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| 1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "gpos.h" | |
| 6 | |
| 7 #include <limits> | |
| 8 #include <vector> | |
| 9 | |
| 10 #include "layout.h" | |
| 11 #include "maxp.h" | |
| 12 | |
| 13 // GPOS - The Glyph Positioning Table | |
| 14 // http://www.microsoft.com/typography/otspec/gpos.htm | |
| 15 | |
| 16 #define TABLE_NAME "GPOS" | |
| 17 | |
| 18 namespace { | |
| 19 | |
| 20 enum GPOS_TYPE { | |
| 21 GPOS_TYPE_SINGLE_ADJUSTMENT = 1, | |
| 22 GPOS_TYPE_PAIR_ADJUSTMENT = 2, | |
| 23 GPOS_TYPE_CURSIVE_ATTACHMENT = 3, | |
| 24 GPOS_TYPE_MARK_TO_BASE_ATTACHMENT = 4, | |
| 25 GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT = 5, | |
| 26 GPOS_TYPE_MARK_TO_MARK_ATTACHMENT = 6, | |
| 27 GPOS_TYPE_CONTEXT_POSITIONING = 7, | |
| 28 GPOS_TYPE_CHAINED_CONTEXT_POSITIONING = 8, | |
| 29 GPOS_TYPE_EXTENSION_POSITIONING = 9, | |
| 30 GPOS_TYPE_RESERVED = 10 | |
| 31 }; | |
| 32 | |
| 33 // The size of gpos header. | |
| 34 const unsigned kGposHeaderSize = 10; | |
| 35 // The maximum format number for anchor tables. | |
| 36 const uint16_t kMaxAnchorFormat = 3; | |
| 37 // The maximum number of class value. | |
| 38 const uint16_t kMaxClassDefValue = 0xFFFF; | |
| 39 | |
| 40 // Lookup type parsers. | |
| 41 bool ParseSingleAdjustment(const ots::OpenTypeFile *file, | |
| 42 const uint8_t *data, const size_t length); | |
| 43 bool ParsePairAdjustment(const ots::OpenTypeFile *file, | |
| 44 const uint8_t *data, const size_t length); | |
| 45 bool ParseCursiveAttachment(const ots::OpenTypeFile *file, | |
| 46 const uint8_t *data, const size_t length); | |
| 47 bool ParseMarkToBaseAttachment(const ots::OpenTypeFile *file, | |
| 48 const uint8_t *data, const size_t length); | |
| 49 bool ParseMarkToLigatureAttachment(const ots::OpenTypeFile *file, | |
| 50 const uint8_t *data, const size_t length); | |
| 51 bool ParseMarkToMarkAttachment(const ots::OpenTypeFile *file, | |
| 52 const uint8_t *data, const size_t length); | |
| 53 bool ParseContextPositioning(const ots::OpenTypeFile *file, | |
| 54 const uint8_t *data, const size_t length); | |
| 55 bool ParseChainedContextPositioning(const ots::OpenTypeFile *file, | |
| 56 const uint8_t *data, const size_t length); | |
| 57 bool ParseExtensionPositioning(const ots::OpenTypeFile *file, | |
| 58 const uint8_t *data, const size_t length); | |
| 59 | |
| 60 const ots::LookupSubtableParser::TypeParser kGposTypeParsers[] = { | |
| 61 {GPOS_TYPE_SINGLE_ADJUSTMENT, ParseSingleAdjustment}, | |
| 62 {GPOS_TYPE_PAIR_ADJUSTMENT, ParsePairAdjustment}, | |
| 63 {GPOS_TYPE_CURSIVE_ATTACHMENT, ParseCursiveAttachment}, | |
| 64 {GPOS_TYPE_MARK_TO_BASE_ATTACHMENT, ParseMarkToBaseAttachment}, | |
| 65 {GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT, ParseMarkToLigatureAttachment}, | |
| 66 {GPOS_TYPE_MARK_TO_MARK_ATTACHMENT, ParseMarkToMarkAttachment}, | |
| 67 {GPOS_TYPE_CONTEXT_POSITIONING, ParseContextPositioning}, | |
| 68 {GPOS_TYPE_CHAINED_CONTEXT_POSITIONING, ParseChainedContextPositioning}, | |
| 69 {GPOS_TYPE_EXTENSION_POSITIONING, ParseExtensionPositioning} | |
| 70 }; | |
| 71 | |
| 72 const ots::LookupSubtableParser kGposLookupSubtableParser = { | |
| 73 arraysize(kGposTypeParsers), | |
| 74 GPOS_TYPE_EXTENSION_POSITIONING, kGposTypeParsers | |
| 75 }; | |
| 76 | |
| 77 // Shared Tables: ValueRecord, Anchor Table, and MarkArray | |
| 78 | |
| 79 bool ParseValueRecord(const ots::OpenTypeFile *file, | |
| 80 ots::Buffer* subtable, const uint8_t *data, | |
| 81 const size_t length, const uint16_t value_format) { | |
| 82 // Check existence of adjustment fields. | |
| 83 for (unsigned i = 0; i < 4; ++i) { | |
| 84 if ((value_format >> i) & 0x1) { | |
| 85 // Just read the field since these fileds could take an arbitrary values. | |
| 86 if (!subtable->Skip(2)) { | |
| 87 return OTS_FAILURE_MSG("Failed to read value reacord component"); | |
| 88 } | |
| 89 } | |
| 90 } | |
| 91 | |
| 92 // Check existence of offsets to device table. | |
| 93 for (unsigned i = 0; i < 4; ++i) { | |
| 94 if ((value_format >> (i + 4)) & 0x1) { | |
| 95 uint16_t offset = 0; | |
| 96 if (!subtable->ReadU16(&offset)) { | |
| 97 return OTS_FAILURE_MSG("Failed to read value record offset"); | |
| 98 } | |
