ksakamoto@chromium.org | eea4836 | 2014-01-20 02:15:37 +0000 | [diff] [blame] | 1 | // Copyright (c) 2014 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 | // We use an underscore to avoid confusion with the standard math.h library. |
| 6 | #include "math_.h" |
| 7 | |
| 8 | #include <limits> |
| 9 | #include <vector> |
| 10 | |
| 11 | #include "layout.h" |
| 12 | #include "maxp.h" |
| 13 | |
| 14 | // MATH - The MATH Table |
| 15 | // The specification is not yet public but has been submitted to the MPEG group |
| 16 | // in response to the 'Call for Proposals for ISO/IEC 14496-22 "Open Font |
| 17 | // Format" Color Font Technology and MATH layout support'. Meanwhile, you can |
| 18 | // contact Microsoft's engineer Murray Sargent to obtain a copy. |
| 19 | |
| 20 | namespace { |
| 21 | |
| 22 | // The size of MATH header. |
| 23 | // Version |
| 24 | // MathConstants |
| 25 | // MathGlyphInfo |
| 26 | // MathVariants |
| 27 | const unsigned kMathHeaderSize = 4 + 3 * 2; |
| 28 | |
| 29 | // The size of the MathGlyphInfo header. |
| 30 | // MathItalicsCorrectionInfo |
| 31 | // MathTopAccentAttachment |
| 32 | // ExtendedShapeCoverage |
| 33 | // MathKernInfo |
| 34 | const unsigned kMathGlyphInfoHeaderSize = 4 * 2; |
| 35 | |
| 36 | // The size of the MathValueRecord. |
| 37 | // Value |
| 38 | // DeviceTable |
| 39 | const unsigned kMathValueRecordSize = 2 * 2; |
| 40 | |
| 41 | // The size of the GlyphPartRecord. |
| 42 | // glyph |
| 43 | // StartConnectorLength |
| 44 | // EndConnectorLength |
| 45 | // FullAdvance |
| 46 | // PartFlags |
| 47 | const unsigned kGlyphPartRecordSize = 5 * 2; |
| 48 | |
| 49 | // Shared Table: MathValueRecord |
| 50 | |
| 51 | bool ParseMathValueRecord(ots::Buffer* subtable, const uint8_t *data, |
| 52 | const size_t length) { |
| 53 | // Check the Value field. |
| 54 | if (!subtable->Skip(2)) { |
| 55 | return OTS_FAILURE(); |
| 56 | } |
| 57 | |
| 58 | // Check the offset to device table. |
| 59 | uint16_t offset = 0; |
| 60 | if (!subtable->ReadU16(&offset)) { |
| 61 | return OTS_FAILURE(); |
| 62 | } |
| 63 | if (offset) { |
| 64 | if (offset >= length) { |
| 65 | return OTS_FAILURE(); |
| 66 | } |
| 67 | if (!ots::ParseDeviceTable(data + offset, length - offset)) { |
| 68 | return OTS_FAILURE(); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | return true; |
| 73 | } |
| 74 | |
| 75 | bool ParseMathConstantsTable(const uint8_t *data, size_t length) { |
| 76 | ots::Buffer subtable(data, length); |
| 77 | |
| 78 | // Part 1: int16 or uint16 constants. |
| 79 | // ScriptPercentScaleDown |
| 80 | // ScriptScriptPercentScaleDown |
| 81 | // DelimitedSubFormulaMinHeight |
| 82 | // DisplayOperatorMinHeight |
| 83 | if (!subtable.Skip(4 * 2)) { |
| 84 | return OTS_FAILURE(); |
| 85 | } |
| 86 | |
| 87 | // Part 2: MathValueRecord constants. |
| 88 | // MathLeading |
| 89 | // AxisHeight |
| 90 | // AccentBaseHeight |
| 91 | // FlattenedAccentBaseHeight |
| 92 | // SubscriptShiftDown |
| 93 | // SubscriptTopMax |
| 94 | // SubscriptBaselineDropMin |
| 95 | // SuperscriptShiftUp |
| 96 | // SuperscriptShiftUpCramped |
| 97 | // SuperscriptBottomMin |
| 98 | // |
| 99 | // SuperscriptBaselineDropMax |
| 100 | // SubSuperscriptGapMin |
| 101 | // SuperscriptBottomMaxWithSubscript |
| 102 | // SpaceAfterScript |
| 103 | // UpperLimitGapMin |
| 104 | // UpperLimitBaselineRiseMin |
| 105 | // LowerLimitGapMin |
| 106 | // LowerLimitBaselineDropMin |
