third_party/harfbuzz-ng/src/hb-ot-shape-complex-private.hh

   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
  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 (indic) \
  56   HB_COMPLEX_SHAPER_IMPLEMENT (myanmar) \
  57   HB_COMPLEX_SHAPER_IMPLEMENT (sea) \
  58   HB_COMPLEX_SHAPER_IMPLEMENT (thai) \
  59   /* ^--- Add new shapers here */
  60
  61
  62 struct hb_ot_complex_shaper_t
  63 {
  64   char name[8];
  65
  66   /* collect_features()
  67    * Called during shape_plan().
  68    * Shapers should use plan->map to add their features and callbacks.
  69    * May be NULL.
  70    */
  71   void (*collect_features) (hb_ot_shape_planner_t *plan);
  72
  73   /* override_features()
  74    * Called during shape_plan().
  75    * Shapers should use plan->map to override features and add callbacks after
  76    * common features are added.
  77    * May be NULL.
  78    */
  79   void (*override_features) (hb_ot_shape_planner_t *plan);
  80
  81
  82   /* data_create()
  83    * Called at the end of shape_plan().
  84    * Whatever shapers return will be accessible through plan->data later.
  85    * If NULL is returned, means a plan failure.
  86    */
  87   void *(*data_create) (const hb_ot_shape_plan_t *plan);
  88
  89   /* data_destroy()
  90    * Called when the shape_plan is being destroyed.
  91    * plan->data is passed here for destruction.
  92    * If NULL is returned, means a plan failure.
  93    * May be NULL.
  94    */
  95   void (*data_destroy) (void *data);
  96
  97
  98   /* preprocess_text()
  99    * Called during shape().
 100    * Shapers can use to modify text before shaping starts.
 101    * May be NULL.
 102    */
 103   void (*preprocess_text) (const hb_ot_shape_plan_t *plan,
 104                            hb_buffer_t              *buffer,
 105                            hb_font_t                *font);
 106
 107
 108   /* normalization_preference()
 109    * Called during shape().
 110    * May be NULL.
 111    */
 112   hb_ot_shape_normalization_mode_t
 113   (*normalization_preference) (const hb_segment_properties_t *props);
 114
 115   /* decompose()
 116    * Called during shape()'s normalization.
 117    * May be NULL.
 118    */
 119   bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
 120                      hb_codepoint_t  ab,
 121                      hb_codepoint_t *a,
 122                      hb_codepoint_t *b);
 123
 124   /* compose()
 125    * Called during shape()'s normalization.
 126    * May be NULL.
 127    */
 128   bool (*compose) (const hb_ot_shape_normalize_context_t *c,
 129                    hb_codepoint_t  a,
 130                    hb_codepoint_t  b,
 131                    hb_codepoint_t *ab);
 132
 133   /* setup_masks()
 134    * Called during shape().
 135    * Shapers should use map to get feature masks and set on buffer.
 136    * Shapers may NOT modify characters.
 137    * May be NULL.
