1 /*
2  * Copyright © 2007,2008,2009  Red Hat, Inc.
3  * Copyright © 2010,2012  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  * Red Hat Author(s): Behdad Esfahbod
26  * Google Author(s): Behdad Esfahbod
27  */
28 
29 #ifndef HB_OT_LAYOUT_COMMON_PRIVATE_HH
30 #define HB_OT_LAYOUT_COMMON_PRIVATE_HH
31 
32 #include "hb-ot-layout-private.hh"
33 #include "hb-open-type-private.hh"
34 #include "hb-set-private.hh"
35 
36 
37 namespace OT {
38 
39 
40 #define NOT_COVERED		((unsigned int) -1)
41 #define MAX_NESTING_LEVEL	8
42 #define MAX_CONTEXT_LENGTH	64
43 
44 
45 
46 /*
47  *
48  * OpenType Layout Common Table Formats
49  *
50  */
51 
52 
53 /*
54  * Script, ScriptList, LangSys, Feature, FeatureList, Lookup, LookupList
55  */
56 
57 template <typename Type>
58 struct Record
59 {
cmpOT::Record60   inline int cmp (hb_tag_t a) const {
61     return tag.cmp (a);
62   }
63 
64   struct sanitize_closure_t {
65     hb_tag_t tag;
66     void *list_base;
67   };
sanitizeOT::Record68   inline bool sanitize (hb_sanitize_context_t *c, void *base) {
69     TRACE_SANITIZE (this);
70     const sanitize_closure_t closure = {tag, base};
71     return TRACE_RETURN (c->check_struct (this) && offset.sanitize (c, base, &closure));
72   }
73 
74   Tag		tag;		/* 4-byte Tag identifier */
75   OffsetTo<Type>
76 		offset;		/* Offset from beginning of object holding
77 				 * the Record */
78   public:
79   DEFINE_SIZE_STATIC (6);
80 };
81 
82 template <typename Type>
83 struct RecordArrayOf : SortedArrayOf<Record<Type> > {
get_tagOT::RecordArrayOf84   inline const Tag& get_tag (unsigned int i) const
85   {
86     /* We cheat slightly and don't define separate Null objects
87      * for Record types.  Instead, we return the correct Null(Tag)
88      * here. */
89     if (unlikely (i >= this->len)) return Null(Tag);
90     return (*this)[i].tag;
91   }
get_tagsOT::RecordArrayOf92   inline unsigned int get_tags (unsigned int start_offset,
93 				unsigned int *record_count /* IN/OUT */,
94 				hb_tag_t     *record_tags /* OUT */) const
95   {
96     if (record_count) {
97       const Record<Type> *arr = this->sub_array (start_offset, record_count);
98       unsigned int count = *record_count;
99       for (unsigned int i = 0; i < count; i++)
100 	record_tags[i] = arr[i].tag;
101     }
102     return this->len;
103   }
find_indexOT::RecordArrayOf104   inline bool find_index (hb_tag_t tag, unsigned int *index) const
105   {
106     /* If we want to allow non-sorted data, we can lsearch(). */
107     int i = this->/*lsearch*/bsearch (tag);
108     if (i != -1) {
109         if (index) *index = i;
110         return true;
111     } else {
112       if (index) *index = Index::NOT_FOUND_INDEX;
113       return false;
114     }
115   }
116 };
117 
118 template <typename Type>
119 struct RecordListOf : RecordArrayOf<Type>
120 {
operator []OT::RecordListOf121   inline const Type& operator [] (unsigned int i) const
122   { return this+RecordArrayOf<Type>::operator [](i).offset; }
123 
sanitizeOT::RecordListOf124   inline bool sanitize (hb_sanitize_context_t *c) {
125     TRACE_SANITIZE (this);
126     return TRACE_RETURN (RecordArrayOf<Type>::sanitize (c, this));
127   }
128 };
129 
130 
131 struct RangeRecord
132 {
cmpOT::RangeRecord133   inline int cmp (hb_codepoint_t g) const {
134     return g < start ? -1 : g <= end ? 0 : +1 ;
135   }
136 
sanitizeOT::RangeRecord137   inline bool sanitize (hb_sanitize_context_t *c) {
138     TRACE_SANITIZE (this);
139     return TRACE_RETURN (c->check_struct (this));
140   }
141 
intersectsOT::RangeRecord142   inline bool intersects (const hb_set_t *glyphs) const {
143     return glyphs->intersects (start, end);
144   }
145 
146   template <typename set_t>
add_coverageOT::RangeRecord147   inline void add_coverage (set_t *glyphs) const {
148     glyphs->add_range (start, end);
149   }
150 
151   GlyphID	start;		/* First GlyphID in the range */
152   GlyphID	end;		/* Last GlyphID in the range */
153   USHORT	value;		/* Value */
154   public:
155   DEFINE_SIZE_STATIC (6);
156 };
157 DEFINE_NULL_DATA (RangeRecord, "\000\001");
158 
159 
160 struct IndexArray : ArrayOf<Index>
161 {
get_indexesOT::IndexArray162   inline unsigned int get_indexes (unsigned int start_offset,
163 				   unsigned int *_count /* IN/OUT */,
164 				   unsigned int *_indexes /* OUT */) const
165   {
166     if (_count) {
167       const USHORT *arr = this->sub_array (start_offset, _count);
168       unsigned int count = *_count;
169       for (unsigned int i = 0; i < count; i++)
170 	_indexes[i] = arr[i];
171     }
172     return this->len;
173   }
174 };
175 
176 
177 struct Script;
178 struct LangSys;
179 struct Feature;
180 
181 
182 struct LangSys
183 {
get_feature_countOT::LangSys184   inline unsigned int get_feature_count (void) const
185   { return featureIndex.len; }
get_feature_indexOT::LangSys186   inline hb_tag_t get_feature_index (unsigned int i) const
187   { return featureIndex[i]; }
get_feature_indexesOT::LangSys188   inline unsigned int get_feature_indexes (unsigned int start_offset,
