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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 #include "hb.hh"
30 
31 #ifdef HAVE_CORETEXT
32 
33 #include "hb-shaper-impl.hh"
34 
35 #include "hb-coretext.h"
36 #include "hb-aat-layout.hh"
37 
38 
39 /**
40  * SECTION:hb-coretext
41  * @title: hb-coretext
42  * @short_description: CoreText integration
43  * @include: hb-coretext.h
44  *
45  * Functions for using HarfBuzz with the CoreText fonts.
46  **/
47 
48 /* https://developer.apple.com/documentation/coretext/1508745-ctfontcreatewithgraphicsfont */
49 #define HB_CORETEXT_DEFAULT_FONT_SIZE 12.f
50 
51 static void
release_table_data(void * user_data)52 release_table_data (void *user_data)
53 {
54   CFDataRef cf_data = reinterpret_cast<CFDataRef> (user_data);
55   CFRelease(cf_data);
56 }
57 
58 static hb_blob_t *
_hb_cg_reference_table(hb_face_t * face HB_UNUSED,hb_tag_t tag,void * user_data)59 _hb_cg_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
60 {
61   CGFontRef cg_font = reinterpret_cast<CGFontRef> (user_data);
62   CFDataRef cf_data = CGFontCopyTableForTag (cg_font, tag);
63   if (unlikely (!cf_data))
64     return nullptr;
65 
66   const char *data = reinterpret_cast<const char*> (CFDataGetBytePtr (cf_data));
67   const size_t length = CFDataGetLength (cf_data);
68   if (!data || !length)
69   {
70     CFRelease (cf_data);
71     return nullptr;
72   }
73 
74   return hb_blob_create (data, length, HB_MEMORY_MODE_READONLY,
75 			 reinterpret_cast<void *> (const_cast<__CFData *> (cf_data)),
76 			 release_table_data);
77 }
78 
79 static void
_hb_cg_font_release(void * data)80 _hb_cg_font_release (void *data)
81 {
82   CGFontRelease ((CGFontRef) data);
83 }
84 
85 
86 static CTFontDescriptorRef
get_last_resort_font_desc()87 get_last_resort_font_desc ()
88 {
89   // TODO Handle allocation failures?
90   CTFontDescriptorRef last_resort = CTFontDescriptorCreateWithNameAndSize (CFSTR("LastResort"), 0);
91   CFArrayRef cascade_list = CFArrayCreate (kCFAllocatorDefault,
92 					   (const void **) &last_resort,
93 					   1,
94 					   &kCFTypeArrayCallBacks);
95   CFRelease (last_resort);
96   CFDictionaryRef attributes = CFDictionaryCreate (kCFAllocatorDefault,
97 						   (const void **) &kCTFontCascadeListAttribute,
98 						   (const void **) &cascade_list,
99 						   1,
100 						   &kCFTypeDictionaryKeyCallBacks,
101 						   &kCFTypeDictionaryValueCallBacks);
102   CFRelease (cascade_list);
103 
104   CTFontDescriptorRef font_desc = CTFontDescriptorCreateWithAttributes (attributes);
105   CFRelease (attributes);
106   return font_desc;
107 }
108 
109 static void
release_data(void * info,const void * data,size_t size)110 release_data (void *info, const void *data, size_t size)
111 {
112   assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
113 	  hb_blob_get_data ((hb_blob_t *) info, nullptr) == data);
114 
115   hb_blob_destroy ((hb_blob_t *) info);
116 }
117 
118 static CGFontRef
create_cg_font(hb_face_t * face)119 create_cg_font (hb_face_t *face)
120 {
121   CGFontRef cg_font = nullptr;
122   if (face->destroy == _hb_cg_font_release)
123   {
124     cg_font = CGFontRetain ((CGFontRef) face->user_data);
125   }
126   else
127   {
128     hb_blob_t *blob = hb_face_reference_blob (face);
129     unsigned int blob_length;
130     const char *blob_data = hb_blob_get_data (blob, &blob_length);
131     if (unlikely (!blob_length))
132       DEBUG_MSG (CORETEXT, face, "Face has empty blob");
133 
134     CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
135     if (likely (provider))
136     {
137       cg_font = CGFontCreateWithDataProvider (provider);
138       if (unlikely (!cg_font))
139 	DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
140       CGDataProviderRelease (provider);
141     }
142   }
143   return cg_font;
144 }
145 
146 static CTFontRef
create_ct_font(CGFontRef cg_font,CGFloat font_size)147 create_ct_font (CGFontRef cg_font, CGFloat font_size)
148 {
149   CTFontRef ct_font = nullptr;
150 
151   /* CoreText does not enable trak table usage / tracking when creating a CTFont
152    * using CTFontCreateWithGraphicsFont. The only way of enabling tracking seems
153    * to be through the CTFontCreateUIFontForLanguage call. */
154   CFStringRef cg_postscript_name = CGFontCopyPostScriptName (cg_font);
155   if (CFStringHasPrefix (cg_postscript_name, CFSTR (".SFNSText")) ||
156       CFStringHasPrefix (cg_postscript_name, CFSTR (".SFNSDisplay")))
157   {
158 #if !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1080
159 # define kCTFontUIFontSystem kCTFontSystemFontType
160 # define kCTFontUIFontEmphasizedSystem kCTFontEmphasizedSystemFontType
161 #endif
162     CTFontUIFontType font_type = kCTFontUIFontSystem;
163     if (CFStringHasSuffix (cg_postscript_name, CFSTR ("-Bold")))
164       font_type = kCTFontUIFontEmphasizedSystem;
165 
166     ct_font = CTFontCreateUIFontForLanguage (font_type, font_size, nullptr);
