case HB_SCRIPT_MODI:
    343     case HB_SCRIPT_PAHAWH_HMONG:
    344     //case HB_SCRIPT_PSALTER_PAHLAVI:
    345     case HB_SCRIPT_SIDDHAM:
    346     case HB_SCRIPT_TIRHUTA:
    347 
    348       /* If the designer designed the font for the 'DFLT' script,
    349        * use the default shaper.  Otherwise, use the specific shaper.
    350        * Note that for some simple scripts, there may not be *any*
    351        * GSUB/GPOS needed, so there may be no scripts found! */
    352       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
    353 	return &_hb_ot_complex_shaper_default;
    354       else
    355 	return &_hb_ot_complex_shaper_use;
    356   }
    357 }
    358 
    359 
    360 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */
    361