src/hb-coretext.cc

   1 /*
   2  * Copyright © 2012,2013  Mozilla Foundation.
   3  * Copyright © 2012,2013  Google, Inc.
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Mozilla Author(s): Jonathan Kew
  26  * Google Author(s): Behdad Esfahbod
  27  */
  28
  29 #define HB_SHAPER coretext
  30 #define hb_coretext_shaper_face_data_t CGFont
  31 #include "hb-shaper-impl-private.hh"
  32
  33 #include "hb-coretext.h"
  34
  35
  36 #ifndef HB_DEBUG_CORETEXT
  37 #define HB_DEBUG_CORETEXT (HB_DEBUG+0)
  38 #endif
  39
  40
  41 static void
  42 release_table_data (void *user_data)
  43 {
  44   CFDataRef cf_data = reinterpret_cast<CFDataRef> (user_data);
  45   CFRelease(cf_data);
  46 }
  47
  48 static hb_blob_t *
  49 reference_table  (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
  50 {
  51   CGFontRef cg_font = reinterpret_cast<CGFontRef> (user_data);
  52   CFDataRef cf_data = CGFontCopyTableForTag (cg_font, tag);
  53   if (unlikely (!cf_data))
  54     return NULL;
  55
  56   const char *data = reinterpret_cast<const char*> (CFDataGetBytePtr (cf_data));
  57   const size_t length = CFDataGetLength (cf_data);
  58   if (!data || !length)
  59     return NULL;
  60
  61   return hb_blob_create (data, length, HB_MEMORY_MODE_READONLY,
  62                          reinterpret_cast<void *> (const_cast<__CFData *> (cf_data)),
  63                          release_table_data);
  64 }
  65
  66 hb_face_t *
  67 hb_coretext_face_create (CGFontRef cg_font)
  68 {
  69   return hb_face_create_for_tables (reference_table, CGFontRetain (cg_font), (hb_destroy_func_t) CGFontRelease);
  70 }
  71
  72
  73 HB_SHAPER_DATA_ENSURE_DECLARE(coretext, face)
  74 HB_SHAPER_DATA_ENSURE_DECLARE(coretext, font)
  75
  76
  77 /*
  78  * shaper face data
  79  */
  80
  81 static void
  82 release_data (void *info, const void *data, size_t size)
  83 {
  84   assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
  85           hb_blob_get_data ((hb_blob_t *) info, NULL) == data);
  86
  87   hb_blob_destroy ((hb_blob_t *) info);
  88 }
  89
  90 hb_coretext_shaper_face_data_t *
  91 _hb_coretext_shaper_face_data_create (hb_face_t *face)
  92 {
  93   hb_coretext_shaper_face_data_t *data = NULL;
  94
  95   if (face->destroy == (hb_destroy_func_t) CGFontRelease)
  96   {
  97     data = CGFontRetain ((CGFontRef) face->user_data);
  98   }
  99   else
 100   {
 101     hb_blob_t *blob = hb_face_reference_blob (face);
 102     unsigned int blob_length;
 103     const char *blob_data = hb_blob_get_data (blob, &blob_length);
 104     if (unlikely (!blob_length))
 105       DEBUG_MSG (CORETEXT, face, "Face has empty blob");
 106
 107     CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
 108     if (likely (provider))
 109     {
 110       data = CGFontCreateWithDataProvider (provider);
 111       CGDataProviderRelease (provider);
 112     }
 113   }
 114
 115   if (unlikely (!data)) {
 116     DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
 117   }
 118
 119   return data;
 120 }
 121
 122 void
 123 _hb_coretext_shaper_face_data_destroy (hb_coretext_shaper_face_data_t *data)
 124 {
 125   CFRelease (data);
 126 }
 127
 128 CGFontRef
 129 hb_coretext_face_get_cg_font (hb_face_t *face)
 130 {
 131   if (unlikely (!hb_coretext_shaper_face_data_ensure (face))) return NULL;
 132   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
 133   return face_data;
 134 }
 135
 136
 137 /*
 138  * shaper font data
 139  */
 140
 141 struct hb_coretext_shaper_font_data_t {
 142   CTFontRef ct_font;
 143 };
 144
 145 hb_coretext_shaper_font_data_t *
 146 _hb_coretext_shaper_font_data_create (hb_font_t *font)
 147 {
 148   if (unlikely (!hb_coretext_shaper_face_data_ensure (font->face))) return NULL;
 149
 150   hb_coretext_shaper_font_data_t *data = (hb_coretext_shaper_font_data_t *) calloc (1, sizeof (hb_coretext_shaper_font_data_t));
 151   if (unlikely (!data))
 152     return NULL;
 153
 154   hb_face_t *face = font->face;
 155   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
 156
 157   data->ct_font = CTFontCreateWithGraphicsFont (face_data, font->y_scale, NULL, NULL);
 158   if (unlikely (!data->ct_font)) {
 159     DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
 160     free (data);
 161     return NULL;
 162   }
 163
 164   return data;
 165 }
 166
 167 void
 168 _hb_coretext_shaper_font_data_destroy (hb_coretext_shaper_font_data_t *data)
 169 {
 170   CFRelease (data->ct_font);
 171   free (data);
 172 }
 173
 174
 175 /*
 176  * shaper shape_plan data
 177  */
 178
 179 struct hb_coretext_shaper_shape_plan_data_t {};
 180
 181 hb_coretext_shaper_shape_plan_data_t *
 182 _hb_coretext_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
 183                                              const hb_feature_t *user_features HB_UNUSED,
 184                                              unsigned int        num_user_features HB_UNUSED)
 185 {
 186   return (hb_coretext_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
 187 }
 188
 189 void
 190 _hb_coretext_shaper_shape_plan_data_destroy (hb_coretext_shaper_shape_plan_data_t *data HB_UNUSED)
 191 {
 192 }
 193
 194 CTFontRef
 195 hb_coretext_font_get_ct_font (hb_font_t *font)
 196 {
 197   if (unlikely (!hb_coretext_shaper_font_data_ensure (font))) return NULL;
 198   hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
 199   return font_data->ct_font;
 200 }
 201
 202
 203 /*
 204  * shaper
 205  */
 206
 207 struct feature_record_t {
 208   unsigned int feature;
 209   unsigned int setting;
 210 };
 211
 212 struct active_feature_t {
 213   feature_record_t rec;
 214   unsigned int order;
 215
 216   static int cmp (const active_feature_t *a, const active_feature_t *b) {
 217     return a->rec.feature < b->rec.feature ? -1 : a->rec.feature > b->rec.feature ? 1 :
 218            a->order < b->order ? -1 : a->order > b->order ? 1 :
 219            a->rec.setting < b->rec.setting ? -1 : a->rec.setting > b->rec.setting ? 1 :
 220            0;
 221   }
 222   bool operator== (const active_feature_t *f) {
 223     return cmp (this, f) == 0;
 224   }
 225 };
 226
 227 struct feature_event_t {
 228   unsigned int index;
 229   bool start;
 230   active_feature_t feature;
 231
 232   static int cmp (const feature_event_t *a, const feature_event_t *b) {
 233     return a->index < b->index ? -1 : a->index > b->index ? 1 :