189 					   unsigned int *feature_count /* IN/OUT */,
190 					   unsigned int *feature_indexes /* OUT */) const
191   { return featureIndex.get_indexes (start_offset, feature_count, feature_indexes); }
192 
has_required_featureOT::LangSys193   inline bool has_required_feature (void) const { return reqFeatureIndex != 0xFFFFu; }
get_required_feature_indexOT::LangSys194   inline unsigned int get_required_feature_index (void) const
195   {
196     if (reqFeatureIndex == 0xFFFFu)
197       return Index::NOT_FOUND_INDEX;
198    return reqFeatureIndex;;
199   }
200 
sanitizeOT::LangSys201   inline bool sanitize (hb_sanitize_context_t *c,
202 			const Record<LangSys>::sanitize_closure_t * = NULL) {
203     TRACE_SANITIZE (this);
204     return TRACE_RETURN (c->check_struct (this) && featureIndex.sanitize (c));
205   }
206 
207   Offset<>	lookupOrderZ;	/* = Null (reserved for an offset to a
208 				 * reordering table) */
209   USHORT	reqFeatureIndex;/* Index of a feature required for this
210 				 * language system--if no required features
211 				 * = 0xFFFFu */
212   IndexArray	featureIndex;	/* Array of indices into the FeatureList */
213   public:
214   DEFINE_SIZE_ARRAY (6, featureIndex);
215 };
216 DEFINE_NULL_DATA (LangSys, "\0\0\xFF\xFF");
217 
218 
219 struct Script
220 {
get_lang_sys_countOT::Script221   inline unsigned int get_lang_sys_count (void) const
222   { return langSys.len; }
get_lang_sys_tagOT::Script223   inline const Tag& get_lang_sys_tag (unsigned int i) const
224   { return langSys.get_tag (i); }
get_lang_sys_tagsOT::Script225   inline unsigned int get_lang_sys_tags (unsigned int start_offset,
226 					 unsigned int *lang_sys_count /* IN/OUT */,
227 					 hb_tag_t     *lang_sys_tags /* OUT */) const
228   { return langSys.get_tags (start_offset, lang_sys_count, lang_sys_tags); }
get_lang_sysOT::Script229   inline const LangSys& get_lang_sys (unsigned int i) const
230   {
231     if (i == Index::NOT_FOUND_INDEX) return get_default_lang_sys ();
232     return this+langSys[i].offset;
233   }
find_lang_sys_indexOT::Script234   inline bool find_lang_sys_index (hb_tag_t tag, unsigned int *index) const
235   { return langSys.find_index (tag, index); }
236 
has_default_lang_sysOT::Script237   inline bool has_default_lang_sys (void) const { return defaultLangSys != 0; }
get_default_lang_sysOT::Script238   inline const LangSys& get_default_lang_sys (void) const { return this+defaultLangSys; }
239 
sanitizeOT::Script240   inline bool sanitize (hb_sanitize_context_t *c,
241 			const Record<Script>::sanitize_closure_t * = NULL) {
242     TRACE_SANITIZE (this);
243     return TRACE_RETURN (defaultLangSys.sanitize (c, this) && langSys.sanitize (c, this));
244   }
245 
246   protected:
247   OffsetTo<LangSys>
248 		defaultLangSys;	/* Offset to DefaultLangSys table--from
249 				 * beginning of Script table--may be Null */
250   RecordArrayOf<LangSys>
251 		langSys;	/* Array of LangSysRecords--listed
252 				 * alphabetically by LangSysTag */
253   public:
254   DEFINE_SIZE_ARRAY (4, langSys);
255 };
256 
257 typedef RecordListOf<Script> ScriptList;
258 
259 
260 /* http://www.microsoft.com/typography/otspec/features_pt.htm#size */
261 struct FeatureParamsSize
262 {
sanitizeOT::FeatureParamsSize263   inline bool sanitize (hb_sanitize_context_t *c) {
264     TRACE_SANITIZE (this);
265     if (unlikely (!c->check_struct (this))) return TRACE_RETURN (false);
266 
267     /* This subtable has some "history", if you will.  Some earlier versions of
268      * Adobe tools calculated the offset of the FeatureParams sutable from the
269      * beginning of the FeatureList table!  Now, that is dealt with in the
270      * Feature implementation.  But we still need to be able to tell junk from
271      * real data.  Note: We don't check that the nameID actually exists.
272      *
273      * Read Roberts wrote on 9/15/06 on opentype-list@indx.co.uk :
274      *
275      * Yes, it is correct that a new version of the AFDKO (version 2.0) will be
276      * coming out soon, and that the makeotf program will build a font with a
277      * 'size' feature that is correct by the specification.
278      *
279      * The specification for this feature tag is in the "OpenType Layout Tag
280      * Registry". You can see a copy of this at:
281      * http://partners.adobe.com/public/developer/opentype/index_tag8.html#size
282      *
283      * Here is one set of rules to determine if the 'size' feature is built
284      * correctly, or as by the older versions of MakeOTF. You may be able to do
285      * better.
286      *
287      * Assume that the offset to the size feature is according to specification,
288      * and make the following value checks. If it fails, assume the the size
289      * feature is calculated as versions of MakeOTF before the AFDKO 2.0 built it.
290      * If this fails, reject the 'size' feature. The older makeOTF's calculated the
291      * offset from the beginning of the FeatureList table, rather than from the
292      * beginning of the 'size' Feature table.