167     CFStringRef ct_result_name = CTFontCopyPostScriptName(ct_font);
168     if (CFStringCompare (ct_result_name, cg_postscript_name, 0) != kCFCompareEqualTo)
169     {
170       CFRelease(ct_font);
171       ct_font = nullptr;
172     }
173     CFRelease (ct_result_name);
174   }
175   CFRelease (cg_postscript_name);
176 
177   if (!ct_font)
178     ct_font = CTFontCreateWithGraphicsFont (cg_font, font_size, nullptr, nullptr);
179 
180   if (unlikely (!ct_font)) {
181     DEBUG_MSG (CORETEXT, cg_font, "Font CTFontCreateWithGraphicsFont() failed");
182     return nullptr;
183   }
184 
185   /* crbug.com/576941 and crbug.com/625902 and the investigation in the latter
186    * bug indicate that the cascade list reconfiguration occasionally causes
187    * crashes in CoreText on OS X 10.9, thus let's skip this step on older
188    * operating system versions. Except for the emoji font, where _not_
189    * reconfiguring the cascade list causes CoreText crashes. For details, see
190    * crbug.com/549610 */
191   // 0x00070000 stands for "kCTVersionNumber10_10", see CoreText.h
192 #pragma GCC diagnostic push
193 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
194   if (&CTGetCoreTextVersion != nullptr && CTGetCoreTextVersion() < 0x00070000) {
195 #pragma GCC diagnostic pop
196     CFStringRef fontName = CTFontCopyPostScriptName (ct_font);
197     bool isEmojiFont = CFStringCompare (fontName, CFSTR("AppleColorEmoji"), 0) == kCFCompareEqualTo;
198     CFRelease (fontName);
199     if (!isEmojiFont)
200       return ct_font;
201   }
202 
203   CFURLRef original_url = nullptr;
204 #if !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
205   ATSFontRef atsFont;
206   FSRef fsref;
207   OSStatus status;
208   atsFont = CTFontGetPlatformFont (ct_font, NULL);
209   status = ATSFontGetFileReference (atsFont, &fsref);
210   if (status == noErr)
211     original_url = CFURLCreateFromFSRef (NULL, &fsref);
212 #else
213   original_url = (CFURLRef) CTFontCopyAttribute (ct_font, kCTFontURLAttribute);
214 #endif
215 
216   /* Create font copy with cascade list that has LastResort first; this speeds up CoreText
217    * font fallback which we don't need anyway. */
218   {
219     CTFontDescriptorRef last_resort_font_desc = get_last_resort_font_desc ();
220     CTFontRef new_ct_font = CTFontCreateCopyWithAttributes (ct_font, 0.0, nullptr, last_resort_font_desc);
221     CFRelease (last_resort_font_desc);
222     if (new_ct_font)
223     {
224       /* The CTFontCreateCopyWithAttributes call fails to stay on the same font
225        * when reconfiguring the cascade list and may switch to a different font
226        * when there are fonts that go by the same name, since the descriptor is
227        * just name and size.
228        *
229        * Avoid reconfiguring the cascade lists if the new font is outside the
230        * system locations that we cannot access from the sandboxed renderer
231        * process in Blink. This can be detected by the new file URL location
232        * that the newly found font points to. */
233       CFURLRef new_url = nullptr;
234 #if !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
235       atsFont = CTFontGetPlatformFont (new_ct_font, NULL);
236       status = ATSFontGetFileReference (atsFont, &fsref);
237       if (status == noErr)
238 	new_url = CFURLCreateFromFSRef (NULL, &fsref);
239 #else
240       new_url = (CFURLRef) CTFontCopyAttribute (new_ct_font, kCTFontURLAttribute);
241 #endif
242       // Keep reconfigured font if URL cannot be retrieved (seems to be the case
243       // on Mac OS 10.12 Sierra), speculative fix for crbug.com/625606
244       if (!original_url || !new_url || CFEqual (original_url, new_url)) {
245 	CFRelease (ct_font);
246 	ct_font = new_ct_font;
247       } else {
248 	CFRelease (new_ct_font);
249 	DEBUG_MSG (CORETEXT, ct_font, "Discarding reconfigured CTFont, location changed.");
250       }
251       if (new_url)
252 	CFRelease (new_url);
253     }
254     else
255       DEBUG_MSG (CORETEXT, ct_font, "Font copy with empty cascade list failed");
256   }
257 
258   if (original_url)
259     CFRelease (original_url);
260   return ct_font;
261 }
262 
263 hb_coretext_face_data_t *
_hb_coretext_shaper_face_data_create(hb_face_t * face)264 _hb_coretext_shaper_face_data_create (hb_face_t *face)
265 {
266   CGFontRef cg_font = create_cg_font (face);
267 
268   if (unlikely (!cg_font))
269   {
270     DEBUG_MSG (CORETEXT, face, "CGFont creation failed..");
271     return nullptr;
272   }
273 
274   return (hb_coretext_face_data_t *) cg_font;
275 }
276 
277 void
_hb_coretext_shaper_face_data_destroy(hb_coretext_face_data_t * data)278 _hb_coretext_shaper_face_data_destroy (hb_coretext_face_data_t *data)
279 {
280   CFRelease ((CGFontRef) data);
281 }
282 
283 /**
284  * hb_coretext_face_create:
285  * @cg_font: The CGFontRef to work upon
286  *
287  * Creates an #hb_face_t face object from the specified
288  * CGFontRef.