 234            a->start < b->start ? -1 : a->start > b->start ? 1 :
 235            active_feature_t::cmp (&a->feature, &b->feature);
 236   }
 237 };
 238
 239 struct range_record_t {
 240   CTFontRef font;
 241   unsigned int index_first; /* == start */
 242   unsigned int index_last;  /* == end - 1 */
 243 };
 244
 245
 246 /* The following enum members are added in OS X 10.8. */
 247 #define kAltHalfWidthTextSelector               6
 248 #define kAltProportionalTextSelector            5
 249 #define kAlternateHorizKanaOffSelector          1
 250 #define kAlternateHorizKanaOnSelector           0
 251 #define kAlternateKanaType                      34
 252 #define kAlternateVertKanaOffSelector           3
 253 #define kAlternateVertKanaOnSelector            2
 254 #define kCaseSensitiveLayoutOffSelector         1
 255 #define kCaseSensitiveLayoutOnSelector          0
 256 #define kCaseSensitiveLayoutType                33
 257 #define kCaseSensitiveSpacingOffSelector        3
 258 #define kCaseSensitiveSpacingOnSelector         2
 259 #define kContextualAlternatesOffSelector        1
 260 #define kContextualAlternatesOnSelector         0
 261 #define kContextualAlternatesType               36
 262 #define kContextualLigaturesOffSelector         19
 263 #define kContextualLigaturesOnSelector          18
 264 #define kContextualSwashAlternatesOffSelector   5
 265 #define kContextualSwashAlternatesOnSelector    4
 266 #define kDefaultLowerCaseSelector               0
 267 #define kDefaultUpperCaseSelector               0
 268 #define kHistoricalLigaturesOffSelector         21
 269 #define kHistoricalLigaturesOnSelector          20
 270 #define kHojoCharactersSelector                 12
 271 #define kJIS2004CharactersSelector              11
 272 #define kLowerCasePetiteCapsSelector            2
 273 #define kLowerCaseSmallCapsSelector             1
 274 #define kLowerCaseType                          37
 275 #define kMathematicalGreekOffSelector           11
 276 #define kMathematicalGreekOnSelector            10
 277 #define kNLCCharactersSelector                  13
 278 #define kQuarterWidthTextSelector               4
 279 #define kScientificInferiorsSelector            4
 280 #define kStylisticAltEightOffSelector           17
 281 #define kStylisticAltEightOnSelector            16
 282 #define kStylisticAltEighteenOffSelector        37
 283 #define kStylisticAltEighteenOnSelector         36
 284 #define kStylisticAltElevenOffSelector          23
 285 #define kStylisticAltElevenOnSelector           22
 286 #define kStylisticAltFifteenOffSelector         31
 287 #define kStylisticAltFifteenOnSelector          30
 288 #define kStylisticAltFiveOffSelector            11
 289 #define kStylisticAltFiveOnSelector             10
 290 #define kStylisticAltFourOffSelector            9
 291 #define kStylisticAltFourOnSelector             8
 292 #define kStylisticAltFourteenOffSelector        29
 293 #define kStylisticAltFourteenOnSelector         28
 294 #define kStylisticAltNineOffSelector            19
 295 #define kStylisticAltNineOnSelector             18
 296 #define kStylisticAltNineteenOffSelector        39
 297 #define kStylisticAltNineteenOnSelector         38
 298 #define kStylisticAltOneOffSelector             3
 299 #define kStylisticAltOneOnSelector              2
 300 #define kStylisticAltSevenOffSelector           15
 301 #define kStylisticAltSevenOnSelector            14
 302 #define kStylisticAltSeventeenOffSelector       35
 303 #define kStylisticAltSeventeenOnSelector        34
 304 #define kStylisticAltSixOffSelector             13
 305 #define kStylisticAltSixOnSelector              12
 306 #define kStylisticAltSixteenOffSelector         33
 307 #define kStylisticAltSixteenOnSelector          32
 308 #define kStylisticAltTenOffSelector             21
 309 #define kStylisticAltTenOnSelector              20
 310 #define kStylisticAltThirteenOffSelector        27
 311 #define kStylisticAltThirteenOnSelector         26
 312 #define kStylisticAltThreeOffSelector           7
 313 #define kStylisticAltThreeOnSelector            6
 314 #define kStylisticAltTwelveOffSelector          25
 315 #define kStylisticAltTwelveOnSelector           24
 316 #define kStylisticAltTwentyOffSelector          41
 317 #define kStylisticAltTwentyOnSelector           40
 318 #define kStylisticAltTwoOffSelector             5
 319 #define kStylisticAltTwoOnSelector              4
 320 #define kStylisticAlternativesType              35
 321 #define kSwashAlternatesOffSelector             3
 322 #define kSwashAlternatesOnSelector              2
 323 #define kThirdWidthTextSelector                 3
 324 #define kTraditionalNamesCharactersSelector     14
 325 #define kUpperCasePetiteCapsSelector            2
 326 #define kUpperCaseSmallCapsSelector             1
 327 #define kUpperCaseType                          38
 328
 329 /* Table data courtesy of Apple. */
 330 struct feature_mapping_t {
 331     FourCharCode otFeatureTag;
 332     uint16_t aatFeatureType;
 333     uint16_t selectorToEnable;
 334     uint16_t selectorToDisable;
 335 } feature_mappings[] = {
 336     { 'c2pc',   kUpperCaseType,             kUpperCasePetiteCapsSelector,           kDefaultUpperCaseSelector },
 337     { 'c2sc',   kUpperCaseType,             kUpperCaseSmallCapsSelector,            kDefaultUpperCaseSelector },
 338     { 'calt',   kContextualAlternatesType,  kContextualAlternatesOnSelector,        kContextualAlternatesOffSelector },
 339     { 'case',   kCaseSensitiveLayoutType,   kCaseSensitiveLayoutOnSelector,         kCaseSensitiveLayoutOffSelector },
 340     { 'clig',   kLigaturesType,             kContextualLigaturesOnSelector,         kContextualLigaturesOffSelector },
 341     { 'cpsp',   kCaseSensitiveLayoutType,   kCaseSensitiveSpacingOnSelector,        kCaseSensitiveSpacingOffSelector },
 342     { 'cswh',   kContextualAlternatesType,  kContextualSwashAlternatesOnSelector,   kContextualSwashAlternatesOffSelector },
 343     { 'dlig',   kLigaturesType,             kRareLigaturesOnSelector,               kRareLigaturesOffSelector },
 344     { 'expt',   kCharacterShapeType,        kExpertCharactersSelector,              16 },
 345     { 'frac',   kFractionsType,             kDiagonalFractionsSelector,             kNoFractionsSelector },
 346     { 'fwid',   kTextSpacingType,           kMonospacedTextSelector,                7 },
