third_party/harfbuzz-ng/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 #include "hb-shaper-impl-private.hh"
  31
  32 #include "hb-coretext.h"
  33
  34
  35 #ifndef HB_DEBUG_CORETEXT
  36 #define HB_DEBUG_CORETEXT (HB_DEBUG+0)
  37 #endif
  38
  39
  40 HB_SHAPER_DATA_ENSURE_DECLARE(coretext, face)
  41 HB_SHAPER_DATA_ENSURE_DECLARE(coretext, font)
  42
  43
  44 /*
  45  * shaper face data
  46  */
  47
  48 struct hb_coretext_shaper_face_data_t {
  49   CGFontRef cg_font;
  50 };
  51
  52 static void
  53 release_data (void *info, const void *data, size_t size)
  54 {
  55   assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
  56           hb_blob_get_data ((hb_blob_t *) info, NULL) == data);
  57
  58   hb_blob_destroy ((hb_blob_t *) info);
  59 }
  60
  61 hb_coretext_shaper_face_data_t *
  62 _hb_coretext_shaper_face_data_create (hb_face_t *face)
  63 {
  64   hb_coretext_shaper_face_data_t *data = (hb_coretext_shaper_face_data_t *) calloc (1, sizeof (hb_coretext_shaper_face_data_t));
  65   if (unlikely (!data))
  66     return NULL;
  67
  68   hb_blob_t *blob = hb_face_reference_blob (face);
  69   unsigned int blob_length;
  70   const char *blob_data = hb_blob_get_data (blob, &blob_length);
  71   if (unlikely (!blob_length))
  72     DEBUG_MSG (CORETEXT, face, "Face has empty blob");
  73
  74   CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
  75   data->cg_font = CGFontCreateWithDataProvider (provider);
  76   CGDataProviderRelease (provider);
  77
  78   if (unlikely (!data->cg_font)) {
  79     DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
  80     free (data);
  81     return NULL;
  82   }
  83
  84   return data;
  85 }
  86
  87 void
  88 _hb_coretext_shaper_face_data_destroy (hb_coretext_shaper_face_data_t *data)
  89 {
  90   CFRelease (data->cg_font);
  91   free (data);
  92 }
  93
  94 CGFontRef
  95 hb_coretext_face_get_cg_font (hb_face_t *face)
  96 {
  97   if (unlikely (!hb_coretext_shaper_face_data_ensure (face))) return NULL;
  98   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
  99   return face_data->cg_font;
 100 }
 101
 102
 103 /*
 104  * shaper font data
 105  */
 106
 107 struct hb_coretext_shaper_font_data_t {
 108   CTFontRef ct_font;
 109 };
 110
 111 hb_coretext_shaper_font_data_t *
 112 _hb_coretext_shaper_font_data_create (hb_font_t *font)
 113 {
 114   if (unlikely (!hb_coretext_shaper_face_data_ensure (font->face))) return NULL;
 115
 116   hb_coretext_shaper_font_data_t *data = (hb_coretext_shaper_font_data_t *) calloc (1, sizeof (hb_coretext_shaper_font_data_t));
 117   if (unlikely (!data))
 118     return NULL;
 119
 120   hb_face_t *face = font->face;
 121   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
 122
 123   data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale, NULL, NULL);
 124   if (unlikely (!data->ct_font)) {
 125     DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
 126     free (data);
 127     return NULL;
 128   }
 129
 130   return data;
 131 }
 132
 133 void
 134 _hb_coretext_shaper_font_data_destroy (hb_coretext_shaper_font_data_t *data)
 135 {
 136   CFRelease (data->ct_font);
 137   free (data);
 138 }
 139
 140
 141 /*
 142  * shaper shape_plan data
 143  */
 144
 145 struct hb_coretext_shaper_shape_plan_data_t {};
 146
 147 hb_coretext_shaper_shape_plan_data_t *
 148 _hb_coretext_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
 149                                              const hb_feature_t *user_features HB_UNUSED,
 150                                              unsigned int        num_user_features HB_UNUSED)
 151 {
 152   return (hb_coretext_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
 153 }
 154
 155 void
 156 _hb_coretext_shaper_shape_plan_data_destroy (hb_coretext_shaper_shape_plan_data_t *data HB_UNUSED)
 157 {
 158 }
 159
 160 CTFontRef