289  *
290  * Return value: the new #hb_face_t face object
291  *
292  * Since: 0.9.10
293  */
294 hb_face_t *
hb_coretext_face_create(CGFontRef cg_font)295 hb_coretext_face_create (CGFontRef cg_font)
296 {
297   return hb_face_create_for_tables (_hb_cg_reference_table, CGFontRetain (cg_font), _hb_cg_font_release);
298 }
299 
300 /**
301  * hb_coretext_face_get_cg_font:
302  * @face: The #hb_face_t to work upon
303  *
304  * Fetches the CGFontRef associated with an #hb_face_t
305  * face object
306  *
307  * Return value: the CGFontRef found
308  *
309  * Since: 0.9.10
310  */
311 CGFontRef
hb_coretext_face_get_cg_font(hb_face_t * face)312 hb_coretext_face_get_cg_font (hb_face_t *face)
313 {
314   return (CGFontRef) (const void *) face->data.coretext;
315 }
316 
317 
318 hb_coretext_font_data_t *
_hb_coretext_shaper_font_data_create(hb_font_t * font)319 _hb_coretext_shaper_font_data_create (hb_font_t *font)
320 {
321   hb_face_t *face = font->face;
322   const hb_coretext_face_data_t *face_data = face->data.coretext;
323   if (unlikely (!face_data)) return nullptr;
324   CGFontRef cg_font = (CGFontRef) (const void *) face->data.coretext;
325 
326   CGFloat font_size = (CGFloat) (font->ptem <= 0.f ? HB_CORETEXT_DEFAULT_FONT_SIZE : font->ptem);
327   CTFontRef ct_font = create_ct_font (cg_font, font_size);
328 
329   if (unlikely (!ct_font))
330   {
331     DEBUG_MSG (CORETEXT, font, "CGFont creation failed..");
332     return nullptr;
333   }
334 
335   if (font->num_coords)
336   {
337     CFMutableDictionaryRef variations =
338       CFDictionaryCreateMutable (kCFAllocatorDefault,
339 				 font->num_coords,
340 				 &kCFTypeDictionaryKeyCallBacks,
341 				 &kCFTypeDictionaryValueCallBacks);
342 
343     for (unsigned i = 0; i < font->num_coords; i++)
344     {
345       if (font->coords[i] == 0.) continue;
346 
347       hb_ot_var_axis_info_t info;
348       unsigned int c = 1;
349       hb_ot_var_get_axis_infos (font->face, i, &c, &info);
350       float v = hb_clamp (font->design_coords[i], info.min_value, info.max_value);
351 
352       CFNumberRef tag_number = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &info.tag);
353       CFNumberRef value_number = CFNumberCreate (kCFAllocatorDefault, kCFNumberFloatType, &v);
354       CFDictionarySetValue (variations, tag_number, value_number);
355       CFRelease (tag_number);
356       CFRelease (value_number);
357     }
358 
359     CFDictionaryRef attributes =
360       CFDictionaryCreate (kCFAllocatorDefault,
361 			  (const void **) &kCTFontVariationAttribute,
362 			  (const void **) &variations,
363 			  1,
364 			  &kCFTypeDictionaryKeyCallBacks,
365 			  &kCFTypeDictionaryValueCallBacks);
366 
367     CTFontDescriptorRef varDesc = CTFontDescriptorCreateWithAttributes (attributes);
368     CTFontRef new_ct_font = CTFontCreateCopyWithAttributes (ct_font, 0, nullptr, varDesc);
369 
370     CFRelease (ct_font);
371     CFRelease (attributes);
372     CFRelease (variations);
373     ct_font = new_ct_font;
374   }
375 
376   return (hb_coretext_font_data_t *) ct_font;
377 }
378 
379 void
_hb_coretext_shaper_font_data_destroy(hb_coretext_font_data_t * data)380 _hb_coretext_shaper_font_data_destroy (hb_coretext_font_data_t *data)
381 {
382   CFRelease ((CTFontRef) data);
383 }
384 
385 /**
386  * hb_coretext_font_create:
387  * @ct_font: The CTFontRef to work upon
388  *
389  * Creates an #hb_font_t font object from the specified
390  * CTFontRef.
391  *
392  * Return value: the new #hb_font_t font object
393  *
394  * Since: 1.7.2
395  **/
396 hb_font_t *
hb_coretext_font_create(CTFontRef ct_font)397 hb_coretext_font_create (CTFontRef ct_font)
398 {
399   CGFontRef cg_font = CTFontCopyGraphicsFont (ct_font, nullptr);
400   hb_face_t *face = hb_coretext_face_create (cg_font);
401   CFRelease (cg_font);
402   hb_font_t *font = hb_font_create (face);
403   hb_face_destroy (face);
404 
405   if (unlikely (hb_object_is_immutable (font)))
406     return font;
407 
408   hb_font_set_ptem (font, CTFontGetSize (ct_font));
409 
410   /* Let there be dragons here... */
411   font->data.coretext.cmpexch (nullptr, (hb_coretext_font_data_t *) CFRetain (ct_font));
412 
413   return font;
414 }
415 
416 /**
417  * hb_coretext_font_get_ct_font:
418  * @font: #hb_font_t to work upon
419  *
420  * Fetches the CTFontRef associated with the specified
421  * #hb_font_t font object.
422  *
423  * Return value: the CTFontRef found
424  *
425  * Since: 0.9.10
426  */
427 CTFontRef
hb_coretext_font_get_ct_font(hb_font_t * font)428 hb_coretext_font_get_ct_font (hb_font_t *font)
429 {
430   CTFontRef ct_font = (CTFontRef) (const void *) font->data.coretext;
431   return ct_font ? (CTFontRef) ct_font : nullptr;
432 }
433 
434 
435 /*
436  * shaper
437  */
438 
439 struct feature_record_t {
440   unsigned int feature;
441   unsigned int setting;
442 };
443 
444 struct active_feature_t {
445   feature_record_t rec;
446   unsigned int order;
447 
cmpactive_feature_t448   HB_INTERNAL static int cmp (const void *pa, const void *pb) {
449     const active_feature_t *a = (const active_feature_t *) pa;
450     const active_feature_t *b = (const active_feature_t *) pb;
451     return a->rec.feature < b->rec.feature ? -1 : a->rec.feature > b->rec.feature ? 1 :
452 	   a->order < b->order ? -1 : a->order > b->order ? 1 :
453 	   a->rec.setting < b->rec.setting ? -1 : a->rec.setting > b->rec.setting ? 1 :
454 	   0;
455   }
operator ==active_feature_t456   bool operator== (const active_feature_t& f) const {
457     return cmp (this, &f) == 0;
458   }
459 };
460 
461 struct feature_event_t {
462   unsigned int index;
463   bool start;
464   active_feature_t feature;
465 
cmpfeature_event_t466   HB_INTERNAL static int cmp (const void *pa, const void *pb) {
467     const feature_event_t *a = (const feature_event_t *) pa;
468     const feature_event_t *b = (const feature_event_t *) pb;
469     return a->index < b->index ? -1 : a->index > b->index ? 1 :
470 	   a->start < b->start ? -1 : a->start > b->start ? 1 :
471 	   active_feature_t::cmp (&a->feature, &b->feature);
472   }
473 };
474 
475 struct range_record_t {
476   CTFontRef font;
477   unsigned int index_first; /* == start */
478   unsigned int index_last;  /* == end - 1 */
479 };
480 
481 
482 hb_bool_t
_hb_coretext_shape(hb_shape_plan_t * shape_plan,hb_font_t * font,hb_buffer_t * buffer,const hb_feature_t * features,unsigned int num_features)483 _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
484 		    hb_font_t          *font,
485 		    hb_buffer_t        *buffer,
486 		    const hb_feature_t *features,
487 		    unsigned int        num_features)
488 {
489   hb_face_t *face = font->face;
490   CGFontRef cg_font = (CGFontRef) (const void *) face->data.coretext;
491   CTFontRef ct_font = (CTFontRef) (const void *) font->data.coretext;
492 
493   CGFloat ct_font_size = CTFontGetSize (ct_font);
494   CGFloat x_mult = (CGFloat) font->x_scale / ct_font_size;
495   CGFloat y_mult = (CGFloat) font->y_scale / ct_font_size;
496 
497   /* Attach marks to their bases, to match the 'ot' shaper.