293      *
294      * If "design size" == 0:
295      *     fails check
296      *
297      * Else if ("subfamily identifier" == 0 and
298      *     "range start" == 0 and
299      *     "range end" == 0 and
300      *     "range start" == 0 and
301      *     "menu name ID" == 0)
302      *     passes check: this is the format used when there is a design size
303      * specified, but there is no recommended size range.
304      *
305      * Else if ("design size" <  "range start" or
306      *     "design size" >   "range end" or
307      *     "range end" <= "range start" or
308      *     "menu name ID"  < 256 or
309      *     "menu name ID"  > 32767 or
310      *     menu name ID is not a name ID which is actually in the name table)
311      *     fails test
312      * Else
313      *     passes test.
314      */
315 
316     if (!designSize)
317       return TRACE_RETURN (false);
318     else if (subfamilyID == 0 &&
319 	     subfamilyNameID == 0 &&
320 	     rangeStart == 0 &&
321 	     rangeEnd == 0)
322       return TRACE_RETURN (true);
323     else if (designSize < rangeStart ||
324 	     designSize > rangeEnd ||
325 	     subfamilyNameID < 256 ||
326 	     subfamilyNameID > 32767)
327       return TRACE_RETURN (false);
328     else
329       return TRACE_RETURN (true);
330   }
331 
332   USHORT	designSize;	/* Represents the design size in 720/inch
333 				 * units (decipoints).  The design size entry
334 				 * must be non-zero.  When there is a design
335 				 * size but no recommended size range, the
336 				 * rest of the array will consist of zeros. */
337   USHORT	subfamilyID;	/* Has no independent meaning, but serves
338 				 * as an identifier that associates fonts
339 				 * in a subfamily. All fonts which share a
340 				 * Preferred or Font Family name and which
341 				 * differ only by size range shall have the
342 				 * same subfamily value, and no fonts which
343 				 * differ in weight or style shall have the
344 				 * same subfamily value. If this value is
345 				 * zero, the remaining fields in the array
346 				 * will be ignored. */
347   USHORT	subfamilyNameID;/* If the preceding value is non-zero, this
348 				 * value must be set in the range 256 - 32767
349 				 * (inclusive). It records the value of a
350 				 * field in the name table, which must
351 				 * contain English-language strings encoded
352 				 * in Windows Unicode and Macintosh Roman,
353 				 * and may contain additional strings
354 				 * localized to other scripts and languages.
355 				 * Each of these strings is the name an
356 				 * application should use, in combination
357 				 * with the family name, to represent the
358 				 * subfamily in a menu.  Applications will
359 				 * choose the appropriate version based on
360 				 * their selection criteria. */
361   USHORT	rangeStart;	/* Large end of the recommended usage range
362 				 * (inclusive), stored in 720/inch units
363 				 * (decipoints). */
364   USHORT	rangeEnd;	/* Small end of the recommended usage range
365 				   (exclusive), stored in 720/inch units
366 				 * (decipoints). */
367   public:
368   DEFINE_SIZE_STATIC (10);
369 };
370 
371 /* http://www.microsoft.com/typography/otspec/features_pt.htm#ssxx */
372 struct FeatureParamsStylisticSet
373 {
sanitizeOT::FeatureParamsStylisticSet374   inline bool sanitize (hb_sanitize_context_t *c) {
375     TRACE_SANITIZE (this);
376     /* Right now minorVersion is at zero.  Which means, any table supports
377      * the uiNameID field. */
378     return TRACE_RETURN (c->check_struct (this));
379   }
380 
381   USHORT	version;	/* (set to 0): This corresponds to a “minor”
382 				 * version number. Additional data may be
383 				 * added to the end of this Feature Parameters
384 				 * table in the future. */
385 
386   USHORT	uiNameID;	/* The 'name' table name ID that specifies a
387 				 * string (or strings, for multiple languages)
388 				 * for a user-interface label for this
389 				 * feature.  The values of uiLabelNameId and
390 				 * sampleTextNameId are expected to be in the
391 				 * font-specific name ID range (256-32767),
392 				 * though that is not a requirement in this
393 				 * Feature Parameters specification. The
394 				 * user-interface label for the feature can
395 				 * be provided in multiple languages. An
396 				 * English string should be included as a
397 				 * fallback. The string should be kept to a
398 				 * minimal length to fit comfortably with
399 				 * different application interfaces. */
400   public:
401   DEFINE_SIZE_STATIC (4);
402 };
403 
404 /* http://www.microsoft.com/typography/otspec/features_ae.htm#cv01-cv99 */
405 struct FeatureParamsCharacterVariants
406 {
sanitizeOT::FeatureParamsCharacterVariants407   inline bool sanitize (hb_sanitize_context_t *c) {
408     TRACE_SANITIZE (this);
409     return TRACE_RETURN (c->check_struct (this) &&
410 			 characters.sanitize (c));
411   }
412 
413   USHORT	format;			/* Format number is set to 0. */
414   USHORT	featUILableNameID;	/* The ‘name’ table name ID that
415 					 * specifies a string (or strings,
416 					 * for multiple languages) for a
417 					 * user-interface label for this
418 					 * feature. (May be NULL.) */
419   USHORT	featUITooltipTextNameID;/* The ‘name’ table name ID that
420 					 * specifies a string (or strings,
421 					 * for multiple languages) that an
422 					 * application can use for tooltip
423 					 * text for this feature. (May be
424 					 * NULL.) */
425   USHORT	sampleTextNameID;	/* The ‘name’ table name ID that
426 					 * specifies sample text that
427 					 * illustrates the effect of this
428 					 * feature. (May be NULL.) */
429   USHORT	numNamedParameters;	/* Number of named parameters. (May
430 					 * be zero.) */
431   USHORT	firstParamUILabelNameID;/* The first ‘name’ table name ID
432 					 * used to specify strings for
433 					 * user-interface labels for the
434 					 * feature parameters. (Must be zero
435 					 * if numParameters is zero.) */
436   ArrayOf<UINT24>
437 		characters;		/* Array of the Unicode Scalar Value
438 					 * of the characters for which this
439 					 * feature provides glyph variants.
