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comparison mupdf-source/thirdparty/harfbuzz/src/hb-ot-var-gvar-table.hh @ 2:b50eed0cc0ef upstream

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ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
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1:1d09e1dec1d9 2:b50eed0cc0ef
1 /*
2 * Copyright © 2019 Adobe Inc.
3 * Copyright © 2019 Ebrahim Byagowi
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 * Adobe Author(s): Michiharu Ariza
26 */
27
28 #ifndef HB_OT_VAR_GVAR_TABLE_HH
29 #define HB_OT_VAR_GVAR_TABLE_HH
30
31 #include "hb-open-type.hh"
32
33 /*
34 * gvar -- Glyph Variation Table
35 * https://docs.microsoft.com/en-us/typography/opentype/spec/gvar
36 */
37 #define HB_OT_TAG_gvar HB_TAG('g','v','a','r')
38
39 namespace OT {
40
41 struct contour_point_t
42 {
43 void init (float x_ = 0.f, float y_ = 0.f, bool is_end_point_ = false)
44 { flag = 0; x = x_; y = y_; is_end_point = is_end_point_; }
45
46 void translate (const contour_point_t &p) { x += p.x; y += p.y; }
47
48 float x = 0.f;
49 float y = 0.f;
50 uint8_t flag = 0;
51 bool is_end_point = false;
52 };
53
54 struct contour_point_vector_t : hb_vector_t<contour_point_t>
55 {
56 void extend (const hb_array_t<contour_point_t> &a)
57 {
58 unsigned int old_len = length;
59 if (unlikely (!resize (old_len + a.length, false)))
60 return;
61 auto arrayZ = this->arrayZ + old_len;
62 unsigned count = a.length;
63 hb_memcpy (arrayZ, a.arrayZ, count * sizeof (arrayZ[0]));
64 }
65
66 void transform (const float (&matrix)[4])
67 {
68 if (matrix[0] == 1.f && matrix[1] == 0.f &&
69 matrix[2] == 0.f && matrix[3] == 1.f)
70 return;
71 auto arrayZ = this->arrayZ;
72 unsigned count = length;
73 for (unsigned i = 0; i < count; i++)
74 {
75 contour_point_t &p = arrayZ[i];
76 float x_ = p.x * matrix[0] + p.y * matrix[2];
77 p.y = p.x * matrix[1] + p.y * matrix[3];
78 p.x = x_;
79 }
80 }
81
82 void translate (const contour_point_t& delta)
83 {
84 if (delta.x == 0.f && delta.y == 0.f)
85 return;
86 auto arrayZ = this->arrayZ;
87 unsigned count = length;
88 for (unsigned i = 0; i < count; i++)
89 arrayZ[i].translate (delta);
90 }
91 };
92
93 /* https://docs.microsoft.com/en-us/typography/opentype/spec/otvarcommonformats#tuplevariationheader */
94 struct TupleVariationHeader
95 {
96 unsigned get_size (unsigned axis_count) const
97 { return min_size + get_all_tuples (axis_count).get_size (); }
98
99 unsigned get_data_size () const { return varDataSize; }
100
101 const TupleVariationHeader &get_next (unsigned axis_count) const
102 { return StructAtOffset<TupleVariationHeader> (this, get_size (axis_count)); }
103
104 float calculate_scalar (hb_array_t<int> coords, unsigned int coord_count,
105 const hb_array_t<const F2DOT14> shared_tuples) const
106 {
107 hb_array_t<const F2DOT14> peak_tuple;
108
109 if (has_peak ())
110 peak_tuple = get_peak_tuple (coord_count);
111 else
112 {
113 unsigned int index = get_index ();
114 if (unlikely (index * coord_count >= shared_tuples.length))
115 return 0.f;
116 peak_tuple = shared_tuples.sub_array (coord_count * index, coord_count);
117 }
118
119 hb_array_t<const F2DOT14> start_tuple;
120 hb_array_t<const F2DOT14> end_tuple;
121 if (has_intermediate ())
122 {
123 start_tuple = get_start_tuple (coord_count);
124 end_tuple = get_end_tuple (coord_count);
125 }
126
127 float scalar = 1.f;
128 for (unsigned int i = 0; i < coord_count; i++)
129 {
130 int v = coords[i];
131 int peak = peak_tuple[i];
132 if (!peak || v == peak) continue;
133
134 if (has_intermediate ())
135 {
136 int start = start_tuple[i];
137 int end = end_tuple[i];
138 if (unlikely (start > peak || peak > end ||