| 107 | // StackTopShiftUp |
| 108 | // StackTopDisplayStyleShiftUp |
| 109 | // |
| 110 | // StackBottomShiftDown |
| 111 | // StackBottomDisplayStyleShiftDown |
| 112 | // StackGapMin |
| 113 | // StackDisplayStyleGapMin |
| 114 | // StretchStackTopShiftUp |
| 115 | // StretchStackBottomShiftDown |
| 116 | // StretchStackGapAboveMin |
| 117 | // StretchStackGapBelowMin |
| 118 | // FractionNumeratorShiftUp |
| 119 | // FractionNumeratorDisplayStyleShiftUp |
| 120 | // |
| 121 | // FractionDenominatorShiftDown |
| 122 | // FractionDenominatorDisplayStyleShiftDown |
| 123 | // FractionNumeratorGapMin |
| 124 | // FractionNumDisplayStyleGapMin |
| 125 | // FractionRuleThickness |
| 126 | // FractionDenominatorGapMin |
| 127 | // FractionDenomDisplayStyleGapMin |
| 128 | // SkewedFractionHorizontalGap |
| 129 | // SkewedFractionVerticalGap |
| 130 | // OverbarVerticalGap |
| 131 | // |
| 132 | // OverbarRuleThickness |
| 133 | // OverbarExtraAscender |
| 134 | // UnderbarVerticalGap |
| 135 | // UnderbarRuleThickness |
| 136 | // UnderbarExtraDescender |
| 137 | // RadicalVerticalGap |
| 138 | // RadicalDisplayStyleVerticalGap |
| 139 | // RadicalRuleThickness |
| 140 | // RadicalExtraAscender |
| 141 | // RadicalKernBeforeDegree |
| 142 | // |
| 143 | // RadicalKernAfterDegree |
| 144 | for (unsigned i = 0; i < static_cast<unsigned>(51); ++i) { |
| 145 | if (!ParseMathValueRecord(&subtable, data, length)) { |
| 146 | return OTS_FAILURE(); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | // Part 3: uint16 constant |
| 151 | // RadicalDegreeBottomRaisePercent |
| 152 | if (!subtable.Skip(2)) { |
| 153 | return OTS_FAILURE(); |
| 154 | } |
| 155 | |
| 156 | return true; |
| 157 | } |
| 158 | |
| 159 | bool ParseMathValueRecordSequenceForGlyphs(ots::Buffer* subtable, |
| 160 | const uint8_t *data, |
| 161 | const size_t length, |
| 162 | const uint16_t num_glyphs) { |
| 163 | // Check the header. |
| 164 | uint16_t offset_coverage = 0; |
| 165 | uint16_t sequence_count = 0; |
| 166 | if (!subtable->ReadU16(&offset_coverage) || |
| 167 | !subtable->ReadU16(&sequence_count)) { |
| 168 | return OTS_FAILURE(); |
| 169 | } |
| 170 | |
| 171 | const unsigned sequence_end = static_cast<unsigned>(2 * 2) + |
| 172 | sequence_count * kMathValueRecordSize; |
| 173 | if (sequence_end > std::numeric_limits<uint16_t>::max()) { |
| 174 | return OTS_FAILURE(); |
| 175 | } |
| 176 | |
| 177 | // Check coverage table. |
| 178 | if (offset_coverage < sequence_end || offset_coverage >= length) { |
| 179 | return OTS_FAILURE(); |
| 180 | } |
| 181 | if (!ots::ParseCoverageTable(data + offset_coverage, |
| 182 | length - offset_coverage, |
| 183 | num_glyphs, sequence_count)) { |
| 184 | return OTS_FAILURE(); |
| 185 | } |
| 186 | |
| 187 | // Check sequence. |
| 188 | for (unsigned i = 0; i < sequence_count; ++i) { |
| 189 | if (!ParseMathValueRecord(subtable, data, length)) { |
| 190 | return OTS_FAILURE(); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | return true; |
| 195 | } |
| 196 | |
| 197 | bool ParseMathItalicsCorrectionInfoTable(const uint8_t *data, |
| 198 | size_t length, |
| 199 | const uint16_t num_glyphs) { |
| 200 | ots::Buffer subtable(data, length); |
| 201 | return ParseMathValueRecordSequenceForGlyphs(&subtable, data, length, |
| 202 | num_glyphs); |
| 203 | } |
| 204 | |
| 205 | bool ParseMathTopAccentAttachmentTable(const uint8_t *data, |
| 206 | size_t length, |
| 207 | const uint16_t num_glyphs) { |
