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-cff2.hh"
35#include "hb-subset-plan.hh"
36#include "hb-subset-cff-common.hh"
37#include "hb-cff2-interp-cs.hh"
38
39using namespace CFF;
40
41struct cff2_sub_table_offsets_t : cff_sub_table_offsets_t
42{
43 cff2_sub_table_offsets_t ()
44 : cff_sub_table_offsets_t (),
45 varStoreOffset (0)
46 {}
47
48 unsigned int varStoreOffset;
49};
50
51struct cff2_top_dict_op_serializer_t : cff_top_dict_op_serializer_t<>
52{
53 bool serialize (hb_serialize_context_t *c,
54 const op_str_t &opstr,
55 const cff2_sub_table_offsets_t &offsets) const
56 {
57 TRACE_SERIALIZE (this);
58
59 switch (opstr.op)
60 {
61 case OpCode_vstore:
62 return_trace (FontDict::serialize_offset4_op(c, opstr.op, offsets.varStoreOffset));
63
64 default:
65 return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, offsets));
66 }
67 }
68
69 unsigned int calculate_serialized_size (const op_str_t &opstr) const
70 {
71 switch (opstr.op)
72 {
73 case OpCode_vstore:
74 return OpCode_Size (OpCode_longintdict) + 4 + OpCode_Size (opstr.op);
75
76 default:
77 return cff_top_dict_op_serializer_t<>::calculate_serialized_size (opstr);
78 }
79 }
80};
81
82struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
83{
84 static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
85 {
86 switch (op)
87 {
88 case OpCode_return:
89 case OpCode_endchar:
90 /* dummy opcodes in CFF2. ignore */
91 break;
92
93 case OpCode_hstem:
94 case OpCode_hstemhm:
95 case OpCode_vstem:
96 case OpCode_vstemhm:
97 case OpCode_hintmask:
98 case OpCode_cntrmask:
99 if (param.drop_hints)
100 {
101 env.clear_args ();
102 return;
103 }
104 HB_FALLTHROUGH;
105
106 default:
107 SUPER::flush_args_and_op (op, env, param);
108 break;
109 }
110 }
111
112 static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
113 {
114 for (unsigned int i = 0; i < env.argStack.get_count ();)
115 {
116 const blend_arg_t &arg = env.argStack[i];
117 if (arg.blending ())
118 {
119 if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
120 {
121 env.set_error ();
122 return;
123 }
124 flatten_blends (arg, i, env, param);
125 i += arg.numValues;
126 }
127 else
128 {
129 str_encoder_t encoder (param.flatStr);
130 encoder.encode_num (arg);
131 i++;
132 }
133 }
134 SUPER::flush_args (env, param);
135 }
136
137 static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t &env, flatten_param_t& param)
138 {
139 /* flatten the default values */
140 str_encoder_t encoder (param.flatStr);
141 for (unsigned int j = 0; j < arg.numValues; j++)
142 {
143 const blend_arg_t &arg1 = env.argStack[i + j];
144 if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
145 (arg1.deltas.length == env.get_region_count ())))))
146 {
147 env.set_error ();
148 return;
149 }
150 encoder.encode_num (arg1);
151 }
152 /* flatten deltas for each value */
153 for (unsigned int j = 0; j < arg.numValues; j++)
154 {
155 const blend_arg_t &arg1 = env.argStack[i + j];
156 for (unsigned int k = 0; k < arg1.deltas.length; k++)
157 encoder.encode_num (arg1.deltas[k]);
158 }
159 /* flatten the number of values followed by blend operator */
160 encoder.encode_int (arg.numValues);
161 encoder.encode_op (OpCode_blendcs);
162 }
163
164 static void flush_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
165 {
166 switch (op)
167 {
168 case OpCode_return:
169 case OpCode_endchar:
170 return;
171 default:
172 str_encoder_t encoder (param.flatStr);
173 encoder.encode_op (op);
174 }
175 }
176
177 private:
178 typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t> SUPER;