 161 hb_coretext_font_get_ct_font (hb_font_t *font)
 162 {
 163   if (unlikely (!hb_coretext_shaper_font_data_ensure (font))) return NULL;
 164   hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
 165   return font_data->ct_font;
 166 }
 167
 168
 169 /*
 170  * shaper
 171  */
 172
 173 struct feature_record_t {
 174   unsigned int feature;
 175   unsigned int setting;
 176 };
 177
 178 struct active_feature_t {
 179   feature_record_t rec;
 180   unsigned int order;
 181
 182   static int cmp (const active_feature_t *a, const active_feature_t *b) {
 183     return a->rec.feature < b->rec.feature ? -1 : a->rec.feature > b->rec.feature ? 1 :
 184            a->order < b->order ? -1 : a->order > b->order ? 1 :
 185            a->rec.setting < b->rec.setting ? -1 : a->rec.setting > b->rec.setting ? 1 :
 186            0;
 187   }
 188   bool operator== (const active_feature_t *f) {
 189     return cmp (this, f) == 0;
 190   }
 191 };
 192
 193 struct feature_event_t {
 194   unsigned int index;
 195   bool start;
 196   active_feature_t feature;
 197
 198   static int cmp (const feature_event_t *a, const feature_event_t *b) {
 199     return a->index < b->index ? -1 : a->index > b->index ? 1 :
 200            a->start < b->start ? -1 : a->start > b->start ? 1 :
 201            active_feature_t::cmp (&a->feature, &b->feature);
 202   }
 203 };
 204
 205 struct range_record_t {
 206   CTFontRef font;
 207   unsigned int index_first; /* == start */
 208   unsigned int index_last;  /* == end - 1 */
 209 };
 210
 211
 212 /* The following enum members are added in OS X 10.8. */
 213 #define kAltHalfWidthTextSelector               6
 214 #define kAltProportionalTextSelector            5
 215 #define kAlternateHorizKanaOffSelector          1
 216 #define kAlternateHorizKanaOnSelector           0
 217 #define kAlternateKanaType                      34
 218 #define kAlternateVertKanaOffSelector           3
 219 #define kAlternateVertKanaOnSelector            2
 220 #define kCaseSensitiveLayoutOffSelector         1
 221 #define kCaseSensitiveLayoutOnSelector          0
 222 #define kCaseSensitiveLayoutType                33
 223 #define kCaseSensitiveSpacingOffSelector        3
 224 #define kCaseSensitiveSpacingOnSelector         2
 225 #define kContextualAlternatesOffSelector        1
 226 #define kContextualAlternatesOnSelector         0
 227 #define kContextualAlternatesType               36
 228 #define kContextualLigaturesOffSelector         19
 229 #define kContextualLigaturesOnSelector          18
 230 #define kContextualSwashAlternatesOffSelector   5
 231 #define kContextualSwashAlternatesOnSelector    4
 232 #define kDefaultLowerCaseSelector               0
 233 #define kDefaultUpperCaseSelector               0
 234 #define kHistoricalLigaturesOffSelector         21
 235 #define kHistoricalLigaturesOnSelector          20
 236 #define kHojoCharactersSelector                 12
 237 #define kJIS2004CharactersSelector              11
 238 #define kLowerCasePetiteCapsSelector            2
 239 #define kLowerCaseSmallCapsSelector             1
 240 #define kLowerCaseType                          37
 241 #define kMathematicalGreekOffSelector           11
 242 #define kMathematicalGreekOnSelector            10
 243 #define kNLCCharactersSelector                  13
 244 #define kQuarterWidthTextSelector               4
 245 #define kScientificInferiorsSelector            4
 246 #define kStylisticAltEightOffSelector           17
 247 #define kStylisticAltEightOnSelector            16
 248 #define kStylisticAltEighteenOffSelector        37
 249 #define kStylisticAltEighteenOnSelector         36
 250 #define kStylisticAltElevenOffSelector          23
 251 #define kStylisticAltElevenOnSelector           22
 252 #define kStylisticAltFifteenOffSelector         31
 253 #define kStylisticAltFifteenOnSelector          30