498    * Adapted from a very old version of hb-ot-shape:hb_form_clusters().
499    * Note that this only makes us be closer to the 'ot' shaper,
500    * but by no means the same.  For example, if there's
501    * B1 M1 B2 M2, and B1-B2 form a ligature, M2's cluster will
502    * continue pointing to B2 even though B2 was merged into B1's
503    * cluster... */
504   if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
505   {
506     hb_unicode_funcs_t *unicode = buffer->unicode;
507     unsigned int count = buffer->len;
508     hb_glyph_info_t *info = buffer->info;
509     for (unsigned int i = 1; i < count; i++)
510       if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (unicode->general_category (info[i].codepoint)))
511 	buffer->merge_clusters (i - 1, i + 1);
512   }
513 
514   hb_vector_t<feature_record_t> feature_records;
515   hb_vector_t<range_record_t> range_records;
516 
517   /*
518    * Set up features.
519    * (copied + modified from code from hb-uniscribe.cc)
520    */
521   if (num_features)
522   {
523     /* Sort features by start/end events. */
524     hb_vector_t<feature_event_t> feature_events;
525     for (unsigned int i = 0; i < num_features; i++)
526     {
527       active_feature_t feature;
528 
529 #if MAC_OS_X_VERSION_MIN_REQUIRED < 101000
530       const hb_aat_feature_mapping_t * mapping = hb_aat_layout_find_feature_mapping (features[i].tag);
531       if (!mapping)
532 	continue;
533 
534       feature.rec.feature = mapping->aatFeatureType;
535       feature.rec.setting = features[i].value ? mapping->selectorToEnable : mapping->selectorToDisable;
536 #else
537       feature.rec.feature = features[i].tag;
538       feature.rec.setting = features[i].value;
539 #endif
540       feature.order = i;
541 
542       feature_event_t *event;
543 
544       event = feature_events.push ();
545       event->index = features[i].start;
546       event->start = true;
547       event->feature = feature;
548 
549       event = feature_events.push ();
550       event->index = features[i].end;
551       event->start = false;
552       event->feature = feature;
553     }
554     feature_events.qsort ();
555     /* Add a strategic final event. */
556     {
557       active_feature_t feature;
558       feature.rec.feature = HB_TAG_NONE;
559       feature.rec.setting = 0;
560       feature.order = num_features + 1;
561 
562       feature_event_t *event = feature_events.push ();
563       event->index = 0; /* This value does magic. */
564       event->start = false;
565       event->feature = feature;
566     }
567 
568     /* Scan events and save features for each range. */
569     hb_vector_t<active_feature_t> active_features;
570     unsigned int last_index = 0;
571     for (unsigned int i = 0; i < feature_events.length; i++)
572     {
573       feature_event_t *event = &feature_events[i];
574 
575       if (event->index != last_index)
576       {
577 	/* Save a snapshot of active features and the range. */
578 	range_record_t *range = range_records.push ();
579 
580 	if (active_features.length)
581 	{
582 	  CFMutableArrayRef features_array = CFArrayCreateMutable(kCFAllocatorDefault, 0, &kCFTypeArrayCallBacks);
583 
584 	  /* TODO sort and resolve conflicting features? */
585 	  /* active_features.qsort (); */
586 	  for (unsigned int j = 0; j < active_features.length; j++)
587 	  {
588 #if MAC_OS_X_VERSION_MIN_REQUIRED < 101000
589 	    CFStringRef keys[] = {
590 	      kCTFontFeatureTypeIdentifierKey,
591 	      kCTFontFeatureSelectorIdentifierKey
592 	    };
593 	    CFNumberRef values[] = {
594 	      CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.feature),
595 	      CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
596 	    };
597 #else
598 	    char tag[5] = {HB_UNTAG (active_features[j].rec.feature)};
599 	    CFTypeRef keys[] = {
600 	      kCTFontOpenTypeFeatureTag,
601 	      kCTFontOpenTypeFeatureValue
602 	    };
603 	    CFTypeRef values[] = {
604 	      CFStringCreateWithCString (kCFAllocatorDefault, tag, kCFStringEncodingASCII),
605 	      CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
606 	    };
607 #endif
608 	    static_assert ((ARRAY_LENGTH_CONST (keys) == ARRAY_LENGTH_CONST (values)), "");
609 	    CFDictionaryRef dict = CFDictionaryCreate (kCFAllocatorDefault,
610 						       (const void **) keys,
611 						       (const void **) values,
612 						       ARRAY_LENGTH (keys),
613 						       &kCFTypeDictionaryKeyCallBacks,
614 						       &kCFTypeDictionaryValueCallBacks);
615 	    for (unsigned int i = 0; i < ARRAY_LENGTH (values); i++)
616 	      CFRelease (values[i]);
617 
618 	    CFArrayAppendValue (features_array, dict);
619 	    CFRelease (dict);
620 
621 	  }
622 
623 	  CFDictionaryRef attributes = CFDictionaryCreate (kCFAllocatorDefault,
624 							   (const void **) &kCTFontFeatureSettingsAttribute,
625 							   (const void **) &features_array,
626 							   1,
627 							   &kCFTypeDictionaryKeyCallBacks,
628 							   &kCFTypeDictionaryValueCallBacks);
629 	  CFRelease (features_array);
630 
