1/*
2 * Copyright © 2015 Google, Inc.
3 * Copyright © 2019 Adobe Inc.
4 * Copyright © 2019 Ebrahim Byagowi
5 *
6 * This is part of HarfBuzz, a text shaping library.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Google Author(s): Behdad Esfahbod, Garret Rieger, Roderick Sheeter
27 * Adobe Author(s): Michiharu Ariza
28 */
29
30#ifndef HB_OT_GLYF_TABLE_HH
31#define HB_OT_GLYF_TABLE_HH
32
33#include "hb-open-type.hh"
34#include "hb-ot-head-table.hh"
35#include "hb-ot-hmtx-table.hh"
36#include "hb-ot-var-gvar-table.hh"
37#include "hb-draw.hh"
38
39namespace OT {
40
41
42/*
43 * loca -- Index to Location
44 * https://docs.microsoft.com/en-us/typography/opentype/spec/loca
45 */
46#define HB_OT_TAG_loca HB_TAG('l','o','c','a')
47
48
49struct loca
50{
51 friend struct glyf;
52
53 static constexpr hb_tag_t tableTag = HB_OT_TAG_loca;
54
55 bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
56 {
57 TRACE_SANITIZE (this);
58 return_trace (true);
59 }
60
61 protected:
62 UnsizedArrayOf<HBUINT8>
63 dataZ; /* Location data. */
64 public:
65 DEFINE_SIZE_MIN (0); /* In reality, this is UNBOUNDED() type; but since we always
66 * check the size externally, allow Null() object of it by
67 * defining it _MIN instead. */
68};
69
70
71/*
72 * glyf -- TrueType Glyph Data
73 * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf
74 */
75#define HB_OT_TAG_glyf HB_TAG('g','l','y','f')
76
77
78struct glyf
79{
80 static constexpr hb_tag_t tableTag = HB_OT_TAG_glyf;
81
82 bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const
83 {
84 TRACE_SANITIZE (this);
85 /* Runtime checks as eager sanitizing each glyph is costy */
86 return_trace (true);
87 }
88
89 template<typename Iterator,
90 hb_requires (hb_is_source_of (Iterator, unsigned int))>
91 static bool
92 _add_loca_and_head (hb_subset_plan_t * plan, Iterator padded_offsets)
93 {
94 unsigned max_offset = + padded_offsets | hb_reduce(hb_add, 0);
95 unsigned num_offsets = padded_offsets.len () + 1;
96 bool use_short_loca = max_offset < 0x1FFFF;
97 unsigned entry_size = use_short_loca ? 2 : 4;
98 char *loca_prime_data = (char *) calloc (entry_size, num_offsets);
99
100 if (unlikely (!loca_prime_data)) return false;
101
102 DEBUG_MSG (SUBSET, nullptr, "loca entry_size %d num_offsets %d "
103 "max_offset %d size %d",
104 entry_size, num_offsets, max_offset, entry_size * num_offsets);
105
106 if (use_short_loca)
107 _write_loca (padded_offsets, 1, hb_array ((HBUINT16*) loca_prime_data, num_offsets));
108 else
109 _write_loca (padded_offsets, 0, hb_array ((HBUINT32*) loca_prime_data, num_offsets));
110
111 hb_blob_t * loca_blob = hb_blob_create (loca_prime_data,
112 entry_size * num_offsets,
113 HB_MEMORY_MODE_WRITABLE,
114 loca_prime_data,
115 free);
116
117 bool result = plan->add_table (HB_OT_TAG_loca, loca_blob)
118 && _add_head_and_set_loca_version (plan, use_short_loca);
119
120 hb_blob_destroy (loca_blob);
121 return result;
122 }
123
124 template<typename IteratorIn, typename IteratorOut,
125 hb_requires (hb_is_source_of (IteratorIn, unsigned int)),
126 hb_requires (hb_is_sink_of (IteratorOut, unsigned))>
127 static void
128 _write_loca (IteratorIn it, unsigned right_shift, IteratorOut dest)
129 {
130 unsigned int offset = 0;
131 dest << 0;
132 + it
133 | hb_map ([=, &offset] (unsigned int padded_size)
134 {
135 offset += padded_size;
136 DEBUG_MSG (SUBSET, nullptr, "loca entry offset %d", offset);
137 return offset >> right_shift;
138 })
139 | hb_sink (dest)
140 ;
141 }
142
143 /* requires source of SubsetGlyph complains the identifier isn't declared */
144 template <typename Iterator>
145 bool serialize (hb_serialize_context_t *c,
146 Iterator it,
147 const hb_subset_plan_t *plan)
148 {
149 TRACE_SERIALIZE (this);
150 unsigned init_len = c->length ();
151 for (const auto &_ : it) _.serialize (c, plan);
152
153 /* As a special case when all glyph in the font are empty, add a zero byte
154 * to the table, so that OTS doesn’t reject it, and to make the table work
155 * on Windows as well.
