| OLD | NEW |
| (Empty) |
| 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 "gdef.h" | |
| 6 | |
| 7 #include <limits> | |
| 8 #include <vector> | |
| 9 | |
| 10 #include "gpos.h" | |
| 11 #include "gsub.h" | |
| 12 #include "layout.h" | |
| 13 #include "maxp.h" | |
| 14 | |
| 15 // GDEF - The Glyph Definition Table | |
| 16 // http://www.microsoft.com/typography/otspec/gdef.htm | |
| 17 | |
| 18 #define TABLE_NAME "GDEF" | |
| 19 | |
| 20 namespace { | |
| 21 | |
| 22 // The maximum class value in class definition tables. | |
| 23 const uint16_t kMaxClassDefValue = 0xFFFF; | |
| 24 // The maximum class value in the glyph class definision table. | |
| 25 const uint16_t kMaxGlyphClassDefValue = 4; | |
| 26 // The maximum format number of caret value tables. | |
| 27 // We don't support format 3 for now. See the comment in | |
| 28 // ParseLigCaretListTable() for the reason. | |
| 29 const uint16_t kMaxCaretValueFormat = 2; | |
| 30 | |
| 31 bool ParseGlyphClassDefTable(ots::OpenTypeFile *file, const uint8_t *data, | |
| 32 size_t length, const uint16_t num_glyphs) { | |
| 33 return ots::ParseClassDefTable(file, data, length, num_glyphs, | |
| 34 kMaxGlyphClassDefValue); | |
| 35 } | |
| 36 | |
| 37 bool ParseAttachListTable(ots::OpenTypeFile *file, const uint8_t *data, | |
| 38 size_t length, const uint16_t num_glyphs) { | |
| 39 ots::Buffer subtable(data, length); | |
| 40 | |
| 41 uint16_t offset_coverage = 0; | |
| 42 uint16_t glyph_count = 0; | |
| 43 if (!subtable.ReadU16(&offset_coverage) || | |
| 44 !subtable.ReadU16(&glyph_count)) { | |
| 45 return OTS_FAILURE_MSG("Failed to read gdef header"); | |
| 46 } | |
| 47 const unsigned attach_points_end = | |
| 48 2 * static_cast<unsigned>(glyph_count) + 4; | |
| 49 if (attach_points_end > std::numeric_limits<uint16_t>::max()) { | |
| 50 return OTS_FAILURE_MSG("Bad glyph count in gdef"); | |
| 51 } | |
| 52 if (offset_coverage == 0 || offset_coverage >= length || | |
| 53 offset_coverage < attach_points_end) { | |
| 54 return OTS_FAILURE_MSG("Bad coverage offset %d", offset_coverage); | |
| 55 } | |
| 56 if (glyph_count > num_glyphs) { | |
| 57 return OTS_FAILURE_MSG("Bad glyph count %u", glyph_count); | |
| 58 } | |
| 59 | |
| 60 std::vector<uint16_t> attach_points; | |
| 61 attach_points.resize(glyph_count); | |
| 62 for (unsigned i = 0; i < glyph_count; ++i) { | |
| 63 if (!subtable.ReadU16(&attach_points[i])) { | |
| 64 return OTS_FAILURE_MSG("Can't read attachment point %d", i); | |
| 65 } | |
| 66 if (attach_points[i] >= length || | |
| 67 attach_points[i] < attach_points_end) { | |
| 68 return OTS_FAILURE_MSG("Bad attachment point %d of %d", i, attach_points[i
]); | |
| 69 } | |
| 70 } | |
| 71 | |
| 72 // Parse coverage table | |
| 73 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 74 length - offset_coverage, num_glyphs)) { | |
| 75 return OTS_FAILURE_MSG("Bad coverage table"); | |
| 76 } | |
| 77 | |
| 78 // Parse attach point table | |
| 79 for (unsigned i = 0; i < attach_points.size(); ++i) { | |