 254 #define kStylisticAltFiveOffSelector            11
 255 #define kStylisticAltFiveOnSelector             10
 256 #define kStylisticAltFourOffSelector            9
 257 #define kStylisticAltFourOnSelector             8
 258 #define kStylisticAltFourteenOffSelector        29
 259 #define kStylisticAltFourteenOnSelector         28
 260 #define kStylisticAltNineOffSelector            19
 261 #define kStylisticAltNineOnSelector             18
 262 #define kStylisticAltNineteenOffSelector        39
 263 #define kStylisticAltNineteenOnSelector         38
 264 #define kStylisticAltOneOffSelector             3
 265 #define kStylisticAltOneOnSelector              2
 266 #define kStylisticAltSevenOffSelector           15
 267 #define kStylisticAltSevenOnSelector            14
 268 #define kStylisticAltSeventeenOffSelector       35
 269 #define kStylisticAltSeventeenOnSelector        34
 270 #define kStylisticAltSixOffSelector             13
 271 #define kStylisticAltSixOnSelector              12
 272 #define kStylisticAltSixteenOffSelector         33
 273 #define kStylisticAltSixteenOnSelector          32
 274 #define kStylisticAltTenOffSelector             21
 275 #define kStylisticAltTenOnSelector              20
 276 #define kStylisticAltThirteenOffSelector        27
 277 #define kStylisticAltThirteenOnSelector         26
 278 #define kStylisticAltThreeOffSelector           7
 279 #define kStylisticAltThreeOnSelector            6
 280 #define kStylisticAltTwelveOffSelector          25
 281 #define kStylisticAltTwelveOnSelector           24
 282 #define kStylisticAltTwentyOffSelector          41
 283 #define kStylisticAltTwentyOnSelector           40
 284 #define kStylisticAltTwoOffSelector             5
 285 #define kStylisticAltTwoOnSelector              4
 286 #define kStylisticAlternativesType              35
 287 #define kSwashAlternatesOffSelector             3
 288 #define kSwashAlternatesOnSelector              2
 289 #define kThirdWidthTextSelector                 3
 290 #define kTraditionalNamesCharactersSelector     14
 291 #define kUpperCasePetiteCapsSelector            2
 292 #define kUpperCaseSmallCapsSelector             1
 293 #define kUpperCaseType                          38
 294
 295 /* Table data courtesy of Apple. */
 296 struct feature_mapping_t {
 297     FourCharCode otFeatureTag;
 298     uint16_t aatFeatureType;
 299     uint16_t selectorToEnable;
 300     uint16_t selectorToDisable;
 301 } feature_mappings[] = {
 302     { 'c2pc',   kUpperCaseType,             kUpperCasePetiteCapsSelector,           kDefaultUpperCaseSelector },
 303     { 'c2sc',   kUpperCaseType,             kUpperCaseSmallCapsSelector,            kDefaultUpperCaseSelector },
 304     { 'calt',   kContextualAlternatesType,  kContextualAlternatesOnSelector,        kContextualAlternatesOffSelector },
 305     { 'case',   kCaseSensitiveLayoutType,   kCaseSensitiveLayoutOnSelector,         kCaseSensitiveLayoutOffSelector },
 306     { 'clig',   kLigaturesType,             kContextualLigaturesOnSelector,         kContextualLigaturesOffSelector },
 307     { 'cpsp',   kCaseSensitiveLayoutType,   kCaseSensitiveSpacingOnSelector,        kCaseSensitiveSpacingOffSelector },
 308     { 'cswh',   kContextualAlternatesType,  kContextualSwashAlternatesOnSelector,   kContextualSwashAlternatesOffSelector },
 309     { 'dlig',   kLigaturesType,             kRareLigaturesOnSelector,               kRareLigaturesOffSelector },
 310     { 'expt',   kCharacterShapeType,        kExpertCharactersSelector,              16 },
 311     { 'frac',   kFractionsType,             kDiagonalFractionsSelector,             kNoFractionsSelector },
 312     { 'fwid',   kTextSpacingType,           kMonospacedTextSelector,                7 },
 313     { 'halt',   kTextSpacingType,           kAltHalfWidthTextSelector,              7 },