179 typedef cs_opset_t<blend_arg_t, cff2_cs_opset_flatten_t, cff2_cs_opset_flatten_t, cff2_cs_interp_env_t, flatten_param_t> CSOPSET;
180};
181
182struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
183{
184 static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
185 {
186 switch (op) {
187
188 case OpCode_return:
189 param.current_parsed_str->set_parsed ();
190 env.return_from_subr ();
191 param.set_current_str (env, false);
192 break;
193
194 case OpCode_endchar:
195 param.current_parsed_str->set_parsed ();
196 SUPER::process_op (op, env, param);
197 break;
198
199 case OpCode_callsubr:
200 process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
201 break;
202
203 case OpCode_callgsubr:
204 process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
205 break;
206
207 default:
208 SUPER::process_op (op, env, param);
209 param.current_parsed_str->add_op (op, env.str_ref);
210 break;
211 }
212 }
213
214 protected:
215 static void process_call_subr (op_code_t op, cs_type_t type,
216 cff2_cs_interp_env_t &env, subr_subset_param_t& param,
217 cff2_biased_subrs_t& subrs, hb_set_t *closure)
218 {
219 byte_str_ref_t str_ref = env.str_ref;
220 env.call_subr (subrs, type);
221 param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
222 closure->add (env.context.subr_num);
223 param.set_current_str (env, true);
224 }
225
226 private:
227 typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t> SUPER;
228};
229
230struct cff2_subr_subsetter_t : subr_subsetter_t<cff2_subr_subsetter_t, CFF2Subrs, const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_subr_subset_t>
231{
232 cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc_, const hb_subset_plan_t *plan_)
233 : subr_subsetter_t (acc_, plan_) {}
234
235 static void finalize_parsed_str (cff2_cs_interp_env_t &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
236 {
237 /* vsindex is inserted at the beginning of the charstring as necessary */
238 if (env.seen_vsindex ())
239 {
240 number_t ivs;
241 ivs.set_int ((int)env.get_ivs ());
242 charstring.set_prefix (ivs, OpCode_vsindexcs);
243 }
244 }
245};
246
247struct cff2_subset_plan {
248 cff2_subset_plan ()
249 : final_size (0),
250 orig_fdcount (0),
251 subset_fdcount(1),
252 subset_fdselect_format (0),
253 drop_hints (false),
254 desubroutinize (false)
255 {
256 subset_fdselect_ranges.init ();
257 fdmap.init ();
258 subset_charstrings.init ();
259 subset_globalsubrs.init ();
260 subset_localsubrs.init ();
261 privateDictInfos.init ();
262 }
263
264 ~cff2_subset_plan ()
265 {
266 subset_fdselect_ranges.fini ();
267 fdmap.fini ();
268 subset_charstrings.fini_deep ();
269 subset_globalsubrs.fini_deep ();
270 subset_localsubrs.fini_deep ();
271 privateDictInfos.fini ();
272 }
273
274 bool create (const OT::cff2::accelerator_subset_t &acc,
275 hb_subset_plan_t *plan)
276 {
277 final_size = 0;
278 orig_fdcount = acc.fdArray->count;
279
280 drop_hints = plan->drop_hints;
281 desubroutinize = plan->desubroutinize;
282
283 /* CFF2 header */
284 final_size += OT::cff2::static_size;
285
286 /* top dict */
287 {
288 cff2_top_dict_op_serializer_t topSzr;
289 offsets.topDictInfo.size = TopDict::calculate_serialized_size (acc.topDict, topSzr);
290 final_size += offsets.topDictInfo.size;
291 }
292
293 if (desubroutinize)
294 {
295 /* Flatten global & local subrs */
296 subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_flatten_t>
297 flattener(acc, plan);
298 if (!flattener.flatten (subset_charstrings))
299 return false;
300
301 /* no global/local subroutines */