440 					 * (May be zero.) */
441   public:
442   DEFINE_SIZE_ARRAY (14, characters);
443 };
444 
445 struct FeatureParams
446 {
sanitizeOT::FeatureParams447   inline bool sanitize (hb_sanitize_context_t *c, hb_tag_t tag) {
448     TRACE_SANITIZE (this);
449     if (tag == HB_TAG ('s','i','z','e'))
450       return TRACE_RETURN (u.size.sanitize (c));
451     if ((tag & 0xFFFF0000u) == HB_TAG ('s','s','\0','\0')) /* ssXX */
452       return TRACE_RETURN (u.stylisticSet.sanitize (c));
453     if ((tag & 0xFFFF0000u) == HB_TAG ('c','v','\0','\0')) /* cvXX */
454       return TRACE_RETURN (u.characterVariants.sanitize (c));
455     return TRACE_RETURN (true);
456   }
457 
get_size_paramsOT::FeatureParams458   inline const FeatureParamsSize& get_size_params (hb_tag_t tag) const
459   {
460     if (tag == HB_TAG ('s','i','z','e'))
461       return u.size;
462     return Null(FeatureParamsSize);
463   }
464 
465   private:
466   union {
467   FeatureParamsSize			size;
468   FeatureParamsStylisticSet		stylisticSet;
469   FeatureParamsCharacterVariants	characterVariants;
470   } u;
471   DEFINE_SIZE_STATIC (17);
472 };
473 
474 struct Feature
475 {
get_lookup_countOT::Feature476   inline unsigned int get_lookup_count (void) const
477   { return lookupIndex.len; }
get_lookup_indexOT::Feature478   inline hb_tag_t get_lookup_index (unsigned int i) const
479   { return lookupIndex[i]; }
get_lookup_indexesOT::Feature480   inline unsigned int get_lookup_indexes (unsigned int start_index,
481 					  unsigned int *lookup_count /* IN/OUT */,
482 					  unsigned int *lookup_tags /* OUT */) const
483   { return lookupIndex.get_indexes (start_index, lookup_count, lookup_tags); }
484 
get_feature_paramsOT::Feature485   inline const FeatureParams &get_feature_params (void) const
486   { return this+featureParams; }
487 
sanitizeOT::Feature488   inline bool sanitize (hb_sanitize_context_t *c,
489 			const Record<Feature>::sanitize_closure_t *closure) {
490     TRACE_SANITIZE (this);
491     if (unlikely (!(c->check_struct (this) && lookupIndex.sanitize (c))))
492       return TRACE_RETURN (false);
493 
494     /* Some earlier versions of Adobe tools calculated the offset of the
495      * FeatureParams subtable from the beginning of the FeatureList table!
496      *
497      * If sanitizing "failed" for the FeatureParams subtable, try it with the
498      * alternative location.  We would know sanitize "failed" if old value
499      * of the offset was non-zero, but it's zeroed now.
500      *
501      * Only do this for the 'size' feature, since at the time of the faulty
502      * Adobe tools, only the 'size' feature had FeatureParams defined.
503      */
504 
505     OffsetTo<FeatureParams> orig_offset = featureParams;
506     if (unlikely (!featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE)))
507       return TRACE_RETURN (false);
508 
509     if (likely (orig_offset.is_null ()))
510       return TRACE_RETURN (true);
511 
512     if (featureParams == 0 && closure &&
513 	closure->tag == HB_TAG ('s','i','z','e') &&
514 	closure->list_base && closure->list_base < this)
515     {
516       unsigned int new_offset_int = (unsigned int) orig_offset -
517 				    (((char *) this) - ((char *) closure->list_base));
518 
519       OffsetTo<FeatureParams> new_offset;
520       /* Check that it did not overflow. */
521       new_offset.set (new_offset_int);
522       if (new_offset == new_offset_int &&
523 	  c->try_set (&featureParams, new_offset) &&
524 	  !featureParams.sanitize (c, this, closure ? closure->tag : HB_TAG_NONE))
525 	return TRACE_RETURN (false);
526     }
527 
528     return TRACE_RETURN (true);
529   }
530 
531   OffsetTo<FeatureParams>
532 		 featureParams;	/* Offset to Feature Parameters table (if one
533 				 * has been defined for the feature), relative
534 				 * to the beginning of the Feature Table; = Null
535 				 * if not required */
536   IndexArray	 lookupIndex;	/* Array of LookupList indices */
537   public:
538   DEFINE_SIZE_ARRAY (4, lookupIndex);
539 };
540 
541 typedef RecordListOf<Feature> FeatureList;
542 
543 
544 struct LookupFlag : USHORT
545 {
546   enum Flags {
547     RightToLeft		= 0x0001u,
548     IgnoreBaseGlyphs	= 0x0002u,
549     IgnoreLigatures	= 0x0004u,
550     IgnoreMarks		= 0x0008u,
551     IgnoreFlags		= 0x000Eu,
552     UseMarkFilteringSet	= 0x0010u,
553     Reserved		= 0x00E0u,
554     MarkAttachmentType	= 0xFF00u
555   };
556   public:
557   DEFINE_SIZE_STATIC (2);
558 };
559 
560 struct Lookup
561 {
get_subtable_countOT::Lookup562   inline unsigned int get_subtable_count (void) const { return subTable.len; }
563 
get_typeOT::Lookup564   inline unsigned int get_type (void) const { return lookupType; }
565 
566   /* lookup_props is a 32-bit integer where the lower 16-bit is LookupFlag and
567    * higher 16-bit is mark-filtering-set if the lookup uses one.