 314     { 'hist',   kLigaturesType,             kHistoricalLigaturesOnSelector,         kHistoricalLigaturesOffSelector },
 315     { 'hkna',   kAlternateKanaType,         kAlternateHorizKanaOnSelector,          kAlternateHorizKanaOffSelector, },
 316     { 'hlig',   kLigaturesType,             kHistoricalLigaturesOnSelector,         kHistoricalLigaturesOffSelector },
 317     { 'hngl',   kTransliterationType,       kHanjaToHangulSelector,                 kNoTransliterationSelector },
 318     { 'hojo',   kCharacterShapeType,        kHojoCharactersSelector,                16 },
 319     { 'hwid',   kTextSpacingType,           kHalfWidthTextSelector,                 7 },
 320     { 'ital',   kItalicCJKRomanType,        kCJKItalicRomanOnSelector,              kCJKItalicRomanOffSelector },
 321     { 'jp04',   kCharacterShapeType,        kJIS2004CharactersSelector,             16 },
 322     { 'jp78',   kCharacterShapeType,        kJIS1978CharactersSelector,             16 },
 323     { 'jp83',   kCharacterShapeType,        kJIS1983CharactersSelector,             16 },
 324     { 'jp90',   kCharacterShapeType,        kJIS1990CharactersSelector,             16 },
 325     { 'liga',   kLigaturesType,             kCommonLigaturesOnSelector,             kCommonLigaturesOffSelector },
 326     { 'lnum',   kNumberCaseType,            kUpperCaseNumbersSelector,              2 },
 327     { 'mgrk',   kMathematicalExtrasType,    kMathematicalGreekOnSelector,           kMathematicalGreekOffSelector },
 328     { 'nlck',   kCharacterShapeType,        kNLCCharactersSelector,                 16 },
 329     { 'onum',   kNumberCaseType,            kLowerCaseNumbersSelector,              2 },
 330     { 'ordn',   kVerticalPositionType,      kOrdinalsSelector,                      kNormalPositionSelector },
 331     { 'palt',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 332     { 'pcap',   kLowerCaseType,             kLowerCasePetiteCapsSelector,           kDefaultLowerCaseSelector },
 333     { 'pkna',   kTextSpacingType,           kProportionalTextSelector,              7 },
 334     { 'pnum',   kNumberSpacingType,         kProportionalNumbersSelector,           4 },
 335     { 'pwid',   kTextSpacingType,           kProportionalTextSelector,              7 },
 336     { 'qwid',   kTextSpacingType,           kQuarterWidthTextSelector,              7 },
 337     { 'ruby',   kRubyKanaType,              kRubyKanaOnSelector,                    kRubyKanaOffSelector },
 338     { 'sinf',   kVerticalPositionType,      kScientificInferiorsSelector,           kNormalPositionSelector },
 339     { 'smcp',   kLowerCaseType,             kLowerCaseSmallCapsSelector,            kDefaultLowerCaseSelector },
 340     { 'smpl',   kCharacterShapeType,        kSimplifiedCharactersSelector,          16 },
 341     { 'ss01',   kStylisticAlternativesType, kStylisticAltOneOnSelector,             kStylisticAltOneOffSelector },
 342     { 'ss02',   kStylisticAlternativesType, kStylisticAltTwoOnSelector,             kStylisticAltTwoOffSelector },
 343     { 'ss03',   kStylisticAlternativesType, kStylisticAltThreeOnSelector,           kStylisticAltThreeOffSelector },
 344     { 'ss04',   kStylisticAlternativesType, kStylisticAltFourOnSelector,            kStylisticAltFourOffSelector },
 345     { 'ss05',   kStylisticAlternativesType, kStylisticAltFiveOnSelector,            kStylisticAltFiveOffSelector },
 346     { 'ss06',   kStylisticAlternativesType, kStylisticAltSixOnSelector,             kStylisticAltSixOffSelector },
 347     { 'ss07',   kStylisticAlternativesType, kStylisticAltSevenOnSelector,           kStylisticAltSevenOffSelector },
 348     { 'ss08',   kStylisticAlternativesType, kStylisticAltEightOnSelector,           kStylisticAltEightOffSelector },
 349     { 'ss09',   kStylisticAlternativesType, kStylisticAltNineOnSelector,            kStylisticAltNineOffSelector },