 347     { 'halt',   kTextSpacingType,           kAltHalfWidthTextSelector,              7 },
 348     { 'hist',   kLigaturesType,             kHistoricalLigaturesOnSelector,         kHistoricalLigaturesOffSelector },
 349     { 'hkna',   kAlternateKanaType,         kAlternateHorizKanaOnSelector,          kAlternateHorizKanaOffSelector, },
 350     { 'hlig',   kLigaturesType,             kHistoricalLigaturesOnSelector,         kHistoricalLigaturesOffSelector },
 351     { 'hngl',   kTransliterationType,       kHanjaToHangulSelector,                 kNoTransliterationSelector },
 352     { 'hojo',   kCharacterShapeType,        kHojoCharactersSelector,                16 },
 353     { 'hwid',   kTextSpacingType,           kHalfWidthTextSelector,                 7 },
 354     { 'ital',   kItalicCJKRomanType,        kCJKItalicRomanOnSelector,              kCJKItalicRomanOffSelector },
 355     { 'jp04',   kCharacterShapeType,        kJIS2004CharactersSelector,             16 },
 356     { 'jp78',   kCharacterShapeType,        kJIS1978CharactersSelector,             16 },
 357     { 'jp83',   kCharacterShapeType,        kJIS1983CharactersSelector,             16 },
 358     { 'jp90',   kCharacterShapeType,        kJIS1990CharactersSelector,             16 },
 359     { 'liga',   kLigaturesType,             kCommonLigaturesOnSelector,             kCommonLigaturesOffSelector },
 360     { 'lnum',   kNumberCaseType,            kUpperCaseNumbersSelector,              2 },
 361     { 'mgrk',   kMathematicalExtrasType,    kMathematicalGreekOnSelector,           kMathematicalGreekOffSelector },
 362     { 'nlck',   kCharacterShapeType,        kNLCCharactersSelector,                 16 },
 363     { 'onum',   kNumberCaseType,            kLowerCaseNumbersSelector,              2 },
 364     { 'ordn',   kVerticalPositionType,      kOrdinalsSelector,                      kNormalPositionSelector },
 365     { 'palt',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 366     { 'pcap',   kLowerCaseType,             kLowerCasePetiteCapsSelector,           kDefaultLowerCaseSelector },
 367     { 'pkna',   kTextSpacingType,           kProportionalTextSelector,              7 },
 368     { 'pnum',   kNumberSpacingType,         kProportionalNumbersSelector,           4 },
 369     { 'pwid',   kTextSpacingType,           kProportionalTextSelector,              7 },
 370     { 'qwid',   kTextSpacingType,           kQuarterWidthTextSelector,              7 },
 371     { 'ruby',   kRubyKanaType,              kRubyKanaOnSelector,                    kRubyKanaOffSelector },
 372     { 'sinf',   kVerticalPositionType,      kScientificInferiorsSelector,           kNormalPositionSelector },
 373     { 'smcp',   kLowerCaseType,             kLowerCaseSmallCapsSelector,            kDefaultLowerCaseSelector },
 374     { 'smpl',   kCharacterShapeType,        kSimplifiedCharactersSelector,          16 },
 375     { 'ss01',   kStylisticAlternativesType, kStylisticAltOneOnSelector,             kStylisticAltOneOffSelector },
 376     { 'ss02',   kStylisticAlternativesType, kStylisticAltTwoOnSelector,             kStylisticAltTwoOffSelector },
 377     { 'ss03',   kStylisticAlternativesType, kStylisticAltThreeOnSelector,           kStylisticAltThreeOffSelector },
 378     { 'ss04',   kStylisticAlternativesType, kStylisticAltFourOnSelector,            kStylisticAltFourOffSelector },
 379     { 'ss05',   kStylisticAlternativesType, kStylisticAltFiveOnSelector,            kStylisticAltFiveOffSelector },
 380     { 'ss06',   kStylisticAlternativesType, kStylisticAltSixOnSelector,             kStylisticAltSixOffSelector },
 381     { 'ss07',   kStylisticAlternativesType, kStylisticAltSevenOnSelector,           kStylisticAltSevenOffSelector },
 382     { 'ss08',   kStylisticAlternativesType, kStylisticAltEightOnSelector,           kStylisticAltEightOffSelector },
 383     { 'ss09',   kStylisticAlternativesType, kStylisticAltNineOnSelector,            kStylisticAltNineOffSelector },
 384     { 'ss10',   kStylisticAlternativesType, kStylisticAltTenOnSelector,             kStylisticAltTenOffSelector },
 385     { 'ss11',   kStylisticAlternativesType, kStylisticAltElevenOnSelector,          kStylisticAltElevenOffSelector },
 386     { 'ss12',   kStylisticAlternativesType, kStylisticAltTwelveOnSelector,          kStylisticAltTwelveOffSelector },
 387     { 'ss13',   kStylisticAlternativesType, kStylisticAltThirteenOnSelector,        kStylisticAltThirteenOffSelector },
 388     { 'ss14',   kStylisticAlternativesType, kStylisticAltFourteenOnSelector,        kStylisticAltFourteenOffSelector },
 389     { 'ss15',   kStylisticAlternativesType, kStylisticAltFifteenOnSelector,         kStylisticAltFifteenOffSelector },
 390     { 'ss16',   kStylisticAlternativesType, kStylisticAltSixteenOnSelector,         kStylisticAltSixteenOffSelector },
 391     { 'ss17',   kStylisticAlternativesType, kStylisticAltSeventeenOnSelector,       kStylisticAltSeventeenOffSelector },
 392     { 'ss18',   kStylisticAlternativesType, kStylisticAltEighteenOnSelector,        kStylisticAltEighteenOffSelector },
 393     { 'ss19',   kStylisticAlternativesType, kStylisticAltNineteenOnSelector,        kStylisticAltNineteenOffSelector },
 394     { 'ss20',   kStylisticAlternativesType, kStylisticAltTwentyOnSelector,          kStylisticAltTwentyOffSelector },
 395     { 'subs',   kVerticalPositionType,      kInferiorsSelector,                     kNormalPositionSelector },
 396     { 'sups',   kVerticalPositionType,      kSuperiorsSelector,                     kNormalPositionSelector },
 397     { 'swsh',   kContextualAlternatesType,  kSwashAlternatesOnSelector,             kSwashAlternatesOffSelector },
 398     { 'titl',   kStyleOptionsType,          kTitlingCapsSelector,                   kNoStyleOptionsSelector },
 399     { 'tnam',   kCharacterShapeType,        kTraditionalNamesCharactersSelector,    16 },
 400     { 'tnum',   kNumberSpacingType,         kMonospacedNumbersSelector,             4 },
 401     { 'trad',   kCharacterShapeType,        kTraditionalCharactersSelector,         16 },
 402     { 'twid',   kTextSpacingType,           kThirdWidthTextSelector,                7 },
 403     { 'unic',   kLetterCaseType,            14,                                     15 },
 404     { 'valt',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 405     { 'vert',   kVerticalSubstitutionType,  kSubstituteVerticalFormsOnSelector,     kSubstituteVerticalFormsOffSelector },