631 	  CTFontDescriptorRef font_desc = CTFontDescriptorCreateWithAttributes (attributes);
632 	  CFRelease (attributes);
633 
634 	  range->font = CTFontCreateCopyWithAttributes (ct_font, 0.0, nullptr, font_desc);
635 	  CFRelease (font_desc);
636 	}
637 	else
638 	{
639 	  range->font = nullptr;
640 	}
641 
642 	range->index_first = last_index;
643 	range->index_last  = event->index - 1;
644 
645 	last_index = event->index;
646       }
647 
648       if (event->start)
649       {
650 	active_features.push (event->feature);
651       } else {
652 	active_feature_t *feature = active_features.lsearch (event->feature);
653 	if (feature)
654 	  active_features.remove_ordered (feature - active_features.arrayZ);
655       }
656     }
657   }
658 
659   unsigned int scratch_size;
660   hb_buffer_t::scratch_buffer_t *scratch = buffer->get_scratch_buffer (&scratch_size);
661 
662 #define ALLOCATE_ARRAY(Type, name, len, on_no_room) \
663   Type *name = (Type *) scratch; \
664   do { \
665     unsigned int _consumed = DIV_CEIL ((len) * sizeof (Type), sizeof (*scratch)); \
666     if (unlikely (_consumed > scratch_size)) \
667     { \
668       on_no_room; \
669       assert (0); \
670     } \
671     scratch += _consumed; \
672     scratch_size -= _consumed; \
673   } while (0)
674 
675   ALLOCATE_ARRAY (UniChar, pchars, buffer->len * 2, ((void)nullptr) /*nothing*/);
676   unsigned int chars_len = 0;
677   for (unsigned int i = 0; i < buffer->len; i++) {
678     hb_codepoint_t c = buffer->info[i].codepoint;
679     if (likely (c <= 0xFFFFu))
680       pchars[chars_len++] = c;
681     else if (unlikely (c > 0x10FFFFu))
682       pchars[chars_len++] = 0xFFFDu;
683     else {
684       pchars[chars_len++] = 0xD800u + ((c - 0x10000u) >> 10);
685       pchars[chars_len++] = 0xDC00u + ((c - 0x10000u) & ((1u << 10) - 1));
686     }
687   }
688 
689   ALLOCATE_ARRAY (unsigned int, log_clusters, chars_len, ((void)nullptr) /*nothing*/);
690   chars_len = 0;
691   for (unsigned int i = 0; i < buffer->len; i++)
692   {
693     hb_codepoint_t c = buffer->info[i].codepoint;
694     unsigned int cluster = buffer->info[i].cluster;
695     log_clusters[chars_len++] = cluster;
696     if (hb_in_range (c, 0x10000u, 0x10FFFFu))
697       log_clusters[chars_len++] = cluster; /* Surrogates. */
698   }
699 
700 #define FAIL(...) \
701   HB_STMT_START { \
702     DEBUG_MSG (CORETEXT, nullptr, __VA_ARGS__); \
703     ret = false; \
704     goto fail; \
705   } HB_STMT_END
706 
707   bool ret = true;
708   CFStringRef string_ref = nullptr;
709   CTLineRef line = nullptr;
710 
711   if (false)
712   {
713 resize_and_retry:
714     DEBUG_MSG (CORETEXT, buffer, "Buffer resize");
715     /* string_ref uses the scratch-buffer for backing store, and line references
716      * string_ref (via attr_string).  We must release those before resizing buffer. */
717     assert (string_ref);
718     assert (line);
719     CFRelease (string_ref);
720     CFRelease (line);
721     string_ref = nullptr;
722     line = nullptr;
723 
724     /* Get previous start-of-scratch-area, that we use later for readjusting
725      * our existing scratch arrays. */
726     unsigned int old_scratch_used;
727     hb_buffer_t::scratch_buffer_t *old_scratch;
728     old_scratch = buffer->get_scratch_buffer (&old_scratch_used);
729     old_scratch_used = scratch - old_scratch;
730 
731     if (unlikely (!buffer->ensure (buffer->allocated * 2)))
732       FAIL ("Buffer resize failed");
733 
734     /* Adjust scratch, pchars, and log_cluster arrays.  This is ugly, but really the
735      * cleanest way to do without completely restructuring the rest of this shaper. */
736     scratch = buffer->get_scratch_buffer (&scratch_size);
737     pchars = reinterpret_cast<UniChar *> (((char *) scratch + ((char *) pchars - (char *) old_scratch)));
738     log_clusters = reinterpret_cast<unsigned int *> (((char *) scratch + ((char *) log_clusters - (char *) old_scratch)));
739     scratch += old_scratch_used;
740     scratch_size -= old_scratch_used;
741   }
742   {
743     string_ref = CFStringCreateWithCharactersNoCopy (nullptr,
744 						     pchars, chars_len,
745 						     kCFAllocatorNull);
746     if (unlikely (!string_ref))
747       FAIL ("CFStringCreateWithCharactersNoCopy failed");
748 
749     /* Create an attributed string, populate it, and create a line from it, then release attributed string. */
750     {
751       CFMutableAttributedStringRef attr_string = CFAttributedStringCreateMutable (kCFAllocatorDefault,
752 										  chars_len);
753       if (unlikely (!attr_string))
754 	FAIL ("CFAttributedStringCreateMutable failed");
755       CFAttributedStringReplaceString (attr_string, CFRangeMake (0, 0), string_ref);
756       if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
757       {
758 	CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
759 					kCTVerticalFormsAttributeName, kCFBooleanTrue);
760       }
761 
762       if (buffer->props.language)
763       {
764 /* What's the iOS equivalent of this check?
765  * The symbols was introduced in iOS 7.0.