| 99 if (offset) { | |
| 100 // TODO(bashi): Is it possible that device tables locate before | |
| 101 // this record? No fonts contain such offset AKAIF. | |
| 102 if (offset >= length) { | |
| 103 return OTS_FAILURE_MSG("Value record offset too high %d >= %ld", offse
t, length); | |
| 104 } | |
| 105 if (!ots::ParseDeviceTable(file, data + offset, length - offset)) { | |
| 106 return OTS_FAILURE_MSG("Failed to parse device table in value record")
; | |
| 107 } | |
| 108 } | |
| 109 } | |
| 110 } | |
| 111 return true; | |
| 112 } | |
| 113 | |
| 114 bool ParseAnchorTable(const ots::OpenTypeFile *file, | |
| 115 const uint8_t *data, const size_t length) { | |
| 116 ots::Buffer subtable(data, length); | |
| 117 | |
| 118 uint16_t format = 0; | |
| 119 // Read format and skip 2 2-byte fields that could be arbitrary values. | |
| 120 if (!subtable.ReadU16(&format) || | |
| 121 !subtable.Skip(4)) { | |
| 122 return OTS_FAILURE_MSG("Faled to read anchor table"); | |
| 123 } | |
| 124 | |
| 125 if (format == 0 || format > kMaxAnchorFormat) { | |
| 126 return OTS_FAILURE_MSG("Bad Anchor table format %d", format); | |
| 127 } | |
| 128 | |
| 129 // Format 2 and 3 has additional fields. | |
| 130 if (format == 2) { | |
| 131 // Format 2 provides an index to a glyph contour point, which will take | |
| 132 // arbitrary value. | |
| 133 uint16_t anchor_point = 0; | |
| 134 if (!subtable.ReadU16(&anchor_point)) { | |
| 135 return OTS_FAILURE_MSG("Failed to read anchor point in format 2 Anchor Tab
le"); | |
| 136 } | |
| 137 } else if (format == 3) { | |
| 138 uint16_t offset_x_device = 0; | |
| 139 uint16_t offset_y_device = 0; | |
| 140 if (!subtable.ReadU16(&offset_x_device) || | |
| 141 !subtable.ReadU16(&offset_y_device)) { | |
| 142 return OTS_FAILURE_MSG("Failed to read device table offsets in format 3 an
chor table"); | |
| 143 } | |
| 144 const unsigned format_end = static_cast<unsigned>(10); | |
| 145 if (offset_x_device) { | |
| 146 if (offset_x_device < format_end || offset_x_device >= length) { | |
| 147 return OTS_FAILURE_MSG("Bad x device table offset %d", offset_x_device); | |
| 148 } | |
| 149 if (!ots::ParseDeviceTable(file, data + offset_x_device, | |
| 150 length - offset_x_device)) { | |
| 151 return OTS_FAILURE_MSG("Failed to parse device table in anchor table"); | |
| 152 } | |
| 153 } | |
| 154 if (offset_y_device) { | |
| 155 if (offset_y_device < format_end || offset_y_device >= length) { | |
| 156 return OTS_FAILURE_MSG("Bad y device table offset %d", offset_y_device); | |
| 157 } | |
| 158 if (!ots::ParseDeviceTable(file, data + offset_y_device, | |
| 159 length - offset_y_device)) { | |
| 160 return OTS_FAILURE_MSG("Failed to parse device table in anchor table"); | |
| 161 } | |
| 162 } | |
| 163 } | |
| 164 return true; | |
| 165 } | |
| 166 | |
| 167 bool ParseMarkArrayTable(const ots::OpenTypeFile *file, | |
| 168 const uint8_t *data, const size_t length, | |
| 169 const uint16_t class_count) { | |
| 170 ots::Buffer subtable(data, length); | |
| 171 | |
| 172 uint16_t mark_count = 0; | |
| 173 if (!subtable.ReadU16(&mark_count)) { | |
| 174 return OTS_FAILURE_MSG("Can't read mark table length"); | |
| 175 } | |
| 176 | |
| 177 // MarkRecord consists of 4-bytes. | |
| 178 const unsigned mark_records_end = 4 * static_cast<unsigned>(mark_count) + 2; | |
| 179 if (mark_records_end > std::numeric_limits<uint16_t>::max()) { | |
| 180 return OTS_FAILURE_MSG("Bad mark table length"); | |
| 181 } | |
| 182 for (unsigned i = 0; i < mark_count; ++i) { | |
| 183 uint16_t class_value = 0; | |
| 184 uint16_t offset_mark_anchor = 0; | |
| 185 if (!subtable.ReadU16(&class_value) || | |
| 186 !subtable.ReadU16(&offset_mark_anchor)) { | |
| 187 return OTS_FAILURE_MSG("Can't read mark table %d", i); | |
| 188 } | |
| 189 // |class_value| may take arbitrary values including 0 here so we don't | |
| 190 // check the value. | |
| 191 if (offset_mark_anchor < mark_records_end || | |
| 192 offset_mark_anchor >= length) { | |
| 193 return OTS_FAILURE_MSG("Bad mark anchor offset %d for mark table %d", offs
et_mark_anchor, i); | |
| 194 } | |
| 195 if (!ParseAnchorTable(file, data + offset_mark_anchor, | |
| 196 length - offset_mark_anchor)) { | |
| 197 return OTS_FAILURE_MSG("Faled to parse anchor table for mark table %d", i)