 406     { 'vhal',   kTextSpacingType,           kAltHalfWidthTextSelector,              7 },
 407     { 'vkna',   kAlternateKanaType,         kAlternateVertKanaOnSelector,           kAlternateVertKanaOffSelector },
 408     { 'vpal',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 409     { 'vrt2',   kVerticalSubstitutionType,  kSubstituteVerticalFormsOnSelector,     kSubstituteVerticalFormsOffSelector },
 410     { 'zero',   kTypographicExtrasType,     kSlashedZeroOnSelector,                 kSlashedZeroOffSelector },
 411 };
 412
 413 static int
 414 _hb_feature_mapping_cmp (const void *key_, const void *entry_)
 415 {
 416   unsigned int key = * (unsigned int *) key_;
 417   const feature_mapping_t * entry = (const feature_mapping_t *) entry_;
 418   return key < entry->otFeatureTag ? -1 :
 419          key > entry->otFeatureTag ? 1 :
 420          0;
 421 }
 422
 423 hb_bool_t
 424 _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
 425                     hb_font_t          *font,
 426                     hb_buffer_t        *buffer,
 427                     const hb_feature_t *features,
 428                     unsigned int        num_features)
 429 {
 430   hb_face_t *face = font->face;
 431   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
 432   hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
 433
 434   /* Attach marks to their bases, to match the 'ot' shaper.
 435    * Adapted from hb-ot-shape:hb_form_clusters().
 436    * Note that this only makes us be closer to the 'ot' shaper,
 437    * but by no means the same.  For example, if there's
 438    * B1 M1 B2 M2, and B1-B2 form a ligature, M2's cluster will
 439    * continue pointing to B2 even though B2 was merged into B1's
 440    * cluster... */
 441   {
 442     hb_unicode_funcs_t *unicode = buffer->unicode;
 443     unsigned int count = buffer->len;
 444     hb_glyph_info_t *info = buffer->info;
 445     for (unsigned int i = 1; i < count; i++)
 446       if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (unicode->general_category (info[i].codepoint)))
 447         buffer->merge_clusters (i - 1, i + 1);
 448   }
 449
 450   hb_auto_array_t<feature_record_t> feature_records;
 451   hb_auto_array_t<range_record_t> range_records;
 452
 453   /*
 454    * Set up features.
 455    * (copied + modified from code from hb-uniscribe.cc)
 456    */
 457   if (num_features)
 458   {
 459     /* Sort features by start/end events. */
 460     hb_auto_array_t<feature_event_t> feature_events;
 461     for (unsigned int i = 0; i < num_features; i++)
 462     {
 463       const feature_mapping_t * mapping = (const feature_mapping_t *) bsearch (&features[i].tag,
 464                                                                                feature_mappings,
 465                                                                                ARRAY_LENGTH (feature_mappings),
 466                                                                                sizeof (feature_mappings[0]),
 467                                                                                _hb_feature_mapping_cmp);
 468       if (!mapping)
 469         continue;
 470
 471       active_feature_t feature;
 472       feature.rec.feature = mapping->aatFeatureType;
 473       feature.rec.setting = features[i].value ? mapping->selectorToEnable : mapping->selectorToDisable;
 474       feature.order = i;
 475
 476       feature_event_t *event;
 477
 478       event = feature_events.push ();
 479       if (unlikely (!event))
 480         goto fail_features;
 481       event->index = features[i].start;
 482       event->start = true;
 483       event->feature = feature;
 484
 485       event = feature_events.push ();
 486       if (unlikely (!event))
 487         goto fail_features;
 488       event->index = features[i].end;
 489       event->start = false;
 490       event->feature = feature;
 491     }
 492     feature_events.qsort ();
 493     /* Add a strategic final event. */
 494     {
 495       active_feature_t feature;
 496       feature.rec.feature = HB_TAG_NONE;
 497       feature.rec.setting = 0;
 498       feature.order = num_features + 1;
 499
 500       feature_event_t *event = feature_events.push ();
 501       if (unlikely (!event))
 502         goto fail_features;
 503       event->index = 0; /* This value does magic. */
 504       event->start = false;
 505       event->feature = feature;
 506     }
 507
 508     /* Scan events and save features for each range. */
 509     hb_auto_array_t<active_feature_t> active_features;
 510     unsigned int last_index = 0;
 511     for (unsigned int i = 0; i < feature_events.len; i++)
 512     {
 513       feature_event_t *event = &feature_events[i];
 514
 515       if (event->index != last_index)
 516       {
 517         /* Save a snapshot of active features and the range. */
 518         range_record_t *range = range_records.push ();
 519         if (unlikely (!range))
 520           goto fail_features;
 521
 522         if (active_features.len)
 523         {
 524           CFMutableArrayRef features_array = CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);
 525
 526           /* TODO sort and resolve conflicting features? */
 527           /* active_features.qsort (); */
 528           for (unsigned int j = 0; j < active_features.len; j++)
 529           {
 530             CFStringRef keys[2] = {
 531               kCTFontFeatureTypeIdentifierKey,
 532               kCTFontFeatureSelectorIdentifierKey
 533             };
 534             CFNumberRef values[2] = {
 535               CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.feature),
 536               CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
 537             };
 538             CFDictionaryRef dict = CFDictionaryCreate (kCFAllocatorDefault,
 539                                                        (const void **) keys,
 540                                                        (const void **) values,
 541                                                        2,
 542                                                        &kCFTypeDictionaryKeyCallBacks,
 543                                                        &kCFTypeDictionaryValueCallBacks);
 544             CFRelease (values[0]);