766  * At any rate, our fallback is safe and works fine. */
767 #if !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1090
768 #  define kCTLanguageAttributeName CFSTR ("NSLanguage")
769 #endif
770 	CFStringRef lang = CFStringCreateWithCStringNoCopy (kCFAllocatorDefault,
771 							    hb_language_to_string (buffer->props.language),
772 							    kCFStringEncodingUTF8,
773 							    kCFAllocatorNull);
774 	if (unlikely (!lang))
775 	{
776 	  CFRelease (attr_string);
777 	  FAIL ("CFStringCreateWithCStringNoCopy failed");
778 	}
779 	CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
780 					kCTLanguageAttributeName, lang);
781 	CFRelease (lang);
782       }
783       CFAttributedStringSetAttribute (attr_string, CFRangeMake (0, chars_len),
784 				      kCTFontAttributeName, ct_font);
785 
786       if (num_features && range_records.length)
787       {
788 	unsigned int start = 0;
789 	range_record_t *last_range = &range_records[0];
790 	for (unsigned int k = 0; k < chars_len; k++)
791 	{
792 	  range_record_t *range = last_range;
793 	  while (log_clusters[k] < range->index_first)
794 	    range--;
795 	  while (log_clusters[k] > range->index_last)
796 	    range++;
797 	  if (range != last_range)
798 	  {
799 	    if (last_range->font)
800 	      CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, k - start),
801 					      kCTFontAttributeName, last_range->font);
802 
803 	    start = k;
804 	  }
805 
806 	  last_range = range;
807 	}
808 	if (start != chars_len && last_range->font)
809 	  CFAttributedStringSetAttribute (attr_string, CFRangeMake (start, chars_len - start),
810 					  kCTFontAttributeName, last_range->font);
811       }
812       /* Enable/disable kern if requested.
813        *
814        * Note: once kern is disabled, reenabling it doesn't currently seem to work in CoreText.
815        */
816       if (num_features)
817       {
818 	unsigned int zeroint = 0;
819 	CFNumberRef zero = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &zeroint);
820 	for (unsigned int i = 0; i < num_features; i++)
821 	{
822 	  const hb_feature_t &feature = features[i];
823 	  if (feature.tag == HB_TAG('k','e','r','n') &&
824 	      feature.start < chars_len && feature.start < feature.end)
825 	  {
826 	    CFRange feature_range = CFRangeMake (feature.start,
827 						 hb_min (feature.end, chars_len) - feature.start);
828 	    if (feature.value)
829 	      CFAttributedStringRemoveAttribute (attr_string, feature_range, kCTKernAttributeName);
830 	    else
831 	      CFAttributedStringSetAttribute (attr_string, feature_range, kCTKernAttributeName, zero);
832 	  }
833 	}
834 	CFRelease (zero);
835       }
836 
837       int level = HB_DIRECTION_IS_FORWARD (buffer->props.direction) ? 0 : 1;
838       CFNumberRef level_number = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &level);
839 #if !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
840       extern const CFStringRef kCTTypesetterOptionForcedEmbeddingLevel;
841 #endif
842       CFDictionaryRef options = CFDictionaryCreate (kCFAllocatorDefault,
843 						    (const void **) &kCTTypesetterOptionForcedEmbeddingLevel,
844 						    (const void **) &level_number,
845 						    1,
846 						    &kCFTypeDictionaryKeyCallBacks,
847 						    &kCFTypeDictionaryValueCallBacks);
848       CFRelease (level_number);
849       if (unlikely (!options))
850       {
851 	CFRelease (attr_string);
852 	FAIL ("CFDictionaryCreate failed");
853       }
854 
855       CTTypesetterRef typesetter = CTTypesetterCreateWithAttributedStringAndOptions (attr_string, options);
856       CFRelease (options);
857       CFRelease (attr_string);
858       if (unlikely (!typesetter))
859 	FAIL ("CTTypesetterCreateWithAttributedStringAndOptions failed");
860 
861       line = CTTypesetterCreateLine (typesetter, CFRangeMake(0, 0));
862       CFRelease (typesetter);
863       if (unlikely (!line))
864 	FAIL ("CTTypesetterCreateLine failed");
865     }
866 
867     CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
868     unsigned int num_runs = CFArrayGetCount (glyph_runs);
869     DEBUG_MSG (CORETEXT, nullptr, "Num runs: %d", num_runs);
870 
871     buffer->len = 0;
872     uint32_t status_or = 0;
873     CGFloat advances_so_far = 0;
874     /* For right-to-left runs, CoreText returns the glyphs positioned such that
875      * any trailing whitespace is to the left of (0,0).  Adjust coordinate system
876      * to fix for that.  Test with any RTL string with trailing spaces.
877      * https://crbug.com/469028
878      */
879     if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
880     {
881       advances_so_far -= CTLineGetTrailingWhitespaceWidth (line);
882       if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
883 	  advances_so_far = -advances_so_far;
884     }
885 
886     const CFRange range_all = CFRangeMake (0, 0);
887 
888     for (unsigned int i = 0; i < num_runs; i++)
889     {
890       CTRunRef run = static_cast<CTRunRef>(CFArrayGetValueAtIndex (glyph_runs, i));
891       CTRunStatus run_status = CTRunGetStatus (run);
892       status_or  |= run_status;
893       DEBUG_MSG (CORETEXT, run, "CTRunStatus: %x", run_status);
894       CGFloat run_advance = CTRunGetTypographicBounds (run, range_all, nullptr, nullptr, nullptr);
895       if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
896 	  run_advance = -run_advance;
897       DEBUG_MSG (CORETEXT, run, "Run advance: %g", (double) run_advance);
898 
899       /* CoreText does automatic font fallback (AKA "cascading") for  characters
900        * not supported by the requested font, and provides no way to turn it off,
901        * so we must detect if the returned run uses a font other than the requested
902        * one and fill in the buffer with .notdef glyphs instead of random glyph
903        * indices from a different font.
904        */
905       CFDictionaryRef attributes = CTRunGetAttributes (run);
906       CTFontRef run_ct_font = static_cast<CTFontRef>(CFDictionaryGetValue (attributes, kCTFontAttributeName));
907       if (!CFEqual (run_ct_font, ct_font))
908       {
909 	/* The run doesn't use our main font instance.  We have to figure out
910 	 * whether font fallback happened, or this is just CoreText giving us
911 	 * another CTFont using the same underlying CGFont.  CoreText seems
912 	 * to do that in a variety of situations, one of which being vertical
913 	 * text, but also perhaps for caching reasons.