568    * Not to be confused with glyph_props which is very similar. */
get_propsOT::Lookup569   inline uint32_t get_props (void) const
570   {
571     unsigned int flag = lookupFlag;
572     if (unlikely (flag & LookupFlag::UseMarkFilteringSet))
573     {
574       const USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
575       flag += (markFilteringSet << 16);
576     }
577     return flag;
578   }
579 
serializeOT::Lookup580   inline bool serialize (hb_serialize_context_t *c,
581 			 unsigned int lookup_type,
582 			 uint32_t lookup_props,
583 			 unsigned int num_subtables)
584   {
585     TRACE_SERIALIZE (this);
586     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
587     lookupType.set (lookup_type);
588     lookupFlag.set (lookup_props & 0xFFFFu);
589     if (unlikely (!subTable.serialize (c, num_subtables))) return TRACE_RETURN (false);
590     if (lookupFlag & LookupFlag::UseMarkFilteringSet)
591     {
592       USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
593       markFilteringSet.set (lookup_props >> 16);
594     }
595     return TRACE_RETURN (true);
596   }
597 
sanitizeOT::Lookup598   inline bool sanitize (hb_sanitize_context_t *c) {
599     TRACE_SANITIZE (this);
600     /* Real sanitize of the subtables is done by GSUB/GPOS/... */
601     if (!(c->check_struct (this) && subTable.sanitize (c))) return TRACE_RETURN (false);
602     if (lookupFlag & LookupFlag::UseMarkFilteringSet)
603     {
604       USHORT &markFilteringSet = StructAfter<USHORT> (subTable);
605       if (!markFilteringSet.sanitize (c)) return TRACE_RETURN (false);
606     }
607     return TRACE_RETURN (true);
608   }
609 
610   USHORT	lookupType;		/* Different enumerations for GSUB and GPOS */
611   USHORT	lookupFlag;		/* Lookup qualifiers */
612   ArrayOf<Offset<> >
613 		subTable;		/* Array of SubTables */
614   USHORT	markFilteringSetX[VAR];	/* Index (base 0) into GDEF mark glyph sets
615 					 * structure. This field is only present if bit
616 					 * UseMarkFilteringSet of lookup flags is set. */
617   public:
618   DEFINE_SIZE_ARRAY2 (6, subTable, markFilteringSetX);
619 };
620 
621 typedef OffsetListOf<Lookup> LookupList;
622 
623 
624 /*
625  * Coverage Table
626  */
627 
628 struct CoverageFormat1
629 {
630   friend struct Coverage;
631 
632   private:
get_coverageOT::CoverageFormat1633   inline unsigned int get_coverage (hb_codepoint_t glyph_id) const
634   {
635     int i = glyphArray.bsearch (glyph_id);
636     ASSERT_STATIC (((unsigned int) -1) == NOT_COVERED);
637     return i;
638   }
639 
serializeOT::CoverageFormat1640   inline bool serialize (hb_serialize_context_t *c,
641 			 Supplier<GlyphID> &glyphs,
642 			 unsigned int num_glyphs)
643   {
644     TRACE_SERIALIZE (this);
645     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
646     glyphArray.len.set (num_glyphs);
647     if (unlikely (!c->extend (glyphArray))) return TRACE_RETURN (false);
648     for (unsigned int i = 0; i < num_glyphs; i++)
649       glyphArray[i] = glyphs[i];
650     glyphs.advance (num_glyphs);
651     return TRACE_RETURN (true);
652   }
653 
sanitizeOT::CoverageFormat1654   inline bool sanitize (hb_sanitize_context_t *c) {
655     TRACE_SANITIZE (this);
656     return TRACE_RETURN (glyphArray.sanitize (c));
657   }
658 
intersects_coverageOT::CoverageFormat1659   inline bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const {
660     return glyphs->has (glyphArray[index]);
661   }
662 
663   template <typename set_t>
add_coverageOT::CoverageFormat1664   inline void add_coverage (set_t *glyphs) const {
665     unsigned int count = glyphArray.len;
666     for (unsigned int i = 0; i < count; i++)
667       glyphs->add (glyphArray[i]);
668   }
669 
670   public:
671   /* Older compilers need this to be public. */
672   struct Iter {
initOT::CoverageFormat1::Iter673     inline void init (const struct CoverageFormat1 &c_) { c = &c_; i = 0; };
moreOT::CoverageFormat1::Iter674     inline bool more (void) { return i < c->glyphArray.len; }
nextOT::CoverageFormat1::Iter675     inline void next (void) { i++; }
get_glyphOT::CoverageFormat1::Iter676     inline uint16_t get_glyph (void) { return c->glyphArray[i]; }
get_coverageOT::CoverageFormat1::Iter677     inline uint16_t get_coverage (void) { return i; }
678 
679     private:
680     const struct CoverageFormat1 *c;
681     unsigned int i;
682   };
683   private:
684 
685   protected:
686   USHORT	coverageFormat;	/* Format identifier--format = 1 */
687   SortedArrayOf<GlyphID>
688 		glyphArray;	/* Array of GlyphIDs--in numerical order */
689   public:
690   DEFINE_SIZE_ARRAY (4, glyphArray);
691 };
692 
693 struct CoverageFormat2
694 {
695   friend struct Coverage;
696 
697   private:
get_coverageOT::CoverageFormat2698   inline unsigned int get_coverage (hb_codepoint_t glyph_id) const
699   {
700     int i = rangeRecord.bsearch (glyph_id);
701     if (i != -1) {
702       const RangeRecord &range = rangeRecord[i];
703       return (unsigned int) range.value + (glyph_id - range.start);
704     }
705     return NOT_COVERED;
706   }
707 
serializeOT::CoverageFormat2708   inline bool serialize (hb_serialize_context_t *c,
709 			 Supplier<GlyphID> &glyphs,