; | |
| 198 } | |
| 199 } | |
| 200 | |
| 201 return true; | |
| 202 } | |
| 203 | |
| 204 // Lookup Type 1: | |
| 205 // Single Adjustment Positioning Subtable | |
| 206 bool ParseSingleAdjustment(const ots::OpenTypeFile *file, const uint8_t *data, | |
| 207 const size_t length) { | |
| 208 ots::Buffer subtable(data, length); | |
| 209 | |
| 210 uint16_t format = 0; | |
| 211 uint16_t offset_coverage = 0; | |
| 212 uint16_t value_format = 0; | |
| 213 if (!subtable.ReadU16(&format) || | |
| 214 !subtable.ReadU16(&offset_coverage) || | |
| 215 !subtable.ReadU16(&value_format)) { | |
| 216 return OTS_FAILURE_MSG("Can't read single adjustment information"); | |
| 217 } | |
| 218 | |
| 219 if (format == 1) { | |
| 220 // Format 1 exactly one value record. | |
| 221 if (!ParseValueRecord(file, &subtable, data, length, value_format)) { | |
| 222 return OTS_FAILURE_MSG("Failed to parse format 1 single adjustment table")
; | |
| 223 } | |
| 224 } else if (format == 2) { | |
| 225 uint16_t value_count = 0; | |
| 226 if (!subtable.ReadU16(&value_count)) { | |
| 227 return OTS_FAILURE_MSG("Failed to parse format 2 single adjustment table")
; | |
| 228 } | |
| 229 for (unsigned i = 0; i < value_count; ++i) { | |
| 230 if (!ParseValueRecord(file, &subtable, data, length, value_format)) { | |
| 231 return OTS_FAILURE_MSG("Failed to parse value record %d in format 2 sing
le adjustment table", i); | |
| 232 } | |
| 233 } | |
| 234 } else { | |
| 235 return OTS_FAILURE_MSG("Bad format %d in single adjustment table", format); | |
| 236 } | |
| 237 | |
| 238 if (offset_coverage < subtable.offset() || offset_coverage >= length) { | |
| 239 return OTS_FAILURE_MSG("Bad coverage offset %d in single adjustment table",
offset_coverage); | |
| 240 } | |
| 241 | |
| 242 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 243 length - offset_coverage, | |
| 244 file->maxp->num_glyphs)) { | |
| 245 return OTS_FAILURE_MSG("Failed to parse coverage table in single adjustment
table"); | |
| 246 } | |
| 247 | |
| 248 return true; | |
| 249 } | |
| 250 | |
| 251 bool ParsePairSetTable(const ots::OpenTypeFile *file, | |
| 252 const uint8_t *data, const size_t length, | |
| 253 const uint16_t value_format1, | |
| 254 const uint16_t value_format2, | |
| 255 const uint16_t num_glyphs) { | |
| 256 ots::Buffer subtable(data, length); | |
| 257 | |
| 258 uint16_t value_count = 0; | |
| 259 if (!subtable.ReadU16(&value_count)) { | |
| 260 return OTS_FAILURE_MSG("Failed to read pair set table structure"); | |
| 261 } | |
| 262 for (unsigned i = 0; i < value_count; ++i) { | |
| 263 // Check pair value record. | |
| 264 uint16_t glyph_id = 0; | |
| 265 if (!subtable.ReadU16(&glyph_id)) { | |
| 266 return OTS_FAILURE_MSG("Failed to read glyph in pair value record %d", i); | |
| 267 } | |
| 268 if (glyph_id >= num_glyphs) { | |
| 269 return OTS_FAILURE_MSG("glyph id %d too high >= %d", glyph_id, num_glyphs)
; | |
| 270 } | |
| 271 if (!ParseValueRecord(file, &subtable, data, length, value_format1)) { | |
| 272 return OTS_FAILURE_MSG("Failed to parse value record in format 1 pair set
table"); | |
| 273 } | |
| 274 if (!ParseValueRecord(file, &subtable, data, length, value_format2)) { | |
| 275 return OTS_FAILURE_MSG("Failed to parse value record in format 2 pair set
table"); | |
| 276 } | |
| 277 } | |
| 278 return true; | |
| 279 } | |
| 280 | |
| 281 bool ParsePairPosFormat1(const ots::OpenTypeFile *file, | |
| 282 const uint8_t *data, const size_t length, | |
| 283 const uint16_t value_format1, | |
| 284 const uint16_t value_format2, | |
| 285 const uint16_t num_glyphs) { | |
| 286 ots::Buffer subtable(data, length); | |
| 287 | |
| 288 // Skip 8 bytes that are already read before. | |
| 289 if (!subtable.Skip(8)) { | |
| 290 return OTS_FAILURE_MSG("Failed to read pair pos table structure"); | |
| 291 } | |
| 292 | |
| 293 uint16_t pair_set_count = 0; | |
| 294 if (!subtable.ReadU16(&pair_set_count)) { | |
| 295 return OTS_FAILURE_MSG("Failed to read pair pos set count"); | |
| 296 } | |
| 297 | |
| 298 const unsigned pair_pos_end = 2 * static_cast<unsigned>(pair_set_count) + 10; | |
| 299 if (pair_pos_end > std::numeric_limits<uint16_t>::max()) { | |
| 300 return OTS_FAILURE_MSG("Bad pair set length %d", pair_pos_end); | |
