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_info_t : cff_sub_table_info_t
42{
43 cff2_sub_table_info_t ()
44 : cff_sub_table_info_t (),
45 var_store_link (0)
46 {}
47
48 objidx_t var_store_link;
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_info_t &info) const
56 {
57 TRACE_SERIALIZE (this);
58
59 switch (opstr.op)
60 {
61 case OpCode_vstore:
62 return_trace (FontDict::serialize_link4_op(c, opstr.op, info.var_store_link));
63
64 default:
65 return_trace (cff_top_dict_op_serializer_t<>::serialize (c, opstr, info));
66 }
67 }
68};
69
70struct cff2_cs_opset_flatten_t : cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t>
71{
72 static void flush_args_and_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
73 {
74 switch (op)
75 {
76 case OpCode_return:
77 case OpCode_endchar:
78 /* dummy opcodes in CFF2. ignore */
79 break;
80
81 case OpCode_hstem:
82 case OpCode_hstemhm:
83 case OpCode_vstem:
84 case OpCode_vstemhm:
85 case OpCode_hintmask:
86 case OpCode_cntrmask:
87 if (param.drop_hints)
88 {
89 env.clear_args ();
90 return;
91 }
92 HB_FALLTHROUGH;
93
94 default:
95 SUPER::flush_args_and_op (op, env, param);
96 break;
97 }
98 }
99
100 static void flush_args (cff2_cs_interp_env_t &env, flatten_param_t& param)
101 {
102 for (unsigned int i = 0; i < env.argStack.get_count ();)
103 {
104 const blend_arg_t &arg = env.argStack[i];
105 if (arg.blending ())
106 {
107 if (unlikely (!((arg.numValues > 0) && (env.argStack.get_count () >= arg.numValues))))
108 {
109 env.set_error ();
110 return;
111 }
112 flatten_blends (arg, i, env, param);
113 i += arg.numValues;
114 }
115 else
116 {
117 str_encoder_t encoder (param.flatStr);
118 encoder.encode_num (arg);
119 i++;
120 }
121 }
122 SUPER::flush_args (env, param);
123 }
124
125 static void flatten_blends (const blend_arg_t &arg, unsigned int i, cff2_cs_interp_env_t &env, flatten_param_t& param)
126 {
127 /* flatten the default values */
128 str_encoder_t encoder (param.flatStr);
129 for (unsigned int j = 0; j < arg.numValues; j++)
130 {
131 const blend_arg_t &arg1 = env.argStack[i + j];
132 if (unlikely (!((arg1.blending () && (arg.numValues == arg1.numValues) && (arg1.valueIndex == j) &&
133 (arg1.deltas.length == env.get_region_count ())))))
134 {
135 env.set_error ();
136 return;
137 }
138 encoder.encode_num (arg1);
139 }
140 /* flatten deltas for each value */
141 for (unsigned int j = 0; j < arg.numValues; j++)
142 {
143 const blend_arg_t &arg1 = env.argStack[i + j];
144 for (unsigned int k = 0; k < arg1.deltas.length; k++)
145 encoder.encode_num (arg1.deltas[k]);
146 }
147 /* flatten the number of values followed by blend operator */
148 encoder.encode_int (arg.numValues);
149 encoder.encode_op (OpCode_blendcs);
150 }
151
152 static void flush_op (op_code_t op, cff2_cs_interp_env_t &env, flatten_param_t& param)
153 {
154 switch (op)
155 {
156 case OpCode_return:
157 case OpCode_endchar:
158 return;
159 default:
160 str_encoder_t encoder (param.flatStr);
161 encoder.encode_op (op);
162 }
163 }
164
165 private:
166 typedef cff2_cs_opset_t<cff2_cs_opset_flatten_t, flatten_param_t> SUPER;
167 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;
168};
169
170struct cff2_cs_opset_subr_subset_t : cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t>
171{
172 static void process_op (op_code_t op, cff2_cs_interp_env_t &env, subr_subset_param_t& param)
173 {
174 switch (op) {
175
176 case OpCode_return:
177 param.current_parsed_str->set_parsed ();
178 env.return_from_subr ();
179 param.set_current_str (env, false);
180 break;
181
182 case OpCode_endchar:
183 param.current_parsed_str->set_parsed ();
184 SUPER::process_op (op, env, param);
185 break;
186
187 case OpCode_callsubr:
188 process_call_subr (op, CSType_LocalSubr, env, param, env.localSubrs, param.local_closure);
189 break;
190
191 case OpCode_callgsubr:
192 process_call_subr (op, CSType_GlobalSubr, env, param, env.globalSubrs, param.global_closure);
193 break;
194
195 default:
196 SUPER::process_op (op, env, param);
197 param.current_parsed_str->add_op (op, env.str_ref);