139 (start < 0 && end > 0 && peak))) continue;
140 if (v < start || v > end) return 0.f;
141 if (v < peak)
142 { if (peak != start) scalar *= (float) (v - start) / (peak - start); }
143 else
144 { if (peak != end) scalar *= (float) (end - v) / (end - peak); }
145 }
146 else if (!v || v < hb_min (0, peak) || v > hb_max (0, peak)) return 0.f;
147 else
148 scalar *= (float) v / peak;
149 }
150 return scalar;
151 }
152
153 bool has_peak () const { return tupleIndex & TuppleIndex::EmbeddedPeakTuple; }
154 bool has_intermediate () const { return tupleIndex & TuppleIndex::IntermediateRegion; }
155 bool has_private_points () const { return tupleIndex & TuppleIndex::PrivatePointNumbers; }
156 unsigned get_index () const { return tupleIndex & TuppleIndex::TupleIndexMask; }
157
158 protected:
159 struct TuppleIndex : HBUINT16
160 {
161 enum Flags {
162 EmbeddedPeakTuple = 0x8000u,
163 IntermediateRegion = 0x4000u,
164 PrivatePointNumbers = 0x2000u,
165 TupleIndexMask = 0x0FFFu
166 };
167
168 DEFINE_SIZE_STATIC (2);
169 };
170
171 hb_array_t<const F2DOT14> get_all_tuples (unsigned axis_count) const
172 { return StructAfter<UnsizedArrayOf<F2DOT14>> (tupleIndex).as_array ((has_peak () + has_intermediate () * 2) * axis_count); }
173 hb_array_t<const F2DOT14> get_peak_tuple (unsigned axis_count) const
174 { return get_all_tuples (axis_count).sub_array (0, axis_count); }
175 hb_array_t<const F2DOT14> get_start_tuple (unsigned axis_count) const
176 { return get_all_tuples (axis_count).sub_array (has_peak () * axis_count, axis_count); }
177 hb_array_t<const F2DOT14> get_end_tuple (unsigned axis_count) const
178 { return get_all_tuples (axis_count).sub_array (has_peak () * axis_count + axis_count, axis_count); }
179
180 HBUINT16 varDataSize; /* The size in bytes of the serialized
181 * data for this tuple variation table. */
182 TuppleIndex tupleIndex; /* A packed field. The high 4 bits are flags (see below).
183 The low 12 bits are an index into a shared tuple
184 records array. */
185 /* UnsizedArrayOf<F2DOT14> peakTuple - optional */
186 /* Peak tuple record for this tuple variation table — optional,
187 * determined by flags in the tupleIndex value.
188 *
189 * Note that this must always be included in the 'cvar' table. */
190 /* UnsizedArrayOf<F2DOT14> intermediateStartTuple - optional */
191 /* Intermediate start tuple record for this tuple variation table — optional,
192 determined by flags in the tupleIndex value. */
193 /* UnsizedArrayOf<F2DOT14> intermediateEndTuple - optional */
194 /* Intermediate end tuple record for this tuple variation table — optional,
195 * determined by flags in the tupleIndex value. */
196 public:
197 DEFINE_SIZE_MIN (4);
198 };
199
200 struct GlyphVariationData
201 {
202 const TupleVariationHeader &get_tuple_var_header (void) const
203 { return StructAfter<TupleVariationHeader> (data); }
204
205 struct tuple_iterator_t
206 {
207 void init (hb_bytes_t var_data_bytes_, unsigned int axis_count_)
208 {
209 var_data_bytes = var_data_bytes_;
210 var_data = var_data_bytes_.as<GlyphVariationData> ();
211 index = 0;
212 axis_count = axis_count_;
213 current_tuple = &var_data->get_tuple_var_header ();
214 data_offset = 0;
215 }
216
217 bool get_shared_indices (hb_vector_t<unsigned int> &shared_indices /* OUT */)
218 {
219 if (var_data->has_shared_point_numbers ())
220 {
221 const HBUINT8 *base = &(var_data+var_data->data);
222 const HBUINT8 *p = base;
223 if (!unpack_points (p, shared_indices, (const HBUINT8 *) (var_data_bytes.arrayZ + var_data_bytes.length))) return false;
224 data_offset = p - base;
225 }
226 return true;
227 }
228
229 bool is_valid () const
230 {