156 * See https://github.com/khaledhosny/ots/issues/52 */
157 if (init_len == c->length ())
158 {
159 HBUINT8 empty_byte;
160 empty_byte = 0;
161 c->copy (empty_byte);
162 }
163 return_trace (true);
164 }
165
166 /* Byte region(s) per glyph to output
167 unpadded, hints removed if so requested
168 If we fail to process a glyph we produce an empty (0-length) glyph */
169 bool subset (hb_subset_context_t *c) const
170 {
171 TRACE_SUBSET (this);
172
173 glyf *glyf_prime = c->serializer->start_embed <glyf> ();
174 if (unlikely (!c->serializer->check_success (glyf_prime))) return_trace (false);
175
176 hb_vector_t<SubsetGlyph> glyphs;
177 _populate_subset_glyphs (c->plan, &glyphs);
178
179 glyf_prime->serialize (c->serializer, hb_iter (glyphs), c->plan);
180
181 auto padded_offsets =
182 + hb_iter (glyphs)
183 | hb_map (&SubsetGlyph::padded_size)
184 ;
185
186 if (c->serializer->in_error ()) return_trace (false);
187 return_trace (c->serializer->check_success (_add_loca_and_head (c->plan,
188 padded_offsets)));
189 }
190
191 template <typename SubsetGlyph>
192 void
193 _populate_subset_glyphs (const hb_subset_plan_t *plan,
194 hb_vector_t<SubsetGlyph> *glyphs /* OUT */) const
195 {
196 OT::glyf::accelerator_t glyf;
197 glyf.init (plan->source);
198
199 + hb_range (plan->num_output_glyphs ())
200 | hb_map ([&] (hb_codepoint_t new_gid)
201 {
202 SubsetGlyph subset_glyph = {0};
203 subset_glyph.new_gid = new_gid;
204
205 /* should never fail: all old gids should be mapped */
206 if (!plan->old_gid_for_new_gid (new_gid, &subset_glyph.old_gid))
207 return subset_glyph;
208
209 subset_glyph.source_glyph = glyf.glyph_for_gid (subset_glyph.old_gid, true);
210 if (plan->drop_hints) subset_glyph.drop_hints_bytes ();
211 else subset_glyph.dest_start = subset_glyph.source_glyph.get_bytes ();
212
213 return subset_glyph;
214 })
215 | hb_sink (glyphs)
216 ;
217
218 glyf.fini ();
219 }
220
221 static bool
222 _add_head_and_set_loca_version (hb_subset_plan_t *plan, bool use_short_loca)
223 {
224 hb_blob_t *head_blob = hb_sanitize_context_t ().reference_table<head> (plan->source);
225 hb_blob_t *head_prime_blob = hb_blob_copy_writable_or_fail (head_blob);
226 hb_blob_destroy (head_blob);
227
228 if (unlikely (!head_prime_blob))
229 return false;
230
231 head *head_prime = (head *) hb_blob_get_data_writable (head_prime_blob, nullptr);
232 head_prime->indexToLocFormat = use_short_loca ? 0 : 1;
233 bool success = plan->add_table (HB_OT_TAG_head, head_prime_blob);
234
235 hb_blob_destroy (head_prime_blob);
236 return success;
237 }
238
239 struct CompositeGlyphChain
240 {
241 enum composite_glyph_flag_t
242 {
243 ARG_1_AND_2_ARE_WORDS = 0x0001,
244 ARGS_ARE_XY_VALUES = 0x0002,
245 ROUND_XY_TO_GRID = 0x0004,
246 WE_HAVE_A_SCALE = 0x0008,
247 MORE_COMPONENTS = 0x0020,
248 WE_HAVE_AN_X_AND_Y_SCALE = 0x0040,
249 WE_HAVE_A_TWO_BY_TWO = 0x0080,
250 WE_HAVE_INSTRUCTIONS = 0x0100,
251 USE_MY_METRICS = 0x0200,
252 OVERLAP_COMPOUND = 0x0400,
253 SCALED_COMPONENT_OFFSET = 0x0800,
254 UNSCALED_COMPONENT_OFFSET = 0x1000
255 };
256
257 unsigned int get_size () const
258 {
259 unsigned int size = min_size;
260 /* arg1 and 2 are int16 */
261 if (flags & ARG_1_AND_2_ARE_WORDS) size += 4;
262 /* arg1 and 2 are int8 */
263 else size += 2;
264
265 /* One x 16 bit (scale) */
266 if (flags & WE_HAVE_A_SCALE) size += 2;
267 /* Two x 16 bit (xscale, yscale) */
268 else if (flags & WE_HAVE_AN_X_AND_Y_SCALE) size += 4;
269 /* Four x 16 bit (xscale, scale01, scale10, yscale) */
270 else if (flags & WE_HAVE_A_TWO_BY_TWO) size += 8;
271
272 return size;
273 }
274
275 bool is_use_my_metrics () const { return flags & USE_MY_METRICS; }
276 bool is_anchored () const { return !(flags & ARGS_ARE_XY_VALUES); }
277 void get_anchor_points (unsigned int &point1, unsigned int &point2) const
278 {
279 const HBUINT8 *p = &StructAfter<const HBUINT8> (glyphIndex);
280 if (flags & ARG_1_AND_2_ARE_WORDS)
281 {
282 point1 = ((const HBUINT16 *) p)[0];
283 point2 = ((const HBUINT16 *) p)[1];
284 }
285 else
286 {
287 point1 = p[0];
288 point2 = p[1];
289 }
290 }
291
292 void transform_points (contour_point_vector_t &points) const
293 {
294 float matrix[4];
295 contour_point_t trans;
296 if (get_transformation (matrix, trans))
297 {
298 if (scaled_offsets ())
299 {
300 points.translate (trans);
301 points.transform (matrix);
302 }
303 else
304 {
305 points.transform (matrix);
306 points.translate (trans);
307 }
308 }
309 }
310
311 protected:
312 bool scaled_offsets () const
313 { return (flags & (SCALED_COMPONENT_OFFSET | UNSCALED_COMPONENT_OFFSET)) == SCALED_COMPONENT_OFFSET; }
314
315 bool get_transformation (float (&matrix)[4], contour_point_t &trans) const
316 {
317 matrix[0] = matrix[3] = 1.f;
318 matrix[1] = matrix[2] = 0.f;
319
320 int tx, ty;
321 const HBINT8 *p = &StructAfter<const HBINT8> (glyphIndex);
322 if (flags & ARG_1_AND_2_ARE_WORDS)
323 {
324 tx = *(const HBINT16 *) p;
325 p += HBINT16::static_size;
