1/*
2 * Copyright © 2018 Adobe Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Adobe Author(s): Michiharu Ariza
25 */
26
27#include "hb.hh"
28
29#ifndef HB_NO_SUBSET_CFF
30
31#include "hb-open-type.hh"
32#include "hb-ot-cff2-table.hh"
33#include "hb-set.h"
34#include "hb-subset-plan.hh"
35#include "hb-subset-cff-common.hh"
36#include "hb-cff2-interp-cs.hh"
37
38using namespace CFF;
39
40struct cff2_sub_table_info_t : cff_sub_table_info_t
41{
42 cff2_sub_table_info_t ()
43 : cff_sub_table_info_t (),
44 var_store_link (0)
45 {}
46
47 objidx_t var_store_link;
48};
49
50struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
51{
52 bool serialize (hb_serialize_context_t *c,
53 const op_str_t &opstr,
54 const cff2_sub_table_info_t &info) const
55 {
56 TRACE_SERIALIZE (this);
57
58 switch (opstr.op)
59 {
60 case OpCode_vstore:
61 if (info.var_store_link)
62 return_trace (FontDict::serialize_link4_op(c, opstr.op, info.var_store_link));
63 else
64 return_trace (true);
65
66 default:
67 return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, info));
68 }
69 }
70};
71
72struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t, blend_arg_t>
73{
74 static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
75 {
76 switch (op)
77 {
78 case OpCode_return:
79 case OpCode_endchar:
80 /* dummy opcodes in CFF2. ignore */
81 break;
82
83 case OpCode_hstem:
84 case OpCode_hstemhm:
85 case OpCode_vstem:
86 case OpCode_vstemhm:
87 case OpCode_hintmask:
88 case OpCode_cntrmask:
89 if (param.drop_hints)
90 {
91 env.clear_args ();
92 return;
93 }
94 HB_FALLTHROUGH;
95
96 default:
97 SUPER::flush_args_and_op (op, env, param);
98 break;
99 }
100 }
101
102 static void flush_args (cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
103 {
104 for (unsigned int i = 0; i < env.argStack.get_count ();)
105 {
106 const blend_arg_t &arg = env.argStack[i];
107 if (arg.blending ())
108 {
109 if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
110 {
111 env.set_error ();
112 return;
113 }
114 flatten_blends (arg, i, env, param);
115 i += arg.numValues;
116 }
117 else
118 {
119 str_encoder_t encoder (param.flatStr);
120 encoder.encode_num_cs (arg);
121 i++;
122 }
123 }
124 SUPER::flush_args (env, param);
125 }
126
127 static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
128 {
129 /* flatten the default values */
130 str_encoder_t encoder (param.flatStr);
131 for (unsigned int j = 0; j < arg.numValues; j++)
132 {
133 const blend_arg_t &arg1 = env.argStack[i + j];
134 if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
135 (arg1.deltas.length == env.get_region_count ())))))
136 {
137 env.set_error ();
138 return;
139 }
140 encoder.encode_num_cs (arg1);
141 }
142 /* flatten deltas for each value */
143 for (unsigned int j = 0; j < arg.numValues; j++)
144 {
145 const blend_arg_t &arg1 = env.argStack[i + j];
146 for (unsigned int k = 0; k < arg1.deltas.length; k++)
147 encoder.encode_num_cs (arg1.deltas[k]);
148 }
149 /* flatten the number of values followed by blend operator */
150 encoder.encode_int (arg.numValues);
151 encoder.encode_op (OpCode_blendcs);
152 }
153
154 static void flush_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
155 {
156 switch (op)
157 {
158 case OpCode_return:
159 case OpCode_endchar:
160 return;
161 default:
162 str_encoder_t encoder (param.flatStr);
163 encoder.encode_op (op);
164 }
165 }
166
167 static void flush_hintmask (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, flatten_param_t& param)
168 {
169 SUPER::flush_hintmask (op, env, param);
