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