326 ty = *(const HBINT16 *) p;
327 p += HBINT16::static_size;
328 }
329 else
330 {
331 tx = *p++;
332 ty = *p++;
333 }
334 if (is_anchored ()) tx = ty = 0;
335
336 trans.init ((float) tx, (float) ty);
337
338 {
339 const F2DOT14 *points = (const F2DOT14 *) p;
340 if (flags & WE_HAVE_A_SCALE)
341 {
342 matrix[0] = matrix[3] = points[0].to_float ();
343 return true;
344 }
345 else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)
346 {
347 matrix[0] = points[0].to_float ();
348 matrix[3] = points[1].to_float ();
349 return true;
350 }
351 else if (flags & WE_HAVE_A_TWO_BY_TWO)
352 {
353 matrix[0] = points[0].to_float ();
354 matrix[1] = points[1].to_float ();
355 matrix[2] = points[2].to_float ();
356 matrix[3] = points[3].to_float ();
357 return true;
358 }
359 }
360 return tx || ty;
361 }
362
363 public:
364 HBUINT16 flags;
365 HBGlyphID glyphIndex;
366 public:
367 DEFINE_SIZE_MIN (4);
368 };
369
370 struct composite_iter_t : hb_iter_with_fallback_t<composite_iter_t, const CompositeGlyphChain &>
371 {
372 typedef const CompositeGlyphChain *__item_t__;
373 composite_iter_t (hb_bytes_t glyph_, __item_t__ current_) :
374 glyph (glyph_), current (current_)
375 { if (!check_range (current)) current = nullptr; }
376 composite_iter_t () : glyph (hb_bytes_t ()), current (nullptr) {}
377
378 const CompositeGlyphChain &__item__ () const { return *current; }
379 bool __more__ () const { return current; }
380 void __next__ ()
381 {
382 if (!(current->flags & CompositeGlyphChain::MORE_COMPONENTS)) { current = nullptr; return; }
383
384 const CompositeGlyphChain *possible = &StructAfter<CompositeGlyphChain,
385 CompositeGlyphChain> (*current);
386 if (!check_range (possible)) { current = nullptr; return; }
387 current = possible;
388 }
389 bool operator != (const composite_iter_t& o) const
390 { return glyph != o.glyph || current != o.current; }
391
392 bool check_range (const CompositeGlyphChain *composite) const
393 {
394 return glyph.check_range (composite, CompositeGlyphChain::min_size)
395 && glyph.check_range (composite, composite->get_size ());
396 }
397
398 private:
399 hb_bytes_t glyph;
400 __item_t__ current;
401 };
402
403 enum phantom_point_index_t
404 {
405 PHANTOM_LEFT = 0,
406 PHANTOM_RIGHT = 1,
407 PHANTOM_TOP = 2,
408 PHANTOM_BOTTOM = 3,
409 PHANTOM_COUNT = 4
410 };
411
412 struct Glyph
413 {
414 enum simple_glyph_flag_t
415 {
416 FLAG_ON_CURVE = 0x01,
417 FLAG_X_SHORT = 0x02,
418 FLAG_Y_SHORT = 0x04,
419 FLAG_REPEAT = 0x08,
420 FLAG_X_SAME = 0x10,
421 FLAG_Y_SAME = 0x20,
422 FLAG_RESERVED1 = 0x40,
423 FLAG_RESERVED2 = 0x80
424 };
425
426 private:
427 struct GlyphHeader
428 {
429 bool has_data () const { return numberOfContours; }
430
431 bool get_extents (hb_font_t *font, hb_codepoint_t gid, hb_glyph_extents_t *extents) const
432 {
433 /* Undocumented rasterizer behavior: shift glyph to the left by (lsb - xMin), i.e., xMin = lsb */
434 /* extents->x_bearing = hb_min (glyph_header.xMin, glyph_header.xMax); */
435 extents->x_bearing = font->em_scale_x (font->face->table.hmtx->get_side_bearing (gid));
436 extents->y_bearing = font->em_scale_y (hb_max (yMin, yMax));
437 extents->width = font->em_scale_x (hb_max (xMin, xMax) - hb_min (xMin, xMax));
438 extents->height = font->em_scale_y (hb_min (yMin, yMax) - hb_max (yMin, yMax));
439
440 return true;
441 }
442
443 HBINT16 numberOfContours;
444 /* If the number of contours is
445 * greater than or equal to zero,
446 * this is a simple glyph; if negative,
447 * this is a composite glyph. */
448 FWORD xMin; /* Minimum x for coordinate data. */
449 FWORD yMin; /* Minimum y for coordinate data. */
450 FWORD xMax; /* Maximum x for coordinate data. */
451 FWORD yMax; /* Maximum y for coordinate data. */
452 public:
453 DEFINE_SIZE_STATIC (10);
454 };
455
456 struct SimpleGlyph
457 {
458 const GlyphHeader &header;
459 hb_bytes_t bytes;
460 SimpleGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
461 header (header_), bytes (bytes_) {}
462
463 unsigned int instruction_len_offset () const
464 { return GlyphHeader::static_size + 2 * header.numberOfContours; }
465
466 unsigned int length (unsigned int instruction_len) const
467 { return instruction_len_offset () + 2 + instruction_len; }
468
469 unsigned int instructions_length () const
470 {
471 unsigned int instruction_length_offset = instruction_len_offset ();
472 if (unlikely (instruction_length_offset + 2 > bytes.length)) return 0;
473
474 const HBUINT16 &instructionLength = StructAtOffset<HBUINT16> (&bytes, instruction_length_offset);
475 /* Out of bounds of the current glyph */
476 if (unlikely (length (instructionLength) > bytes.length)) return 0;
477 return instructionLength;
478 }
479
480 const Glyph trim_padding () const
481 {
482 /* based on FontTools _g_l_y_f.py::trim */
483 const char *glyph = bytes.arrayZ;
484 const char *glyph_end = glyph + bytes.length;
485 /* simple glyph w/contours, possibly trimmable */
486 glyph += instruction_len_offset ();