170 if (!param.drop_hints)
171 {
172 str_encoder_t encoder (param.flatStr);
173 for (unsigned int i = 0; i < env.hintmask_size; i++)
174 encoder.encode_byte (env.str_ref[i]);
175 }
176 }
177
178 private:
179 typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t, blend_arg_t> SUPER;
180 typedef cs_opset_t<blend_arg_t, cff2_cs_opset_flatten_t, cff2_cs_opset_flatten_t, cff2_cs_interp_env_t<blend_arg_t>, flatten_param_t> CSOPSET;
181};
182
183struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t, blend_arg_t>
184{
185 static void process_op (op_code_t op, cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param)
186 {
187 switch (op) {
188
189 case OpCode_return:
190 param.current_parsed_str->set_parsed ();
191 env.return_from_subr ();
192 param.set_current_str (env, false);
193 break;
194
195 case OpCode_endchar:
196 param.current_parsed_str->set_parsed ();
197 SUPER::process_op (op, env, param);
198 break;
199
200 case OpCode_callsubr:
201 process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
202 break;
203
204 case OpCode_callgsubr:
205 process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
206 break;
207
208 default:
209 SUPER::process_op (op, env, param);
210 param.current_parsed_str->add_op (op, env.str_ref);
211 break;
212 }
213 }
214
215 protected:
216 static void process_call_subr (op_code_t op, cs_type_t type,
217 cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param,
218 cff2_biased_subrs_t& subrs, hb_set_t *closure)
219 {
220 byte_str_ref_t str_ref = env.str_ref;
221 env.call_subr (subrs, type);
222 param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
223 closure->add (env.context.subr_num);
224 param.set_current_str (env, true);
225 }
226
227 private:
228 typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t, blend_arg_t> SUPER;
229};
230
231struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs, const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t<blend_arg_t>, cff2_cs_opset_subr_subset_t>
232{
233 cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc_, const hb_subset_plan_t *plan_)
234 : subr_subsetter_t (acc_, plan_) {}
235
236 static void complete_parsed_str (cff2_cs_interp_env_t<blend_arg_t> &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
237 {
238 /* vsindex is inserted at the beginning of the charstring as necessary */
239 if (env.seen_vsindex ())
240 {
241 number_t ivs;
242 ivs.set_int ((int)env.get_ivs ());
243 charstring.set_prefix (ivs, OpCode_vsindexcs);
244 }
245 }
246};
247
248struct cff2_private_blend_encoder_param_t
249{
250 cff2_private_blend_encoder_param_t (hb_serialize_context_t *c,
251 const CFF2VariationStore *varStore,
252 hb_array_t<int> normalized_coords) :
253 c (c), varStore (varStore), normalized_coords (normalized_coords) {}
254
255 void init () {}
256
257 void process_blend ()
258 {
259 if (!seen_blend)
260 {
261 region_count = varStore->varStore.get_region_index_count (ivs);
262 scalars.resize_exact (region_count);
263 varStore->varStore.get_region_scalars (ivs, normalized_coords.arrayZ, normalized_coords.length,
264 &scalars[0], region_count);
265 seen_blend = true;
266 }
267 }
268
269 double blend_deltas (hb_array_t<const number_t> deltas) const
270 {
271 double v = 0;
272 if (likely (scalars.length == deltas.length))
273 {
274 unsigned count = scalars.length;
275 for (unsigned i = 0; i < count; i++)
276 v += (double) scalars.arrayZ[i] * deltas.arrayZ[i].to_real ();
277 }
278 return v;
279 }
280
281
282 hb_serialize_context_t *c = nullptr;
283 bool seen_blend = false;
284 unsigned ivs = 0;