198 break;
199 }
200 }
201
202 protected:
203 static void process_call_subr (op_code_t op, cs_type_t type,
204 cff2_cs_interp_env_t &env, subr_subset_param_t& param,
205 cff2_biased_subrs_t& subrs, hb_set_t *closure)
206 {
207 byte_str_ref_t str_ref = env.str_ref;
208 env.call_subr (subrs, type);
209 param.current_parsed_str->add_call_op (op, str_ref, env.context.subr_num);
210 closure->add (env.context.subr_num);
211 param.set_current_str (env, true);
212 }
213
214 private:
215 typedef cff2_cs_opset_t<cff2_cs_opset_subr_subset_t, subr_subset_param_t> SUPER;
216};
217
218struct 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>
219{
220 cff2_subr_subsetter_t (const OT::cff2::accelerator_subset_t &acc_, const hb_subset_plan_t *plan_)
221 : subr_subsetter_t (acc_, plan_) {}
222
223 static void complete_parsed_str (cff2_cs_interp_env_t &env, subr_subset_param_t& param, parsed_cs_str_t &charstring)
224 {
225 /* vsindex is inserted at the beginning of the charstring as necessary */
226 if (env.seen_vsindex ())
227 {
228 number_t ivs;
229 ivs.set_int ((int)env.get_ivs ());
230 charstring.set_prefix (ivs, OpCode_vsindexcs);
231 }
232 }
233};
234
235struct cff2_subset_plan {
236 cff2_subset_plan ()
237 : orig_fdcount (0),
238 subset_fdcount(1),
239 subset_fdselect_size (0),
240 subset_fdselect_format (0),
241 drop_hints (false),
242 desubroutinize (false)
243 {
244 subset_fdselect_ranges.init ();
245 fdmap.init ();
246 subset_charstrings.init ();
247 subset_globalsubrs.init ();
248 subset_localsubrs.init ();
249 }
250
251 ~cff2_subset_plan ()
252 {
253 subset_fdselect_ranges.fini ();
254 fdmap.fini ();
255 subset_charstrings.fini_deep ();
256 subset_globalsubrs.fini_deep ();
257 subset_localsubrs.fini_deep ();
258 }
259
260 bool create (const OT::cff2::accelerator_subset_t &acc,
261 hb_subset_plan_t *plan)
262 {
263 orig_fdcount = acc.fdArray->count;
264
265 drop_hints = plan->drop_hints;
266 desubroutinize = plan->desubroutinize;
267
268 if (desubroutinize)
269 {
270 /* Flatten global & local subrs */
271 subr_flattener_t<const OT::cff2::accelerator_subset_t, cff2_cs_interp_env_t, cff2_cs_opset_flatten_t>
272 flattener(acc, plan);
273 if (!flattener.flatten (subset_charstrings))
274 return false;
275 }
276 else
277 {
278 cff2_subr_subsetter_t subr_subsetter (acc, plan);
279
280 /* Subset subrs: collect used subroutines, leaving all unused ones behind */
281 if (!subr_subsetter.subset ())
282 return false;
283
284 /* encode charstrings, global subrs, local subrs with new subroutine numbers */
285 if (!subr_subsetter.encode_charstrings (subset_charstrings))
286 return false;
287
288 if (!subr_subsetter.encode_globalsubrs (subset_globalsubrs))
289 return false;
290
291 /* local subrs */
292 if (!subset_localsubrs.resize (orig_fdcount))
293 return false;
294 for (unsigned int fd = 0; fd < orig_fdcount; fd++)
295 {
296 subset_localsubrs[fd].init ();
297 if (!subr_subsetter.encode_localsubrs (fd, subset_localsubrs[fd]))
298 return false;
299 }
300 }
301
302 /* FDSelect */
303 if (acc.fdSelect != &Null (CFF2FDSelect))
304 {
305 if (unlikely (!hb_plan_subset_cff_fdselect (plan,
306 orig_fdcount,
307 *(const FDSelect *)acc.fdSelect,
308 subset_fdcount,
309 subset_fdselect_size,
310 subset_fdselect_format,
311 subset_fdselect_ranges,
312 fdmap)))
313 return false;
314 }
315 else
316 fdmap.identity (1);
317
318 return true;
319 }
320
321 cff2_sub_table_info_t info;
322
323 unsigned int orig_fdcount;
324 unsigned int subset_fdcount;
325 unsigned int subset_fdselect_size;
326 unsigned int subset_fdselect_format;
327 hb_vector_t<code_pair_t> subset_fdselect_ranges;
328
329 hb_inc_bimap_t fdmap;
330
331 str_buff_vec_t subset_charstrings;
332 str_buff_vec_t subset_globalsubrs;
333 hb_vector_t<str_buff_vec_t> subset_localsubrs;
334
335 bool drop_hints;
336 bool desubroutinize;
337};
338
339static bool _serialize_cff2 (hb_serialize_context_t *c,
340 cff2_subset_plan &plan,
341 const OT::cff2::accelerator_subset_t &acc,
342 unsigned int num_glyphs)
343{