710 			 unsigned int num_glyphs)
711   {
712     TRACE_SERIALIZE (this);
713     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
714 
715     if (unlikely (!num_glyphs)) return TRACE_RETURN (true);
716 
717     unsigned int num_ranges = 1;
718     for (unsigned int i = 1; i < num_glyphs; i++)
719       if (glyphs[i - 1] + 1 != glyphs[i])
720         num_ranges++;
721     rangeRecord.len.set (num_ranges);
722     if (unlikely (!c->extend (rangeRecord))) return TRACE_RETURN (false);
723 
724     unsigned int range = 0;
725     rangeRecord[range].start = glyphs[0];
726     rangeRecord[range].value.set (0);
727     for (unsigned int i = 1; i < num_glyphs; i++)
728       if (glyphs[i - 1] + 1 != glyphs[i]) {
729 	range++;
730 	rangeRecord[range].start = glyphs[i];
731 	rangeRecord[range].value.set (i);
732         rangeRecord[range].end = glyphs[i];
733       } else {
734         rangeRecord[range].end = glyphs[i];
735       }
736     glyphs.advance (num_glyphs);
737     return TRACE_RETURN (true);
738   }
739 
sanitizeOT::CoverageFormat2740   inline bool sanitize (hb_sanitize_context_t *c) {
741     TRACE_SANITIZE (this);
742     return TRACE_RETURN (rangeRecord.sanitize (c));
743   }
744 
intersects_coverageOT::CoverageFormat2745   inline bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const {
746     unsigned int i;
747     unsigned int count = rangeRecord.len;
748     for (i = 0; i < count; i++) {
749       const RangeRecord &range = rangeRecord[i];
750       if (range.value <= index &&
751 	  index < (unsigned int) range.value + (range.end - range.start) &&
752 	  range.intersects (glyphs))
753         return true;
754       else if (index < range.value)
755         return false;
756     }
757     return false;
758   }
759 
760   template <typename set_t>
add_coverageOT::CoverageFormat2761   inline void add_coverage (set_t *glyphs) const {
762     unsigned int count = rangeRecord.len;
763     for (unsigned int i = 0; i < count; i++)
764       rangeRecord[i].add_coverage (glyphs);
765   }
766 
767   public:
768   /* Older compilers need this to be public. */
769   struct Iter {
initOT::CoverageFormat2::Iter770     inline void init (const CoverageFormat2 &c_) {
771       c = &c_;
772       coverage = 0;
773       i = 0;
774       j = c->rangeRecord.len ? c_.rangeRecord[0].start : 0;
775     }
moreOT::CoverageFormat2::Iter776     inline bool more (void) { return i < c->rangeRecord.len; }
nextOT::CoverageFormat2::Iter777     inline void next (void) {
778       coverage++;
779       if (j == c->rangeRecord[i].end) {
780         i++;
781 	if (more ())
782 	  j = c->rangeRecord[i].start;
783 	return;
784       }
785       j++;
786     }
get_glyphOT::CoverageFormat2::Iter787     inline uint16_t get_glyph (void) { return j; }
get_coverageOT::CoverageFormat2::Iter788     inline uint16_t get_coverage (void) { return coverage; }
789 
790     private:
791     const struct CoverageFormat2 *c;
792     unsigned int i, j, coverage;
793   };
794   private:
795 
796   protected:
797   USHORT	coverageFormat;	/* Format identifier--format = 2 */
798   SortedArrayOf<RangeRecord>
799 		rangeRecord;	/* Array of glyph ranges--ordered by
800 				 * Start GlyphID. rangeCount entries
801 				 * long */
802   public:
803   DEFINE_SIZE_ARRAY (4, rangeRecord);
804 };
805 
806 struct Coverage
807 {
get_coverageOT::Coverage808   inline unsigned int get_coverage (hb_codepoint_t glyph_id) const
809   {
810     switch (u.format) {
811     case 1: return u.format1.get_coverage(glyph_id);
812     case 2: return u.format2.get_coverage(glyph_id);
813     default:return NOT_COVERED;
814     }
815   }
816 
serializeOT::Coverage817   inline bool serialize (hb_serialize_context_t *c,
818 			 Supplier<GlyphID> &glyphs,
819 			 unsigned int num_glyphs)
820   {
821     TRACE_SERIALIZE (this);
822     if (unlikely (!c->extend_min (*this))) return TRACE_RETURN (false);
823     unsigned int num_ranges = 1;
824     for (unsigned int i = 1; i < num_glyphs; i++)
825       if (glyphs[i - 1] + 1 != glyphs[i])
826         num_ranges++;
827     u.format.set (num_glyphs * 2 < num_ranges * 3 ? 1 : 2);
828     switch (u.format) {
829     case 1: return TRACE_RETURN (u.format1.serialize (c, glyphs, num_glyphs));
830     case 2: return TRACE_RETURN (u.format2.serialize (c, glyphs, num_glyphs));
831     default:return TRACE_RETURN (false);
832     }
833   }
834 
sanitizeOT::Coverage835   inline bool sanitize (hb_sanitize_context_t *c) {
836     TRACE_SANITIZE (this);
837     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
838     switch (u.format) {
839     case 1: return TRACE_RETURN (u.format1.sanitize (c));
840     case 2: return TRACE_RETURN (u.format2.sanitize (c));
841     default:return TRACE_RETURN (true);
842     }
843   }
844 
intersectsOT::Coverage845   inline bool intersects (const hb_set_t *glyphs) const {
846     /* TODO speed this up */
847     Coverage::Iter iter;
848     for (iter.init (*this); iter.more (); iter.next ()) {
849       if (glyphs->has (iter.get_glyph ()))
850         return true;
851     }
852     return false;
853   }
854 
intersects_coverageOT::Coverage855   inline bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const {