302 offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (1, 0, 0);
303 }
304 else
305 {
306 cff2_subr_subsetter_t subr_subsetter (acc, plan);
307
308 /* Subset subrs: collect used subroutines, leaving all unused ones behind */
309 if (!subr_subsetter.subset ())
310 return false;
311
312 /* encode charstrings, global subrs, local subrs with new subroutine numbers */
313 if (!subr_subsetter.encode_charstrings (subset_charstrings))
314 return false;
315
316 if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
317 return false;
318
319 /* global subrs */
320 unsigned int dataSize = subset_globalsubrs.total_size ();
321 offsets.globalSubrsInfo.offSize = calcOffSize (dataSize);
322 offsets.globalSubrsInfo.size = CFF2Subrs::calculate_serialized_size (offsets.globalSubrsInfo.offSize, subset_globalsubrs.length, dataSize);
323
324 /* local subrs */
325 if (!offsets.localSubrsInfos.resize (orig_fdcount))
326 return false;
327 if (!subset_localsubrs.resize (orig_fdcount))
328 return false;
329 for (unsigned int fd = 0; fd < orig_fdcount; fd++)
330 {
331 subset_localsubrs[fd].init ();
332 offsets.localSubrsInfos[fd].init ();
333 if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
334 return false;
335
336 unsigned int dataSize = subset_localsubrs[fd].total_size ();
337 if (dataSize > 0)
338 {
339 offsets.localSubrsInfos[fd].offset = final_size;
340 offsets.localSubrsInfos[fd].offSize = calcOffSize (dataSize);
341 offsets.localSubrsInfos[fd].size = CFF2Subrs::calculate_serialized_size (offsets.localSubrsInfos[fd].offSize, subset_localsubrs[fd].length, dataSize);
342 }
343 }
344 }
345
346 /* global subrs */
347 offsets.globalSubrsInfo.offset = final_size;
348 final_size += offsets.globalSubrsInfo.size;
349
350 /* variation store */
351 if (acc.varStore != &Null(CFF2VariationStore))
352 {
353 offsets.varStoreOffset = final_size;
354 final_size += acc.varStore->get_size ();
355 }
356
357 /* FDSelect */
358 if (acc.fdSelect != &Null(CFF2FDSelect))
359 {
360 offsets.FDSelectInfo.offset = final_size;
361 if (unlikely (!hb_plan_subset_cff_fdselect (plan,
362 orig_fdcount,
363 *(const FDSelect *)acc.fdSelect,
364 subset_fdcount,
365 offsets.FDSelectInfo.size,
366 subset_fdselect_format,
367 subset_fdselect_ranges,
368 fdmap)))
369 return false;
370
371 final_size += offsets.FDSelectInfo.size;
372 }
373 else
374 fdmap.identity (1);
375
376 /* FDArray (FDIndex) */
377 {
378 offsets.FDArrayInfo.offset = final_size;
379 cff_font_dict_op_serializer_t fontSzr;
380 unsigned int dictsSize = 0;
381 for (unsigned int i = 0; i < acc.fontDicts.length; i++)
382 if (fdmap.has (i))
383 dictsSize += FontDict::calculate_serialized_size (acc.fontDicts[i], fontSzr);
384
385 offsets.FDArrayInfo.offSize = calcOffSize (dictsSize);
386 final_size += CFF2Index::calculate_serialized_size (offsets.FDArrayInfo.offSize, subset_fdcount, dictsSize);
387 }
388
389 /* CharStrings */
390 {
391 offsets.charStringsInfo.offset = final_size;
392 unsigned int dataSize = subset_charstrings.total_size ();
393 offsets.charStringsInfo.offSize = calcOffSize (dataSize);
394 final_size += CFF2CharStrings::calculate_serialized_size (offsets.charStringsInfo.offSize, plan->num_output_glyphs (), dataSize);
395 }
396
397 /* private dicts & local subrs */
398 offsets.privateDictsOffset = final_size;
399 for (unsigned int i = 0; i < orig_fdcount; i++)
400 {
401 if (fdmap.has (i))
402 {
403 bool has_localsubrs = offsets.localSubrsInfos[i].size > 0;
404 cff_private_dict_op_serializer_t privSzr (desubroutinize, drop_hints);