231 return (index < var_data->tupleVarCount.get_count ()) &&
232 var_data_bytes.check_range (current_tuple, TupleVariationHeader::min_size) &&
233 var_data_bytes.check_range (current_tuple, hb_max (current_tuple->get_data_size (),
234 current_tuple->get_size (axis_count)));
235 }
236
237 bool move_to_next ()
238 {
239 data_offset += current_tuple->get_data_size ();
240 current_tuple = &current_tuple->get_next (axis_count);
241 index++;
242 return is_valid ();
243 }
244
245 const HBUINT8 *get_serialized_data () const
246 { return &(var_data+var_data->data) + data_offset; }
247
248 private:
249 const GlyphVariationData *var_data;
250 unsigned int index;
251 unsigned int axis_count;
252 unsigned int data_offset;
253
254 public:
255 hb_bytes_t var_data_bytes;
256 const TupleVariationHeader *current_tuple;
257 };
258
259 static bool get_tuple_iterator (hb_bytes_t var_data_bytes, unsigned axis_count,
260 hb_vector_t<unsigned int> &shared_indices /* OUT */,
261 tuple_iterator_t *iterator /* OUT */)
262 {
263 iterator->init (var_data_bytes, axis_count);
264 if (!iterator->get_shared_indices (shared_indices))
265 return false;
266 return iterator->is_valid ();
267 }
268
269 bool has_shared_point_numbers () const { return tupleVarCount.has_shared_point_numbers (); }
270
271 static bool unpack_points (const HBUINT8 *&p /* IN/OUT */,
272 hb_vector_t<unsigned int> &points /* OUT */,
273 const HBUINT8 *end)
274 {
275 enum packed_point_flag_t
276 {
277 POINTS_ARE_WORDS = 0x80,
278 POINT_RUN_COUNT_MASK = 0x7F
279 };
280
281 if (unlikely (p + 1 > end)) return false;
282
283 unsigned count = *p++;
284 if (count & POINTS_ARE_WORDS)
285 {
286 if (unlikely (p + 1 > end)) return false;
287 count = ((count & POINT_RUN_COUNT_MASK) << 8) | *p++;
288 }
289 if (unlikely (!points.resize (count, false))) return false;
290
291 unsigned n = 0;
292 unsigned i = 0;
293 while (i < count)
294 {
295 if (unlikely (p + 1 > end)) return false;
296 unsigned control = *p++;
297 unsigned run_count = (control & POINT_RUN_COUNT_MASK) + 1;
298 if (unlikely (i + run_count > count)) return false;
299 unsigned j;
300 if (control & POINTS_ARE_WORDS)
301 {
302 if (unlikely (p + run_count * HBUINT16::static_size > end)) return false;
303 for (j = 0; j < run_count; j++, i++)
304 {
305 n += *(const HBUINT16 *)p;
306 points.arrayZ[i] = n;
307 p += HBUINT16::static_size;
308 }
309 }
310 else
311 {
312 if (unlikely (p + run_count > end)) return false;
313 for (j = 0; j < run_count; j++, i++)
314 {
315 n += *p++;
316 points.arrayZ[i] = n;
317 }
318 }
319 }
320 return true;
321 }
322
323 static bool unpack_deltas (const HBUINT8 *&p /* IN/OUT */,
324 hb_vector_t<int> &deltas /* IN/OUT */,
325 const HBUINT8 *end)
326 {
327 enum packed_delta_flag_t
328 {
329 DELTAS_ARE_ZERO = 0x80,
330 DELTAS_ARE_WORDS = 0x40,
331 DELTA_RUN_COUNT_MASK = 0x3F
332 };
333
334 unsigned i = 0;
335 unsigned count = deltas.length;
336 while (i < count)
337 {
338 if (unlikely (p + 1 > end)) return false;
339 unsigned control = *p++;
340 unsigned run_count = (control & DELTA_RUN_COUNT_MASK) + 1;
341 if (unlikely (i + run_count > count)) return false;
342 unsigned j;
343 if (control & DELTAS_ARE_ZERO)
344 {
345 for (j = 0; j < run_count; j++, i++)
346 deltas.arrayZ[i] = 0;
347 }
348 else if (control & DELTAS_ARE_WORDS)
349 {
350 if (unlikely (p + run_count * HBUINT16::static_size > end)) return false;
351 for (j = 0; j < run_count; j++, i++)
352 {
353 deltas.arrayZ[i] = * (const HBINT16 *) p;
354 p += HBUINT16::static_size;
355 }
356 }
357 else
358 {
359 if (unlikely (p + run_count > end)) return false;
360 for (j = 0; j < run_count; j++, i++)
361 {
362 deltas.arrayZ[i] = * (const HBINT8 *) p++;
363 }
364 }