487
488 if (unlikely (glyph + 2 >= glyph_end)) return Glyph ();
489 unsigned int num_coordinates = StructAtOffset<HBUINT16> (glyph - 2, 0) + 1;
490 unsigned int num_instructions = StructAtOffset<HBUINT16> (glyph, 0);
491
492 glyph += 2 + num_instructions;
493
494 unsigned int coord_bytes = 0;
495 unsigned int coords_with_flags = 0;
496 while (glyph < glyph_end)
497 {
498 uint8_t flag = *glyph;
499 glyph++;
500
501 unsigned int repeat = 1;
502 if (flag & FLAG_REPEAT)
503 {
504 if (unlikely (glyph >= glyph_end)) return Glyph ();
505 repeat = *glyph + 1;
506 glyph++;
507 }
508
509 unsigned int xBytes, yBytes;
510 xBytes = yBytes = 0;
511 if (flag & FLAG_X_SHORT) xBytes = 1;
512 else if ((flag & FLAG_X_SAME) == 0) xBytes = 2;
513
514 if (flag & FLAG_Y_SHORT) yBytes = 1;
515 else if ((flag & FLAG_Y_SAME) == 0) yBytes = 2;
516
517 coord_bytes += (xBytes + yBytes) * repeat;
518 coords_with_flags += repeat;
519 if (coords_with_flags >= num_coordinates) break;
520 }
521
522 if (unlikely (coords_with_flags != num_coordinates)) return Glyph ();
523 return Glyph (bytes.sub_array (0, bytes.length + coord_bytes - (glyph_end - glyph)));
524 }
525
526 /* zero instruction length */
527 void drop_hints ()
528 {
529 GlyphHeader &glyph_header = const_cast<GlyphHeader &> (header);
530 (HBUINT16 &) StructAtOffset<HBUINT16> (&glyph_header, instruction_len_offset ()) = 0;
531 }
532
533 void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
534 {
535 unsigned int instructions_len = instructions_length ();
536 unsigned int glyph_length = length (instructions_len);
537 dest_start = bytes.sub_array (0, glyph_length - instructions_len);
538 dest_end = bytes.sub_array (glyph_length, bytes.length - glyph_length);
539 }
540
541 static bool read_points (const HBUINT8 *&p /* IN/OUT */,
542 contour_point_vector_t &points_ /* IN/OUT */,
543 const hb_bytes_t &bytes,
544 void (* setter) (contour_point_t &_, float v),
545 const simple_glyph_flag_t short_flag,
546 const simple_glyph_flag_t same_flag)
547 {
548 float v = 0;
549 for (unsigned i = 0; i < points_.length; i++)
550 {
551 uint8_t flag = points_[i].flag;
552 if (flag & short_flag)
553 {
554 if (unlikely (!bytes.check_range (p))) return false;
555 if (flag & same_flag)
556 v += *p++;
557 else
558 v -= *p++;
559 }
560 else
561 {
562 if (!(flag & same_flag))
563 {
564 if (unlikely (!bytes.check_range ((const HBUINT16 *) p))) return false;
565 v += *(const HBINT16 *) p;
566 p += HBINT16::static_size;
567 }
568 }
569 setter (points_[i], v);
570 }
571 return true;
572 }
573
574 bool get_contour_points (contour_point_vector_t &points_ /* OUT */,
575 bool phantom_only = false) const
576 {
577 const HBUINT16 *endPtsOfContours = &StructAfter<HBUINT16> (header);
578 int num_contours = header.numberOfContours;
579 if (unlikely (!bytes.check_range (&endPtsOfContours[num_contours + 1]))) return false;
580 unsigned int num_points = endPtsOfContours[num_contours - 1] + 1;
581
582 points_.resize (num_points);
583 for (unsigned int i = 0; i < points_.length; i++) points_[i].init ();
584 if (phantom_only) return true;
585
586 for (int i = 0; i < num_contours; i++)
587 points_[endPtsOfContours[i]].is_end_point = true;
588
589 /* Skip instructions */
590 const HBUINT8 *p = &StructAtOffset<HBUINT8> (&endPtsOfContours[num_contours + 1],
591 endPtsOfContours[num_contours]);
592
593 /* Read flags */
594 for (unsigned int i = 0; i < num_points; i++)
595 {
596 if (unlikely (!bytes.check_range (p))) return false;
597 uint8_t flag = *p++;
598 points_[i].flag = flag;
599 if (flag & FLAG_REPEAT)
600 {
601 if (unlikely (!bytes.check_range (p))) return false;
602 unsigned int repeat_count = *p++;
603 while ((repeat_count-- > 0) && (++i < num_points))
604 points_[i].flag = flag;
605 }
606 }
607
608 /* Read x & y coordinates */
609 return (read_points (p, points_, bytes,
610 [] (contour_point_t &p, float v) { p.x = v; }, FLAG_X_SHORT, FLAG_X_SAME) &&
611 read_points (p, points_, bytes,
612 [] (contour_point_t &p, float v) { p.y = v; }, FLAG_Y_SHORT, FLAG_Y_SAME));
613 }
614 };
615
616 struct CompositeGlyph
617 {
618 const GlyphHeader &header;
619 hb_bytes_t bytes;
620 CompositeGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
621 header (header_), bytes (bytes_) {}
622
623 composite_iter_t get_iterator () const
624 { return composite_iter_t (bytes, &StructAfter<CompositeGlyphChain, GlyphHeader> (header)); }
625
626 unsigned int instructions_length (hb_bytes_t bytes) const
627 {
628 unsigned int start = bytes.length;
629 unsigned int end = bytes.length;
630 const CompositeGlyphChain *last = nullptr;
631 for (auto &item : get_iterator ())
632 last = &item;
633 if (unlikely (!last)) return 0;
634
635 if ((uint16_t) last->flags & CompositeGlyphChain::WE_HAVE_INSTRUCTIONS)
636 start = (char *) last - &bytes + last->get_size ();
637 if (unlikely (start > end)) return 0;
638 return end - start;
639 }
640
641 /* Trimming for composites not implemented.