| 80 subtable.set_offset(attach_points[i]); | |
| 81 uint16_t point_count = 0; | |
| 82 if (!subtable.ReadU16(&point_count)) { | |
| 83 return OTS_FAILURE_MSG("Can't read point count %d", i); | |
| 84 } | |
| 85 if (point_count == 0) { | |
| 86 return OTS_FAILURE_MSG("zero point count %d", i); | |
| 87 } | |
| 88 uint16_t last_point_index = 0; | |
| 89 uint16_t point_index = 0; | |
| 90 for (unsigned j = 0; j < point_count; ++j) { | |
| 91 if (!subtable.ReadU16(&point_index)) { | |
| 92 return OTS_FAILURE_MSG("Can't read point index %d in point %d", j, i); | |
| 93 } | |
| 94 // Contour point indeces are in increasing numerical order | |
| 95 if (last_point_index != 0 && last_point_index >= point_index) { | |
| 96 return OTS_FAILURE_MSG("bad contour indeces: %u >= %u", | |
| 97 last_point_index, point_index); | |
| 98 } | |
| 99 last_point_index = point_index; | |
| 100 } | |
| 101 } | |
| 102 return true; | |
| 103 } | |
| 104 | |
| 105 bool ParseLigCaretListTable(ots::OpenTypeFile *file, const uint8_t *data, | |
| 106 size_t length, const uint16_t num_glyphs) { | |
| 107 ots::Buffer subtable(data, length); | |
| 108 uint16_t offset_coverage = 0; | |
| 109 uint16_t lig_glyph_count = 0; | |
| 110 if (!subtable.ReadU16(&offset_coverage) || | |
| 111 !subtable.ReadU16(&lig_glyph_count)) { | |
| 112 return OTS_FAILURE_MSG("Can't read caret structure"); | |
| 113 } | |
| 114 const unsigned lig_glyphs_end = | |
| 115 2 * static_cast<unsigned>(lig_glyph_count) + 4; | |
| 116 if (lig_glyphs_end > std::numeric_limits<uint16_t>::max()) { | |
| 117 return OTS_FAILURE_MSG("Bad caret structure"); | |
| 118 } | |
| 119 if (offset_coverage == 0 || offset_coverage >= length || | |
| 120 offset_coverage < lig_glyphs_end) { | |
| 121 return OTS_FAILURE_MSG("Bad caret coverate offset %d", offset_coverage); | |
| 122 } | |
| 123 if (lig_glyph_count > num_glyphs) { | |
| 124 return OTS_FAILURE_MSG("bad ligature glyph count: %u", lig_glyph_count); | |
| 125 } | |
| 126 | |
| 127 std::vector<uint16_t> lig_glyphs; | |
| 128 lig_glyphs.resize(lig_glyph_count); | |
| 129 for (unsigned i = 0; i < lig_glyph_count; ++i) { | |
| 130 if (!subtable.ReadU16(&lig_glyphs[i])) { | |
| 131 return OTS_FAILURE_MSG("Can't read ligature glyph location %d", i); | |
| 132 } | |
| 133 if (lig_glyphs[i] >= length || lig_glyphs[i] < lig_glyphs_end) { | |
| 134 return OTS_FAILURE_MSG("Bad ligature glyph location %d in glyph %d", lig_g
lyphs[i], i); | |
| 135 } | |
| 136 } | |
| 137 | |
| 138 // Parse coverage table | |
| 139 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 140 length - offset_coverage, num_glyphs)) { | |
| 141 return OTS_FAILURE_MSG("Can't parse caret coverage table"); | |
| 142 } | |
| 143 | |
| 144 // Parse ligature glyph table | |
| 145 for (unsigned i = 0; i < lig_glyphs.size(); ++i) { | |
| 146 subtable.set_offset(lig_glyphs[i]); | |
| 147 uint16_t caret_count = 0; | |
| 148 if (!subtable.ReadU16(&caret_count)) { | |
| 149 return OTS_FAILURE_MSG("Can't read caret count for glyph %d", i); | |
| 150 } | |