 138    */
 139   void (*setup_masks) (const hb_ot_shape_plan_t *plan,
 140                        hb_buffer_t              *buffer,
 141                        hb_font_t                *font);
 142
 143   hb_ot_shape_zero_width_marks_type_t zero_width_marks;
 144
 145   bool fallback_position;
 146 };
 147
 148 #define HB_COMPLEX_SHAPER_IMPLEMENT(name) extern HB_INTERNAL const hb_ot_complex_shaper_t _hb_ot_complex_shaper_##name;
 149 HB_COMPLEX_SHAPERS_IMPLEMENT_SHAPERS
 150 #undef HB_COMPLEX_SHAPER_IMPLEMENT
 151
 152
 153 static inline const hb_ot_complex_shaper_t *
 154 hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 155 {
 156   switch ((hb_tag_t) planner->props.script)
 157   {
 158     default:
 159       return &_hb_ot_complex_shaper_default;
 160
 161
 162     /* Unicode-1.1 additions */
 163     case HB_SCRIPT_ARABIC:
 164     case HB_SCRIPT_MONGOLIAN:
 165     case HB_SCRIPT_SYRIAC:
 166
 167     /* Unicode-5.0 additions */
 168     case HB_SCRIPT_NKO:
 169     case HB_SCRIPT_PHAGS_PA:
 170
 171     /* Unicode-6.0 additions */
 172     case HB_SCRIPT_MANDAIC:
 173
 174       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
 175        * This is because we do fallback shaping for Arabic script (and not others). */
 176       if (planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||
 177           planner->props.script == HB_SCRIPT_ARABIC)
 178         return &_hb_ot_complex_shaper_arabic;
 179       else
 180         return &_hb_ot_complex_shaper_default;
 181
 182
 183     /* Unicode-1.1 additions */
 184     case HB_SCRIPT_THAI:
 185     case HB_SCRIPT_LAO:
 186
 187       return &_hb_ot_complex_shaper_thai;
 188
 189
 190 #if 0
 191     /* Note:
 192      * Currently we don't have a separate Hangul shaper.  The default shaper handles
 193      * Hangul by enabling jamo features.  We may want to implement a separate shaper
 194      * in the future.  See this thread for details of what such a shaper would do:
 195      *
 196      *   http://lists.freedesktop.org/archives/harfbuzz/2013-April/003070.html
 197      */
 198     /* Unicode-1.1 additions */
 199     case HB_SCRIPT_HANGUL:
 200
 201       return &_hb_ot_complex_shaper_hangul;
 202 #endif
 203
 204
 205     /* ^--- Add new shapers here */
 206
 207
 208 #if 0
 209     /* Note:
 210      *
 211      * These disabled scripts are listed in ucd/IndicSyllabicCategory.txt, but according
 212      * to Martin Hosken and Jonathan Kew do not require complex shaping.
 213      *
 214      * TODO We should automate figuring out which scripts do not need complex shaping
 215      *
 216      * TODO We currently keep data for these scripts in our indic table.  Need to fix the
 217      * generator to not do that.
 218      */
 219
 220
 221     /* Simple? */
 222
 223     /* Unicode-3.2 additions */
 224     case HB_SCRIPT_BUHID:
 225     case HB_SCRIPT_HANUNOO:
 226
 227     /* Unicode-5.1 additions */
 228     case HB_SCRIPT_SAURASHTRA:
 229
 230     /* Unicode-6.0 additions */
 231     case HB_SCRIPT_BATAK:
 232     case HB_SCRIPT_BRAHMI:
 233
 234
 235     /* Simple */
 236
 237     /* Unicode-1.1 additions */
 238     /* These have their own shaper now. */
 239     case HB_SCRIPT_LAO:
 240     case HB_SCRIPT_THAI:
 241
 242     /* Unicode-2.0 additions */
 243     case HB_SCRIPT_TIBETAN:
 244
 245     /* Unicode-3.2 additions */
 246     case HB_SCRIPT_TAGALOG:
 247     case HB_SCRIPT_TAGBANWA:
 248
 249     /* Unicode-4.0 additions */
 250     case HB_SCRIPT_LIMBU:
 251     case HB_SCRIPT_TAI_LE:
 252
 253     /* Unicode-4.1 additions */
 254     case HB_SCRIPT_KHAROSHTHI:
 255     case HB_SCRIPT_SYLOTI_NAGRI:
 256
 257     /* Unicode-5.1 additions */
 258     case HB_SCRIPT_KAYAH_LI:
 259