642 * If removing hints it falls out of that. */
643 const Glyph trim_padding () const { return Glyph (bytes); }
644
645 /* remove WE_HAVE_INSTRUCTIONS flag from composite glyph */
646 void drop_hints ()
647 {
648 for (const auto &_ : get_iterator ())
649 *const_cast<OT::HBUINT16 *> (&_.flags) = (uint16_t) _.flags & ~OT::glyf::CompositeGlyphChain::WE_HAVE_INSTRUCTIONS;
650 }
651
652 /* Chop instructions off the end */
653 void drop_hints_bytes (hb_bytes_t &dest_start) const
654 { dest_start = bytes.sub_array (0, bytes.length - instructions_length (bytes)); }
655 };
656
657 enum glyph_type_t { EMPTY, SIMPLE, COMPOSITE };
658
659 public:
660 composite_iter_t get_composite_iterator () const
661 {
662 if (type != COMPOSITE) return composite_iter_t ();
663 return CompositeGlyph (*header, bytes).get_iterator ();
664 }
665
666 const Glyph trim_padding () const
667 {
668 switch (type) {
669 case COMPOSITE: return CompositeGlyph (*header, bytes).trim_padding ();
670 case SIMPLE: return SimpleGlyph (*header, bytes).trim_padding ();
671 default: return bytes;
672 }
673 }
674
675 void drop_hints ()
676 {
677 switch (type) {
678 case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints (); return;
679 case SIMPLE: SimpleGlyph (*header, bytes).drop_hints (); return;
680 default: return;
681 }
682 }
683
684 void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
685 {
686 switch (type) {
687 case COMPOSITE: CompositeGlyph (*header, bytes).drop_hints_bytes (dest_start); return;
688 case SIMPLE: SimpleGlyph (*header, bytes).drop_hints_bytes (dest_start, dest_end); return;
689 default: return;
690 }
691 }
692
693 /* Note: Recursively calls itself.
694 * all_points includes phantom points
695 */
696 template<typename T>
697 bool get_points (T glyph_for_gid, hb_font_t *font,
698 contour_point_vector_t &all_points /* OUT */,
699 bool phantom_only = false,
700 unsigned int depth = 0) const
701 {
702 if (unlikely (depth > HB_MAX_NESTING_LEVEL)) return false;
703 contour_point_vector_t points;
704
705 switch (type) {
706 case COMPOSITE:
707 {
708 /* pseudo component points for each component in composite glyph */
709 unsigned num_points = hb_len (CompositeGlyph (*header, bytes).get_iterator ());
710 if (unlikely (!points.resize (num_points))) return false;
711 for (unsigned i = 0; i < points.length; i++)
712 points[i].init ();
713 break;
714 }
715 case SIMPLE:
716 if (unlikely (!SimpleGlyph (*header, bytes).get_contour_points (points, phantom_only)))
717 return false;
718 break;
719 default: return false; /* empty glyph */
720 }
721
722 hb_face_t *face = font->face;
723
724 /* Init phantom points */
725 if (unlikely (!points.resize (points.length + PHANTOM_COUNT))) return false;
726 hb_array_t<contour_point_t> phantoms = points.sub_array (points.length - PHANTOM_COUNT, PHANTOM_COUNT);
727 {
728 for (unsigned i = 0; i < PHANTOM_COUNT; ++i) phantoms[i].init ();
729 int h_delta = (int) header->xMin - face->table.hmtx->get_side_bearing (gid);
730 int v_orig = (int) header->yMax + face->table.vmtx->get_side_bearing (gid);
731 unsigned h_adv = face->table.hmtx->get_advance (gid);
732 unsigned v_adv = face->table.vmtx->get_advance (gid);
733 phantoms[PHANTOM_LEFT].x = h_delta;
734 phantoms[PHANTOM_RIGHT].x = h_adv + h_delta;
735 phantoms[PHANTOM_TOP].y = v_orig;
736 phantoms[PHANTOM_BOTTOM].y = v_orig - (int) v_adv;
737 }
738
739#ifndef HB_NO_VAR
740 if (unlikely (!face->table.gvar->apply_deltas_to_points (gid, font, points.as_array ())))
741 return false;
742#endif
743
744 switch (type) {
745 case SIMPLE:
746 all_points.extend (points.as_array ());
747 break;
748 case COMPOSITE:
749 {
750 unsigned int comp_index = 0;
751 for (auto &item : get_composite_iterator ())
752 {
753 contour_point_vector_t comp_points;
754 if (unlikely (!glyph_for_gid (item.glyphIndex).get_points (glyph_for_gid, font, comp_points, phantom_only, depth + 1))
755 || comp_points.length < PHANTOM_COUNT)
756 return false;
757
758 /* Copy phantom points from component if USE_MY_METRICS flag set */
759 if (item.is_use_my_metrics ())
760 for (unsigned int i = 0; i < PHANTOM_COUNT; i++)
761 phantoms[i] = comp_points[comp_points.length - PHANTOM_COUNT + i];
762
763 /* Apply component transformation & translation */
764 item.transform_points (comp_points);
765
766 /* Apply translation from gvar */
767 comp_points.translate (points[comp_index]);
768
769 if (item.is_anchored ())
770 {
771 unsigned int p1, p2;
772 item.get_anchor_points (p1, p2);
773 if (likely (p1 < all_points.length && p2 < comp_points.length))
774 {
775 contour_point_t delta;
776 delta.init (all_points[p1].x - comp_points[p2].x,
777 all_points[p1].y - comp_points[p2].y);
778