| 151 if (caret_count == 0) { | |
| 152 return OTS_FAILURE_MSG("bad caret value count: %u", caret_count); | |
| 153 } | |
| 154 | |
| 155 std::vector<uint16_t> caret_value_offsets; | |
| 156 caret_value_offsets.resize(caret_count); | |
| 157 unsigned caret_value_offsets_end = 2 * static_cast<unsigned>(caret_count) +
2; | |
| 158 for (unsigned j = 0; j < caret_count; ++j) { | |
| 159 if (!subtable.ReadU16(&caret_value_offsets[j])) { | |
| 160 return OTS_FAILURE_MSG("Can't read caret offset %d for glyph %d", j, i); | |
| 161 } | |
| 162 if (caret_value_offsets[j] >= length || caret_value_offsets[j] < caret_val
ue_offsets_end) { | |
| 163 return OTS_FAILURE_MSG("Bad caret offset %d for caret %d glyph %d", care
t_value_offsets[j], j, i); | |
| 164 } | |
| 165 } | |
| 166 | |
| 167 // Parse caret values table | |
| 168 for (unsigned j = 0; j < caret_count; ++j) { | |
| 169 subtable.set_offset(lig_glyphs[i] + caret_value_offsets[j]); | |
| 170 uint16_t caret_format = 0; | |
| 171 if (!subtable.ReadU16(&caret_format)) { | |
| 172 return OTS_FAILURE_MSG("Can't read caret values table %d in glyph %d", j
, i); | |
| 173 } | |
| 174 // TODO(bashi): We only support caret value format 1 and 2 for now | |
| 175 // because there are no fonts which contain caret value format 3 | |
| 176 // as far as we investigated. | |
| 177 if (caret_format == 0 || caret_format > kMaxCaretValueFormat) { | |
| 178 return OTS_FAILURE_MSG("bad caret value format: %u", caret_format); | |
| 179 } | |
| 180 // CaretValueFormats contain a 2-byte field which could be | |
| 181 // arbitrary value. | |
| 182 if (!subtable.Skip(2)) { | |
| 183 return OTS_FAILURE_MSG("Bad caret value table structure %d in glyph %d",
j, i); | |
| 184 } | |
| 185 } | |
| 186 } | |
| 187 return true; | |
| 188 } | |
| 189 | |
| 190 bool ParseMarkAttachClassDefTable(ots::OpenTypeFile *file, const uint8_t *data, | |
| 191 size_t length, const uint16_t num_glyphs) { | |
| 192 return ots::ParseClassDefTable(file, data, length, num_glyphs, kMaxClassDefVal
ue); | |
| 193 } | |
| 194 | |
| 195 bool ParseMarkGlyphSetsDefTable(ots::OpenTypeFile *file, const uint8_t *data, | |
| 196 size_t length, const uint16_t num_glyphs) { | |
| 197 ots::Buffer subtable(data, length); | |
| 198 uint16_t format = 0; | |
| 199 uint16_t mark_set_count = 0; | |
| 200 if (!subtable.ReadU16(&format) || | |
| 201 !subtable.ReadU16(&mark_set_count)) { | |
| 202 return OTS_FAILURE_MSG("Can' read mark glyph table structure"); | |
| 203 } | |
| 204 if (format != 1) { | |
| 205 return OTS_FAILURE_MSG("bad mark glyph set table format: %u", format); | |
| 206 } | |
| 207 | |
| 208 const unsigned mark_sets_end = 2 * static_cast<unsigned>(mark_set_count) + 4; | |
| 209 if (mark_sets_end > std::numeric_limits<uint16_t>::max()) { | |
| 210 return OTS_FAILURE_MSG("Bad mark_set %d", mark_sets_end); | |
| 211 } | |
| 212 for (unsigned i = 0; i < mark_set_count; ++i) { | |
| 213 uint32_t offset_coverage = 0; | |
| 214 if (!subtable.ReadU32(&offset_coverage)) { | |
| 215 return OTS_FAILURE_MSG("Can't read covrage location for mark set %d", i); | |