| 208 | ots::Buffer subtable(data, length); |
| 209 | return ParseMathValueRecordSequenceForGlyphs(&subtable, data, length, |
| 210 | num_glyphs); |
| 211 | } |
| 212 | |
| 213 | bool ParseMathKernTable(const uint8_t *data, size_t length) { |
| 214 | ots::Buffer subtable(data, length); |
| 215 | |
| 216 | // Check the Height count. |
| 217 | uint16_t height_count = 0; |
| 218 | if (!subtable.ReadU16(&height_count)) { |
| 219 | return OTS_FAILURE(); |
| 220 | } |
| 221 | |
| 222 | // Check the Correction Heights. |
| 223 | for (unsigned i = 0; i < height_count; ++i) { |
| 224 | if (!ParseMathValueRecord(&subtable, data, length)) { |
| 225 | return OTS_FAILURE(); |
| 226 | } |
| 227 | } |
| 228 | |
| 229 | // Check the Kern Values. |
| 230 | for (unsigned i = 0; i <= height_count; ++i) { |
| 231 | if (!ParseMathValueRecord(&subtable, data, length)) { |
| 232 | return OTS_FAILURE(); |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | return true; |
| 237 | } |
| 238 | |
| 239 | bool ParseMathKernInfoTable(const uint8_t *data, size_t length, |
| 240 | const uint16_t num_glyphs) { |
| 241 | ots::Buffer subtable(data, length); |
| 242 | |
| 243 | // Check the header. |
| 244 | uint16_t offset_coverage = 0; |
| 245 | uint16_t sequence_count = 0; |
| 246 | if (!subtable.ReadU16(&offset_coverage) || |
| 247 | !subtable.ReadU16(&sequence_count)) { |
| 248 | return OTS_FAILURE(); |
| 249 | } |
| 250 | |
| 251 | const unsigned sequence_end = static_cast<unsigned>(2 * 2) + |
| 252 | sequence_count * 4 * 2; |
| 253 | if (sequence_end > std::numeric_limits<uint16_t>::max()) { |
| 254 | return OTS_FAILURE(); |
| 255 | } |
| 256 | |
| 257 | // Check coverage table. |
| 258 | if (offset_coverage < sequence_end || offset_coverage >= length) { |
| 259 | return OTS_FAILURE(); |
| 260 | } |
| 261 | if (!ots::ParseCoverageTable(data + offset_coverage, length - offset_coverage, |
| 262 | num_glyphs, sequence_count)) { |
| 263 | return OTS_FAILURE(); |
| 264 | } |
| 265 | |
| 266 | // Check sequence of MathKernInfoRecord |
| 267 | for (unsigned i = 0; i < sequence_count; ++i) { |
| 268 | // Check TopRight, TopLeft, BottomRight and BottomLeft Math Kern. |
| 269 | for (unsigned j = 0; j < 4; ++j) { |
| 270 | uint16_t offset_math_kern = 0; |
| 271 | if (!subtable.ReadU16(&offset_math_kern)) { |
| 272 | return OTS_FAILURE(); |
| 273 | } |
| 274 | if (offset_math_kern) { |
| 275 | if (offset_math_kern < sequence_end || offset_math_kern >= length || |
| 276 | !ParseMathKernTable(data + offset_math_kern, |
| 277 | length - offset_math_kern)) { |
| 278 | return OTS_FAILURE(); |
| 279 | } |
| 280 | } |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | return true; |
| 285 | } |
| 286 | |
| 287 | bool ParseMathGlyphInfoTable(const uint8_t *data, size_t length, |
| 288 | const uint16_t num_glyphs) { |
| 289 | ots::Buffer subtable(data, length); |
| 290 | |
| 291 | // Check Header. |
| 292 | uint16_t offset_math_italics_correction_info = 0; |
| 293 | uint16_t offset_math_top_accent_attachment = 0; |
| 294 | uint16_t offset_extended_shaped_coverage = 0; |
| 295 | uint16_t offset_math_kern_info = 0; |
| 296 | if (!subtable.ReadU16(&offset_math_italics_correction_info) || |
| 297 | !subtable.ReadU16(&offset_math_top_accent_attachment) || |
| 298 | !subtable.ReadU16(&offset_extended_shaped_coverage) || |
| 299 | !subtable.ReadU16(&offset_math_kern_info)) { |
| 300 | return OTS_FAILURE(); |
| 301 | } |
| 302 | |
| 303 | // Check subtables. |