| 301 } | |
| 302 for (unsigned i = 0; i < pair_set_count; ++i) { | |
| 303 uint16_t pair_set_offset = 0; | |
| 304 if (!subtable.ReadU16(&pair_set_offset)) { | |
| 305 return OTS_FAILURE_MSG("Failed to read pair set offset for pair set %d", i
); | |
| 306 } | |
| 307 if (pair_set_offset < pair_pos_end || pair_set_offset >= length) { | |
| 308 return OTS_FAILURE_MSG("Bad pair set offset %d for pair set %d", pair_set_
offset, i); | |
| 309 } | |
| 310 // Check pair set tables | |
| 311 if (!ParsePairSetTable(file, data + pair_set_offset, length - pair_set_offse
t, | |
| 312 value_format1, value_format2, | |
| 313 num_glyphs)) { | |
| 314 return OTS_FAILURE_MSG("Failed to parse pair set table %d", i); | |
| 315 } | |
| 316 } | |
| 317 | |
| 318 return true; | |
| 319 } | |
| 320 | |
| 321 bool ParsePairPosFormat2(const ots::OpenTypeFile *file, | |
| 322 const uint8_t *data, const size_t length, | |
| 323 const uint16_t value_format1, | |
| 324 const uint16_t value_format2, | |
| 325 const uint16_t num_glyphs) { | |
| 326 ots::Buffer subtable(data, length); | |
| 327 | |
| 328 // Skip 8 bytes that are already read before. | |
| 329 if (!subtable.Skip(8)) { | |
| 330 return OTS_FAILURE_MSG("Failed to read pair pos format 2 structure"); | |
| 331 } | |
| 332 | |
| 333 uint16_t offset_class_def1 = 0; | |
| 334 uint16_t offset_class_def2 = 0; | |
| 335 uint16_t class1_count = 0; | |
| 336 uint16_t class2_count = 0; | |
| 337 if (!subtable.ReadU16(&offset_class_def1) || | |
| 338 !subtable.ReadU16(&offset_class_def2) || | |
| 339 !subtable.ReadU16(&class1_count) || | |
| 340 !subtable.ReadU16(&class2_count)) { | |
| 341 return OTS_FAILURE_MSG("Failed to read pair pos format 2 data"); | |
| 342 } | |
| 343 | |
| 344 // Check class 1 records. | |
| 345 for (unsigned i = 0; i < class1_count; ++i) { | |
| 346 // Check class 2 records. | |
| 347 for (unsigned j = 0; j < class2_count; ++j) { | |
| 348 if (value_format1 && !ParseValueRecord(file, &subtable, data, length, | |
| 349 value_format1)) { | |
| 350 return OTS_FAILURE_MSG("Failed to parse value record 1 %d and %d", j, i)
; | |
| 351 } | |
| 352 if (value_format2 && !ParseValueRecord(file, &subtable, data, length, | |
| 353 value_format2)) { | |
| 354 return OTS_FAILURE_MSG("Falied to parse value record 2 %d and %d", j, i)
; | |
| 355 } | |
| 356 } | |
| 357 } | |
| 358 | |
| 359 // Check class definition tables. | |
| 360 if (offset_class_def1 < subtable.offset() || offset_class_def1 >= length || | |
| 361 offset_class_def2 < subtable.offset() || offset_class_def2 >= length) { | |
| 362 return OTS_FAILURE_MSG("Bad class definition table offsets %d or %d", offset
_class_def1, offset_class_def2); | |
| 363 } | |
| 364 if (!ots::ParseClassDefTable(file, data + offset_class_def1, | |
| 365 length - offset_class_def1, | |
| 366 num_glyphs, kMaxClassDefValue)) { | |
| 367 return OTS_FAILURE_MSG("Failed to parse class definition table 1"); | |
| 368 } | |
| 369 if (!ots::ParseClassDefTable(file, data + offset_class_def2, | |
| 370 length - offset_class_def2, | |
| 371 num_glyphs, kMaxClassDefValue)) { | |
| 372 return OTS_FAILURE_MSG("Failed to parse class definition table 2"); | |
| 373 } | |
| 374 | |
| 375 return true; | |
| 376 } | |
| 377 | |
| 378 // Lookup Type 2: | |
| 379 // Pair Adjustment Positioning Subtable | |
| 380 bool ParsePairAdjustment(const ots::OpenTypeFile *file, const uint8_t *data, | |
| 381 const size_t length) { | |
| 382 ots::Buffer subtable(data, length); | |
| 383 | |
| 384 uint16_t format = 0; | |
| 385 uint16_t offset_coverage = 0; | |
| 386 uint16_t value_format1 = 0; | |
| 387 uint16_t value_format2 = 0; | |
| 388 if (!subtable.ReadU16(&format) || | |
| 389 !subtable.ReadU16(&offset_coverage) || | |
| 390 !subtable.ReadU16(&value_format1) || | |
| 391 !subtable.ReadU16(&value_format2)) { | |
| 392 return OTS_FAILURE_MSG("Failed to read pair adjustment structure"); | |
| 393 } | |
| 394 | |
| 395 if (format == 1) { | |
| 396 if (!ParsePairPosFormat1(file, data, length, value_format1, value_format2, | |
| 397 file->maxp->num_glyphs)) { | |
| 398 return OTS_FAILURE_MSG("Failed to parse pair pos format 1"); | |
| 399 } | |
| 400 } else if (format == 2) { | |
| 401 if (!ParsePairPosFormat2(file, data, length, value_format1, value_format2, | |