365 }
366 return true;
367 }
368
369 bool has_data () const { return tupleVarCount; }
370
371 protected:
372 struct TupleVarCount : HBUINT16
373 {
374 bool has_shared_point_numbers () const { return ((*this) & SharedPointNumbers); }
375 unsigned int get_count () const { return (*this) & CountMask; }
376
377 protected:
378 enum Flags
379 {
380 SharedPointNumbers= 0x8000u,
381 CountMask = 0x0FFFu
382 };
383 public:
384 DEFINE_SIZE_STATIC (2);
385 };
386
387 TupleVarCount tupleVarCount; /* A packed field. The high 4 bits are flags, and the
388 * low 12 bits are the number of tuple variation tables
389 * for this glyph. The number of tuple variation tables
390 * can be any number between 1 and 4095. */
391 Offset16To<HBUINT8>
392 data; /* Offset from the start of the GlyphVariationData table
393 * to the serialized data. */
394 /* TupleVariationHeader tupleVariationHeaders[] *//* Array of tuple variation headers. */
395 public:
396 DEFINE_SIZE_MIN (4);
397 };
398
399 struct gvar
400 {
401 static constexpr hb_tag_t tableTag = HB_OT_TAG_gvar;
402
403 bool sanitize_shallow (hb_sanitize_context_t *c) const
404 {
405 TRACE_SANITIZE (this);
406 return_trace (c->check_struct (this) && (version.major == 1) &&
407 sharedTuples.sanitize (c, this, axisCount * sharedTupleCount) &&
408 (is_long_offset () ?
409 c->check_array (get_long_offset_array (), glyphCount+1) :
410 c->check_array (get_short_offset_array (), glyphCount+1)));
411 }
412
413 /* GlyphVariationData not sanitized here; must be checked while accessing each glyph variation data */
414 bool sanitize (hb_sanitize_context_t *c) const
415 { return sanitize_shallow (c); }
416
417 bool subset (hb_subset_context_t *c) const
418 {
419 TRACE_SUBSET (this);
420
421 gvar *out = c->serializer->allocate_min<gvar> ();
422 if (unlikely (!out)) return_trace (false);
423
424 out->version.major = 1;
425 out->version.minor = 0;
426 out->axisCount = axisCount;
427 out->sharedTupleCount = sharedTupleCount;
428
429 unsigned int num_glyphs = c->plan->num_output_glyphs ();
430 out->glyphCount = num_glyphs;
431
432 unsigned int subset_data_size = 0;
433 for (hb_codepoint_t gid = (c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE) ? 0 : 1;
434 gid < num_glyphs;
435 gid++)
436 {
437 hb_codepoint_t old_gid;
438 if (!c->plan->old_gid_for_new_gid (gid, &old_gid)) continue;
439 subset_data_size += get_glyph_var_data_bytes (c->source_blob, old_gid).length;
440 }
441
442 bool long_offset = subset_data_size & ~0xFFFFu;
443 out->flags = long_offset ? 1 : 0;
444
445 HBUINT8 *subset_offsets = c->serializer->allocate_size<HBUINT8> ((long_offset ? 4 : 2) * (num_glyphs + 1));
446 if (!subset_offsets) return_trace (false);
447
448 /* shared tuples */
449 if (!sharedTupleCount || !sharedTuples)
450 out->sharedTuples = 0;
451 else
452 {
453 unsigned int shared_tuple_size = F2DOT14::static_size * axisCount * sharedTupleCount;
454 F2DOT14 *tuples = c->serializer->allocate_size<F2DOT14> (shared_tuple_size);
455 if (!tuples) return_trace (false);
456 out->sharedTuples = (char *) tuples - (char *) out;
457 hb_memcpy (tuples, this+sharedTuples, shared_tuple_size);
458 }
459
460 char *subset_data = c->serializer->allocate_size<char> (subset_data_size);
461 if (!subset_data) return_trace (false);
462 out->dataZ = subset_data - (char *) out;
463
464 unsigned int glyph_offset = 0;
465 for (hb_codepoint_t gid = (c->plan->flags & HB_SUBSET_FLAGS_NOTDEF_OUTLINE) ? 0 : 1;
466 gid < num_glyphs;
467 gid++)
468 {
469 hb_codepoint_t old_gid;
470 hb_bytes_t var_data_bytes = c->plan->old_gid_for_new_gid (gid, &old_gid)
471 ? get_glyph_var_data_bytes (c->source_blob, old_gid)
472 : hb_bytes_t ();
473