 545             CFRelease (values[1]);
 546
 547             CFArrayAppendValue (features_array, dict);
 548             CFRelease (dict);
 549
 550           }
 551
 552           CFDictionaryRef attributes = CFDictionaryCreate (kCFAllocatorDefault,
 553                                                            (const void **) &kCTFontFeatureSettingsAttribute,
 554                                                            (const void **) &features_array,
 555                                                            1,
 556                                                            &kCFTypeDictionaryKeyCallBacks,
 557                                                            &kCFTypeDictionaryValueCallBacks);
 558           CFRelease (features_array);
 559
 560           CTFontDescriptorRef font_desc = CTFontDescriptorCreateWithAttributes (attributes);
 561           CFRelease (attributes);
 562
 563           range->font = CTFontCreateCopyWithAttributes (font_data->ct_font, 0.0, NULL, font_desc);
 564           CFRelease (font_desc);
 565         }
 566         else
 567         {
 568           range->font = NULL;
 569         }
 570
 571         range->index_first = last_index;
 572         range->index_last  = event->index - 1;
 573
 574         last_index = event->index;
 575       }
 576
 577       if (event->start) {
 578         active_feature_t *feature = active_features.push ();
 579         if (unlikely (!feature))
 580           goto fail_features;
 581         *feature = event->feature;
 582       } else {
 583         active_feature_t *feature = active_features.find (&event->feature);
 584         if (feature)
 585           active_features.remove (feature - active_features.array);
 586       }
 587     }
 588
 589     if (!range_records.len) /* No active feature found. */
 590       goto fail_features;
 591   }
 592   else
 593   {
 594   fail_features:
 595     num_features = 0;
 596   }
 597
 598   unsigned int scratch_size;
 599   hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
 600
 601 #define ALLOCATE_ARRAY(Type, name, len, on_no_room) \
 602   Type *name = (Type *) scratch; \
 603   { \
 604     unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
 605     if (unlikely (_consumed > scratch_size)) \
 606     { \
 607       on_no_room; \
 608       assert (0); \
 609     } \
 610     scratch += _consumed; \
 611     scratch_size -= _consumed; \
 612   }
 613
 614   ALLOCATE_ARRAY (UniChar, pchars, buffer->len * 2, /*nothing*/);
 615   unsigned int chars_len = 0;
 616   for (unsigned int i = 0; i < buffer->len; i++) {
 617     hb_codepoint_t c = buffer->info[i].codepoint;
 618     if (likely (c <= 0xFFFFu))
 619       pchars[chars_len++] = c;
 620     else if (unlikely (c > 0x10FFFFu))
 621       pchars[chars_len++] = 0xFFFDu;
 622     else {
 623       pchars[chars_len++] = 0xD800u + ((c - 0x10000u) >> 10);
 624       pchars[chars_len++] = 0xDC00u + ((c - 0x10000u) & ((1 << 10) - 1));
 625     }
 626   }
 627
 628   ALLOCATE_ARRAY (unsigned int, log_clusters, chars_len, /*nothing*/);
 629   chars_len = 0;
 630   for (unsigned int i = 0; i < buffer->len; i++)
 631   {
 632     hb_codepoint_t c = buffer->info[i].codepoint;
 633     unsigned int cluster = buffer->info[i].cluster;
 634     log_clusters[chars_len++] = cluster;
 635     if (hb_in_range (c, 0x10000u, 0x10FFFFu))
 636       log_clusters[chars_len++] = cluster; /* Surrogates. */
 637   }
 638
 639 #define FAIL(...) \
 640   HB_STMT_START { \
 641     DEBUG_MSG (CORETEXT, NULL, __VA_ARGS__); \
 642     ret = false; \
 643     goto fail; \
 644   } HB_STMT_END;
 645
 646   bool ret = true;
 647   CFStringRef string_ref = NULL;
 648   CTLineRef line = NULL;
 649
 650   if (0)
 651   {
 652 resize_and_retry:
 653     DEBUG_MSG (CORETEXT, buffer, "Buffer resize");
 654     /* string_ref uses the scratch-buffer for backing store, and line references
 655      * string_ref (via attr_string).  We must release those before resizing buffer. */
 656     assert (string_ref);
 657     assert (line);
 658     CFRelease (string_ref);
 659     CFRelease (line);
 660     string_ref = NULL;
 661     line = NULL;
 662
 663     /* Get previous start-of-scratch-area, that we use later for readjusting
 664      * our existing scratch arrays. */
 665     unsigned int old_scratch_used;
 666     hb_buffer_t::scratch_buffer_t *old_scratch;
 667     old_scratch = buffer->get_scratch_buffer (&old_scratch_used);
 668     old_scratch_used = scratch - old_scratch;
 669
 670     if (unlikely (!buffer->ensure (buffer->allocated * 2)))
 671       FAIL ("Buffer resize failed");
 672
 673     /* Adjust scratch, pchars, and log_cluster arrays.  This is ugly, but really the
 674      * cleanest way to do without completely restructuring the rest of this shaper. */
 675     scratch = buffer->get_scratch_buffer (&scratch_size);
 676     pchars = reinterpret_cast<UniChar *> (((char *) scratch + ((char *) pchars - (char *) old_scratch)));
 677     log_clusters = reinterpret_cast<unsigned int *> (((char *) scratch + ((char *) log_clusters - (char *) old_scratch)));
 678     scratch += old_scratch_used;
 679     scratch_size -= old_scratch_used;
 680   }
 681 retry:
 682   {
 683     string_ref = CFStringCreateWithCharactersNoCopy (NULL,
 684                                                      pchars, chars_len,
 685                                                      kCFAllocatorNull);
 686     if (unlikely (!string_ref))
 687       FAIL ("CFStringCreateWithCharactersNoCopy failed");
 688
 689     /* Create an attributed string, populate it, and create a line from it, then release attributed string. */
 690     {
 691       CFMutableAttributedStringRef attr_string = CFAttributedStringCreateMutable (kCFAllocatorDefault,
 692                                                                                   chars_len);
 693       if (unlikely (!attr_string))
 694         FAIL ("CFAttributedStringCreateMutable failed");
 695       CFAttributedStringReplaceString (attr_string, CFRangeMake (0, 0), string_ref);
 696       if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
 697       {
 698         CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
 699                                         kCTVerticalFormsAttributeName, kCFBooleanTrue);
 700       }
 701
 702       if (buffer->props.language)
 703       {
 704 /* What's the iOS equivalent of this check?