| 304 | // The specification does not say whether the offsets for |
| 305 | // MathItalicsCorrectionInfo, MathTopAccentAttachment and MathKernInfo may |
| 306 | // be NULL, but that's the case in some fonts (e.g STIX) so we accept that. |
| 307 | if (offset_math_italics_correction_info) { |
| 308 | if (offset_math_italics_correction_info >= length || |
| 309 | offset_math_italics_correction_info < kMathGlyphInfoHeaderSize || |
| 310 | !ParseMathItalicsCorrectionInfoTable( |
| 311 | data + offset_math_italics_correction_info, |
| 312 | length - offset_math_italics_correction_info, |
| 313 | num_glyphs)) { |
| 314 | return OTS_FAILURE(); |
| 315 | } |
| 316 | } |
| 317 | if (offset_math_top_accent_attachment) { |
| 318 | if (offset_math_top_accent_attachment >= length || |
| 319 | offset_math_top_accent_attachment < kMathGlyphInfoHeaderSize || |
| 320 | !ParseMathTopAccentAttachmentTable(data + |
| 321 | offset_math_top_accent_attachment, |
| 322 | length - |
| 323 | offset_math_top_accent_attachment, |
| 324 | num_glyphs)) { |
| 325 | return OTS_FAILURE(); |
| 326 | } |
| 327 | } |
| 328 | if (offset_extended_shaped_coverage) { |
| 329 | if (offset_extended_shaped_coverage >= length || |
| 330 | offset_extended_shaped_coverage < kMathGlyphInfoHeaderSize || |
| 331 | !ots::ParseCoverageTable(data + offset_extended_shaped_coverage, |
| 332 | length - offset_extended_shaped_coverage, |
| 333 | num_glyphs)) { |
| 334 | return OTS_FAILURE(); |
| 335 | } |
| 336 | } |
| 337 | if (offset_math_kern_info) { |
| 338 | if (offset_math_kern_info >= length || |
| 339 | offset_math_kern_info < kMathGlyphInfoHeaderSize || |
| 340 | !ParseMathKernInfoTable(data + offset_math_kern_info, |
| 341 | length - offset_math_kern_info, num_glyphs)) { |
| 342 | return OTS_FAILURE(); |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | return true; |
| 347 | } |
| 348 | |
| 349 | bool ParseGlyphAssemblyTable(const uint8_t *data, |
| 350 | size_t length, const uint16_t num_glyphs) { |
| 351 | ots::Buffer subtable(data, length); |
| 352 | |
| 353 | // Check the header. |
| 354 | uint16_t part_count = 0; |
| 355 | if (!ParseMathValueRecord(&subtable, data, length) || |
| 356 | !subtable.ReadU16(&part_count)) { |
| 357 | return OTS_FAILURE(); |
| 358 | } |
| 359 | |
| 360 | const unsigned sequence_end = kMathValueRecordSize + |
| 361 | static_cast<unsigned>(2) + part_count * kGlyphPartRecordSize; |
| 362 | if (sequence_end > std::numeric_limits<uint16_t>::max()) { |
| 363 | return OTS_FAILURE(); |
| 364 | } |
| 365 | |
| 366 | // Check the sequence of GlyphPartRecord. |
| 367 | for (unsigned i = 0; i < part_count; ++i) { |
| 368 | uint16_t glyph = 0; |
| 369 | uint16_t part_flags = 0; |
| 370 | if (!subtable.ReadU16(&glyph) || |
| 371 | !subtable.Skip(2 * 3) || |
| 372 | !subtable.ReadU16(&part_flags)) { |
| 373 | return OTS_FAILURE(); |
| 374 | } |
| 375 | if (glyph >= num_glyphs) { |
| 376 | OTS_WARNING("bad glyph ID: %u", glyph); |
| 377 | return OTS_FAILURE(); |
| 378 | } |
| 379 | if (part_flags & ~0x00000001) { |
| 380 | OTS_WARNING("unknown part flag: %u", part_flags); |
| 381 | return OTS_FAILURE(); |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | return true; |
| 386 | } |
| 387 | |
| 388 | bool ParseMathGlyphConstructionTable(const uint8_t *data, |
| 389 | size_t length, const uint16_t num_glyphs) { |
| 390 | ots::Buffer subtable(data, length); |
| 391 | |
| 392 | // Check the header. |