344 /* private dicts & local subrs */
345 hb_vector_t<table_info_t> private_dict_infos;
346 if (unlikely (!private_dict_infos.resize (plan.subset_fdcount))) return false;
347
348 for (int i = (int)acc.privateDicts.length; --i >= 0 ;)
349 {
350 if (plan.fdmap.has (i))
351 {
352 objidx_t subrs_link = 0;
353
354 if (plan.subset_localsubrs[i].length > 0)
355 {
356 CFF2Subrs *dest = c->start_embed <CFF2Subrs> ();
357 if (unlikely (!dest)) return false;
358 c->push ();
359 if (likely (dest->serialize (c, plan.subset_localsubrs[i])))
360 subrs_link = c->pop_pack ();
361 else
362 {
363 c->pop_discard ();
364 return false;
365 }
366 }
367 PrivateDict *pd = c->start_embed<PrivateDict> ();
368 if (unlikely (!pd)) return false;
369 c->push ();
370 cff_private_dict_op_serializer_t privSzr (plan.desubroutinize, plan.drop_hints);
371 if (likely (pd->serialize (c, acc.privateDicts[i], privSzr, subrs_link)))
372 {
373 unsigned fd = plan.fdmap[i];
374 private_dict_infos[fd].size = c->length ();
375 private_dict_infos[fd].link = c->pop_pack ();
376 }
377 else
378 {
379 c->pop_discard ();
380 return false;
381 }
382 }
383 }
384
385 /* CharStrings */
386 {
387 CFF2CharStrings *cs = c->start_embed<CFF2CharStrings> ();
388 if (unlikely (!cs)) return false;
389 c->push ();
390 if (likely (cs->serialize (c, plan.subset_charstrings)))
391 plan.info.char_strings_link = c->pop_pack ();
392 else
393 {
394 c->pop_discard ();
395 return false;
396 }
397 }
398
399 /* FDSelect */
400 if (acc.fdSelect != &Null (CFF2FDSelect))
401 {
402 c->push ();
403 if (likely (hb_serialize_cff_fdselect (c, num_glyphs, *(const FDSelect *)acc.fdSelect, plan.orig_fdcount,
404 plan.subset_fdselect_format, plan.subset_fdselect_size,
405 plan.subset_fdselect_ranges)))
406 plan.info.fd_select.link = c->pop_pack ();
407 else
408 {
409 c->pop_discard ();
410 return false;
411 }
412 }
413
414 /* FDArray (FD Index) */
415 {
416 c->push ();
417 CFF2FDArray *fda = c->start_embed<CFF2FDArray> ();
418 if (unlikely (!fda)) return false;
419 cff_font_dict_op_serializer_t fontSzr;
420 auto it =
421 + hb_zip (+ hb_iter (acc.fontDicts)
422 | hb_filter ([&] (const cff2_font_dict_values_t &_)
423 { return plan.fdmap.has (&_ - &acc.fontDicts[0]); }),
424 hb_iter (private_dict_infos))
425 ;
426 if (unlikely (!fda->serialize (c, it, fontSzr))) return false;
427 plan.info.fd_array_link = c->pop_pack ();
428 }
429
430 /* variation store */
431 if (acc.varStore != &Null (CFF2VariationStore))
432 {
433 c->push ();
434 CFF2VariationStore *dest = c->start_embed<CFF2VariationStore> ();
435 if (unlikely (!dest || !dest->serialize (c, acc.varStore))) return false;
436 plan.info.var_store_link = c->pop_pack ();
437 }
438
439 OT::cff2 *cff2 = c->allocate_min<OT::cff2> ();
440 if (unlikely (!cff2)) return false;
441
442 /* header */
443 cff2->version.major = 0x02;
444 cff2->version.minor = 0x00;
445 cff2->topDict = OT::cff2::static_size;
446
447 /* top dict */
448 {
449 TopDict &dict = cff2 + cff2->topDict;
450 cff2_top_dict_op_serializer_t topSzr;
451 if (unlikely (!dict.serialize (c, acc.topDict, topSzr, plan.info))) return false;
452 cff2->topDictSize = c->head - (const char *)&dict;
453 }
454
455 /* global subrs */
456 {
457 CFF2Subrs *dest = c->start_embed <CFF2Subrs> ();
458 if (unlikely (!dest)) return false;
459 return dest->serialize (c, plan.subset_globalsubrs);
460 }
461}
462
463static bool
464_hb_subset_cff2 (const OT::cff2::accelerator_subset_t &acc,
465 hb_subset_context_t *c)
466{
467 cff2_subset_plan cff2_plan;
468
469 if (unlikely (!cff2_plan.create (acc, c->plan))) return false;
470 return _serialize_cff2 (c->serializer, cff2_plan, acc, c->plan->num_output_glyphs ());
471}
472
473/**
474 * hb_subset_cff2:
475 * Subsets the CFF2 table according to a provided subset context.
476 **/
477bool
478hb_subset_cff2 (hb_subset_context_t *c)
479{
480 OT::cff2::accelerator_subset_t acc;
481 acc.init (c->plan->source);
482 bool result = likely (acc.is_valid ()) && _hb_subset_cff2 (acc, c);
483 acc.fini ();
484
485 return result;
486}
487
488#endif
489