405 unsigned int priv_size = PrivateDict::calculate_serialized_size (acc.privateDicts[i], privSzr, has_localsubrs);
406 table_info_t privInfo = { final_size, priv_size, 0 };
407 privateDictInfos.push (privInfo);
408 final_size += privInfo.size;
409
410 if (!plan->desubroutinize && has_localsubrs)
411 {
412 offsets.localSubrsInfos[i].offset = final_size;
413 final_size += offsets.localSubrsInfos[i].size;
414 }
415 }
416 }
417
418 return true;
419 }
420
421 unsigned int get_final_size () const { return final_size; }
422
423 unsigned int final_size;
424 cff2_sub_table_offsets_t offsets;
425
426 unsigned int orig_fdcount;
427 unsigned int subset_fdcount;
428 unsigned int subset_fdselect_format;
429 hb_vector_t<code_pair_t> subset_fdselect_ranges;
430
431 hb_inc_bimap_t fdmap;
432
433 str_buff_vec_t subset_charstrings;
434 str_buff_vec_t subset_globalsubrs;
435 hb_vector_t<str_buff_vec_t> subset_localsubrs;
436 hb_vector_t<table_info_t> privateDictInfos;
437
438 bool drop_hints;
439 bool desubroutinize;
440};
441
442static inline bool _write_cff2 (const cff2_subset_plan &plan,
443 const OT::cff2::accelerator_subset_t &acc,
444 unsigned int num_glyphs,
445 unsigned int dest_sz,
446 void *dest)
447{
448 hb_serialize_context_t c (dest, dest_sz);
449
450 OT::cff2 *cff2 = c.start_serialize<OT::cff2> ();
451 if (unlikely (!c.extend_min (*cff2)))
452 return false;
453
454 /* header */
455 cff2->version.major = 0x02;
456 cff2->version.minor = 0x00;
457 cff2->topDict = OT::cff2::static_size;
458
459 /* top dict */
460 {
461 assert (cff2->topDict == (unsigned) (c.head - c.start));
462 cff2->topDictSize = plan.offsets.topDictInfo.size;
463 TopDict &dict = cff2 + cff2->topDict;
464 cff2_top_dict_op_serializer_t topSzr;
465 if (unlikely (!dict.serialize (&c, acc.topDict, topSzr, plan.offsets)))
466 {
467 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 top dict");
468 return false;
469 }
470 }
471
472 /* global subrs */
473 {
474 assert (cff2->topDict + plan.offsets.topDictInfo.size == (unsigned) (c.head - c.start));
475 CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
476 if (unlikely (dest == nullptr)) return false;
477 if (unlikely (!dest->serialize (&c, plan.offsets.globalSubrsInfo.offSize, plan.subset_globalsubrs)))
478 {
479 DEBUG_MSG (SUBSET, nullptr, "failed to serialize global subroutines");
480 return false;
481 }
482 }
483
484 /* variation store */
485 if (acc.varStore != &Null(CFF2VariationStore))
486 {
487 assert (plan.offsets.varStoreOffset == (unsigned) (c.head - c.start));
488 CFF2VariationStore *dest = c.start_embed<CFF2VariationStore> ();
489 if (unlikely (!dest->serialize (&c, acc.varStore)))
490 {
491 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 Variation Store");
492 return false;
493 }
494 }
495
496 /* FDSelect */
497 if (acc.fdSelect != &Null(CFF2FDSelect))
498 {
499 assert (plan.offsets.FDSelectInfo.offset == (unsigned) (c.head - c.start));
500
501 if (unlikely (!hb_serialize_cff_fdselect (&c, num_glyphs, *(const FDSelect *)acc.fdSelect, acc.fdArray->count,
502 plan.subset_fdselect_format, plan.offsets.FDSelectInfo.size,
503 plan.subset_fdselect_ranges)))
504 {
505 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 subset FDSelect");
506 return false;
507 }
508 }
509
510 /* FDArray (FD Index) */
511 {
512 assert (plan.offsets.FDArrayInfo.offset == (unsigned) (c.head - c.start));
513 CFF2FDArray *fda = c.start_embed<CFF2FDArray> ();
514 if (unlikely (fda == nullptr)) return false;
515 cff_font_dict_op_serializer_t fontSzr;
516 if (unlikely (!fda->serialize (&c, plan.offsets.FDArrayInfo.offSize,