 705  * The symbols was introduced in iOS 7.0.
 706  * At any rate, our fallback is safe and works fine. */
 707 #if MAC_OS_X_VERSION_MIN_REQUIRED < 1090
 708 #  define kCTLanguageAttributeName CFSTR ("NSLanguage")
 709 #endif
 710         CFStringRef lang = CFStringCreateWithCStringNoCopy (kCFAllocatorDefault,
 711                                                             hb_language_to_string (buffer->props.language),
 712                                                             kCFStringEncodingUTF8,
 713                                                             kCFAllocatorNull);
 714         if (unlikely (!lang))
 715           FAIL ("CFStringCreateWithCStringNoCopy failed");
 716         CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
 717                                         kCTLanguageAttributeName, lang);
 718         CFRelease (lang);
 719       }
 720       CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
 721                                       kCTFontAttributeName, font_data->ct_font);
 722
 723       if (num_features)
 724       {
 725         unsigned int start = 0;
 726         range_record_t *last_range = &range_records[0];
 727         for (unsigned int k = 0; k < chars_len; k++)
 728         {
 729           range_record_t *range = last_range;
 730           while (log_clusters[k] < range->index_first)
 731             range--;
 732           while (log_clusters[k] > range->index_last)
 733             range++;
 734           if (range != last_range)
 735           {
 736             if (last_range->font)
 737               CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, k - start),
 738                                               kCTFontAttributeName, last_range->font);
 739
 740             start = k;
 741           }
 742
 743           last_range = range;
 744         }
 745         if (start != chars_len && last_range->font)
 746           CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, chars_len - start),
 747                                           kCTFontAttributeName, last_range->font);
 748       }
 749
 750       int level = HB_DIRECTION_IS_FORWARD (buffer->props.direction) ? 0 : 1;
 751       CFNumberRef level_number = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &level);
 752       CFDictionaryRef options = CFDictionaryCreate (kCFAllocatorDefault,
 753                                                     (const void **) &kCTTypesetterOptionForcedEmbeddingLevel,
 754                                                     (const void **) &level_number,
 755                                                     1,
 756                                                     &kCFTypeDictionaryKeyCallBacks,
 757                                                     &kCFTypeDictionaryValueCallBacks);
 758       if (unlikely (!options))
 759         FAIL ("CFDictionaryCreate failed");
 760
 761       CTTypesetterRef typesetter = CTTypesetterCreateWithAttributedStringAndOptions (attr_string, options);
 762       CFRelease (options);
 763       CFRelease (attr_string);
 764       if (unlikely (!typesetter))
 765         FAIL ("CTTypesetterCreateWithAttributedStringAndOptions failed");
 766
 767       line = CTTypesetterCreateLine (typesetter, CFRangeMake(0, 0));
 768       CFRelease (typesetter);
 769       if (unlikely (!line))
 770         FAIL ("CTTypesetterCreateLine failed");
 771     }
 772
 773     CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
 774     unsigned int num_runs = CFArrayGetCount (glyph_runs);
 775     DEBUG_MSG (CORETEXT, NULL, "Num runs: %d", num_runs);
 776
 777     buffer->len = 0;
 778     uint32_t status_and = ~0, status_or = 0;
 779
 780     const CFRange range_all = CFRangeMake (0, 0);
 781
 782     for (unsigned int i = 0; i < num_runs; i++)
 783     {
 784       CTRunRef run = static_cast<CTRunRef>(CFArrayGetValueAtIndex (glyph_runs, i));
 785       CTRunStatus run_status = CTRunGetStatus (run);
 786       status_or  |= run_status;
 787       status_and &= run_status;
 788       DEBUG_MSG (CORETEXT, run, "CTRunStatus: %x", run_status);
 789
 790       /* CoreText does automatic font fallback (AKA "cascading") for  characters
 791        * not supported by the requested font, and provides no way to turn it off,
 792        * so we must detect if the returned run uses a font other than the requested
 793        * one and fill in the buffer with .notdef glyphs instead of random glyph
 794        * indices from a different font.
 795        */
 796       CFDictionaryRef attributes = CTRunGetAttributes (run);
 797       CTFontRef run_ct_font = static_cast<CTFontRef>(CFDictionaryGetValue (attributes, kCTFontAttributeName));
 798       if (!CFEqual (run_ct_font, font_data->ct_font))
 799       {
 800         /* The run doesn't use our main font instance.  We have to figure out
 801          * whether font fallback happened, or this is just CoreText giving us
 802          * another CTFont using the same underlying CGFont.  CoreText seems
 803          * to do that in a variety of situations, one of which being vertical
 804          * text, but also perhaps for caching reasons.
 805          *
 806          * First, see if it uses any of our subfonts created to set font features...
 807          *
 808          * Next, compare the CGFont to the one we used to create our fonts.
 809          * Even this doesn't work all the time.
 810          *
 811          * Finally, we compare PS names, which I don't think are unique...
 812          *
 813          * Looks like if we really want to be sure here we have to modify the
 814          * font to change the name table, similar to what we do in the uniscribe
 815          * backend.
 816          *
 817          * However, even that wouldn't work if we were passed in the CGFont to
 818          * begin with.
 819          *
 820          * Webkit uses a slightly different approach: it installs LastResort
 821          * as fallback chain, and then checks PS name of used font against
 822          * LastResort.  That one is safe for any font except for LastResort,
 823          * as opposed to ours, which can fail if we are using any uninstalled
 824          * font that has the same name as an installed font.