474 if (long_offset)
475 ((HBUINT32 *) subset_offsets)[gid] = glyph_offset;
476 else
477 ((HBUINT16 *) subset_offsets)[gid] = glyph_offset / 2;
478
479 if (var_data_bytes.length > 0)
480 hb_memcpy (subset_data, var_data_bytes.arrayZ, var_data_bytes.length);
481 subset_data += var_data_bytes.length;
482 glyph_offset += var_data_bytes.length;
483 }
484 if (long_offset)
485 ((HBUINT32 *) subset_offsets)[num_glyphs] = glyph_offset;
486 else
487 ((HBUINT16 *) subset_offsets)[num_glyphs] = glyph_offset / 2;
488
489 return_trace (true);
490 }
491
492 protected:
493 const hb_bytes_t get_glyph_var_data_bytes (hb_blob_t *blob, hb_codepoint_t glyph) const
494 {
495 unsigned start_offset = get_offset (glyph);
496 unsigned end_offset = get_offset (glyph+1);
497 if (unlikely (end_offset < start_offset)) return hb_bytes_t ();
498 unsigned length = end_offset - start_offset;
499 hb_bytes_t var_data = blob->as_bytes ().sub_array (((unsigned) dataZ) + start_offset, length);
500 return likely (var_data.length >= GlyphVariationData::min_size) ? var_data : hb_bytes_t ();
501 }
502
503 bool is_long_offset () const { return flags & 1; }
504
505 unsigned get_offset (unsigned i) const
506 {
507 if (unlikely (i > glyphCount)) return 0;
508 _hb_compiler_memory_r_barrier ();
509 return is_long_offset () ? get_long_offset_array ()[i] : get_short_offset_array ()[i] * 2;
510 }
511
512 const HBUINT32 * get_long_offset_array () const { return (const HBUINT32 *) &offsetZ; }
513 const HBUINT16 *get_short_offset_array () const { return (const HBUINT16 *) &offsetZ; }
514
515 public:
516 struct accelerator_t
517 {
518 accelerator_t (hb_face_t *face)
519 { table = hb_sanitize_context_t ().reference_table<gvar> (face); }
520 ~accelerator_t () { table.destroy (); }
521
522 private:
523
524 static float infer_delta (const hb_array_t<contour_point_t> points,
525 const hb_array_t<contour_point_t> deltas,
526 unsigned int target, unsigned int prev, unsigned int next,
527 float contour_point_t::*m)
528 {
529 float target_val = points.arrayZ[target].*m;
530 float prev_val = points.arrayZ[prev].*m;
531 float next_val = points.arrayZ[next].*m;
532 float prev_delta = deltas.arrayZ[prev].*m;
533 float next_delta = deltas.arrayZ[next].*m;
534
535 if (prev_val == next_val)
536 return (prev_delta == next_delta) ? prev_delta : 0.f;
537 else if (target_val <= hb_min (prev_val, next_val))
538 return (prev_val < next_val) ? prev_delta : next_delta;
539 else if (target_val >= hb_max (prev_val, next_val))
540 return (prev_val > next_val) ? prev_delta : next_delta;
541
542 /* linear interpolation */
543 float r = (target_val - prev_val) / (next_val - prev_val);
544 return prev_delta + r * (next_delta - prev_delta);
545 }
546
547 static unsigned int next_index (unsigned int i, unsigned int start, unsigned int end)
548 { return (i >= end) ? start : (i + 1); }
549
550 public:
551 bool apply_deltas_to_points (hb_codepoint_t glyph,
552 hb_array_t<int> coords,
553 const hb_array_t<contour_point_t> points) const
554 {
555 if (!coords) return true;
556
557 if (unlikely (glyph >= table->glyphCount)) return true;
558
559 hb_bytes_t var_data_bytes = table->get_glyph_var_data_bytes (table.get_blob (), glyph);
560 if (!var_data_bytes.as<GlyphVariationData> ()->has_data ()) return true;
561 hb_vector_t<unsigned int> shared_indices;
562 GlyphVariationData::tuple_iterator_t iterator;
563 if (!GlyphVariationData::get_tuple_iterator (var_data_bytes, table->axisCount,
564 shared_indices, &iterator))
565 return true; /* so isn't applied at all */
566
567 /* Save original points for inferred delta calculation */
568 contour_point_vector_t orig_points_vec;
569 orig_points_vec.extend (points);