 350     { 'ss10',   kStylisticAlternativesType, kStylisticAltTenOnSelector,             kStylisticAltTenOffSelector },
 351     { 'ss11',   kStylisticAlternativesType, kStylisticAltElevenOnSelector,          kStylisticAltElevenOffSelector },
 352     { 'ss12',   kStylisticAlternativesType, kStylisticAltTwelveOnSelector,          kStylisticAltTwelveOffSelector },
 353     { 'ss13',   kStylisticAlternativesType, kStylisticAltThirteenOnSelector,        kStylisticAltThirteenOffSelector },
 354     { 'ss14',   kStylisticAlternativesType, kStylisticAltFourteenOnSelector,        kStylisticAltFourteenOffSelector },
 355     { 'ss15',   kStylisticAlternativesType, kStylisticAltFifteenOnSelector,         kStylisticAltFifteenOffSelector },
 356     { 'ss16',   kStylisticAlternativesType, kStylisticAltSixteenOnSelector,         kStylisticAltSixteenOffSelector },
 357     { 'ss17',   kStylisticAlternativesType, kStylisticAltSeventeenOnSelector,       kStylisticAltSeventeenOffSelector },
 358     { 'ss18',   kStylisticAlternativesType, kStylisticAltEighteenOnSelector,        kStylisticAltEighteenOffSelector },
 359     { 'ss19',   kStylisticAlternativesType, kStylisticAltNineteenOnSelector,        kStylisticAltNineteenOffSelector },
 360     { 'ss20',   kStylisticAlternativesType, kStylisticAltTwentyOnSelector,          kStylisticAltTwentyOffSelector },
 361     { 'subs',   kVerticalPositionType,      kInferiorsSelector,                     kNormalPositionSelector },
 362     { 'sups',   kVerticalPositionType,      kSuperiorsSelector,                     kNormalPositionSelector },
 363     { 'swsh',   kContextualAlternatesType,  kSwashAlternatesOnSelector,             kSwashAlternatesOffSelector },
 364     { 'titl',   kStyleOptionsType,          kTitlingCapsSelector,                   kNoStyleOptionsSelector },
 365     { 'tnam',   kCharacterShapeType,        kTraditionalNamesCharactersSelector,    16 },
 366     { 'tnum',   kNumberSpacingType,         kMonospacedNumbersSelector,             4 },
 367     { 'trad',   kCharacterShapeType,        kTraditionalCharactersSelector,         16 },
 368     { 'twid',   kTextSpacingType,           kThirdWidthTextSelector,                7 },
 369     { 'unic',   kLetterCaseType,            14,                                     15 },
 370     { 'valt',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 371     { 'vert',   kVerticalSubstitutionType,  kSubstituteVerticalFormsOnSelector,     kSubstituteVerticalFormsOffSelector },
 372     { 'vhal',   kTextSpacingType,           kAltHalfWidthTextSelector,              7 },
 373     { 'vkna',   kAlternateKanaType,         kAlternateVertKanaOnSelector,           kAlternateVertKanaOffSelector },
 374     { 'vpal',   kTextSpacingType,           kAltProportionalTextSelector,           7 },
 375     { 'vrt2',   kVerticalSubstitutionType,  kSubstituteVerticalFormsOnSelector,     kSubstituteVerticalFormsOffSelector },
 376     { 'zero',   kTypographicExtrasType,     kSlashedZeroOnSelector,                 kSlashedZeroOffSelector },
 377 };
 378
 379 static int
 380 _hb_feature_mapping_cmp (const void *key_, const void *entry_)
 381 {
 382   unsigned int key = * (unsigned int *) key_;
 383   const feature_mapping_t * entry = (const feature_mapping_t *) entry_;
 384   return key < entry->otFeatureTag ? -1 :
 385          key > entry->otFeatureTag ? 1 :
 386          0;
 387 }
 388
 389 hb_bool_t
 390 _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
 391                     hb_font_t          *font,
 392                     hb_buffer_t        *buffer,
 393                     const hb_feature_t *features,
 394                     unsigned int        num_features)
 395 {
 396   hb_face_t *face = font->face;
 397   hb_coretext_shaper_font_data_t *font_data = HB_SHAPER_DATA_GET (font);
 398
 399   /*
 400    * Set up features.