 825          *
 826          * See: http://github.com/behdad/harfbuzz/pull/36
 827          */
 828         bool matched = false;
 829         for (unsigned int i = 0; i < range_records.len; i++)
 830           if (range_records[i].font && CFEqual (run_ct_font, range_records[i].font))
 831           {
 832             matched = true;
 833             break;
 834           }
 835         if (!matched)
 836         {
 837           CGFontRef run_cg_font = CTFontCopyGraphicsFont (run_ct_font, 0);
 838           if (run_cg_font)
 839           {
 840             matched = CFEqual (run_cg_font, face_data);
 841             CFRelease (run_cg_font);
 842           }
 843         }
 844         if (!matched)
 845         {
 846           CFStringRef font_ps_name = CTFontCopyName (font_data->ct_font, kCTFontPostScriptNameKey);
 847           CFStringRef run_ps_name = CTFontCopyName (run_ct_font, kCTFontPostScriptNameKey);
 848           CFComparisonResult result = CFStringCompare (run_ps_name, font_ps_name, 0);
 849           CFRelease (run_ps_name);
 850           CFRelease (font_ps_name);
 851           if (result == kCFCompareEqualTo)
 852             matched = true;
 853         }
 854         if (!matched)
 855         {
 856           CFRange range = CTRunGetStringRange (run);
 857           DEBUG_MSG (CORETEXT, run, "Run used fallback font: %ld..%ld",
 858                      range.location, range.location + range.length);
 859           if (!buffer->ensure_inplace (buffer->len + range.length))
 860             goto resize_and_retry;
 861           hb_glyph_info_t *info = buffer->info + buffer->len;
 862
 863           CGGlyph notdef = 0;
 864           double advance = CTFontGetAdvancesForGlyphs (font_data->ct_font, kCTFontHorizontalOrientation, &notdef, NULL, 1);
 865
 866           unsigned int old_len = buffer->len;
 867           for (CFIndex j = range.location; j < range.location + range.length; j++)
 868           {
 869               UniChar ch = CFStringGetCharacterAtIndex (string_ref, j);
 870               if (hb_in_range<UniChar> (ch, 0xDC00u, 0xDFFFu) && range.location < j)
 871               {
 872                 ch = CFStringGetCharacterAtIndex (string_ref, j - 1);
 873                 if (hb_in_range<UniChar> (ch, 0xD800u, 0xDBFFu))
 874                   /* This is the second of a surrogate pair.  Don't need .notdef
 875                    * for this one. */
 876                   continue;
 877               }
 878
 879               info->codepoint = notdef;
 880               info->cluster = log_clusters[j];
 881
 882               info->mask = advance;
 883               info->var1.u32 = 0;
 884               info->var2.u32 = 0;
 885
 886               info++;
 887               buffer->len++;
 888           }
 889           if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
 890             buffer->reverse_range (old_len, buffer->len);
 891           continue;
 892         }
 893       }
 894
 895       unsigned int num_glyphs = CTRunGetGlyphCount (run);
 896       if (num_glyphs == 0)
 897         continue;
 898
 899       if (!buffer->ensure_inplace (buffer->len + num_glyphs))
 900         goto resize_and_retry;
 901
 902       hb_glyph_info_t *run_info = buffer->info + buffer->len;
 903
 904       /* Testing used to indicate that CTRunGetGlyphsPtr, etc (almost?) always
 905        * succeed, and so copying data to our own buffer will be rare.  Reports
 906        * have it that this changed in OS X 10.10 Yosemite, and NULL is returned
 907        * frequently.  At any rate, we can test that codepath by setting USE_PTR
 908        * to false. */
 909
 910 #define USE_PTR true
 911
 912 #define SCRATCH_SAVE() \
 913   unsigned int scratch_size_saved = scratch_size; \
 914   hb_buffer_t::scratch_buffer_t *scratch_saved = scratch
 915
 916 #define SCRATCH_RESTORE() \
 917   scratch_size = scratch_size_saved; \
 918   scratch = scratch_saved;
 919
 920       {
 921         SCRATCH_SAVE();
 922         const CGGlyph* glyphs = USE_PTR ? CTRunGetGlyphsPtr (run) : NULL;
 923         if (!glyphs) {
 924           ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs, goto resize_and_retry);
 925           CTRunGetGlyphs (run, range_all, glyph_buf);
 926           glyphs = glyph_buf;
 927         }
 928         const CFIndex* string_indices = USE_PTR ? CTRunGetStringIndicesPtr (run) : NULL;
 929         if (!string_indices) {
 930           ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs, goto resize_and_retry);
 931           CTRunGetStringIndices (run, range_all, index_buf);
 932           string_indices = index_buf;
 933         }
 934         hb_glyph_info_t *info = run_info;
 935         for (unsigned int j = 0; j < num_glyphs; j++)
 936         {
 937           info->codepoint = glyphs[j];
 938           info->cluster = log_clusters[string_indices[j]];
 939           info++;
 940         }
 941         SCRATCH_RESTORE();
 942       }
 943       {
 944         SCRATCH_SAVE();
 945         const CGPoint* positions = USE_PTR ? CTRunGetPositionsPtr (run) : NULL;
 946         if (!positions) {
 947           ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs, goto resize_and_retry);
 948           CTRunGetPositions (run, range_all, position_buf);
 949           positions = position_buf;
 950         }
 951         double run_advance = CTRunGetTypographicBounds (run, range_all, NULL, NULL, NULL);
 952         DEBUG_MSG (CORETEXT, run, "Run advance: %g", run_advance);
 953         hb_glyph_info_t *info = run_info;
 954         if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
 955         {
 956           for (unsigned int j = 0; j < num_glyphs; j++)
 957           {
 958             double advance = (j + 1 < num_glyphs ? positions[j + 1].x : positions[0].x + run_advance) - positions[j].x;
 959             info->mask = advance;
 960             info->var1.u32 = positions[0].x; /* Yes, zero. */
 961             info->var2.u32 = positions[j].y;
 962             info++;
 963           }
 964         }
 965         else
 966         {
 967           run_advance = -run_advance;
 968           for (unsigned int j = 0; j < num_glyphs; j++)
 969           {
 970             double advance = (j + 1 < num_glyphs ? positions[j + 1].y : positions[0].y + run_advance) - positions[j].y;
 971             info->mask = advance;
 972             info->var1.u32 = positions[j].x;
 973             info->var2.u32 = positions[0].y; /* Yes, zero. */
 974             info++;
 975           }
 976         }
 977         SCRATCH_RESTORE();
 978       }
 979 #undef SCRATCH_RESTORE
 980 #undef SCRATCH_SAVE
 981 #undef USE_PTR
 982 #undef ALLOCATE_ARRAY
 983
 984       buffer->len += num_glyphs;
 985     }
 986
 987     /* Make sure all runs had the expected direction. */
 988     bool backward = HB_DIRECTION_IS_BACKWARD (buffer->props.direction);
 989     assert (bool (status_and & kCTRunStatusRightToLeft) == backward);
 990     assert (bool (status_or  & kCTRunStatusRightToLeft) == backward);
 991
 992     buffer->clear_positions ();
 993
 994     unsigned int count = buffer->len;
 995     hb_glyph_info_t *info = buffer->info;
 996     hb_glyph_position_t *pos = buffer->pos;
 997     if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
 998       for (unsigned int i = 0; i < count; i++)
 999       {
1000         pos->x_advance = info->mask;
1001         pos->x_offset = info->var1.u32;
1002         pos->y_offset = info->var2.u32;
1003         info++, pos++;
1004       }
1005     else
1006       for (unsigned int i = 0; i < count; i++)
1007       {
1008         pos->y_advance = info->mask;
1009         pos->x_offset = info->var1.u32;
1010         pos->y_offset = info->var2.u32;
1011         info++, pos++;
1012       }
1013
1014     /* Fix up clusters so that we never return out-of-order indices;
1015      * if core text has reordered glyphs, we'll merge them to the
1016      * beginning of the reordered cluster.  CoreText is nice enough
1017      * to tell us whenever it has produced nonmonotonic results...