914 	 *
915 	 * First, see if it uses any of our subfonts created to set font features...
916 	 *
917 	 * Next, compare the CGFont to the one we used to create our fonts.
918 	 * Even this doesn't work all the time.
919 	 *
920 	 * Finally, we compare PS names, which I don't think are unique...
921 	 *
922 	 * Looks like if we really want to be sure here we have to modify the
923 	 * font to change the name table, similar to what we do in the uniscribe
924 	 * backend.
925 	 *
926 	 * However, even that wouldn't work if we were passed in the CGFont to
927 	 * construct a hb_face to begin with.
928 	 *
929 	 * See: https://github.com/harfbuzz/harfbuzz/pull/36
930 	 *
931 	 * Also see: https://bugs.chromium.org/p/chromium/issues/detail?id=597098
932 	 */
933 	bool matched = false;
934 	for (unsigned int i = 0; i < range_records.length; i++)
935 	  if (range_records[i].font && CFEqual (run_ct_font, range_records[i].font))
936 	  {
937 	    matched = true;
938 	    break;
939 	  }
940 	if (!matched)
941 	{
942 	  CGFontRef run_cg_font = CTFontCopyGraphicsFont (run_ct_font, nullptr);
943 	  if (run_cg_font)
944 	  {
945 	    matched = CFEqual (run_cg_font, cg_font);
946 	    CFRelease (run_cg_font);
947 	  }
948 	}
949 	if (!matched)
950 	{
951 	  CFStringRef font_ps_name = CTFontCopyName (ct_font, kCTFontPostScriptNameKey);
952 	  CFStringRef run_ps_name = CTFontCopyName (run_ct_font, kCTFontPostScriptNameKey);
953 	  CFComparisonResult result = CFStringCompare (run_ps_name, font_ps_name, 0);
954 	  CFRelease (run_ps_name);
955 	  CFRelease (font_ps_name);
956 	  if (result == kCFCompareEqualTo)
957 	    matched = true;
958 	}
959 	if (!matched)
960 	{
961 	  CFRange range = CTRunGetStringRange (run);
962 	  DEBUG_MSG (CORETEXT, run, "Run used fallback font: %ld..%ld",
963 		     range.location, range.location + range.length);
964 	  if (!buffer->ensure_inplace (buffer->len + range.length))
965 	    goto resize_and_retry;
966 	  hb_glyph_info_t *info = buffer->info + buffer->len;
967 
968 	  hb_codepoint_t notdef = 0;
969 	  hb_direction_t dir = buffer->props.direction;
970 	  hb_position_t x_advance, y_advance, x_offset, y_offset;
971 	  hb_font_get_glyph_advance_for_direction (font, notdef, dir, &x_advance, &y_advance);
972 	  hb_font_get_glyph_origin_for_direction (font, notdef, dir, &x_offset, &y_offset);
973 	  hb_position_t advance = x_advance + y_advance;
974 	  x_offset = -x_offset;
975 	  y_offset = -y_offset;
976 
977 	  unsigned int old_len = buffer->len;
978 	  for (CFIndex j = range.location; j < range.location + range.length; j++)
979 	  {
980 	      UniChar ch = CFStringGetCharacterAtIndex (string_ref, j);
981 	      if (hb_in_range<UniChar> (ch, 0xDC00u, 0xDFFFu) && range.location < j)
982 	      {
983 		ch = CFStringGetCharacterAtIndex (string_ref, j - 1);
984 		if (hb_in_range<UniChar> (ch, 0xD800u, 0xDBFFu))
985 		  /* This is the second of a surrogate pair.  Don't need .notdef
986 		   * for this one. */
987 		  continue;
988 	      }
989 	      if (buffer->unicode->is_default_ignorable (ch))
990 		continue;
991 
992 	      info->codepoint = notdef;
993 	      info->cluster = log_clusters[j];
994 
995 	      info->mask = advance;
996 	      info->var1.i32 = x_offset;
997 	      info->var2.i32 = y_offset;
998 
999 	      info++;
1000 	      buffer->len++;
1001 	  }
1002 	  if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
1003 	    buffer->reverse_range (old_len, buffer->len);
1004 	  advances_so_far += run_advance;
1005 	  continue;
1006 	}
1007       }
1008 
1009       unsigned int num_glyphs = CTRunGetGlyphCount (run);
1010       if (num_glyphs == 0)
1011 	continue;
1012 
1013       if (!buffer->ensure_inplace (buffer->len + num_glyphs))
1014 	goto resize_and_retry;
1015 
1016       hb_glyph_info_t *run_info = buffer->info + buffer->len;
1017 
1018       /* Testing used to indicate that CTRunGetGlyphsPtr, etc (almost?) always
1019        * succeed, and so copying data to our own buffer will be rare.  Reports
1020        * have it that this changed in OS X 10.10 Yosemite, and nullptr is returned
1021        * frequently.  At any rate, we can test that codepath by setting USE_PTR
1022        * to false. */
1023 
1024 #define USE_PTR true
1025 
1026 #define SCRATCH_SAVE() \
1027   unsigned int scratch_size_saved = scratch_size; \
1028   hb_buffer_t::scratch_buffer_t *scratch_saved = scratch
1029 
1030 #define SCRATCH_RESTORE() \
1031   scratch_size = scratch_size_saved; \
1032   scratch = scratch_saved
1033 
1034       { /* Setup glyphs */
1035 	SCRATCH_SAVE();
1036 	const CGGlyph* glyphs = USE_PTR ? CTRunGetGlyphsPtr (run) : nullptr;
1037 	if (!glyphs) {
1038 	  ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs, goto resize_and_retry);
1039 	  CTRunGetGlyphs (run, range_all, glyph_buf);
1040 	  glyphs = glyph_buf;
1041 	}
1042 	const CFIndex* string_indices = USE_PTR ? CTRunGetStringIndicesPtr (run) : nullptr;
1043 	if (!string_indices) {
1044 	  ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs, goto resize_and_retry);
1045 	  CTRunGetStringIndices (run, range_all, index_buf);
1046 	  string_indices = index_buf;
1047 	}
1048 	hb_glyph_info_t *info = run_info;
1049 	for (unsigned int j = 0; j < num_glyphs; j++)
1050 	{
1051 	  info->codepoint = glyphs[j];
1052 	  info->cluster = log_clusters[string_indices[j]];
1053 	  info++;
1054 	}
1055 	SCRATCH_RESTORE();
1056       }
1057       {
1058 	/* Setup positions.