570 if (unlikely (orig_points_vec.in_error ())) return false;
571 auto orig_points = orig_points_vec.as_array ();
572
573 contour_point_vector_t deltas_vec; /* flag is used to indicate referenced point */
574 if (unlikely (!deltas_vec.resize (points.length, false))) return false;
575 auto deltas = deltas_vec.as_array ();
576
577 hb_vector_t<unsigned> end_points;
578 for (unsigned i = 0; i < points.length; ++i)
579 if (points.arrayZ[i].is_end_point)
580 end_points.push (i);
581
582 unsigned num_coords = table->axisCount;
583 hb_array_t<const F2DOT14> shared_tuples = (table+table->sharedTuples).as_array (table->sharedTupleCount * table->axisCount);
584
585 hb_vector_t<unsigned int> private_indices;
586 hb_vector_t<int> x_deltas;
587 hb_vector_t<int> y_deltas;
588 do
589 {
590 float scalar = iterator.current_tuple->calculate_scalar (coords, num_coords, shared_tuples);
591 if (scalar == 0.f) continue;
592 const HBUINT8 *p = iterator.get_serialized_data ();
593 unsigned int length = iterator.current_tuple->get_data_size ();
594 if (unlikely (!iterator.var_data_bytes.check_range (p, length)))
595 return false;
596
597 const HBUINT8 *end = p + length;
598
599 bool has_private_points = iterator.current_tuple->has_private_points ();
600 if (has_private_points &&
601 !GlyphVariationData::unpack_points (p, private_indices, end))
602 return false;
603 const hb_array_t<unsigned int> &indices = has_private_points ? private_indices : shared_indices;
604
605 bool apply_to_all = (indices.length == 0);
606 unsigned int num_deltas = apply_to_all ? points.length : indices.length;
607 if (unlikely (!x_deltas.resize (num_deltas, false))) return false;
608 if (unlikely (!GlyphVariationData::unpack_deltas (p, x_deltas, end))) return false;
609 if (unlikely (!y_deltas.resize (num_deltas, false))) return false;
610 if (unlikely (!GlyphVariationData::unpack_deltas (p, y_deltas, end))) return false;
611
612 hb_memset (deltas.arrayZ, 0, deltas.get_size ());
613
614 unsigned ref_points = 0;
615 if (scalar != 1.0f)
616 for (unsigned int i = 0; i < num_deltas; i++)
617 {
618 unsigned int pt_index = apply_to_all ? i : indices[i];
619 if (unlikely (pt_index >= deltas.length)) continue;
620 auto &delta = deltas.arrayZ[pt_index];
621 ref_points += !delta.flag;
622 delta.flag = 1; /* this point is referenced, i.e., explicit deltas specified */
623 delta.x += x_deltas.arrayZ[i] * scalar;
624 delta.y += y_deltas.arrayZ[i] * scalar;
625 }
626 else
627 for (unsigned int i = 0; i < num_deltas; i++)
628 {
629 unsigned int pt_index = apply_to_all ? i : indices[i];
630 if (unlikely (pt_index >= deltas.length)) continue;
631 auto &delta = deltas.arrayZ[pt_index];
632 ref_points += !delta.flag;
633 delta.flag = 1; /* this point is referenced, i.e., explicit deltas specified */
634 delta.x += x_deltas.arrayZ[i];
635 delta.y += y_deltas.arrayZ[i];
636 }
637
638 /* infer deltas for unreferenced points */
639 if (ref_points && ref_points < orig_points.length)
640 {
641 unsigned start_point = 0;
642 for (unsigned c = 0; c < end_points.length; c++)
643 {
644 unsigned end_point = end_points.arrayZ[c];
645
646 /* Check the number of unreferenced points in a contour. If no unref points or no ref points, nothing to do. */
647 unsigned unref_count = 0;
648 for (unsigned i = start_point; i < end_point + 1; i++)
649 unref_count += deltas.arrayZ[i].flag;
650 unref_count = (end_point - start_point + 1) - unref_count;
651
652 unsigned j = start_point;
653 if (unref_count == 0 || unref_count > end_point - start_point)
654 goto no_more_gaps;
655
656 for (;;)
657 {
658 /* Locate the next gap of unreferenced points between two referenced points prev and next.