| 402 file->maxp->num_glyphs)) { | |
| 403 return OTS_FAILURE_MSG("Failed to parse pair format 2"); | |
| 404 } | |
| 405 } else { | |
| 406 return OTS_FAILURE_MSG("Bad pos pair format %d", format); | |
| 407 } | |
| 408 | |
| 409 if (offset_coverage < subtable.offset() || offset_coverage >= length) { | |
| 410 return OTS_FAILURE_MSG("Bad pair pos offset coverage %d", offset_coverage); | |
| 411 } | |
| 412 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 413 length - offset_coverage, | |
| 414 file->maxp->num_glyphs)) { | |
| 415 return OTS_FAILURE_MSG("Failed to parse coverage table"); | |
| 416 } | |
| 417 | |
| 418 return true; | |
| 419 } | |
| 420 | |
| 421 // Lookup Type 3 | |
| 422 // Cursive Attachment Positioning Subtable | |
| 423 bool ParseCursiveAttachment(const ots::OpenTypeFile *file, const uint8_t *data, | |
| 424 const size_t length) { | |
| 425 ots::Buffer subtable(data, length); | |
| 426 | |
| 427 uint16_t format = 0; | |
| 428 uint16_t offset_coverage = 0; | |
| 429 uint16_t entry_exit_count = 0; | |
| 430 if (!subtable.ReadU16(&format) || | |
| 431 !subtable.ReadU16(&offset_coverage) || | |
| 432 !subtable.ReadU16(&entry_exit_count)) { | |
| 433 return OTS_FAILURE_MSG("Failed to read cursive attachment structure"); | |
| 434 } | |
| 435 | |
| 436 if (format != 1) { | |
| 437 return OTS_FAILURE_MSG("Bad cursive attachment format %d", format); | |
| 438 } | |
| 439 | |
| 440 // Check entry exit records. | |
| 441 const unsigned entry_exit_records_end = | |
| 442 2 * static_cast<unsigned>(entry_exit_count) + 6; | |
| 443 if (entry_exit_records_end > std::numeric_limits<uint16_t>::max()) { | |
| 444 return OTS_FAILURE_MSG("Bad entry exit record end %d", entry_exit_records_en
d); | |
| 445 } | |
| 446 for (unsigned i = 0; i < entry_exit_count; ++i) { | |
| 447 uint16_t offset_entry_anchor = 0; | |
| 448 uint16_t offset_exit_anchor = 0; | |
| 449 if (!subtable.ReadU16(&offset_entry_anchor) || | |
| 450 !subtable.ReadU16(&offset_exit_anchor)) { | |
| 451 return OTS_FAILURE_MSG("Can't read entry exit record %d", i); | |
| 452 } | |
| 453 // These offsets could be NULL. | |
| 454 if (offset_entry_anchor) { | |
| 455 if (offset_entry_anchor < entry_exit_records_end || | |
| 456 offset_entry_anchor >= length) { | |
| 457 return OTS_FAILURE_MSG("Bad entry anchor offset %d in entry exit record
%d", offset_entry_anchor, i); | |
| 458 } | |
| 459 if (!ParseAnchorTable(file, data + offset_entry_anchor, | |
| 460 length - offset_entry_anchor)) { | |
| 461 return OTS_FAILURE_MSG("Failed to parse entry anchor table in entry exit
record %d", i); | |
| 462 } | |
| 463 } | |
| 464 if (offset_exit_anchor) { | |
| 465 if (offset_exit_anchor < entry_exit_records_end || | |
| 466 offset_exit_anchor >= length) { | |
| 467 return OTS_FAILURE_MSG("Bad exit anchor offset %d in entry exit record %
d", offset_exit_anchor, i); | |
| 468 } | |
| 469 if (!ParseAnchorTable(file, data + offset_exit_anchor, | |
| 470 length - offset_exit_anchor)) { | |
| 471 return OTS_FAILURE_MSG("Failed to parse exit anchor table in entry exit
record %d", i); | |
| 472 } | |
| 473 } | |
| 474 } | |
| 475 | |
| 476 if (offset_coverage < subtable.offset() || offset_coverage >= length) { | |
| 477 return OTS_FAILURE_MSG("Bad coverage offset in cursive attachment %d", offse
t_coverage); | |
| 478 } | |
| 479 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 480 length - offset_coverage, | |
| 481 file->maxp->num_glyphs)) { | |
| 482 return OTS_FAILURE_MSG("Failed to parse coverage table in cursive attachment
"); | |
| 483 } | |
| 484 | |
| 485 return true; | |
| 486 } | |
| 487 | |
| 488 bool ParseAnchorArrayTable(const ots::OpenTypeFile *file, | |
| 489 const uint8_t *data, const size_t length, | |
| 490 const uint16_t class_count) { | |
| 491 ots::Buffer subtable(data, length); | |
| 492 | |
| 493 uint16_t record_count = 0; | |
| 494 if (!subtable.ReadU16(&record_count)) { | |
| 495 return OTS_FAILURE_MSG("Can't read anchor array length"); | |
| 496 } | |
| 497 | |
| 498 const unsigned anchor_array_end = 2 * static_cast<unsigned>(record_count) * | |
| 499 static_cast<unsigned>(class_count) + 2; | |
| 500 if (anchor_array_end > std::numeric_limits<uint16_t>::max()) { | |