1059 	 * Note that CoreText does not return advances for glyphs.  As such,
1060 	 * for all but last glyph, we use the delta position to next glyph as
1061 	 * advance (in the advance direction only), and for last glyph we set
1062 	 * whatever is needed to make the whole run's advance add up. */
1063 	SCRATCH_SAVE();
1064 	const CGPoint* positions = USE_PTR ? CTRunGetPositionsPtr (run) : nullptr;
1065 	if (!positions) {
1066 	  ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs, goto resize_and_retry);
1067 	  CTRunGetPositions (run, range_all, position_buf);
1068 	  positions = position_buf;
1069 	}
1070 	hb_glyph_info_t *info = run_info;
1071 	if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
1072 	{
1073 	  hb_position_t x_offset = round ((positions[0].x - advances_so_far) * x_mult);
1074 	  for (unsigned int j = 0; j < num_glyphs; j++)
1075 	  {
1076 	    CGFloat advance;
1077 	    if (likely (j + 1 < num_glyphs))
1078 	      advance = positions[j + 1].x - positions[j].x;
1079 	    else /* last glyph */
1080 	      advance = run_advance - (positions[j].x - positions[0].x);
1081 	    /* int cast necessary to pass through negative values. */
1082 	    info->mask = (int) round (advance * x_mult);
1083 	    info->var1.i32 = x_offset;
1084 	    info->var2.i32 = round (positions[j].y * y_mult);
1085 	    info++;
1086 	  }
1087 	}
1088 	else
1089 	{
1090 	  hb_position_t y_offset = round ((positions[0].y - advances_so_far) * y_mult);
1091 	  for (unsigned int j = 0; j < num_glyphs; j++)
1092 	  {
1093 	    CGFloat advance;
1094 	    if (likely (j + 1 < num_glyphs))
1095 	      advance = positions[j + 1].y - positions[j].y;
1096 	    else /* last glyph */
1097 	      advance = run_advance - (positions[j].y - positions[0].y);
1098 	    /* int cast necessary to pass through negative values. */
1099 	    info->mask = (int) round (advance * y_mult);
1100 	    info->var1.i32 = round (positions[j].x * x_mult);
1101 	    info->var2.i32 = y_offset;
1102 	    info++;
1103 	  }
1104 	}
1105 	SCRATCH_RESTORE();
1106 	advances_so_far += run_advance;
1107       }
1108 #undef SCRATCH_RESTORE
1109 #undef SCRATCH_SAVE
1110 #undef USE_PTR
1111 #undef ALLOCATE_ARRAY
1112 
1113       buffer->len += num_glyphs;
1114     }
1115 
1116     buffer->clear_positions ();
1117 
1118     unsigned int count = buffer->len;
1119     hb_glyph_info_t *info = buffer->info;
1120     hb_glyph_position_t *pos = buffer->pos;
1121     if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
1122       for (unsigned int i = 0; i < count; i++)
1123       {
1124 	pos->x_advance = info->mask;
1125 	pos->x_offset = info->var1.i32;
1126 	pos->y_offset = info->var2.i32;
1127 
1128 	info++; pos++;
1129       }
1130     else
1131       for (unsigned int i = 0; i < count; i++)
1132       {
1133 	pos->y_advance = info->mask;
1134 	pos->x_offset = info->var1.i32;
1135 	pos->y_offset = info->var2.i32;
1136 
1137 	info++; pos++;
1138       }
1139 
1140     /* Fix up clusters so that we never return out-of-order indices;
1141      * if core text has reordered glyphs, we'll merge them to the
1142      * beginning of the reordered cluster.  CoreText is nice enough
1143      * to tell us whenever it has produced nonmonotonic results...
1144      * Note that we assume the input clusters were nonmonotonic to
1145      * begin with.
1146      *
1147      * This does *not* mean we'll form the same clusters as Uniscribe
1148      * or the native OT backend, only that the cluster indices will be
1149      * monotonic in the output buffer. */
1150     if (count > 1 && (status_or & kCTRunStatusNonMonotonic) &&
1151 	buffer->cluster_level != HB_BUFFER_CLUSTER_LEVEL_CHARACTERS)
1152     {
1153       hb_glyph_info_t *info = buffer->info;
1154       if (HB_DIRECTION_IS_FORWARD (buffer->props.direction))
1155       {
1156 	unsigned int cluster = info[count - 1].cluster;
1157 	for (unsigned int i = count - 1; i > 0; i--)
1158 	{
1159 	  cluster = hb_min (cluster, info[i - 1].cluster);
1160 	  info[i - 1].cluster = cluster;
1161 	}
1162       }
1163       else
1164       {
1165 	unsigned int cluster = info[0].cluster;
1166 	for (unsigned int i = 1; i < count; i++)
1167 	{
1168 	  cluster = hb_min (cluster, info[i].cluster);
1169 	  info[i].cluster = cluster;
1170 	}
1171       }
1172     }
1173   }
1174 
1175   /* TODO: Sometimes the above positioning code generates negative
1176    * advance values. Fix them up. Example, with NotoNastaliqUrdu
1177    * font and sequence ابهد. */
1178 
1179   buffer->clear_glyph_flags ();
1180   buffer->unsafe_to_break ();
1181 
1182 #undef FAIL
1183 
1184 fail:
1185   if (string_ref)
1186     CFRelease (string_ref);
1187   if (line)
1188     CFRelease (line);
1189 
1190   for (unsigned int i = 0; i < range_records.length; i++)
1191     if (range_records[i].font)
1192       CFRelease (range_records[i].font);
1193 
1194   return ret;
1195 }
1196 
1197 
1198 #endif
1199