285 unsigned region_count = 0;
286 hb_vector_t<float> scalars;
287 const CFF2VariationStore *varStore = nullptr;
288 hb_array_t<int> normalized_coords;
289};
290
291struct cff2_private_dict_blend_opset_t : dict_opset_t
292{
293 static void process_arg_blend (cff2_private_blend_encoder_param_t& param,
294 number_t &arg,
295 const hb_array_t<const number_t> blends,
296 unsigned n, unsigned i)
297 {
298 arg.set_int (round (arg.to_real () + param.blend_deltas (blends)));
299 }
300
301 static void process_blend (cff2_priv_dict_interp_env_t& env, cff2_private_blend_encoder_param_t& param)
302 {
303 unsigned int n, k;
304
305 param.process_blend ();
306 k = param.region_count;
307 n = env.argStack.pop_uint ();
308 /* copy the blend values into blend array of the default values */
309 unsigned int start = env.argStack.get_count () - ((k+1) * n);
310 /* let an obvious error case fail, but note CFF2 spec doesn't forbid n==0 */
311 if (unlikely (start > env.argStack.get_count ()))
312 {
313 env.set_error ();
314 return;
315 }
316 for (unsigned int i = 0; i < n; i++)
317 {
318 const hb_array_t<const number_t> blends = env.argStack.sub_array (start + n + (i * k), k);
319 process_arg_blend (param, env.argStack[start + i], blends, n, i);
320 }
321
322 /* pop off blend values leaving default values now adorned with blend values */
323 env.argStack.pop (k * n);
324 }
325
326 static void process_op (op_code_t op, cff2_priv_dict_interp_env_t& env, cff2_private_blend_encoder_param_t& param)
327 {
328 switch (op) {
329 case OpCode_StdHW:
330 case OpCode_StdVW:
331 case OpCode_BlueScale:
332 case OpCode_BlueShift:
333 case OpCode_BlueFuzz:
334 case OpCode_ExpansionFactor:
335 case OpCode_LanguageGroup:
336 case OpCode_BlueValues:
337 case OpCode_OtherBlues:
338 case OpCode_FamilyBlues:
339 case OpCode_FamilyOtherBlues:
340 case OpCode_StemSnapH:
341 case OpCode_StemSnapV:
342 break;
343 case OpCode_vsindexdict:
344 env.process_vsindex ();
345 param.ivs = env.get_ivs ();
346 env.clear_args ();
347 return;
348 case OpCode_blenddict:
349 process_blend (env, param);
350 return;
351
352 default:
353 dict_opset_t::process_op (op, env);
354 if (!env.argStack.is_empty ()) return;
355 break;
356 }
357
358 if (unlikely (env.in_error ())) return;
359
360 // Write args then op
361
362 str_buff_t str;
363 str_encoder_t encoder (str);
364
365 unsigned count = env.argStack.get_count ();
366 for (unsigned i = 0; i < count; i++)
367 encoder.encode_num_tp (env.argStack[i]);
368
369 encoder.encode_op (op);
370
371 auto bytes = str.as_bytes ();
372 param.c->embed (&bytes, bytes.length);
373
374 env.clear_args ();
375 }
376};
377
378struct cff2_private_dict_op_serializer_t : op_serializer_t
379{
380 cff2_private_dict_op_serializer_t (bool desubroutinize_, bool drop_hints_, bool pinned_,
381 const CFF::CFF2VariationStore* varStore_,
382 hb_array_t<int> normalized_coords_)
383 : desubroutinize (desubroutinize_), drop_hints (drop_hints_), pinned (pinned_),
384 varStore (varStore_), normalized_coords (normalized_coords_) {}
385
386 bool serialize (hb_serialize_context_t *c,
387 const op_str_t &opstr,
388 objidx_t subrs_link) const
389 {
390 TRACE_SERIALIZE (this);
391
392 if (drop_hints && dict_opset_t::is_hint_op (opstr.op))
393 return_trace (true);
394
395 if (opstr.op == OpCode_Subrs)
396 {
397 if (desubroutinize || !subrs_link)
398 return_trace (true);
399 else
400 return_trace (FontDict::serialize_link2_op (c, opstr.op, subrs_link));
401 }
402
403 if (pinned)
404 {
405 // Reinterpret opstr and process blends.