779 comp_points.translate (delta);
780 }
781 }
782
783 all_points.extend (comp_points.sub_array (0, comp_points.length - PHANTOM_COUNT));
784
785 comp_index++;
786 }
787
788 all_points.extend (phantoms);
789 } break;
790 default: return false;
791 }
792
793 if (depth == 0) /* Apply at top level */
794 {
795 /* Undocumented rasterizer behavior:
796 * Shift points horizontally by the updated left side bearing
797 */
798 contour_point_t delta;
799 delta.init (-phantoms[PHANTOM_LEFT].x, 0.f);
800 if (delta.x) all_points.translate (delta);
801 }
802
803 return true;
804 }
805
806 bool get_extents (hb_font_t *font, hb_glyph_extents_t *extents) const
807 {
808 if (type == EMPTY) return true; /* Empty glyph; zero extents. */
809 return header->get_extents (font, gid, extents);
810 }
811
812 hb_bytes_t get_bytes () const { return bytes; }
813
814 Glyph (hb_bytes_t bytes_ = hb_bytes_t (),
815 hb_codepoint_t gid_ = (hb_codepoint_t) -1) : bytes (bytes_), gid (gid_),
816 header (bytes.as<GlyphHeader> ())
817 {
818 int num_contours = header->numberOfContours;
819 if (unlikely (num_contours == 0)) type = EMPTY;
820 else if (num_contours > 0) type = SIMPLE;
821 else type = COMPOSITE; /* negative numbers */
822 }
823
824 protected:
825 hb_bytes_t bytes;
826 hb_codepoint_t gid;
827 const GlyphHeader *header;
828 unsigned type;
829 };
830
831 struct accelerator_t
832 {
833 void init (hb_face_t *face_)
834 {
835 short_offset = false;
836 num_glyphs = 0;
837 loca_table = nullptr;
838 glyf_table = nullptr;
839 face = face_;
840 const OT::head &head = *face->table.head;
841 if (head.indexToLocFormat > 1 || head.glyphDataFormat > 0)
842 /* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */
843 return;
844 short_offset = 0 == head.indexToLocFormat;
845
846 loca_table = hb_sanitize_context_t ().reference_table<loca> (face);
847 glyf_table = hb_sanitize_context_t ().reference_table<glyf> (face);
848
849 num_glyphs = hb_max (1u, loca_table.get_length () / (short_offset ? 2 : 4)) - 1;
850 num_glyphs = hb_min (num_glyphs, face->get_num_glyphs ());
851 }
852
853 void fini ()
854 {
855 loca_table.destroy ();
856 glyf_table.destroy ();
857 }
858
859 protected:
860 template<typename T>
861 bool get_points (hb_font_t *font, hb_codepoint_t gid, T consumer) const
862 {
863 /* Making this alloc free is not that easy
864 https://github.com/harfbuzz/harfbuzz/issues/2095
865 mostly because of gvar handling in VF fonts,
866 perhaps a separate path for non-VF fonts can be considered */
867 contour_point_vector_t all_points;
868
869 bool phantom_only = !consumer.is_consuming_contour_points ();
870 if (unlikely (!glyph_for_gid (gid).get_points ([this] (hb_codepoint_t gid) -> const Glyph { return this->glyph_for_gid (gid); },
871 font, all_points, phantom_only)))
872 return false;
873
874 if (consumer.is_consuming_contour_points ())
875 {
876 for (unsigned point_index = 0; point_index + 4 < all_points.length; ++point_index)
877 consumer.consume_point (all_points[point_index]);
878 consumer.points_end ();
879 }
880
881 /* Where to write phantoms, nullptr if not requested */
882 contour_point_t *phantoms = consumer.get_phantoms_sink ();
883 if (phantoms)
884 for (unsigned i = 0; i < PHANTOM_COUNT; ++i)
885 phantoms[i] = all_points[all_points.length - PHANTOM_COUNT + i];
886
887 return true;
888 }
889
890 public:
891#ifndef HB_NO_VAR
892 struct points_aggregator_t
893 {
894 hb_font_t *font;
895 hb_glyph_extents_t *extents;
896 contour_point_t *phantoms;
897
898 struct contour_bounds_t
899 {
900 contour_bounds_t () { min_x = min_y = FLT_MAX; max_x = max_y = -FLT_MAX; }
901
902 void add (const contour_point_t &p)
903 {
904 min_x = hb_min (min_x, p.x);
905 min_y = hb_min (min_y, p.y);
906 max_x = hb_max (max_x, p.x);
907 max_y = hb_max (max_y, p.y);
908 }
909
910 bool empty () const { return (min_x >= max_x) || (min_y >= max_y); }
911
912 void get_extents (hb_font_t *font, hb_glyph_extents_t *extents)
913 {
914 if (unlikely (empty ()))
915 {
916 extents->width = 0;
917 extents->x_bearing = 0;
918 extents->height = 0;
919 extents->y_bearing = 0;
920 return;
921 }
922 extents->x_bearing = font->em_scalef_x (min_x);
923 extents->width = font->em_scalef_x (max_x - min_x);
924 extents->y_bearing = font->em_scalef_y (max_y);
925 extents->height = font->em_scalef_y (min_y - max_y);
926 }
927
928 protected:
929 float min_x, min_y, max_x, max_y;
930 } bounds;
931
932 points_aggregator_t (hb_font_t *font_, hb_glyph_extents_t *extents_, contour_point_t *phantoms_)
933 {
934 font = font_;
935 extents = extents_;
936 phantoms = phantoms_;
937 if (extents) bounds = contour_bounds_t ();
938 }
939
940 void consume_point (const contour_point_t &point) { bounds.add (point); }
