1/*
2 * Copyright © 2007,2008,2009,2010 Red Hat, Inc.
3 * Copyright © 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_OPEN_TYPE_HH
30#define HB_OPEN_TYPE_HH
31
32#include "hb.hh"
33#include "hb-blob.hh"
34#include "hb-face.hh"
35#include "hb-machinery.hh"
36#include "hb-subset.hh"
37
38
39namespace OT {
40
41
42/*
43 *
44 * The OpenType Font File: Data Types
45 */
46
47
48/* "The following data types are used in the OpenType font file.
49 * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */
50
51/*
52 * Int types
53 */
54
55/* Integer types in big-endian order and no alignment requirement */
56template <typename Type, unsigned int Size>
57struct IntType
58{
59 inline void set (Type i) { v.set (i); }
60 inline operator Type(void) const { return v; }
61 inline bool operator == (const IntType<Type,Size> &o) const { return (Type) v == (Type) o.v; }
62 inline bool operator != (const IntType<Type,Size> &o) const { return !(*this == o); }
63 static inline int cmp (const IntType<Type,Size> *a, const IntType<Type,Size> *b) { return b->cmp (*a); }
64 template <typename Type2>
65 inline int cmp (Type2 a) const
66 {
67 Type b = v;
68 if (sizeof (Type) < sizeof (int) && sizeof (Type2) < sizeof (int))
69 return (int) a - (int) b;
70 else
71 return a < b ? -1 : a == b ? 0 : +1;
72 }
73 inline bool sanitize (hb_sanitize_context_t *c) const
74 {
75 TRACE_SANITIZE (this);
76 return_trace (likely (c->check_struct (this)));
77 }
78 protected:
79 BEInt<Type, Size> v;
80 public:
81 DEFINE_SIZE_STATIC (Size);
82};
83
84typedef IntType<uint8_t, 1> HBUINT8; /* 8-bit unsigned integer. */
85typedef IntType<int8_t, 1> HBINT8; /* 8-bit signed integer. */
86typedef IntType<uint16_t, 2> HBUINT16; /* 16-bit unsigned integer. */
87typedef IntType<int16_t, 2> HBINT16; /* 16-bit signed integer. */
88typedef IntType<uint32_t, 4> HBUINT32; /* 32-bit unsigned integer. */
89typedef IntType<int32_t, 4> HBINT32; /* 32-bit signed integer. */
90typedef IntType<uint32_t, 3> HBUINT24; /* 24-bit unsigned integer. */
91
92/* 16-bit signed integer (HBINT16) that describes a quantity in FUnits. */
93typedef HBINT16 FWORD;
94
95/* 16-bit unsigned integer (HBUINT16) that describes a quantity in FUnits. */
96typedef HBUINT16 UFWORD;
97
98/* 16-bit signed fixed number with the low 14 bits of fraction (2.14). */
99struct F2DOT14 : HBINT16
100{
101 // 16384 means 1<<14
102 inline float to_float (void) const { return ((int32_t) v) / 16384.f; }
103 inline void set_float (float f) { v.set (round (f * 16384.f)); }
104 public:
105 DEFINE_SIZE_STATIC (2);
106};
107
108/* 32-bit signed fixed-point number (16.16). */
109struct Fixed : HBINT32
110{
111 // 65536 means 1<<16
112 inline float to_float (void) const { return ((int32_t) v) / 65536.f; }
113 inline void set_float (float f) { v.set (round (f * 65536.f)); }
114 public:
115 DEFINE_SIZE_STATIC (4);
116};
117
118/* Date represented in number of seconds since 12:00 midnight, January 1,
119 * 1904. The value is represented as a signed 64-bit integer. */
120struct LONGDATETIME
121{
122 inline bool sanitize (hb_sanitize_context_t *c) const
123 {
124 TRACE_SANITIZE (this);
125 return_trace (likely (c->check_struct (this)));
126 }
127 protected:
128 HBINT32 major;
129 HBUINT32 minor;
130 public:
131 DEFINE_SIZE_STATIC (8);
132};
133
134/* Array of four uint8s (length = 32 bits) used to identify a script, language
135 * system, feature, or baseline */
136struct Tag : HBUINT32
137{
138 /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */
139 inline operator const char* (void) const { return reinterpret_cast<const char *> (&this->v); }
140 inline operator char* (void) { return reinterpret_cast<char *> (&this->v); }
141 public:
142 DEFINE_SIZE_STATIC (4);
143};
144
145/* Glyph index number, same as uint16 (length = 16 bits) */
146typedef HBUINT16 GlyphID;
147
148/* Name-table index, same as uint16 (length = 16 bits) */
149typedef HBUINT16 NameID;
150
151/* Script/language-system/feature index */
152struct Index : HBUINT16 {
153 enum { NOT_FOUND_INDEX = 0xFFFFu };
154};
155DECLARE_NULL_NAMESPACE_BYTES (OT, Index);
156
157/* Offset, Null offset = 0 */
158template <typename Type>
159struct Offset : Type
160{
161 inline bool is_null (void) const { return 0 == *this; }
162
163 inline void *serialize (hb_serialize_context_t *c, const void *base)
164 {
165 void *t = c->start_embed<void> ();
166 this->set ((char *) t - (char *) base); /* TODO(serialize) Overflow? */
167 return t;
168 }
169
170 public:
171 DEFINE_SIZE_STATIC (sizeof(Type));
172};
173
174typedef Offset<HBUINT16> Offset16;
175typedef Offset<HBUINT32> Offset32;
176