 401    * (copied + modified from code from hb-uniscribe.cc)
 402    */
 403   hb_auto_array_t<feature_record_t> feature_records;
 404   hb_auto_array_t<range_record_t> range_records;
 405   if (num_features)
 406   {
 407     /* Sort features by start/end events. */
 408     hb_auto_array_t<feature_event_t> feature_events;
 409     for (unsigned int i = 0; i < num_features; i++)
 410     {
 411       const feature_mapping_t * mapping = (const feature_mapping_t *) bsearch (&features[i].tag,
 412                                                                                feature_mappings,
 413                                                                                ARRAY_LENGTH (feature_mappings),
 414                                                                                sizeof (feature_mappings[0]),
 415                                                                                _hb_feature_mapping_cmp);
 416       if (!mapping)
 417         continue;
 418
 419       active_feature_t feature;
 420       feature.rec.feature = mapping->aatFeatureType;
 421       feature.rec.setting = features[i].value ? mapping->selectorToEnable : mapping->selectorToDisable;
 422       feature.order = i;
 423
 424       feature_event_t *event;
 425
 426       event = feature_events.push ();
 427       if (unlikely (!event))
 428         goto fail_features;
 429       event->index = features[i].start;
 430       event->start = true;
 431       event->feature = feature;
 432
 433       event = feature_events.push ();
 434       if (unlikely (!event))
 435         goto fail_features;
 436       event->index = features[i].end;
 437       event->start = false;
 438       event->feature = feature;
 439     }
 440     feature_events.sort ();
 441     /* Add a strategic final event. */
 442     {
 443       active_feature_t feature;
 444       feature.rec.feature = HB_TAG_NONE;
 445       feature.rec.setting = 0;
 446       feature.order = num_features + 1;
 447
 448       feature_event_t *event = feature_events.push ();
 449       if (unlikely (!event))
 450         goto fail_features;
 451       event->index = 0; /* This value does magic. */
 452       event->start = false;
 453       event->feature = feature;
 454     }
 455
 456     /* Scan events and save features for each range. */
 457     hb_auto_array_t<active_feature_t> active_features;
 458     unsigned int last_index = 0;
 459     for (unsigned int i = 0; i < feature_events.len; i++)
 460     {
 461       feature_event_t *event = &feature_events[i];
 462
 463       if (event->index != last_index)
 464       {
 465         /* Save a snapshot of active features and the range. */
 466         range_record_t *range = range_records.push ();
 467         if (unlikely (!range))
 468           goto fail_features;
 469
 470         unsigned int offset = feature_records.len;
 471
 472         if (active_features.len)
 473         {
 474           CFMutableArrayRef features_array = CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);
 475
 476           /* TODO sort and resolve conflicting features? */
 477           /* active_features.sort (); */
 478           for (unsigned int j = 0; j < active_features.len; j++)
 479           {
 480             CFStringRef keys[2] = {
 481               kCTFontFeatureTypeIdentifierKey,
 482               kCTFontFeatureSelectorIdentifierKey
 483             };
 484             CFNumberRef values[2] = {
 485               CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.feature),
 486               CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
 487             };
 488             CFDictionaryRef dict = CFDictionaryCreate (kCFAllocatorDefault,
 489                                                        (const void **) keys,
 490                                                        (const void **) values,
 491                                                        2,
 492                                                        &kCFTypeDictionaryKeyCallBacks,
 493                                                        &kCFTypeDictionaryValueCallBacks);
 494             CFRelease (values[0]);
 495             CFRelease (values[1]);
 496
 497             CFArrayAppendValue (features_array, dict);
 498             CFRelease (dict);
 499
 500           }
 501
 502           CFDictionaryRef attributes = CFDictionaryCreate (kCFAllocatorDefault,
 503                                                            (const void **) &kCTFontFeatureSettingsAttribute,
 504                                                            (const void **) &features_array,