| 501 return OTS_FAILURE_MSG("Bad end of anchor array %d", anchor_array_end); | |
| 502 } | |
| 503 for (unsigned i = 0; i < record_count; ++i) { | |
| 504 for (unsigned j = 0; j < class_count; ++j) { | |
| 505 uint16_t offset_record = 0; | |
| 506 if (!subtable.ReadU16(&offset_record)) { | |
| 507 return OTS_FAILURE_MSG("Can't read anchor array record offset for class
%d and record %d", j, i); | |
| 508 } | |
| 509 // |offset_record| could be NULL. | |
| 510 if (offset_record) { | |
| 511 if (offset_record < anchor_array_end || offset_record >= length) { | |
| 512 return OTS_FAILURE_MSG("Bad record offset %d in class %d, record %d",
offset_record, j, i); | |
| 513 } | |
| 514 if (!ParseAnchorTable(file, data + offset_record, | |
| 515 length - offset_record)) { | |
| 516 return OTS_FAILURE_MSG("Failed to parse anchor table for class %d, rec
ord %d", j, i); | |
| 517 } | |
| 518 } | |
| 519 } | |
| 520 } | |
| 521 return true; | |
| 522 } | |
| 523 | |
| 524 bool ParseLigatureArrayTable(const ots::OpenTypeFile *file, | |
| 525 const uint8_t *data, const size_t length, | |
| 526 const uint16_t class_count) { | |
| 527 ots::Buffer subtable(data, length); | |
| 528 | |
| 529 uint16_t ligature_count = 0; | |
| 530 if (!subtable.ReadU16(&ligature_count)) { | |
| 531 return OTS_FAILURE_MSG("Failed to read ligature count"); | |
| 532 } | |
| 533 for (unsigned i = 0; i < ligature_count; ++i) { | |
| 534 uint16_t offset_ligature_attach = 0; | |
| 535 if (!subtable.ReadU16(&offset_ligature_attach)) { | |
| 536 return OTS_FAILURE_MSG("Can't read ligature offset %d", i); | |
| 537 } | |
| 538 if (offset_ligature_attach < 2 || offset_ligature_attach >= length) { | |
| 539 return OTS_FAILURE_MSG("Bad ligature attachment offset %d in ligature %d",
offset_ligature_attach, i); | |
| 540 } | |
| 541 if (!ParseAnchorArrayTable(file, data + offset_ligature_attach, | |
| 542 length - offset_ligature_attach, class_count)) { | |
| 543 return OTS_FAILURE_MSG("Failed to parse anchor table for ligature %d", i); | |
| 544 } | |
| 545 } | |
| 546 return true; | |
| 547 } | |
| 548 | |
| 549 // Common parser for Lookup Type 4, 5 and 6. | |
| 550 bool ParseMarkToAttachmentSubtables(const ots::OpenTypeFile *file, | |
| 551 const uint8_t *data, const size_t length, | |
| 552 const GPOS_TYPE type) { | |
| 553 ots::Buffer subtable(data, length); | |
| 554 | |
| 555 uint16_t format = 0; | |
| 556 uint16_t offset_coverage1 = 0; | |
| 557 uint16_t offset_coverage2 = 0; | |
| 558 uint16_t class_count = 0; | |
| 559 uint16_t offset_mark_array = 0; | |
| 560 uint16_t offset_type_specific_array = 0; | |
| 561 if (!subtable.ReadU16(&format) || | |
| 562 !subtable.ReadU16(&offset_coverage1) || | |
| 563 !subtable.ReadU16(&offset_coverage2) || | |
| 564 !subtable.ReadU16(&class_count) || | |
| 565 !subtable.ReadU16(&offset_mark_array) || | |
| 566 !subtable.ReadU16(&offset_type_specific_array)) { | |
| 567 return OTS_FAILURE_MSG("Failed to read mark attachment subtable header"); | |
| 568 } | |
| 569 | |
| 570 if (format != 1) { | |
| 571 return OTS_FAILURE_MSG("bad mark attachment subtable format %d", format); | |
| 572 } | |
| 573 | |
| 574 const unsigned header_end = static_cast<unsigned>(subtable.offset()); | |
| 575 if (header_end > std::numeric_limits<uint16_t>::max()) { | |
| 576 return OTS_FAILURE_MSG("Bad mark attachment subtable size ending at %d", hea
der_end); | |
| 577 } | |
| 578 if (offset_coverage1 < header_end || offset_coverage1 >= length) { | |
| 579 return OTS_FAILURE_MSG("Bad coverage 1 offset %d", offset_coverage1); | |
| 580 } | |
| 581 if (!ots::ParseCoverageTable(file, data + offset_coverage1, | |
| 582 length - offset_coverage1, | |
| 583 file->maxp->num_glyphs)) { | |
| 584 return OTS_FAILURE_MSG("Failed to parse converge 1 table"); | |
| 585 } | |
| 586 if (offset_coverage2 < header_end || offset_coverage2 >= length) { | |
| 587 return OTS_FAILURE_MSG("Bad coverage 2 offset %d", offset_coverage2); | |
| 588 } | |
| 589 if (!ots::ParseCoverageTable(file, data + offset_coverage2, | |
| 590 length - offset_coverage2, | |
| 591 file->maxp->num_glyphs)) { | |
| 592 return OTS_FAILURE_MSG("Failed to parse coverage table 2"); | |
| 593 } | |
| 594 | |
| 595 if (offset_mark_array < header_end || offset_mark_array >= length) { | |
