third_party/harfbuzz-ng/src/hb-ot-shape-complex-default.cc

   1 /*
   2  * Copyright © 2010,2012  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 #include "hb-ot-shape-complex-private.hh"
  28
  29
  30 /* TODO Add kana, and other small shapers here */
  31
  32
  33 /* The default shaper *only* adds additional per-script features.*/
  34
  35 static const hb_tag_t hangul_features[] =
  36 {
  37   HB_TAG('l','j','m','o'),
  38   HB_TAG('v','j','m','o'),
  39   HB_TAG('t','j','m','o'),
  40   HB_TAG_NONE
  41 };
  42
  43 static const hb_tag_t tibetan_features[] =
  44 {
  45   HB_TAG('a','b','v','s'),
  46   HB_TAG('b','l','w','s'),
  47   HB_TAG('a','b','v','m'),
  48   HB_TAG('b','l','w','m'),
  49   HB_TAG_NONE
  50 };
  51
  52 static void
  53 collect_features_default (hb_ot_shape_planner_t *plan)
  54 {
  55   const hb_tag_t *script_features = NULL;
  56
  57   switch ((hb_tag_t) plan->props.script)
  58   {
  59     /* Unicode-1.1 additions */
  60     case HB_SCRIPT_HANGUL:
  61       script_features = hangul_features;
  62       break;
  63
  64     /* Unicode-2.0 additions */
  65     case HB_SCRIPT_TIBETAN:
  66       script_features = tibetan_features;
  67       break;
  68   }
  69
  70   for (; script_features && *script_features; script_features++)
  71     plan->map.add_global_bool_feature (*script_features);
  72 }
  73
  74 static hb_ot_shape_normalization_mode_t
  75 normalization_preference_default (const hb_segment_properties_t *props)
  76 {
  77   return HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS;
  78 }
  79
  80 static bool
  81 compose_default (const hb_ot_shape_normalize_context_t *c,
  82                  hb_codepoint_t  a,
  83                  hb_codepoint_t  b,
  84                  hb_codepoint_t *ab)
  85 {
  86   /* Hebrew presentation-form shaping.
  87    * https://bugzilla.mozilla.org/show_bug.cgi?id=728866
  88    * Hebrew presentation forms with dagesh, for characters 0x05D0..0x05EA;
  89    * Note that some letters do not have a dagesh presForm encoded.
  90    */
  91   static const hb_codepoint_t sDageshForms[0x05EA - 0x05D0 + 1] = {
  92     0xFB30, /* ALEF */
  93     0xFB31, /* BET */
  94     0xFB32, /* GIMEL */
  95     0xFB33, /* DALET */
  96     0xFB34, /* HE */
  97     0xFB35, /* VAV */
  98     0xFB36, /* ZAYIN */
  99     0x0000, /* HET */
 100     0xFB38, /* TET */
 101     0xFB39, /* YOD */
 102     0xFB3A, /* FINAL KAF */
 103     0xFB3B, /* KAF */
 104     0xFB3C, /* LAMED */
 105     0x0000, /* FINAL MEM */
 106     0xFB3E, /* MEM */
 107     0x0000, /* FINAL NUN */
 108     0xFB40, /* NUN */
 109     0xFB41, /* SAMEKH */
 110     0x0000, /* AYIN */
 111     0xFB43, /* FINAL PE */
 112     0xFB44, /* PE */
 113     0x0000, /* FINAL TSADI */
 114     0xFB46, /* TSADI */
 115     0xFB47, /* QOF */
 116     0xFB48, /* RESH */
 117     0xFB49, /* SHIN */
 118     0xFB4A /* TAV */
 119   };
 120
 121   bool found = c->unicode->compose (a, b, ab);
 122
 123   if (!found && (b & ~0x7F) == 0x0580) {
 124       /* Special-case Hebrew presentation forms that are excluded from
 125        * standard normalization, but wanted for old fonts. */
 126       switch (b) {
 127       case 0x05B4: /* HIRIQ */
 128           if (a == 0x05D9) { /* YOD */
 129               *ab = 0xFB1D;
 130               found = true;
 131           }
 132           break;
 133       case 0x05B7: /* patah */
 134           if (a == 0x05F2) { /* YIDDISH YOD YOD */
 135               *ab = 0xFB1F;
 136               found = true;
 137           } else if (a == 0x05D0) { /* ALEF */
 138               *ab = 0xFB2E;
 139               found = true;
 140           }
 141           break;
 142       case 0x05B8: /* QAMATS */
 143           if (a == 0x05D0) { /* ALEF */
 144               *ab = 0xFB2F;
 145               found = true;
 146           }
 147           break;
 148       case 0x05B9: /* HOLAM */
 149           if (a == 0x05D5) { /* VAV */
 150               *ab = 0xFB4B;
 151               found = true;
 152           }
 153           break;
 154       case 0x05BC: /* DAGESH */
 155           if (a >= 0x05D0 && a <= 0x05EA) {
 156               *ab = sDageshForms[a - 0x05D0];
 157               found = (*ab != 0);
 158           } else if (a == 0xFB2A) { /* SHIN WITH SHIN DOT */
 159               *ab = 0xFB2C;
 160               found = true;
 161           } else if (a == 0xFB2B) { /* SHIN WITH SIN DOT */
 162               *ab = 0xFB2D;
 163               found = true;
 164           }
 165           break;
 166       case 0x05BF: /* RAFE */
 167           switch (a) {
 168           case 0x05D1: /* BET */
 169               *ab = 0xFB4C;
 170               found = true;
 171               break;
 172           case 0x05DB: /* KAF */
 173               *ab = 0xFB4D;
 174               found = true;
 175               break;
 176           case 0x05E4: /* PE */
 177               *ab = 0xFB4E;
 178               found = true;
 179               break;
 180           }
 181           break;
 182       case 0x05C1: /* SHIN DOT */
 183           if (a == 0x05E9) { /* SHIN */
 184               *ab = 0xFB2A;
 185               found = true;
 186           } else if (a == 0xFB49) { /* SHIN WITH DAGESH */
 187               *ab = 0xFB2C;
 188               found = true;
 189           }
 190           break;
 191       case 0x05C2: /* SIN DOT */
 192           if (a == 0x05E9) { /* SHIN */
 193               *ab = 0xFB2B;
 194               found = true;
 195           } else if (a == 0xFB49) { /* SHIN WITH DAGESH */
 196               *ab = 0xFB2D;
 197               found = true;
 198           }
 199           break;
 200       }
 201   }
 202
 203   return found;
 204 }
 205
 206 const hb_ot_complex_shaper_t _hb_ot_complex_shaper_default =
 207 {
 208   "default",
 209   collect_features_default,
 210   NULL, /* override_features */
 211   NULL, /* data_create */
 212   NULL, /* data_destroy */
 213   NULL, /* preprocess_text */
 214   normalization_preference_default,
 215   NULL, /* decompose */
 216   compose_default,
 217   NULL, /* setup_masks */
 218   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_UNICODE_LATE,
 219   true, /* fallback_position */
 220 };