 505                                                            1,
 506                                                            &kCFTypeDictionaryKeyCallBacks,
 507                                                            &kCFTypeDictionaryValueCallBacks);
 508           CFRelease (features_array);
 509
 510           CTFontDescriptorRef font_desc = CTFontDescriptorCreateWithAttributes (attributes);
 511           CFRelease (attributes);
 512
 513           range->font = CTFontCreateCopyWithAttributes (font_data->ct_font, 0.0, NULL, font_desc);
 514
 515           CFRelease (font_desc);
 516         }
 517         else
 518         {
 519           range->font = NULL;
 520         }
 521
 522         range->index_first = last_index;
 523         range->index_last  = event->index - 1;
 524
 525         last_index = event->index;
 526       }
 527
 528       if (event->start) {
 529         active_feature_t *feature = active_features.push ();
 530         if (unlikely (!feature))
 531           goto fail_features;
 532         *feature = event->feature;
 533       } else {
 534         active_feature_t *feature = active_features.find (&event->feature);
 535         if (feature)
 536           active_features.remove (feature - active_features.array);
 537       }
 538     }
 539
 540     if (!range_records.len) /* No active feature found. */
 541       goto fail_features;
 542   }
 543   else
 544   {
 545   fail_features:
 546     num_features = 0;
 547   }
 548
 549 #define FAIL(...) \
 550   HB_STMT_START { \
 551     DEBUG_MSG (CORETEXT, NULL, __VA_ARGS__); \
 552     return false; \
 553   } HB_STMT_END;
 554
 555   unsigned int scratch_size;
 556   hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
 557
 558 #define ALLOCATE_ARRAY(Type, name, len) \
 559   Type *name = (Type *) scratch; \
 560   { \
 561     unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
 562     assert (_consumed <= scratch_size); \
 563     scratch += _consumed; \
 564     scratch_size -= _consumed; \
 565   }
 566
 567 #define utf16_index() var1.u32
 568
 569   ALLOCATE_ARRAY (UniChar, pchars, buffer->len * 2);
 570
 571   unsigned int chars_len = 0;
 572   for (unsigned int i = 0; i < buffer->len; i++) {
 573     hb_codepoint_t c = buffer->info[i].codepoint;
 574     buffer->info[i].utf16_index() = chars_len;
 575     if (likely (c < 0x10000))
 576       pchars[chars_len++] = c;
 577     else if (unlikely (c >= 0x110000))
 578       pchars[chars_len++] = 0xFFFD;
 579     else {
 580       pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
 581       pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
 582     }
 583   }
 584
 585 #undef utf16_index
 586
 587   CFStringRef string_ref = CFStringCreateWithCharactersNoCopy (NULL,
 588                                                                pchars, chars_len,
 589                                                                kCFAllocatorNull);
 590
 591   CFMutableAttributedStringRef attr_string = CFAttributedStringCreateMutable (NULL, chars_len);
 592   CFAttributedStringReplaceString (attr_string, CFRangeMake (0, 0), string_ref);
 593   CFRelease (string_ref);
 594   CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
 595                                   kCTFontAttributeName, font_data->ct_font);
 596
 597   if (num_features)
 598   {
 599     ALLOCATE_ARRAY (unsigned int, log_clusters, chars_len);
 600
 601     /* Need log_clusters to assign features. */
 602     chars_len = 0;
 603     for (unsigned int i = 0; i < buffer->len; i++)
 604     {
 605       hb_codepoint_t c = buffer->info[i].codepoint;
 606       unsigned int cluster = buffer->info[i].cluster;
 607       log_clusters[chars_len++] = cluster;
 608       if (c >= 0x10000 && c < 0x110000)
 609         log_clusters[chars_len++] = cluster; /* Surrogates. */
 610     }
 611
 612     unsigned int start = 0;
 613     range_record_t *last_range = &range_records[0];
 614     for (unsigned int k = 0; k < chars_len; k++)
 615     {
 616       range_record_t *range = last_range;
 617       while (log_clusters[k] < range->index_first)
 618         range--;
 619       while (log_clusters[k] > range->index_last)
 620         range++;
 621       if (range != last_range)
 622       {
 623         if (last_range->font)
 624           CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, k - start),
 625                                           kCTFontAttributeName, last_range->font);
 626
 627         start = k;
 628       }
 629
 630       last_range = range;
 631     }
 632     if (start != chars_len && last_range->font)
 633       CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, chars_len - start - 1),