 260     /* Unicode-5.2 additions */
 261     case HB_SCRIPT_TAI_VIET:
 262
 263
 264 #endif
 265
 266     /* Unicode-1.1 additions */
 267     case HB_SCRIPT_BENGALI:
 268     case HB_SCRIPT_DEVANAGARI:
 269     case HB_SCRIPT_GUJARATI:
 270     case HB_SCRIPT_GURMUKHI:
 271     case HB_SCRIPT_KANNADA:
 272     case HB_SCRIPT_MALAYALAM:
 273     case HB_SCRIPT_ORIYA:
 274     case HB_SCRIPT_TAMIL:
 275     case HB_SCRIPT_TELUGU:
 276
 277     /* Unicode-3.0 additions */
 278     case HB_SCRIPT_SINHALA:
 279
 280     /* Unicode-4.1 additions */
 281     case HB_SCRIPT_BUGINESE:
 282
 283     /* Unicode-5.0 additions */
 284     case HB_SCRIPT_BALINESE:
 285
 286     /* Unicode-5.1 additions */
 287     case HB_SCRIPT_LEPCHA:
 288     case HB_SCRIPT_REJANG:
 289     case HB_SCRIPT_SUNDANESE:
 290
 291     /* Unicode-5.2 additions */
 292     case HB_SCRIPT_JAVANESE:
 293     case HB_SCRIPT_KAITHI:
 294     case HB_SCRIPT_MEETEI_MAYEK:
 295
 296     /* Unicode-6.0 additions */
 297
 298     /* Unicode-6.1 additions */
 299     case HB_SCRIPT_CHAKMA:
 300     case HB_SCRIPT_SHARADA:
 301     case HB_SCRIPT_TAKRI:
 302
 303       /* If the designer designed the font for the 'DFLT' script,
 304        * use the default shaper.  Otherwise, use the Indic shaper.
 305        * Note that for some simple scripts, there may not be *any*
 306        * GSUB/GPOS needed, so there may be no scripts found! */
 307       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 308         return &_hb_ot_complex_shaper_default;
 309       else
 310         return &_hb_ot_complex_shaper_indic;
 311
 312     case HB_SCRIPT_KHMER:
 313       /* A number of Khmer fonts in the wild don't have a 'pref' feature,
 314        * and as such won't shape properly via the Indic shaper;
 315        * however, they typically have 'liga' / 'clig' features that implement
 316        * the necessary "reordering" by means of ligature substitutions.
 317        * So we send such pref-less fonts through the generic shaper instead. */
 318       if (planner->map.found_script[0] &&
 319           hb_ot_layout_language_find_feature (planner->face, HB_OT_TAG_GSUB,
 320                                               planner->map.script_index[0],
 321                                               planner->map.language_index[0],
 322                                               HB_TAG ('p','r','e','f'),
 323                                               NULL))
 324         return &_hb_ot_complex_shaper_indic;
 325       else
 326         return &_hb_ot_complex_shaper_default;
 327
 328     case HB_SCRIPT_MYANMAR:
 329       /* For Myanmar, we only want to use the Myanmar shaper if the "new" script
 330        * tag is found.  For "old" script tag we want to use the default shaper. */
 331       if (planner->map.chosen_script[0] == HB_TAG ('m','y','m','2'))
 332         return &_hb_ot_complex_shaper_myanmar;
 333       else
 334         return &_hb_ot_complex_shaper_default;
 335
 336     /* Unicode-4.1 additions */
 337     case HB_SCRIPT_NEW_TAI_LUE:
 338
 339     /* Unicode-5.1 additions */
 340     case HB_SCRIPT_CHAM:
 341
 342     /* Unicode-5.2 additions */
 343     case HB_SCRIPT_TAI_THAM:
 344
 345       /* If the designer designed the font for the 'DFLT' script,
 346        * use the default shaper.  Otherwise, use the Indic shaper.
 347        * Note that for some simple scripts, there may not be *any*
 348        * GSUB/GPOS needed, so there may be no scripts found! */
 349       if (planner->map.chosen_script[0] == HB_TAG ('D','F','L','T'))
 350         return &_hb_ot_complex_shaper_default;
 351       else
 352         return &_hb_ot_complex_shaper_sea;
 353   }
 354 }
 355
 356
 357 #endif /* HB_OT_SHAPE_COMPLEX_PRIVATE_HH */