406 cff2_priv_dict_interp_env_t env {hb_ubytes_t (opstr.ptr, opstr.length)};
407 cff2_private_blend_encoder_param_t param (c, varStore, normalized_coords);
408 dict_interpreter_t<cff2_private_dict_blend_opset_t, cff2_private_blend_encoder_param_t, cff2_priv_dict_interp_env_t> interp (env);
409 return_trace (interp.interpret (param));
410 }
411
412 return_trace (copy_opstr (c, opstr));
413 }
414
415 protected:
416 const bool desubroutinize;
417 const bool drop_hints;
418 const bool pinned;
419 const CFF::CFF2VariationStore* varStore;
420 hb_array_t<int> normalized_coords;
421};
422
423
424namespace OT {
425struct cff2_subset_plan
426{
427 bool create (const OT::cff2::accelerator_subset_t &acc,
428 hb_subset_plan_t *plan)
429 {
430 /* make sure notdef is first */
431 hb_codepoint_t old_glyph;
432 if (!plan->old_gid_for_new_gid (0, &old_glyph) || (old_glyph != 0)) return false;
433
434 num_glyphs = plan->num_output_glyphs ();
435 orig_fdcount = acc.fdArray->count;
436
437 drop_hints = plan->flags & HB_SUBSET_FLAGS_NO_HINTING;
438 pinned = (bool) plan->normalized_coords;
439 desubroutinize = plan->flags & HB_SUBSET_FLAGS_DESUBROUTINIZE ||
440 pinned; // For instancing we need this path
441
442 if (desubroutinize)
443 {
444 /* Flatten global & local subrs */
445 subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t<blend_arg_t>, cff2_cs_opset_flatten_t>
446 flattener(acc, plan);
447 if (!flattener.flatten (subset_charstrings))
448 return false;
449 }
450 else
451 {
452 cff2_subr_subsetter_t subr_subsetter (acc, plan);
453
454 /* Subset subrs: collect used subroutines, leaving all unused ones behind */
455 if (!subr_subsetter.subset ())
456 return false;
457
458 /* encode charstrings, global subrs, local subrs with new subroutine numbers */
459 if (!subr_subsetter.encode_charstrings (subset_charstrings, !pinned))
460 return false;
461
462 if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
463 return false;
464
465 /* local subrs */
466 if (!subset_localsubrs.resize (orig_fdcount))
467 return false;
468 for (unsigned int fd = 0; fd < orig_fdcount; fd++)
469 {
470 subset_localsubrs[fd].init ();
471 if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
472 return false;
473 }
474 }
475
476 /* FDSelect */
477 if (acc.fdSelect != &Null (CFF2FDSelect))
478 {
479 if (unlikely (!hb_plan_subset_cff_fdselect (plan,
480 orig_fdcount,
481 *(const FDSelect *)acc.fdSelect,
482 subset_fdcount,
483 subset_fdselect_size,
484 subset_fdselect_format,
485 subset_fdselect_ranges,
486 fdmap)))
487 return false;
488 }
489 else
490 fdmap.identity (1);
491
492 return true;
493 }
494
495 cff2_sub_table_info_t info;
496
497 unsigned int num_glyphs;
498 unsigned int orig_fdcount = 0;
499 unsigned int subset_fdcount = 1;
500 unsigned int subset_fdselect_size = 0;
501 unsigned int subset_fdselect_format = 0;
502 bool pinned = false;
503 hb_vector_t<code_pair_t> subset_fdselect_ranges;
504
505 hb_inc_bimap_t fdmap;
506
507 str_buff_vec_t subset_charstrings;
508 str_buff_vec_t subset_globalsubrs;
509 hb_vector_t<str_buff_vec_t> subset_localsubrs;
510
511 bool drop_hints = false;
512 bool desubroutinize = false;
513};
514} // namespace OT
515
516bool
517OT::cff2::accelerator_subset_t::serialize (hb_serialize_context_t *c,
518 struct cff2_subset_plan &plan,
519 hb_array_t<int> normalized_coords) const
520{
521 /* private dicts & local subrs */
522 hb_vector_t<table_info_t> private_dict_infos;
523 if (unlikely (!private_dict_infos.resize (plan.subset_fdcount))) return false;