659 * Note that a gap may wrap around at left (start_point) and/or at right (end_point).
660 */
661 unsigned int prev, next, i;
662 for (;;)
663 {
664 i = j;
665 j = next_index (i, start_point, end_point);
666 if (deltas.arrayZ[i].flag && !deltas.arrayZ[j].flag) break;
667 }
668 prev = j = i;
669 for (;;)
670 {
671 i = j;
672 j = next_index (i, start_point, end_point);
673 if (!deltas.arrayZ[i].flag && deltas.arrayZ[j].flag) break;
674 }
675 next = j;
676 /* Infer deltas for all unref points in the gap between prev and next */
677 i = prev;
678 for (;;)
679 {
680 i = next_index (i, start_point, end_point);
681 if (i == next) break;
682 deltas.arrayZ[i].x = infer_delta (orig_points, deltas, i, prev, next, &contour_point_t::x);
683 deltas.arrayZ[i].y = infer_delta (orig_points, deltas, i, prev, next, &contour_point_t::y);
684 if (--unref_count == 0) goto no_more_gaps;
685 }
686 }
687 no_more_gaps:
688 start_point = end_point + 1;
689 }
690 }
691
692 /* apply specified / inferred deltas to points */
693 for (unsigned int i = 0; i < points.length; i++)
694 {
695 points.arrayZ[i].x += deltas.arrayZ[i].x;
696 points.arrayZ[i].y += deltas.arrayZ[i].y;
697 }
698 } while (iterator.move_to_next ());
699
700 return true;
701 }
702
703 unsigned int get_axis_count () const { return table->axisCount; }
704
705 private:
706 hb_blob_ptr_t<gvar> table;
707 };
708
709 protected:
710 FixedVersion<>version; /* Version number of the glyph variations table
711 * Set to 0x00010000u. */
712 HBUINT16 axisCount; /* The number of variation axes for this font. This must be
713 * the same number as axisCount in the 'fvar' table. */
714 HBUINT16 sharedTupleCount;
715 /* The number of shared tuple records. Shared tuple records
716 * can be referenced within glyph variation data tables for
717 * multiple glyphs, as opposed to other tuple records stored
718 * directly within a glyph variation data table. */
719 NNOffset32To<UnsizedArrayOf<F2DOT14>>
720 sharedTuples; /* Offset from the start of this table to the shared tuple records.
721 * Array of tuple records shared across all glyph variation data tables. */
722 HBUINT16 glyphCount; /* The number of glyphs in this font. This must match the number of
723 * glyphs stored elsewhere in the font. */
724 HBUINT16 flags; /* Bit-field that gives the format of the offset array that follows.
725 * If bit 0 is clear, the offsets are uint16; if bit 0 is set, the
726 * offsets are uint32. */
727 Offset32To<GlyphVariationData>
728 dataZ; /* Offset from the start of this table to the array of
729 * GlyphVariationData tables. */
730 UnsizedArrayOf<HBUINT8>
731 offsetZ; /* Offsets from the start of the GlyphVariationData array
732 * to each GlyphVariationData table. */
733 public:
734 DEFINE_SIZE_ARRAY (20, offsetZ);
735 };
736
737 struct gvar_accelerator_t : gvar::accelerator_t {
738 gvar_accelerator_t (hb_face_t *face) : gvar::accelerator_t (face) {}
739 };
740
741 } /* namespace OT */
742
743 #endif /* HB_OT_VAR_GVAR_TABLE_HH */