517 acc.fontDicts, plan.subset_fdcount, plan.fdmap,
518 fontSzr, plan.privateDictInfos)))
519 {
520 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 FDArray");
521 return false;
522 }
523 }
524
525 /* CharStrings */
526 {
527 assert (plan.offsets.charStringsInfo.offset == (unsigned) (c.head - c.start));
528 CFF2CharStrings *cs = c.start_embed<CFF2CharStrings> ();
529 if (unlikely (cs == nullptr)) return false;
530 if (unlikely (!cs->serialize (&c, plan.offsets.charStringsInfo.offSize, plan.subset_charstrings)))
531 {
532 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF2 CharStrings");
533 return false;
534 }
535 }
536
537 /* private dicts & local subrs */
538 assert (plan.offsets.privateDictsOffset == (unsigned) (c.head - c.start));
539 for (unsigned int i = 0; i < acc.privateDicts.length; i++)
540 {
541 if (plan.fdmap.has (i))
542 {
543 PrivateDict *pd = c.start_embed<PrivateDict> ();
544 if (unlikely (pd == nullptr)) return false;
545 unsigned int priv_size = plan.privateDictInfos[plan.fdmap[i]].size;
546 bool result;
547 cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
548 /* N.B. local subrs immediately follows its corresponding private dict. i.e., subr offset == private dict size */
549 unsigned int subroffset = (plan.offsets.localSubrsInfos[i].size > 0) ? priv_size : 0;
550 result = pd->serialize (&c, acc.privateDicts[i], privSzr, subroffset);
551 if (unlikely (!result))
552 {
553 DEBUG_MSG (SUBSET, nullptr, "failed to serialize CFF Private Dict[%d]", i);
554 return false;
555 }
556 if (plan.offsets.localSubrsInfos[i].size > 0)
557 {
558 CFF2Subrs *dest = c.start_embed <CFF2Subrs> ();
559 if (unlikely (dest == nullptr)) return false;
560 if (unlikely (!dest->serialize (&c, plan.offsets.localSubrsInfos[i].offSize, plan.subset_localsubrs[i])))
561 {
562 DEBUG_MSG (SUBSET, nullptr, "failed to serialize local subroutines");
563 return false;
564 }
565 }
566 }
567 }
568
569 assert (c.head == c.end);
570 c.end_serialize ();
571
572 return true;
573}
574
575static inline bool
576_hb_subset_cff2 (const OT::cff2::accelerator_subset_t &acc,
577 const char *data,
578 hb_subset_plan_t *plan,
579 hb_blob_t **prime /* OUT */)
580{
581 cff2_subset_plan cff2_plan;
582
583 if (unlikely (!cff2_plan.create (acc, plan)))
584 {
585 DEBUG_MSG(SUBSET, nullptr, "Failed to generate a cff2 subsetting plan.");
586 return false;
587 }
588
589 unsigned int cff2_prime_size = cff2_plan.get_final_size ();
590 char *cff2_prime_data = (char *) calloc (1, cff2_prime_size);
591
592 if (unlikely (!_write_cff2 (cff2_plan, acc, plan->num_output_glyphs (),
593 cff2_prime_size, cff2_prime_data))) {
594 DEBUG_MSG(SUBSET, nullptr, "Failed to write a subset cff2.");
595 free (cff2_prime_data);
596 return false;
597 }
598
599 *prime = hb_blob_create (cff2_prime_data,
600 cff2_prime_size,
601 HB_MEMORY_MODE_READONLY,
602 cff2_prime_data,
603 free);
604 return true;
605}
606
607/**
608 * hb_subset_cff2:
609 * Subsets the CFF2 table according to a provided plan.
610 *
611 * Return value: subsetted cff2 table.
612 **/
613bool
614hb_subset_cff2 (hb_subset_plan_t *plan,
615 hb_blob_t **prime /* OUT */)
616{
617 hb_blob_t *cff2_blob = hb_sanitize_context_t().reference_table<CFF::cff2> (plan->source);
618 const char *data = hb_blob_get_data(cff2_blob, nullptr);
619
620 OT::cff2::accelerator_subset_t acc;
621 acc.init(plan->source);
622 bool result = likely (acc.is_valid ()) &&
623 _hb_subset_cff2 (acc, data, plan, prime);
624
625 hb_blob_destroy (cff2_blob);
626 acc.fini ();
627
628 return result;
629}
630
631
632#endif
633