856     switch (u.format) {
857     case 1: return u.format1.intersects_coverage (glyphs, index);
858     case 2: return u.format2.intersects_coverage (glyphs, index);
859     default:return false;
860     }
861   }
862 
863   template <typename set_t>
add_coverageOT::Coverage864   inline void add_coverage (set_t *glyphs) const {
865     switch (u.format) {
866     case 1: u.format1.add_coverage (glyphs); break;
867     case 2: u.format2.add_coverage (glyphs); break;
868     default:                                 break;
869     }
870   }
871 
872   struct Iter {
IterOT::Coverage::Iter873     Iter (void) : format (0) {};
initOT::Coverage::Iter874     inline void init (const Coverage &c_) {
875       format = c_.u.format;
876       switch (format) {
877       case 1: u.format1.init (c_.u.format1); return;
878       case 2: u.format2.init (c_.u.format2); return;
879       default:                               return;
880       }
881     }
moreOT::Coverage::Iter882     inline bool more (void) {
883       switch (format) {
884       case 1: return u.format1.more ();
885       case 2: return u.format2.more ();
886       default:return false;
887       }
888     }
nextOT::Coverage::Iter889     inline void next (void) {
890       switch (format) {
891       case 1: u.format1.next (); break;
892       case 2: u.format2.next (); break;
893       default:                   break;
894       }
895     }
get_glyphOT::Coverage::Iter896     inline uint16_t get_glyph (void) {
897       switch (format) {
898       case 1: return u.format1.get_glyph ();
899       case 2: return u.format2.get_glyph ();
900       default:return 0;
901       }
902     }
get_coverageOT::Coverage::Iter903     inline uint16_t get_coverage (void) {
904       switch (format) {
905       case 1: return u.format1.get_coverage ();
906       case 2: return u.format2.get_coverage ();
907       default:return -1;
908       }
909     }
910 
911     private:
912     unsigned int format;
913     union {
914     CoverageFormat1::Iter	format1;
915     CoverageFormat2::Iter	format2;
916     } u;
917   };
918 
919   protected:
920   union {
921   USHORT		format;		/* Format identifier */
922   CoverageFormat1	format1;
923   CoverageFormat2	format2;
924   } u;
925   public:
926   DEFINE_SIZE_UNION (2, format);
927 };
928 
929 
930 /*
931  * Class Definition Table
932  */
933 
934 struct ClassDefFormat1
935 {
936   friend struct ClassDef;
937 
938   private:
get_classOT::ClassDefFormat1939   inline unsigned int get_class (hb_codepoint_t glyph_id) const
940   {
941     if (unlikely ((unsigned int) (glyph_id - startGlyph) < classValue.len))
942       return classValue[glyph_id - startGlyph];
943     return 0;
944   }
945 
sanitizeOT::ClassDefFormat1946   inline bool sanitize (hb_sanitize_context_t *c) {
947     TRACE_SANITIZE (this);
948     return TRACE_RETURN (c->check_struct (this) && classValue.sanitize (c));
949   }
950 
951   template <typename set_t>
add_classOT::ClassDefFormat1952   inline void add_class (set_t *glyphs, unsigned int klass) const {
953     unsigned int count = classValue.len;
954     for (unsigned int i = 0; i < count; i++)
955       if (classValue[i] == klass)
956         glyphs->add (startGlyph + i);
957   }
958 
intersects_classOT::ClassDefFormat1959   inline bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const {
960     unsigned int count = classValue.len;
961     if (klass == 0)
962     {
963       /* Match if there's any glyph that is not listed! */
964       hb_codepoint_t g = -1;
965       if (!hb_set_next (glyphs, &g))
966         return false;
967       if (g < startGlyph)
968         return true;
969       g = startGlyph + count - 1;
970       if (hb_set_next (glyphs, &g))
971         return true;
972       /* Fall through. */
973     }
974     for (unsigned int i = 0; i < count; i++)
975       if (classValue[i] == klass && glyphs->has (startGlyph + i))
976         return true;
977     return false;
978   }
979 
980   protected:
981   USHORT	classFormat;		/* Format identifier--format = 1 */
982   GlyphID	startGlyph;		/* First GlyphID of the classValueArray */
983   ArrayOf<USHORT>
984 		classValue;		/* Array of Class Values--one per GlyphID */
985   public:
986   DEFINE_SIZE_ARRAY (6, classValue);
987 };
988 
989 struct ClassDefFormat2
990 {
991   friend struct ClassDef;
992 
993   private:
get_classOT::ClassDefFormat2994   inline unsigned int get_class (hb_codepoint_t glyph_id) const
995   {
996     int i = rangeRecord.bsearch (glyph_id);
997     if (i != -1)
998       return rangeRecord[i].value;
999     return 0;
1000   }
1001 
sanitizeOT::ClassDefFormat21002   inline bool sanitize (hb_sanitize_context_t *c) {
1003     TRACE_SANITIZE (this);
1004     return TRACE_RETURN (rangeRecord.sanitize (c));
1005   }
1006 
1007   template <typename set_t>
add_classOT::ClassDefFormat21008   inline void add_class (set_t *glyphs, unsigned int klass) const {
1009     unsigned int count = rangeRecord.len;
1010     for (unsigned int i = 0; i < count; i++)
1011       if (rangeRecord[i].value == klass)
1012         rangeRecord[i].add_coverage (glyphs);
1013   }
1014 
intersects_classOT::ClassDefFormat21015   inline bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const {