| 216 } | |
| 217 if (offset_coverage >= length || | |
| 218 offset_coverage < mark_sets_end) { | |
| 219 return OTS_FAILURE_MSG("Bad coverage location %d for mark set %d", offset_
coverage, i); | |
| 220 } | |
| 221 if (!ots::ParseCoverageTable(file, data + offset_coverage, | |
| 222 length - offset_coverage, num_glyphs)) { | |
| 223 return OTS_FAILURE_MSG("Failed to parse coverage table for mark set %d", i
); | |
| 224 } | |
| 225 } | |
| 226 file->gdef->num_mark_glyph_sets = mark_set_count; | |
| 227 return true; | |
| 228 } | |
| 229 | |
| 230 } // namespace | |
| 231 | |
| 232 #define DROP_THIS_TABLE(msg_) \ | |
| 233 do { \ | |
| 234 OTS_FAILURE_MSG(msg_ ", table discarded"); \ | |
| 235 file->gdef->data = 0; \ | |
| 236 file->gdef->length = 0; \ | |
| 237 } while (0) | |
| 238 | |
| 239 namespace ots { | |
| 240 | |
| 241 bool ots_gdef_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { | |
| 242 // Grab the number of glyphs in the file from the maxp table to check | |
| 243 // GlyphIDs in GDEF table. | |
| 244 if (!file->maxp) { | |
| 245 return OTS_FAILURE_MSG("No maxp table in font, needed by GDEF"); | |
| 246 } | |
| 247 const uint16_t num_glyphs = file->maxp->num_glyphs; | |
| 248 | |
| 249 Buffer table(data, length); | |
| 250 | |
| 251 OpenTypeGDEF *gdef = new OpenTypeGDEF; | |
| 252 file->gdef = gdef; | |
| 253 | |
| 254 uint32_t version = 0; | |
| 255 if (!table.ReadU32(&version)) { | |
| 256 DROP_THIS_TABLE("Incomplete table"); | |
| 257 return true; | |
| 258 } | |
| 259 if (version < 0x00010000 || version == 0x00010001) { | |
| 260 DROP_THIS_TABLE("Bad version"); | |
| 261 return true; | |
| 262 } | |
| 263 | |
| 264 if (version >= 0x00010002) { | |
| 265 gdef->version_2 = true; | |
| 266 } | |
| 267 | |
| 268 uint16_t offset_glyph_class_def = 0; | |
| 269 uint16_t offset_attach_list = 0; | |
| 270 uint16_t offset_lig_caret_list = 0; | |
| 271 uint16_t offset_mark_attach_class_def = 0; | |
| 272 if (!table.ReadU16(&offset_glyph_class_def) || | |
| 273 !table.ReadU16(&offset_attach_list) || | |
| 274 !table.ReadU16(&offset_lig_caret_list) || | |
| 275 !table.ReadU16(&offset_mark_attach_class_def)) { | |
| 276 DROP_THIS_TABLE("Incomplete table"); | |
| 277 return true; | |
| 278 } | |
| 279 uint16_t offset_mark_glyph_sets_def = 0; | |
| 280 if (gdef->version_2) { | |
| 281 if (!table.ReadU16(&offset_mark_glyph_sets_def)) { | |
| 282 DROP_THIS_TABLE("Incomplete table"); | |
| 283 return true; | |
| 284 } | |
| 285 } | |
| 286 | |
| 287 unsigned gdef_header_end = 4 + 4 * 2; | |
| 288 if (gdef->version_2) | |
| 289 gdef_header_end += 2; | |
| 290 | |
| 291 // Parse subtables | |
| 292 if (offset_glyph_class_def) { | |
| 293 if (offset_glyph_class_def >= length || | |
| 294 offset_glyph_class_def < gdef_header_end) { | |
| 295 DROP_THIS_TABLE("Invalid offset to glyph classes"); | |
| 296 return true; | |
| 297 } | |
| 298 if (!ParseGlyphClassDefTable(file, data + offset_glyph_class_def, | |
| 299 length - offset_glyph_class_def, | |