941 void points_end () { bounds.get_extents (font, extents); }
942
943 bool is_consuming_contour_points () { return extents; }
944 contour_point_t *get_phantoms_sink () { return phantoms; }
945 };
946
947 unsigned int
948 get_advance_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
949 {
950 bool success = false;
951
952 contour_point_t phantoms[PHANTOM_COUNT];
953 if (likely (font->num_coords == face->table.gvar->get_axis_count ()))
954 success = get_points (font, gid, points_aggregator_t (font, nullptr, phantoms));
955
956 if (unlikely (!success))
957 return is_vertical
958 ? face->table.vmtx->get_advance (gid)
959 : face->table.hmtx->get_advance (gid);
960
961 return is_vertical
962 ? roundf (phantoms[PHANTOM_TOP].y - phantoms[PHANTOM_BOTTOM].y)
963 : roundf (phantoms[PHANTOM_RIGHT].x - phantoms[PHANTOM_LEFT].x);
964 }
965
966 int get_side_bearing_var (hb_font_t *font, hb_codepoint_t gid, bool is_vertical) const
967 {
968 hb_glyph_extents_t extents;
969
970 contour_point_t phantoms[PHANTOM_COUNT];
971 if (unlikely (!get_points (font, gid, points_aggregator_t (font, &extents, phantoms))))
972 return is_vertical
973 ? face->table.vmtx->get_side_bearing (gid)
974 : face->table.hmtx->get_side_bearing (gid);
975
976 return is_vertical
977 ? ceilf (phantoms[PHANTOM_TOP].y) - extents.y_bearing
978 : floorf (phantoms[PHANTOM_LEFT].x);
979 }
980#endif
981
982 bool get_extents (hb_font_t *font, hb_codepoint_t gid, hb_glyph_extents_t *extents) const
983 {
984 if (unlikely (gid >= num_glyphs)) return false;
985#ifndef HB_NO_VAR
986 if (font->num_coords && font->num_coords == face->table.gvar->get_axis_count ())
987 return get_points (font, gid, points_aggregator_t (font, extents, nullptr));
988#endif
989 return glyph_for_gid (gid).get_extents (font, extents);
990 }
991
992 const Glyph
993 glyph_for_gid (hb_codepoint_t gid, bool needs_padding_removal = false) const
994 {
995 unsigned int start_offset, end_offset;
996 if (unlikely (gid >= num_glyphs)) return Glyph ();
997
998 if (short_offset)
999 {
1000 const HBUINT16 *offsets = (const HBUINT16 *) loca_table->dataZ.arrayZ;
1001 start_offset = 2 * offsets[gid];
1002 end_offset = 2 * offsets[gid + 1];
1003 }
1004 else
1005 {
1006 const HBUINT32 *offsets = (const HBUINT32 *) loca_table->dataZ.arrayZ;
1007 start_offset = offsets[gid];
1008 end_offset = offsets[gid + 1];
1009 }
1010
1011 if (unlikely (start_offset > end_offset || end_offset > glyf_table.get_length ()))
1012 return Glyph ();
1013
1014 Glyph glyph (hb_bytes_t ((const char *) this->glyf_table + start_offset,
1015 end_offset - start_offset), gid);
1016 return needs_padding_removal ? glyph.trim_padding () : glyph;
1017 }
1018
1019 void
1020 add_gid_and_children (hb_codepoint_t gid, hb_set_t *gids_to_retain,
1021 unsigned int depth = 0) const
1022 {
1023 if (unlikely (depth++ > HB_MAX_NESTING_LEVEL)) return;
1024 /* Check if is already visited */
1025 if (gids_to_retain->has (gid)) return;
1026
1027 gids_to_retain->add (gid);
1028
1029 for (auto &item : glyph_for_gid (gid).get_composite_iterator ())
1030 add_gid_and_children (item.glyphIndex, gids_to_retain, depth);
1031 }
1032
1033#ifdef HB_EXPERIMENTAL_API
1034 struct path_builder_t
1035 {
1036 hb_font_t *font;
1037 draw_helper_t *draw_helper;
1038
1039 struct optional_point_t
1040 {
1041 optional_point_t () { has_data = false; }
1042 optional_point_t (float x_, float y_) { x = x_; y = y_; has_data = true; }
1043
1044 bool has_data;
1045 float x;
1046 float y;
1047
1048 optional_point_t lerp (optional_point_t p, float t)
1049 { return optional_point_t (x + t * (p.x - x), y + t * (p.y - y)); }
1050 } first_oncurve, first_offcurve, last_offcurve;
1051
1052 path_builder_t (hb_font_t *font_, draw_helper_t &draw_helper_)
1053 {
1054 font = font_;
1055 draw_helper = &draw_helper_;
1056 first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
1057 }
1058
1059 /* based on https://github.com/RazrFalcon/ttf-parser/blob/4f32821/src/glyf.rs#L287
1060 See also:
1061 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM01/Chap1.html
1062 * https://stackoverflow.com/a/20772557 */
1063 void consume_point (const contour_point_t &point)
1064 {
1065 /* Skip empty contours */
1066 if (unlikely (point.is_end_point && !first_oncurve.has_data && !first_offcurve.has_data))
1067 return;
1068
1069 bool is_on_curve = point.flag & Glyph::FLAG_ON_CURVE;
1070 optional_point_t p (point.x, point.y);
1071 if (!first_oncurve.has_data)
1072 {
1073 if (is_on_curve)
1074 {
1075 first_oncurve = p;
1076 draw_helper->move_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1077 }
1078 else
1079 {
1080 if (first_offcurve.has_data)
1081 {