1016     unsigned int count = rangeRecord.len;
1017     if (klass == 0)
1018     {
1019       /* Match if there's any glyph that is not listed! */
1020       hb_codepoint_t g = (hb_codepoint_t) -1;
1021       for (unsigned int i = 0; i < count; i++)
1022       {
1023 	if (!hb_set_next (glyphs, &g))
1024 	  break;
1025 	if (g < rangeRecord[i].start)
1026 	  return true;
1027 	g = rangeRecord[i].end;
1028       }
1029       if (g != (hb_codepoint_t) -1 && hb_set_next (glyphs, &g))
1030         return true;
1031       /* Fall through. */
1032     }
1033     for (unsigned int i = 0; i < count; i++)
1034       if (rangeRecord[i].value == klass && rangeRecord[i].intersects (glyphs))
1035         return true;
1036     return false;
1037   }
1038 
1039   protected:
1040   USHORT	classFormat;	/* Format identifier--format = 2 */
1041   SortedArrayOf<RangeRecord>
1042 		rangeRecord;	/* Array of glyph ranges--ordered by
1043 				 * Start GlyphID */
1044   public:
1045   DEFINE_SIZE_ARRAY (4, rangeRecord);
1046 };
1047 
1048 struct ClassDef
1049 {
get_classOT::ClassDef1050   inline unsigned int get_class (hb_codepoint_t glyph_id) const
1051   {
1052     switch (u.format) {
1053     case 1: return u.format1.get_class(glyph_id);
1054     case 2: return u.format2.get_class(glyph_id);
1055     default:return 0;
1056     }
1057   }
1058 
sanitizeOT::ClassDef1059   inline bool sanitize (hb_sanitize_context_t *c) {
1060     TRACE_SANITIZE (this);
1061     if (!u.format.sanitize (c)) return TRACE_RETURN (false);
1062     switch (u.format) {
1063     case 1: return TRACE_RETURN (u.format1.sanitize (c));
1064     case 2: return TRACE_RETURN (u.format2.sanitize (c));
1065     default:return TRACE_RETURN (true);
1066     }
1067   }
1068 
add_classOT::ClassDef1069   inline void add_class (hb_set_t *glyphs, unsigned int klass) const {
1070     switch (u.format) {
1071     case 1: u.format1.add_class (glyphs, klass); return;
1072     case 2: u.format2.add_class (glyphs, klass); return;
1073     default:return;
1074     }
1075   }
1076 
intersects_classOT::ClassDef1077   inline bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const {
1078     switch (u.format) {
1079     case 1: return u.format1.intersects_class (glyphs, klass);
1080     case 2: return u.format2.intersects_class (glyphs, klass);
1081     default:return false;
1082     }
1083   }
1084 
1085   protected:
1086   union {
1087   USHORT		format;		/* Format identifier */
1088   ClassDefFormat1	format1;
1089   ClassDefFormat2	format2;
1090   } u;
1091   public:
1092   DEFINE_SIZE_UNION (2, format);
1093 };
1094 
1095 
1096 /*
1097  * Device Tables
1098  */
1099 
1100 struct Device
1101 {
1102 
get_x_deltaOT::Device1103   inline hb_position_t get_x_delta (hb_font_t *font) const
1104   { return get_delta (font->x_ppem, font->x_scale); }
1105 
get_y_deltaOT::Device1106   inline hb_position_t get_y_delta (hb_font_t *font) const
1107   { return get_delta (font->y_ppem, font->y_scale); }
1108 
get_deltaOT::Device1109   inline int get_delta (unsigned int ppem, int scale) const
1110   {
1111     if (!ppem) return 0;
1112 
1113     int pixels = get_delta_pixels (ppem);
1114 
1115     if (!pixels) return 0;
1116 
1117     return (int) (pixels * (int64_t) scale / ppem);
1118   }
1119 
1120 
get_delta_pixelsOT::Device1121   inline int get_delta_pixels (unsigned int ppem_size) const
1122   {
1123     unsigned int f = deltaFormat;
1124     if (unlikely (f < 1 || f > 3))
1125       return 0;
1126 
1127     if (ppem_size < startSize || ppem_size > endSize)
1128       return 0;
1129 
1130     unsigned int s = ppem_size - startSize;
1131 
1132     unsigned int byte = deltaValue[s >> (4 - f)];
1133     unsigned int bits = (byte >> (16 - (((s & ((1 << (4 - f)) - 1)) + 1) << f)));
1134     unsigned int mask = (0xFFFFu >> (16 - (1 << f)));
1135 
1136     int delta = bits & mask;
1137 
1138     if ((unsigned int) delta >= ((mask + 1) >> 1))
1139       delta -= mask + 1;
1140 
1141     return delta;
1142   }
1143 
get_sizeOT::Device1144   inline unsigned int get_size (void) const
1145   {
1146     unsigned int f = deltaFormat;
1147     if (unlikely (f < 1 || f > 3 || startSize > endSize)) return 3 * USHORT::static_size;
1148     return USHORT::static_size * (4 + ((endSize - startSize) >> (4 - f)));
1149   }
1150 
sanitizeOT::Device1151   inline bool sanitize (hb_sanitize_context_t *c) {
1152     TRACE_SANITIZE (this);
1153     return TRACE_RETURN (c->check_struct (this) && c->check_range (this, this->get_size ()));
1154   }
1155 
1156   protected:
1157   USHORT	startSize;		/* Smallest size to correct--in ppem */
1158   USHORT	endSize;		/* Largest size to correct--in ppem */
1159   USHORT	deltaFormat;		/* Format of DeltaValue array data: 1, 2, or 3
1160 					 * 1	Signed 2-bit value, 8 values per uint16
1161 					 * 2	Signed 4-bit value, 4 values per uint16
1162 					 * 3	Signed 8-bit value, 2 values per uint16
1163 					 */
1164   USHORT	deltaValue[VAR];	/* Array of compressed data */
1165   public:
1166   DEFINE_SIZE_ARRAY (6, deltaValue);
1167 };
1168 
1169 
1170 } /* namespace OT */
1171 
1172 
1173 #endif /* HB_OT_LAYOUT_COMMON_PRIVATE_HH */
1174