177
178/* CheckSum */
179struct CheckSum : HBUINT32
180{
181 /* This is reference implementation from the spec. */
182 static inline uint32_t CalcTableChecksum (const HBUINT32 *Table, uint32_t Length)
183 {
184 uint32_t Sum = 0L;
185 assert (0 == (Length & 3));
186 const HBUINT32 *EndPtr = Table + Length / HBUINT32::static_size;
187
188 while (Table < EndPtr)
189 Sum += *Table++;
190 return Sum;
191 }
192
193 /* Note: data should be 4byte aligned and have 4byte padding at the end. */
194 inline void set_for_data (const void *data, unsigned int length)
195 { set (CalcTableChecksum ((const HBUINT32 *) data, length)); }
196
197 public:
198 DEFINE_SIZE_STATIC (4);
199};
200
201
202/*
203 * Version Numbers
204 */
205
206template <typename FixedType=HBUINT16>
207struct FixedVersion
208{
209 inline uint32_t to_int (void) const { return (major << (sizeof(FixedType) * 8)) + minor; }
210
211 inline bool sanitize (hb_sanitize_context_t *c) const
212 {
213 TRACE_SANITIZE (this);
214 return_trace (c->check_struct (this));
215 }
216
217 FixedType major;
218 FixedType minor;
219 public:
220 DEFINE_SIZE_STATIC (2 * sizeof(FixedType));
221};
222
223
224/*
225 * Template subclasses of Offset that do the dereferencing.
226 * Use: (base+offset)
227 */
228
229template <typename Type, typename OffsetType=HBUINT16>
230struct OffsetTo : Offset<OffsetType>
231{
232 inline const Type& operator () (const void *base) const
233 {
234 unsigned int offset = *this;
235 if (unlikely (!offset)) return Null(Type);
236 return StructAtOffset<const Type> (base, offset);
237 }
238 inline Type& operator () (void *base) const
239 {
240 unsigned int offset = *this;
241 if (unlikely (!offset)) return Crap(Type);
242 return StructAtOffset<Type> (base, offset);
243 }
244
245 inline Type& serialize (hb_serialize_context_t *c, const void *base)
246 {
247 return * (Type *) Offset<OffsetType>::serialize (c, base);
248 }
249
250 template <typename T>
251 inline void serialize_subset (hb_subset_context_t *c, const T &src, const void *base)
252 {
253 if (&src == &Null(T))
254 {
255 this->set (0);
256 return;
257 }
258 serialize (c->serializer, base);
259 if (!src.subset (c))
260 this->set (0);
261 }
262
263 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
264 {
265 TRACE_SANITIZE (this);
266 if (unlikely (!c->check_struct (this))) return_trace (false);
267 unsigned int offset = *this;
268 if (unlikely (!offset)) return_trace (true);
269 if (unlikely (!c->check_range (base, offset))) return_trace (false);
270 const Type &obj = StructAtOffset<Type> (base, offset);
271 return_trace (likely (obj.sanitize (c)) || neuter (c));
272 }
273 template <typename T>
274 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
275 {
276 TRACE_SANITIZE (this);
277 if (unlikely (!c->check_struct (this))) return_trace (false);
278 unsigned int offset = *this;
279 if (unlikely (!offset)) return_trace (true);
280 if (unlikely (!c->check_range (base, offset))) return_trace (false);
281 const Type &obj = StructAtOffset<Type> (base, offset);
282 return_trace (likely (obj.sanitize (c, user_data)) || neuter (c));
283 }
284
285 /* Set the offset to Null */
286 inline bool neuter (hb_sanitize_context_t *c) const {
287 return c->try_set (this, 0);
288 }
289 DEFINE_SIZE_STATIC (sizeof(OffsetType));
290};
291template <typename Type> struct LOffsetTo : OffsetTo<Type, HBUINT32> {};
292template <typename Base, typename OffsetType, typename Type>
293static inline const Type& operator + (const Base &base, const OffsetTo<Type, OffsetType> &offset) { return offset (base); }
294template <typename Base, typename OffsetType, typename Type>
295static inline Type& operator + (Base &base, OffsetTo<Type, OffsetType> &offset) { return offset (base); }
296
297
298/*
299 * Array Types
300 */
301
302/* TODO Use it in ArrayOf, HeadlessArrayOf, and other places around the code base?? */
303template <typename Type>
304struct UnsizedArrayOf
305{
306 inline const Type& operator [] (unsigned int i) const { return arrayZ[i]; }
307 inline Type& operator [] (unsigned int i) { return arrayZ[i]; }
308
309 inline bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
310 {
311 TRACE_SANITIZE (this);
312 if (unlikely (!sanitize_shallow (c, count))) return_trace (false);
313
314 /* Note: for structs that do not reference other structs,
315 * we do not need to call their sanitize() as we already did
316 * a bound check on the aggregate array size. We just include
317 * a small unreachable expression to make sure the structs
318 * pointed to do have a simple sanitize(), ie. they do not
319 * reference other structs via offsets.