524
525 for (int i = (int)privateDicts.length; --i >= 0 ;)
526 {
527 if (plan.fdmap.has (i))
528 {
529 objidx_t subrs_link = 0;
530
531 if (plan.subset_localsubrs[i].length > 0)
532 {
533 auto *dest = c->push <CFF2Subrs> ();
534 if (likely (dest->serialize (c, plan.subset_localsubrs[i])))
535 subrs_link = c->pop_pack (false);
536 else
537 {
538 c->pop_discard ();
539 return false;
540 }
541 }
542 auto *pd = c->push<PrivateDict> ();
543 cff2_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints, plan.pinned,
544 varStore, normalized_coords);
545 if (likely (pd->serialize (c, privateDicts[i], privSzr, subrs_link)))
546 {
547 unsigned fd = plan.fdmap[i];
548 private_dict_infos[fd].size = c->length ();
549 private_dict_infos[fd].link = c->pop_pack ();
550 }
551 else
552 {
553 c->pop_discard ();
554 return false;
555 }
556 }
557 }
558
559 /* CharStrings */
560 {
561 c->push ();
562
563 unsigned data_size = 0;
564 unsigned total_size = CFF2CharStrings::total_size (plan.subset_charstrings, &data_size);
565 if (unlikely (!c->start_zerocopy (total_size)))
566 return false;
567
568 auto *cs = c->start_embed<CFF2CharStrings> ();
569 if (likely (cs->serialize (c, plan.subset_charstrings, &data_size)))
570 plan.info.char_strings_link = c->pop_pack (false);
571 else
572 {
573 c->pop_discard ();
574 return false;
575 }
576 }
577
578 /* FDSelect */
579 if (fdSelect != &Null (CFF2FDSelect))
580 {
581 c->push ();
582 if (likely (hb_serialize_cff_fdselect (c, plan.num_glyphs, *(const FDSelect *)fdSelect,
583 plan.orig_fdcount,
584 plan.subset_fdselect_format, plan.subset_fdselect_size,
585 plan.subset_fdselect_ranges)))
586 plan.info.fd_select.link = c->pop_pack ();
587 else
588 {
589 c->pop_discard ();
590 return false;
591 }
592 }
593
594 /* FDArray (FD Index) */
595 {
596 auto *fda = c->push<CFF2FDArray> ();
597 cff_font_dict_op_serializer_t fontSzr;
598 auto it =
599 + hb_zip (+ hb_iter (fontDicts)
600 | hb_filter ([&] (const cff2_font_dict_values_t &_)
601 { return plan.fdmap.has (&_ - &fontDicts[0]); }),
602 hb_iter (private_dict_infos))
603 ;
604 if (unlikely (!fda->serialize (c, it, fontSzr)))
605 {
606 c->pop_discard ();
607 return false;
608 }
609 plan.info.fd_array_link = c->pop_pack (false);
610 }
611
612 /* variation store */
613 if (varStore != &Null (CFF2VariationStore) &&
614 !plan.pinned)
615 {
616 auto *dest = c->push<CFF2VariationStore> ();
617 if (unlikely (!dest->serialize (c, varStore)))
618 {
619 c->pop_discard ();
620 return false;
621 }
622 plan.info.var_store_link = c->pop_pack (false);
623 }
624
625 OT::cff2 *cff2 = c->allocate_min<OT::cff2> ();
626 if (unlikely (!cff2)) return false;
627
628 /* header */
629 cff2->version.major = 0x02;
630 cff2->version.minor = 0x00;
631 cff2->topDict = OT::cff2::static_size;
632
633 /* top dict */
634 {
635 TopDict &dict = cff2 + cff2->topDict;
636 cff2_top_dict_op_serializer_t topSzr;
637 if (unlikely (!dict.serialize (c, topDict, topSzr, plan.info))) return false;
638 cff2->topDictSize = c->head - (const char *)&dict;
639 }
640
641 /* global subrs */
642 {
643 auto *dest = c->start_embed <CFF2Subrs> ();
644 return dest->serialize (c, plan.subset_globalsubrs);
645 }
646}
647
648bool
649OT::cff2::accelerator_subset_t::subset (hb_subset_context_t *c) const
650{
651 cff2_subset_plan cff2_plan;
652
653 if (unlikely (!cff2_plan.create (*this, c->plan))) return false;
654 return serialize (c->serializer, cff2_plan,
655 c->plan->normalized_coords.as_array ());
656}
657
658#endif
659