| 596 return OTS_FAILURE_MSG("Bad mark array offset %d", offset_mark_array); | |
| 597 } | |
| 598 if (!ParseMarkArrayTable(file, data + offset_mark_array, | |
| 599 length - offset_mark_array, class_count)) { | |
| 600 return OTS_FAILURE_MSG("Failed to parse mark array"); | |
| 601 } | |
| 602 | |
| 603 if (offset_type_specific_array < header_end || | |
| 604 offset_type_specific_array >= length) { | |
| 605 return OTS_FAILURE_MSG("Bad type specific array offset %d", offset_type_spec
ific_array); | |
| 606 } | |
| 607 if (type == GPOS_TYPE_MARK_TO_BASE_ATTACHMENT || | |
| 608 type == GPOS_TYPE_MARK_TO_MARK_ATTACHMENT) { | |
| 609 if (!ParseAnchorArrayTable(file, data + offset_type_specific_array, | |
| 610 length - offset_type_specific_array, | |
| 611 class_count)) { | |
| 612 return OTS_FAILURE_MSG("Failed to parse anchor array"); | |
| 613 } | |
| 614 } else if (type == GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT) { | |
| 615 if (!ParseLigatureArrayTable(file, data + offset_type_specific_array, | |
| 616 length - offset_type_specific_array, | |
| 617 class_count)) { | |
| 618 return OTS_FAILURE_MSG("Failed to parse ligature array"); | |
| 619 } | |
| 620 } else { | |
| 621 return OTS_FAILURE_MSG("Bad attachment type %d", type); | |
| 622 } | |
| 623 | |
| 624 return true; | |
| 625 } | |
| 626 | |
| 627 // Lookup Type 4: | |
| 628 // MarkToBase Attachment Positioning Subtable | |
| 629 bool ParseMarkToBaseAttachment(const ots::OpenTypeFile *file, | |
| 630 const uint8_t *data, const size_t length) { | |
| 631 return ParseMarkToAttachmentSubtables(file, data, length, | |
| 632 GPOS_TYPE_MARK_TO_BASE_ATTACHMENT); | |
| 633 } | |
| 634 | |
| 635 // Lookup Type 5: | |
| 636 // MarkToLigature Attachment Positioning Subtable | |
| 637 bool ParseMarkToLigatureAttachment(const ots::OpenTypeFile *file, | |
| 638 const uint8_t *data, const size_t length) { | |
| 639 return ParseMarkToAttachmentSubtables(file, data, length, | |
| 640 GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT); | |
| 641 } | |
| 642 | |
| 643 // Lookup Type 6: | |
| 644 // MarkToMark Attachment Positioning Subtable | |
| 645 bool ParseMarkToMarkAttachment(const ots::OpenTypeFile *file, | |
| 646 const uint8_t *data, const size_t length) { | |
| 647 return ParseMarkToAttachmentSubtables(file, data, length, | |
| 648 GPOS_TYPE_MARK_TO_MARK_ATTACHMENT); | |
| 649 } | |
| 650 | |
| 651 // Lookup Type 7: | |
| 652 // Contextual Positioning Subtables | |
| 653 bool ParseContextPositioning(const ots::OpenTypeFile *file, | |
| 654 const uint8_t *data, const size_t length) { | |
| 655 return ots::ParseContextSubtable(file, data, length, file->maxp->num_glyphs, | |
| 656 file->gpos->num_lookups); | |
| 657 } | |
| 658 | |
| 659 // Lookup Type 8: | |
| 660 // Chaining Contexual Positioning Subtable | |
| 661 bool ParseChainedContextPositioning(const ots::OpenTypeFile *file, | |
| 662 const uint8_t *data, const size_t length) { | |
| 663 return ots::ParseChainingContextSubtable(file, data, length, | |
| 664 file->maxp->num_glyphs, | |
| 665 file->gpos->num_lookups); | |
| 666 } | |
| 667 | |
| 668 // Lookup Type 9: | |
| 669 // Extension Positioning | |
| 670 bool ParseExtensionPositioning(const ots::OpenTypeFile *file, | |
| 671 const uint8_t *data, const size_t length) { | |
| 672 return ots::ParseExtensionSubtable(file, data, length, | |
| 673 &kGposLookupSubtableParser); | |
| 674 } | |
| 675 | |
| 676 } // namespace | |
| 677 | |
| 678 #define DROP_THIS_TABLE(msg_) \ | |
| 679 do { \ | |
| 680 OTS_FAILURE_MSG(msg_ ", table discarded"); \ | |
| 681 file->gpos->data = 0; \ | |
| 682 file->gpos->length = 0; \ | |
| 683 } while (0) | |
| 684 | |
| 685 namespace ots { | |
| 686 | |
| 687 // As far as I checked, following fonts contain invalid GPOS table and | |
| 688 // OTS will drop their GPOS table. | |
| 689 // | |
| 690 // # invalid delta format in device table | |
| 691 // samanata.ttf | |
| 692 // | |
| 693 // # bad size range in device table | |
| 694 // Sarai_07.ttf | |
| 695 // | |
| 696 // # bad offset to PairSetTable | |
| 697 // chandas1-2.ttf | |
| 698 // | |
| 699 // # bad offset to FeatureTable | |
| 700 // glrso12.ttf | |
| 701 // gllr12.ttf | |
| 702 // glbo12.ttf | |
| 703 // glb12.ttf | |
| 704 // glro12.ttf | |