320 */
321 (void) (false && arrayZ[0].sanitize (c));
322
323 return_trace (true);
324 }
325 inline bool sanitize (hb_sanitize_context_t *c, unsigned int count, const void *base) const
326 {
327 TRACE_SANITIZE (this);
328 if (unlikely (!sanitize_shallow (c, count))) return_trace (false);
329 for (unsigned int i = 0; i < count; i++)
330 if (unlikely (!arrayZ[i].sanitize (c, base)))
331 return_trace (false);
332 return_trace (true);
333 }
334 template <typename T>
335 inline bool sanitize (hb_sanitize_context_t *c, unsigned int count, const void *base, T user_data) const
336 {
337 TRACE_SANITIZE (this);
338 if (unlikely (!sanitize_shallow (c, count))) return_trace (false);
339 for (unsigned int i = 0; i < count; i++)
340 if (unlikely (!arrayZ[i].sanitize (c, base, user_data)))
341 return_trace (false);
342 return_trace (true);
343 }
344
345 inline bool sanitize_shallow (hb_sanitize_context_t *c, unsigned int count) const
346 {
347 TRACE_SANITIZE (this);
348 return_trace (c->check_array (arrayZ, arrayZ[0].static_size, count));
349 }
350
351 public:
352 Type arrayZ[VAR];
353 public:
354 DEFINE_SIZE_ARRAY (0, arrayZ);
355};
356
357/* Unsized array of offset's */
358template <typename Type, typename OffsetType>
359struct UnsizedOffsetArrayOf : UnsizedArrayOf<OffsetTo<Type, OffsetType> > {};
360
361/* Unsized array of offsets relative to the beginning of the array itself. */
362template <typename Type, typename OffsetType>
363struct UnsizedOffsetListOf : UnsizedOffsetArrayOf<Type, OffsetType>
364{
365 inline const Type& operator [] (unsigned int i) const
366 {
367 return this+this->arrayZ[i];
368 }
369
370 inline bool sanitize (hb_sanitize_context_t *c, unsigned int count) const
371 {
372 TRACE_SANITIZE (this);
373 return_trace ((UnsizedOffsetArrayOf<Type, OffsetType>::sanitize (c, count, this)));
374 }
375 template <typename T>
376 inline bool sanitize (hb_sanitize_context_t *c, unsigned int count, T user_data) const
377 {
378 TRACE_SANITIZE (this);
379 return_trace ((UnsizedOffsetArrayOf<Type, OffsetType>::sanitize (c, count, this, user_data)));
380 }
381};
382
383/* An array with a number of elements. */
384template <typename Type, typename LenType=HBUINT16>
385struct ArrayOf
386{
387 const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const
388 {
389 unsigned int count = len;
390 if (unlikely (start_offset > count))
391 count = 0;
392 else
393 count -= start_offset;
394 count = MIN (count, *pcount);
395 *pcount = count;
396 return arrayZ + start_offset;
397 }
398
399 inline const Type& operator [] (unsigned int i) const
400 {
401 if (unlikely (i >= len)) return Null(Type);
402 return arrayZ[i];
403 }
404 inline Type& operator [] (unsigned int i)
405 {
406 if (unlikely (i >= len)) return Crap(Type);
407 return arrayZ[i];
408 }
409 inline unsigned int get_size (void) const
410 { return len.static_size + len * Type::static_size; }
411
412 inline bool serialize (hb_serialize_context_t *c,
413 unsigned int items_len)
414 {
415 TRACE_SERIALIZE (this);
416 if (unlikely (!c->extend_min (*this))) return_trace (false);
417 len.set (items_len); /* TODO(serialize) Overflow? */
418 if (unlikely (!c->extend (*this))) return_trace (false);
419 return_trace (true);
420 }
421 inline bool serialize (hb_serialize_context_t *c,
422 Supplier<Type> &items,
423 unsigned int items_len)
424 {
425 TRACE_SERIALIZE (this);
426 if (unlikely (!serialize (c, items_len))) return_trace (false);
427 for (unsigned int i = 0; i < items_len; i++)
428 arrayZ[i] = items[i];
429 items += items_len;