| 393 | uint16_t offset_glyph_assembly = 0; |
| 394 | uint16_t variant_count = 0; |
| 395 | if (!subtable.ReadU16(&offset_glyph_assembly) || |
| 396 | !subtable.ReadU16(&variant_count)) { |
| 397 | return OTS_FAILURE(); |
| 398 | } |
| 399 | |
| 400 | const unsigned sequence_end = static_cast<unsigned>(2 * 2) + |
| 401 | variant_count * 2 * 2; |
| 402 | if (sequence_end > std::numeric_limits<uint16_t>::max()) { |
| 403 | return OTS_FAILURE(); |
| 404 | } |
| 405 | |
| 406 | // Check the GlyphAssembly offset. |
| 407 | if (offset_glyph_assembly) { |
| 408 | if (offset_glyph_assembly >= length || |
| 409 | offset_glyph_assembly < sequence_end) { |
| 410 | return OTS_FAILURE(); |
| 411 | } |
| 412 | if (!ParseGlyphAssemblyTable(data + offset_glyph_assembly, |
| 413 | length - offset_glyph_assembly, num_glyphs)) { |
| 414 | return OTS_FAILURE(); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | // Check the sequence of MathGlyphVariantRecord. |
| 419 | for (unsigned i = 0; i < variant_count; ++i) { |
| 420 | uint16_t glyph = 0; |
| 421 | if (!subtable.ReadU16(&glyph) || |
| 422 | !subtable.Skip(2)) { |
| 423 | return OTS_FAILURE(); |
| 424 | } |
| 425 | if (glyph >= num_glyphs) { |
| 426 | OTS_WARNING("bad glyph ID: %u", glyph); |
| 427 | return OTS_FAILURE(); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | return true; |
| 432 | } |
| 433 | |
| 434 | bool ParseMathGlyphConstructionSequence(ots::Buffer* subtable, |
| 435 | const uint8_t *data, |
| 436 | size_t length, |
| 437 | const uint16_t num_glyphs, |
| 438 | uint16_t offset_coverage, |
| 439 | uint16_t glyph_count, |
| 440 | const unsigned sequence_end) { |
| 441 | // Check coverage table. |
| 442 | if (offset_coverage < sequence_end || offset_coverage >= length) { |
| 443 | return OTS_FAILURE(); |
| 444 | } |
| 445 | if (!ots::ParseCoverageTable(data + offset_coverage, |
| 446 | length - offset_coverage, |
| 447 | num_glyphs, glyph_count)) { |
| 448 | return OTS_FAILURE(); |
| 449 | } |
| 450 | |
| 451 | // Check sequence of MathGlyphConstruction. |
| 452 | for (unsigned i = 0; i < glyph_count; ++i) { |
| 453 | uint16_t offset_glyph_construction = 0; |
| 454 | if (!subtable->ReadU16(&offset_glyph_construction)) { |
| 455 | return OTS_FAILURE(); |
| 456 | } |
| 457 | if (offset_glyph_construction < sequence_end || |
| 458 | offset_glyph_construction >= length || |
| 459 | !ParseMathGlyphConstructionTable(data + offset_glyph_construction, |
| 460 | length - offset_glyph_construction, |
| 461 | num_glyphs)) { |
| 462 | return OTS_FAILURE(); |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | return true; |
| 467 | } |
| 468 | |
| 469 | bool ParseMathVariantsTable(const uint8_t *data, |
| 470 | size_t length, const uint16_t num_glyphs) { |
| 471 | ots::Buffer subtable(data, length); |
| 472 | |
| 473 | // Check the header. |
| 474 | uint16_t offset_vert_glyph_coverage = 0; |
| 475 | uint16_t offset_horiz_glyph_coverage = 0; |
| 476 | uint16_t vert_glyph_count = 0; |
| 477 | uint16_t horiz_glyph_count = 0; |
| 478 | if (!subtable.Skip(2) || // MinConnectorOverlap |
| 479 | !subtable.ReadU16(&offset_vert_glyph_coverage) || |
| 480 | !subtable.ReadU16(&offset_horiz_glyph_coverage) || |
| 481 | !subtable.ReadU16(&vert_glyph_count) || |
| 482 | !subtable.ReadU16(&horiz_glyph_count)) { |
| 483 | return OTS_FAILURE(); |
| 484 | } |
| 485 | |
| 486 | const unsigned sequence_end = 5 * 2 + vert_glyph_count * 2 + |
| 487 | horiz_glyph_count * 2; |