| 705 // glbso12.ttf | |
| 706 // glrc12.ttf | |
| 707 // glrsc12.ttf | |
| 708 // glbs12.ttf | |
| 709 // glrs12.ttf | |
| 710 // glr12.ttf | |
| 711 // | |
| 712 // # ScriptRecords aren't sorted by tag | |
| 713 // Garogier_unhinted.otf | |
| 714 // | |
| 715 // # bad start coverage index in CoverageFormat2 | |
| 716 // AndBasR.ttf | |
| 717 // CharisSILB.ttf | |
| 718 // CharisSILBI.ttf | |
| 719 // CharisSILI.ttf | |
| 720 // CharisSILR.ttf | |
| 721 // DoulosSILR.ttf | |
| 722 // GenBasBI.ttf | |
| 723 // GenBasI.ttf | |
| 724 // GenBkBasI.ttf | |
| 725 // GenBkBasB.ttf | |
| 726 // GenBkBasR.ttf | |
| 727 // Padauk-Bold.ttf | |
| 728 // Padauk.ttf | |
| 729 // | |
| 730 // # Contour point indexes aren't sorted | |
| 731 // Arial Unicode.ttf | |
| 732 | |
| 733 bool ots_gpos_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { | |
| 734 // Parsing GPOS table requires num_glyphs which is contained in maxp table. | |
| 735 if (!file->maxp) { | |
| 736 return OTS_FAILURE_MSG("missing maxp table needed in GPOS"); | |
| 737 } | |
| 738 | |
| 739 Buffer table(data, length); | |
| 740 | |
| 741 OpenTypeGPOS *gpos = new OpenTypeGPOS; | |
| 742 file->gpos = gpos; | |
| 743 | |
| 744 uint32_t version = 0; | |
| 745 uint16_t offset_script_list = 0; | |
| 746 uint16_t offset_feature_list = 0; | |
| 747 uint16_t offset_lookup_list = 0; | |
| 748 if (!table.ReadU32(&version) || | |
| 749 !table.ReadU16(&offset_script_list) || | |
| 750 !table.ReadU16(&offset_feature_list) || | |
| 751 !table.ReadU16(&offset_lookup_list)) { | |
| 752 DROP_THIS_TABLE("Incomplete table"); | |
| 753 return true; | |
| 754 } | |
| 755 | |
| 756 if (version != 0x00010000) { | |
| 757 DROP_THIS_TABLE("Bad version"); | |
| 758 return true; | |
| 759 } | |
| 760 | |
| 761 if (offset_lookup_list) { | |
| 762 if (offset_lookup_list < kGposHeaderSize || offset_lookup_list >= length) { | |
| 763 DROP_THIS_TABLE("Bad lookup list offset in table header"); | |
| 764 return true; | |
| 765 } | |
| 766 | |
| 767 if (!ParseLookupListTable(file, data + offset_lookup_list, | |
| 768 length - offset_lookup_list, | |
| 769 &kGposLookupSubtableParser, | |
| 770 &gpos->num_lookups)) { | |
| 771 DROP_THIS_TABLE("Failed to parse lookup list table"); | |
| 772 return true; | |
| 773 } | |
| 774 } | |
| 775 | |
| 776 uint16_t num_features = 0; | |
| 777 if (offset_feature_list) { | |
| 778 if (offset_feature_list < kGposHeaderSize || offset_feature_list >= length)
{ | |
| 779 DROP_THIS_TABLE("Bad feature list offset in table header"); | |
| 780 return true; | |
| 781 } | |
| 782 | |
| 783 if (!ParseFeatureListTable(file, data + offset_feature_list, | |
| 784 length - offset_feature_list, gpos->num_lookups, | |
| 785 &num_features)) { | |
| 786 DROP_THIS_TABLE("Failed to parse feature list table"); | |
| 787 return true; | |
| 788 } | |
| 789 } | |
| 790 | |
| 791 if (offset_script_list) { | |
| 792 if (offset_script_list < kGposHeaderSize || offset_script_list >= length) { | |
| 793 DROP_THIS_TABLE("Bad script list offset in table header"); | |
| 794 return true; | |
| 795 } | |
| 796 | |
| 797 if (!ParseScriptListTable(file, data + offset_script_list, | |
| 798 length - offset_script_list, num_features)) { | |
| 799 DROP_THIS_TABLE("Failed to parse script list table"); | |
| 800 return true; | |
| 801 } | |
| 802 } | |
| 803 | |
| 804 gpos->data = data; | |
| 805 gpos->length = length; | |
| 806 return true; | |
| 807 } | |
| 808 | |
| 809 bool ots_gpos_should_serialise(OpenTypeFile *file) { | |
| 810 return file->gpos != NULL && file->gpos->data != NULL; | |
| 811 } | |
| 812 | |
| 813 bool ots_gpos_serialise(OTSStream *out, OpenTypeFile *file) { | |
| 814 if (!out->Write(file->gpos->data, file->gpos->length)) { | |
| 815 return OTS_FAILURE_MSG("Failed to write GPOS table"); | |
| 816 } | |
| 817 | |
| 818 return true; | |
| 819 } | |
| 820 | |
| 821 void ots_gpos_free(OpenTypeFile *file) { | |
| 822 delete file->gpos; | |
| 823 } | |
| 824 | |
| 825 } // namespace ots | |
| 826 | |
| 827 #undef TABLE_NAME | |
| 828 #undef DROP_THIS_TABLE | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 797183002:
Revert of Updating OTS repo from https://github.com/khaledhosny/ots.git (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master