430 return_trace (true);
431 }
432
433 inline bool sanitize (hb_sanitize_context_t *c) const
434 {
435 TRACE_SANITIZE (this);
436 if (unlikely (!sanitize_shallow (c))) return_trace (false);
437
438 /* Note: for structs that do not reference other structs,
439 * we do not need to call their sanitize() as we already did
440 * a bound check on the aggregate array size. We just include
441 * a small unreachable expression to make sure the structs
442 * pointed to do have a simple sanitize(), ie. they do not
443 * reference other structs via offsets.
444 */
445 (void) (false && arrayZ[0].sanitize (c));
446
447 return_trace (true);
448 }
449 inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
450 {
451 TRACE_SANITIZE (this);
452 if (unlikely (!sanitize_shallow (c))) return_trace (false);
453 unsigned int count = len;
454 for (unsigned int i = 0; i < count; i++)
455 if (unlikely (!arrayZ[i].sanitize (c, base)))
456 return_trace (false);
457 return_trace (true);
458 }
459 template <typename T>
460 inline bool sanitize (hb_sanitize_context_t *c, const void *base, T user_data) const
461 {
462 TRACE_SANITIZE (this);
463 if (unlikely (!sanitize_shallow (c))) return_trace (false);
464 unsigned int count = len;
465 for (unsigned int i = 0; i < count; i++)
466 if (unlikely (!arrayZ[i].sanitize (c, base, user_data)))
467 return_trace (false);
468 return_trace (true);
469 }
470
471 template <typename SearchType>
472 inline int lsearch (const SearchType &x) const
473 {
474 unsigned int count = len;
475 for (unsigned int i = 0; i < count; i++)
476 if (!this->arrayZ[i].cmp (x))
477 return i;
478 return -1;
479 }
480
481 inline void qsort (void)
482 {
483 ::qsort (arrayZ, len, sizeof (Type), Type::cmp);
484 }
485
486 private:
487 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
488 {
489 TRACE_SANITIZE (this);
490 return_trace (len.sanitize (c) && c->check_array (arrayZ, Type::static_size, len));
491 }
492
493 public:
494 LenType len;
495 Type arrayZ[VAR];
496 public:
497 DEFINE_SIZE_ARRAY (sizeof (LenType), arrayZ);
498};
499template <typename Type> struct LArrayOf : ArrayOf<Type, HBUINT32> {};
500typedef ArrayOf<HBUINT8, HBUINT8> PString;
501
502/* Array of Offset's */
503template <typename Type, typename OffsetType=HBUINT16>
504struct OffsetArrayOf : ArrayOf<OffsetTo<Type, OffsetType> > {};
505
506/* Array of offsets relative to the beginning of the array itself. */
507template <typename Type>
508struct OffsetListOf : OffsetArrayOf<Type>
509{
510 inline const Type& operator [] (unsigned int i) const
511 {
512 if (unlikely (i >= this->len)) return Null(Type);
513 return this+this->arrayZ[i];
514 }
515 inline const Type& operator [] (unsigned int i)
516 {
517 if (unlikely (i >= this->len)) return Crap(Type);
518 return this+this->arrayZ[i];
519 }
520
521 inline bool subset (hb_subset_context_t *c) const
522 {
523 TRACE_SUBSET (this);
524 struct OffsetListOf<Type> *out = c->serializer->embed (*this);
525 if (unlikely (!out)) return_trace (false);
526 unsigned int count = this->len;
527 for (unsigned int i = 0; i < count; i++)
528 out->arrayZ[i].serialize_subset (c, (*this)[i], out);
529 return_trace (true);
530 }
531
532 inline bool sanitize (hb_sanitize_context_t *c) const
533 {
534 TRACE_SANITIZE (this);
535 return_trace (OffsetArrayOf<Type>::sanitize (c, this));
536 }
537 template <typename T>
538 inline bool sanitize (hb_sanitize_context_t *c, T user_data) const
539 {
540 TRACE_SANITIZE (this);
541 return_trace (OffsetArrayOf<Type>::sanitize (c, this, user_data));
542 }
543};
544