 634                                       kCTFontAttributeName, last_range->font);
 635
 636     for (unsigned int i = 0; i < range_records.len; i++)
 637       if (range_records[i].font)
 638         CFRelease (range_records[i].font);
 639   }
 640
 641   CTLineRef line = CTLineCreateWithAttributedString (attr_string);
 642   CFRelease (attr_string);
 643
 644   CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
 645   unsigned int num_runs = CFArrayGetCount (glyph_runs);
 646
 647   buffer->len = 0;
 648
 649   const CFRange range_all = CFRangeMake (0, 0);
 650
 651   for (unsigned int i = 0; i < num_runs; i++) {
 652     CTRunRef run = (CTRunRef) CFArrayGetValueAtIndex (glyph_runs, i);
 653
 654     unsigned int num_glyphs = CTRunGetGlyphCount (run);
 655     if (num_glyphs == 0)
 656       continue;
 657
 658     buffer->ensure (buffer->len + num_glyphs);
 659
 660     scratch = buffer->get_scratch_buffer (&scratch_size);
 661
 662     /* Testing indicates that CTRunGetGlyphsPtr, etc (almost?) always
 663      * succeed, and so copying data to our own buffer will be rare. */
 664
 665     const CGGlyph* glyphs = CTRunGetGlyphsPtr (run);
 666     if (!glyphs) {
 667       ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs);
 668       CTRunGetGlyphs (run, range_all, glyph_buf);
 669       glyphs = glyph_buf;
 670     }
 671
 672     const CGPoint* positions = CTRunGetPositionsPtr (run);
 673     if (!positions) {
 674       ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs);
 675       CTRunGetPositions (run, range_all, position_buf);
 676       positions = position_buf;
 677     }
 678
 679     const CFIndex* string_indices = CTRunGetStringIndicesPtr (run);
 680     if (!string_indices) {
 681       ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs);
 682       CTRunGetStringIndices (run, range_all, index_buf);
 683       string_indices = index_buf;
 684     }
 685
 686 #undef ALLOCATE_ARRAY
 687
 688     double run_width = CTRunGetTypographicBounds (run, range_all, NULL, NULL, NULL);
 689
 690     for (unsigned int j = 0; j < num_glyphs; j++) {
 691       double advance = (j + 1 < num_glyphs ? positions[j + 1].x : positions[0].x + run_width) - positions[j].x;
 692
 693       hb_glyph_info_t *info = &buffer->info[buffer->len];
 694
 695       info->codepoint = glyphs[j];
 696       info->cluster = string_indices[j];
 697
 698       /* Currently, we do all x-positioning by setting the advance, we never use x-offset. */
 699       info->mask = advance;
 700       info->var1.u32 = 0;
 701       info->var2.u32 = positions[j].y;
 702
 703       buffer->len++;
 704     }
 705   }
 706
 707   buffer->clear_positions ();
 708
 709   unsigned int count = buffer->len;
 710   for (unsigned int i = 0; i < count; ++i) {
 711     hb_glyph_info_t *info = &buffer->info[i];
 712     hb_glyph_position_t *pos = &buffer->pos[i];
 713
 714     /* TODO vertical */
 715     pos->x_advance = info->mask;
 716     pos->x_offset = info->var1.u32;
 717     pos->y_offset = info->var2.u32;
 718   }
 719
 720   /* Fix up clusters so that we never return out-of-order indices;
 721    * if core text has reordered glyphs, we'll merge them to the
 722    * beginning of the reordered cluster.
 723    *
 724    * This does *not* mean we'll form the same clusters as Uniscribe
 725    * or the native OT backend, only that the cluster indices will be
 726    * monotonic in the output buffer. */
 727   if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
 728     unsigned int prev_cluster = 0;
 729     for (unsigned int i = 0; i < count; i++) {
 730       unsigned int curr_cluster = buffer->info[i].cluster;
 731       if (curr_cluster < prev_cluster) {
 732         for (unsigned int j = i; j > 0; j--) {
 733           if (buffer->info[j - 1].cluster > curr_cluster)
 734             buffer->info[j - 1].cluster = curr_cluster;
 735           else
 736             break;
 737         }
 738       }
 739       prev_cluster = curr_cluster;
 740     }
 741   } else {
 742     unsigned int prev_cluster = (unsigned int)-1;
 743     for (unsigned int i = 0; i < count; i++) {
 744       unsigned int curr_cluster = buffer->info[i].cluster;
 745       if (curr_cluster > prev_cluster) {
 746         for (unsigned int j = i; j > 0; j--) {
 747           if (buffer->info[j - 1].cluster < curr_cluster)
 748             buffer->info[j - 1].cluster = curr_cluster;
 749           else
 750             break;
 751         }
 752       }
 753       prev_cluster = curr_cluster;
 754     }
 755   }
 756
 757   CFRelease (line);
 758
 759   return true;
 760 }