| 300 num_glyphs)) { | |
| 301 DROP_THIS_TABLE("Invalid glyph classes"); | |
| 302 return true; | |
| 303 } | |
| 304 gdef->has_glyph_class_def = true; | |
| 305 } | |
| 306 | |
| 307 if (offset_attach_list) { | |
| 308 if (offset_attach_list >= length || | |
| 309 offset_attach_list < gdef_header_end) { | |
| 310 DROP_THIS_TABLE("Invalid offset to attachment list"); | |
| 311 return true; | |
| 312 } | |
| 313 if (!ParseAttachListTable(file, data + offset_attach_list, | |
| 314 length - offset_attach_list, | |
| 315 num_glyphs)) { | |
| 316 DROP_THIS_TABLE("Invalid attachment list"); | |
| 317 return true; | |
| 318 } | |
| 319 } | |
| 320 | |
| 321 if (offset_lig_caret_list) { | |
| 322 if (offset_lig_caret_list >= length || | |
| 323 offset_lig_caret_list < gdef_header_end) { | |
| 324 DROP_THIS_TABLE("Invalid offset to ligature caret list"); | |
| 325 return true; | |
| 326 } | |
| 327 if (!ParseLigCaretListTable(file, data + offset_lig_caret_list, | |
| 328 length - offset_lig_caret_list, | |
| 329 num_glyphs)) { | |
| 330 DROP_THIS_TABLE("Invalid ligature caret list"); | |
| 331 return true; | |
| 332 } | |
| 333 } | |
| 334 | |
| 335 if (offset_mark_attach_class_def) { | |
| 336 if (offset_mark_attach_class_def >= length || | |
| 337 offset_mark_attach_class_def < gdef_header_end) { | |
| 338 return OTS_FAILURE_MSG("Invalid offset to mark attachment list"); | |
| 339 } | |
| 340 if (!ParseMarkAttachClassDefTable(file, | |
| 341 data + offset_mark_attach_class_def, | |
| 342 length - offset_mark_attach_class_def, | |
| 343 num_glyphs)) { | |
| 344 DROP_THIS_TABLE("Invalid mark attachment list"); | |
| 345 return true; | |
| 346 } | |
| 347 gdef->has_mark_attachment_class_def = true; | |
| 348 } | |
| 349 | |
| 350 if (offset_mark_glyph_sets_def) { | |
| 351 if (offset_mark_glyph_sets_def >= length || | |
| 352 offset_mark_glyph_sets_def < gdef_header_end) { | |
| 353 return OTS_FAILURE_MSG("invalid offset to mark glyph sets"); | |
| 354 } | |
| 355 if (!ParseMarkGlyphSetsDefTable(file, | |
| 356 data + offset_mark_glyph_sets_def, | |
| 357 length - offset_mark_glyph_sets_def, | |
| 358 num_glyphs)) { | |
| 359 DROP_THIS_TABLE("Invalid mark glyph sets"); | |
| 360 return true; | |
| 361 } | |
| 362 gdef->has_mark_glyph_sets_def = true; | |
| 363 } | |
| 364 gdef->data = data; | |
| 365 gdef->length = length; | |
| 366 return true; | |
| 367 } | |
| 368 | |
| 369 bool ots_gdef_should_serialise(OpenTypeFile *file) { | |
| 370 return file->gdef != NULL && file->gdef->data != NULL; | |
| 371 } | |
| 372 | |
| 373 bool ots_gdef_serialise(OTSStream *out, OpenTypeFile *file) { | |
| 374 if (!out->Write(file->gdef->data, file->gdef->length)) { | |
| 375 return OTS_FAILURE_MSG("Failed to write GDEF table"); | |
| 376 } | |
| 377 | |
| 378 return true; | |
| 379 } | |
| 380 | |
| 381 void ots_gdef_free(OpenTypeFile *file) { | |
| 382 delete file->gdef; | |
| 383 } | |
| 384 | |
| 385 } // namespace ots | |
| 386 | |
| 387 #undef TABLE_NAME | |
| 388 #undef DROP_THIS_TABLE | |
| OLD | NEW |