545/* An array starting at second element. */
546template <typename Type, typename LenType=HBUINT16>
547struct HeadlessArrayOf
548{
549 inline const Type& operator [] (unsigned int i) const
550 {
551 if (unlikely (i >= len || !i)) return Null(Type);
552 return arrayZ[i-1];
553 }
554 inline Type& operator [] (unsigned int i)
555 {
556 if (unlikely (i >= len || !i)) return Crap(Type);
557 return arrayZ[i-1];
558 }
559 inline unsigned int get_size (void) const
560 { return len.static_size + (len ? len - 1 : 0) * Type::static_size; }
561
562 inline bool serialize (hb_serialize_context_t *c,
563 Supplier<Type> &items,
564 unsigned int items_len)
565 {
566 TRACE_SERIALIZE (this);
567 if (unlikely (!c->extend_min (*this))) return_trace (false);
568 len.set (items_len); /* TODO(serialize) Overflow? */
569 if (unlikely (!items_len)) return_trace (true);
570 if (unlikely (!c->extend (*this))) return_trace (false);
571 for (unsigned int i = 0; i < items_len - 1; i++)
572 arrayZ[i] = items[i];
573 items += items_len - 1;
574 return_trace (true);
575 }
576
577 inline bool sanitize (hb_sanitize_context_t *c) const
578 {
579 TRACE_SANITIZE (this);
580 if (unlikely (!sanitize_shallow (c))) return_trace (false);
581
582 /* Note: for structs that do not reference other structs,
583 * we do not need to call their sanitize() as we already did
584 * a bound check on the aggregate array size. We just include
585 * a small unreachable expression to make sure the structs
586 * pointed to do have a simple sanitize(), ie. they do not
587 * reference other structs via offsets.
588 */
589 (void) (false && arrayZ[0].sanitize (c));
590
591 return_trace (true);
592 }
593
594 private:
595 inline bool sanitize_shallow (hb_sanitize_context_t *c) const
596 {
597 TRACE_SANITIZE (this);
598 return_trace (len.sanitize (c) &&
599 (!len || c->check_array (arrayZ, Type::static_size, len - 1)));
600 }
601
602 public:
603 LenType len;
604 Type arrayZ[VAR];
605 public:
606 DEFINE_SIZE_ARRAY (sizeof (LenType), arrayZ);
607};
608
609/* An array with sorted elements. Supports binary searching. */
610template <typename Type, typename LenType=HBUINT16>
611struct SortedArrayOf : ArrayOf<Type, LenType>
612{
613 template <typename SearchType>
614 inline int bsearch (const SearchType &x) const
615 {
616 /* Hand-coded bsearch here since this is in the hot inner loop. */
617 const Type *arr = this->arrayZ;
618 int min = 0, max = (int) this->len - 1;
619 while (min <= max)
620 {
621 int mid = (min + max) / 2;
622 int c = arr[mid].cmp (x);
623 if (c < 0)
624 max = mid - 1;
625 else if (c > 0)
626 min = mid + 1;
627 else
628 return mid;
629 }
630 return -1;
631 }
632};
633
634/* Binary-search arrays */
635struct BinSearchHeader
636{
637 inline operator uint32_t (void) const { return len; }
638
639 inline bool sanitize (hb_sanitize_context_t *c) const
640 {
641 TRACE_SANITIZE (this);
642 return_trace (c->check_struct (this));
643 }
644
645 inline void set (unsigned int v)
646 {
647 len.set (v);
648 assert (len == v);
649 entrySelector.set (MAX (1u, hb_bit_storage (v)) - 1);
650 searchRange.set (16 * (1u << entrySelector));
651 rangeShift.set (v * 16 > searchRange
652 ? 16 * v - searchRange
653 : 0);
654 }
655
656 protected:
657 HBUINT16 len;
658 HBUINT16 searchRange;
659 HBUINT16 entrySelector;
660 HBUINT16 rangeShift;
661
662 public:
663 DEFINE_SIZE_STATIC (8);
664};
665
666template <typename Type>
667struct BinSearchArrayOf : SortedArrayOf<Type, BinSearchHeader> {};
668
669
670} /* namespace OT */
671
672
673#endif /* HB_OPEN_TYPE_HH */
674