| 488 | if (sequence_end > std::numeric_limits<uint16_t>::max()) { |
| 489 | return OTS_FAILURE(); |
| 490 | } |
| 491 | |
| 492 | if (!ParseMathGlyphConstructionSequence(&subtable, data, length, num_glyphs, |
| 493 | offset_vert_glyph_coverage, |
| 494 | vert_glyph_count, |
| 495 | sequence_end) || |
| 496 | !ParseMathGlyphConstructionSequence(&subtable, data, length, num_glyphs, |
| 497 | offset_horiz_glyph_coverage, |
| 498 | horiz_glyph_count, |
| 499 | sequence_end)) { |
| 500 | return OTS_FAILURE(); |
| 501 | } |
| 502 | |
| 503 | return true; |
| 504 | } |
| 505 | |
| 506 | } // namespace |
| 507 | |
| 508 | #define DROP_THIS_TABLE \ |
| 509 | do { file->math->data = 0; file->math->length = 0; } while (0) |
| 510 | |
| 511 | namespace ots { |
| 512 | |
| 513 | bool ots_math_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| 514 | // Grab the number of glyphs in the file from the maxp table to check |
| 515 | // GlyphIDs in MATH table. |
| 516 | if (!file->maxp) { |
| 517 | return OTS_FAILURE(); |
| 518 | } |
| 519 | const uint16_t num_glyphs = file->maxp->num_glyphs; |
| 520 | |
| 521 | Buffer table(data, length); |
| 522 | |
| 523 | OpenTypeMATH* math = new OpenTypeMATH; |
| 524 | file->math = math; |
| 525 | |
| 526 | uint32_t version = 0; |
| 527 | if (!table.ReadU32(&version)) { |
| 528 | return OTS_FAILURE(); |
| 529 | } |
| 530 | if (version != 0x00010000) { |
| 531 | OTS_WARNING("bad MATH version"); |
| 532 | DROP_THIS_TABLE; |
| 533 | return true; |
| 534 | } |
| 535 | |
| 536 | uint16_t offset_math_constants = 0; |
| 537 | uint16_t offset_math_glyph_info = 0; |
| 538 | uint16_t offset_math_variants = 0; |
| 539 | if (!table.ReadU16(&offset_math_constants) || |
| 540 | !table.ReadU16(&offset_math_glyph_info) || |
| 541 | !table.ReadU16(&offset_math_variants)) { |
| 542 | return OTS_FAILURE(); |
| 543 | } |
| 544 | |
| 545 | if (offset_math_constants >= length || |
| 546 | offset_math_constants < kMathHeaderSize || |
| 547 | offset_math_glyph_info >= length || |
| 548 | offset_math_glyph_info < kMathHeaderSize || |
| 549 | offset_math_variants >= length || |
| 550 | offset_math_variants < kMathHeaderSize) { |
| 551 | OTS_WARNING("bad offset in MATH header"); |
| 552 | DROP_THIS_TABLE; |
| 553 | return true; |
| 554 | } |
| 555 | |
| 556 | if (!ParseMathConstantsTable(data + offset_math_constants, |
| 557 | length - offset_math_constants)) { |
| 558 | DROP_THIS_TABLE; |
| 559 | return true; |
| 560 | } |
| 561 | if (!ParseMathGlyphInfoTable(data + offset_math_glyph_info, |
| 562 | length - offset_math_glyph_info, num_glyphs)) { |
| 563 | DROP_THIS_TABLE; |
| 564 | return true; |
| 565 | } |
| 566 | if (!ParseMathVariantsTable(data + offset_math_variants, |
| 567 | length - offset_math_variants, num_glyphs)) { |
| 568 | DROP_THIS_TABLE; |
| 569 | return true; |
| 570 | } |
| 571 | |
| 572 | math->data = data; |
| 573 | math->length = length; |
| 574 | return true; |
| 575 | } |
| 576 | |
| 577 | bool ots_math_should_serialise(OpenTypeFile *file) { |
| 578 | return file->math != NULL && file->math->data != NULL; |
| 579 | } |
| 580 | |
| 581 | bool ots_math_serialise(OTSStream *out, OpenTypeFile *file) { |
| 582 | if (!out->Write(file->math->data, file->math->length)) { |
| 583 | return OTS_FAILURE(); |
| 584 | } |
| 585 | |
| 586 | return true; |
| 587 | } |
| 588 | |
| 589 | void ots_math_free(OpenTypeFile *file) { |
| 590 | delete file->math; |
| 591 | } |
| 592 | |
| 593 | } // namespace ots |
| 594 | |