1082 optional_point_t mid = first_offcurve.lerp (p, .5f);
1083 first_oncurve = mid;
1084 last_offcurve = p;
1085 draw_helper->move_to (font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1086 }
1087 else
1088 first_offcurve = p;
1089 }
1090 }
1091 else
1092 {
1093 if (last_offcurve.has_data)
1094 {
1095 if (is_on_curve)
1096 {
1097 draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1098 font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1099 last_offcurve = optional_point_t ();
1100 }
1101 else
1102 {
1103 optional_point_t mid = last_offcurve.lerp (p, .5f);
1104 draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1105 font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1106 last_offcurve = p;
1107 }
1108 }
1109 else
1110 {
1111 if (is_on_curve)
1112 draw_helper->line_to (font->em_scalef_x (p.x), font->em_scalef_y (p.y));
1113 else
1114 last_offcurve = p;
1115 }
1116 }
1117
1118 if (point.is_end_point)
1119 {
1120 if (first_offcurve.has_data && last_offcurve.has_data)
1121 {
1122 optional_point_t mid = last_offcurve.lerp (first_offcurve, .5f);
1123 draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1124 font->em_scalef_x (mid.x), font->em_scalef_y (mid.y));
1125 last_offcurve = optional_point_t ();
1126 /* now check the rest */
1127 }
1128
1129 if (first_offcurve.has_data && first_oncurve.has_data)
1130 draw_helper->quadratic_to (font->em_scalef_x (first_offcurve.x), font->em_scalef_y (first_offcurve.y),
1131 font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1132 else if (last_offcurve.has_data && first_oncurve.has_data)
1133 draw_helper->quadratic_to (font->em_scalef_x (last_offcurve.x), font->em_scalef_y (last_offcurve.y),
1134 font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1135 else if (first_oncurve.has_data)
1136 draw_helper->line_to (font->em_scalef_x (first_oncurve.x), font->em_scalef_y (first_oncurve.y));
1137
1138 /* Getting ready for the next contour */
1139 first_oncurve = first_offcurve = last_offcurve = optional_point_t ();
1140 draw_helper->end_path ();
1141 }
1142 }
1143 void points_end () {}
1144
1145 bool is_consuming_contour_points () { return true; }
1146 contour_point_t *get_phantoms_sink () { return nullptr; }
1147 };
1148
1149 bool
1150 get_path (hb_font_t *font, hb_codepoint_t gid, draw_helper_t &draw_helper) const
1151 { return get_points (font, gid, path_builder_t (font, draw_helper)); }
1152#endif
1153
1154 private:
1155 bool short_offset;
1156 unsigned int num_glyphs;
1157 hb_blob_ptr_t<loca> loca_table;
1158 hb_blob_ptr_t<glyf> glyf_table;
1159 hb_face_t *face;
1160 };
1161
1162 struct SubsetGlyph
1163 {
1164 hb_codepoint_t new_gid;
1165 hb_codepoint_t old_gid;
1166 Glyph source_glyph;
1167 hb_bytes_t dest_start; /* region of source_glyph to copy first */
1168 hb_bytes_t dest_end; /* region of source_glyph to copy second */
1169
1170 bool serialize (hb_serialize_context_t *c,
1171 const hb_subset_plan_t *plan) const
1172 {
1173 TRACE_SERIALIZE (this);
1174
1175 hb_bytes_t dest_glyph = dest_start.copy (c);
1176 dest_glyph = hb_bytes_t (&dest_glyph, dest_glyph.length + dest_end.copy (c).length);
1177 unsigned int pad_length = padding ();
1178 DEBUG_MSG (SUBSET, nullptr, "serialize %d byte glyph, width %d pad %d", dest_glyph.length, dest_glyph.length + pad_length, pad_length);
1179
1180 HBUINT8 pad;
1181 pad = 0;
1182 while (pad_length > 0)
1183 {
1184 c->embed (pad);
1185 pad_length--;
1186 }
1187
1188 if (unlikely (!dest_glyph.length)) return_trace (true);
1189
1190 /* update components gids */
1191 for (auto &_ : Glyph (dest_glyph).get_composite_iterator ())
1192 {
1193 hb_codepoint_t new_gid;
1194 if (plan->new_gid_for_old_gid (_.glyphIndex, &new_gid))
1195 ((OT::glyf::CompositeGlyphChain *) &_)->glyphIndex = new_gid;
1196 }
1197
1198 if (plan->drop_hints) Glyph (dest_glyph).drop_hints ();
1199
1200 return_trace (true);
1201 }
1202
1203 void drop_hints_bytes ()
1204 { source_glyph.drop_hints_bytes (dest_start, dest_end); }
1205
1206 unsigned int length () const { return dest_start.length + dest_end.length; }
1207 /* pad to 2 to ensure 2-byte loca will be ok */
1208 unsigned int padding () const { return length () % 2; }
1209 unsigned int padded_size () const { return length () + padding (); }
1210 };
1211
1212 protected:
1213 UnsizedArrayOf<HBUINT8>
1214 dataZ; /* Glyphs data. */
1215 public:
1216 DEFINE_SIZE_MIN (0); /* In reality, this is UNBOUNDED() type; but since we always
1217 * check the size externally, allow Null() object of it by
1218 * defining it _MIN instead. */
1219};
1220
1221struct glyf_accelerator_t : glyf::accelerator_t {};
1222
1223} /* namespace OT */
1224
1225
1226#endif /* HB_OT_GLYF_TABLE_HH */
1227