1018      * Note that we assume the input clusters were nonmonotonic to
1019      * begin with.
1020      *
1021      * This does *not* mean we'll form the same clusters as Uniscribe
1022      * or the native OT backend, only that the cluster indices will be
1023      * monotonic in the output buffer. */
1024     if (count > 1 && (status_or & kCTRunStatusNonMonotonic))
1025     {
1026       hb_glyph_info_t *info = buffer->info;
1027       if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
1028       {
1029         unsigned int cluster = info[count - 1].cluster;
1030         for (unsigned int i = count - 1; i > 0; i--)
1031         {
1032           cluster = MIN (cluster, info[i - 1].cluster);
1033           info[i - 1].cluster = cluster;
1034         }
1035       }
1036       else
1037       {
1038         unsigned int cluster = info[0].cluster;
1039         for (unsigned int i = 1; i < count; i++)
1040         {
1041           cluster = MIN (cluster, info[i].cluster);
1042           info[i].cluster = cluster;
1043         }
1044       }
1045     }
1046   }
1047
1048 #undef FAIL
1049
1050 fail:
1051   if (string_ref)
1052     CFRelease (string_ref);
1053   if (line)
1054     CFRelease (line);
1055
1056   for (unsigned int i = 0; i < range_records.len; i++)
1057     if (range_records[i].font)
1058       CFRelease (range_records[i].font);
1059
1060   return ret;
1061 }
1062
1063
1064 /*
1065  * AAT shaper
1066  */
1067
1068 HB_SHAPER_DATA_ENSURE_DECLARE(coretext_aat, face)
1069 HB_SHAPER_DATA_ENSURE_DECLARE(coretext_aat, font)
1070
1071
1072 /*
1073  * shaper face data
1074  */
1075
1076 struct hb_coretext_aat_shaper_face_data_t {};
1077
1078 hb_coretext_aat_shaper_face_data_t *
1079 _hb_coretext_aat_shaper_face_data_create (hb_face_t *face)
1080 {
1081   hb_blob_t *mort_blob = face->reference_table (HB_CORETEXT_TAG_MORT);
1082   /* Umm, we just reference the table to check whether it exists.
1083    * Maybe add better API for this? */
1084   if (!hb_blob_get_length (mort_blob))
1085   {
1086     hb_blob_destroy (mort_blob);
1087     mort_blob = face->reference_table (HB_CORETEXT_TAG_MORX);
1088     if (!hb_blob_get_length (mort_blob))
1089     {
1090       hb_blob_destroy (mort_blob);
1091       return NULL;
1092     }
1093   }
1094   hb_blob_destroy (mort_blob);
1095
1096   return hb_coretext_shaper_face_data_ensure (face) ? (hb_coretext_aat_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED : NULL;
1097 }
1098
1099 void
1100 _hb_coretext_aat_shaper_face_data_destroy (hb_coretext_aat_shaper_face_data_t *data HB_UNUSED)
1101 {
1102 }
1103
1104
1105 /*
1106  * shaper font data
1107  */
1108
1109 struct hb_coretext_aat_shaper_font_data_t {};
1110
1111 hb_coretext_aat_shaper_font_data_t *
1112 _hb_coretext_aat_shaper_font_data_create (hb_font_t *font)
1113 {
1114   return hb_coretext_shaper_font_data_ensure (font) ? (hb_coretext_aat_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED : NULL;
1115 }
1116
1117 void
1118 _hb_coretext_aat_shaper_font_data_destroy (hb_coretext_aat_shaper_font_data_t *data HB_UNUSED)
1119 {
1120 }
1121
1122
1123 /*
1124  * shaper shape_plan data
1125  */
1126
1127 struct hb_coretext_aat_shaper_shape_plan_data_t {};
1128
1129 hb_coretext_aat_shaper_shape_plan_data_t *
1130 _hb_coretext_aat_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
1131                                              const hb_feature_t *user_features HB_UNUSED,
1132                                              unsigned int        num_user_features HB_UNUSED)
1133 {
1134   return (hb_coretext_aat_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
1135 }
1136
1137 void
1138 _hb_coretext_aat_shaper_shape_plan_data_destroy (hb_coretext_aat_shaper_shape_plan_data_t *data HB_UNUSED)
1139 {
1140 }
1141
1142
1143 /*
1144  * shaper
1145  */
1146
1147 hb_bool_t
1148 _hb_coretext_aat_shape (hb_shape_plan_t    *shape_plan,
1149                         hb_font_t          *font,
1150                         hb_buffer_t        *buffer,
1151                         const hb_feature_t *features,
1152                         unsigned int        num_features)
1153 {
1154   return _hb_coretext_shape (shape_plan, font, buffer, features, num_features);
1155 }