| // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "cmap.h" |
| |
| #include <algorithm> |
| #include <set> |
| #include <utility> |
| #include <vector> |
| |
| #include "maxp.h" |
| #include "os2.h" |
| |
| // cmap - Character To Glyph Index Mapping Table |
| // http://www.microsoft.com/typography/otspec/cmap.htm |
| |
| #define TABLE_NAME "cmap" |
| |
| namespace { |
| |
| struct CMAPSubtableHeader { |
| uint16_t platform; |
| uint16_t encoding; |
| uint32_t offset; |
| uint16_t format; |
| uint32_t length; |
| uint32_t language; |
| }; |
| |
| struct Subtable314Range { |
| uint16_t start_range; |
| uint16_t end_range; |
| int16_t id_delta; |
| uint16_t id_range_offset; |
| uint32_t id_range_offset_offset; |
| }; |
| |
| // The maximum number of groups in format 12, 13 or 14 subtables. |
| // Note: 0xFFFF is the maximum number of glyphs in a single font file. |
| const unsigned kMaxCMAPGroups = 0xFFFF; |
| |
| // Glyph array size for the Mac Roman (format 0) table. |
| const size_t kFormat0ArraySize = 256; |
| |
| // The upper limit of the Unicode code point. |
| const uint32_t kUnicodeUpperLimit = 0x10FFFF; |
| |
| // The maximum number of UVS records (See below). |
| const uint32_t kMaxCMAPSelectorRecords = 259; |
| // The range of UVSes are: |
| // 0x180B-0x180D (3 code points) |
| // 0xFE00-0xFE0F (16 code points) |
| // 0xE0100-0xE01EF (240 code points) |
| const uint32_t kMongolianVSStart = 0x180B; |
| const uint32_t kMongolianVSEnd = 0x180D; |
| const uint32_t kVSStart = 0xFE00; |
| const uint32_t kVSEnd = 0xFE0F; |
| const uint32_t kIVSStart = 0xE0100; |
| const uint32_t kIVSEnd = 0xE01EF; |
| const uint32_t kUVSUpperLimit = 0xFFFFFF; |
| |
| // Parses Format 4 tables |
| bool ParseFormat4(ots::OpenTypeFile *file, int platform, int encoding, |
| const uint8_t *data, size_t length, uint16_t num_glyphs) { |
| ots::Buffer subtable(data, length); |
| |
| // 0.3.4, 3.0.4 or 3.1.4 subtables are complex and, rather than expanding the |
| // whole thing and recompacting it, we validate it and include it verbatim |
| // in the output. |
| |
| if (!file->os2) { |
| return OTS_FAILURE_MSG("Required OS/2 table missing"); |
| } |
| |
| if (!subtable.Skip(4)) { |
| return OTS_FAILURE_MSG("Can't read 4 bytes at start of cmap format 4 subtable"); |
| } |
| uint16_t language = 0; |
| if (!subtable.ReadU16(&language)) { |
| return OTS_FAILURE_MSG("Can't read language"); |
| } |
| if (language) { |
| // Platform ID 3 (windows) subtables should have language '0'. |
| return OTS_FAILURE_MSG("Languages should be 0 (%d)", language); |
| } |
| |
| uint16_t segcountx2, search_range, entry_selector, range_shift; |
| segcountx2 = search_range = entry_selector = range_shift = 0; |
| if (!subtable.ReadU16(&segcountx2) || |
| !subtable.ReadU16(&search_range) || |
| !subtable.ReadU16(&entry_selector) || |
| !subtable.ReadU16(&range_shift)) { |
| return OTS_FAILURE_MSG("Failed to read subcmap structure"); |
| } |
| |
| if (segcountx2 & 1 || search_range & 1) { |
| return OTS_FAILURE_MSG("Bad subcmap structure"); |
| } |
| const uint16_t segcount = segcountx2 >> 1; |
| // There must be at least one segment according the spec. |
| if (segcount < 1) { |
| return OTS_FAILURE_MSG("Segcount < 1 (%d)", segcount); |
| } |
| |
| // log2segcount is the maximal x s.t. 2^x < segcount |
| unsigned log2segcount = 0; |
| while (1u << (log2segcount + 1) <= segcount) { |
| log2segcount++; |
| } |
| |
| const uint16_t expected_search_range = 2 * 1u << log2segcount; |
| if (expected_search_range != search_range) { |
| return OTS_FAILURE_MSG("expected search range != search range (%d != %d)", expected_search_range, search_range); |
| } |
| |
| if (entry_selector != log2segcount) { |
| return OTS_FAILURE_MSG("entry selector != log2(segement count) (%d != %d)", entry_selector, log2segcount); |
| } |
| |
| const uint16_t expected_range_shift = segcountx2 - search_range; |
| if (range_shift != expected_range_shift) { |
| return OTS_FAILURE_MSG("unexpected range shift (%d != %d)", range_shift, expected_range_shift); |
| } |
| |
| std::vector<Subtable314Range> ranges(segcount); |
| |
| for (unsigned i = 0; i < segcount; ++i) { |
| if (!subtable.ReadU16(&ranges[i].end_range)) { |
| return OTS_FAILURE_MSG("Failed to read segment %d", i); |
| } |
| } |
| |
| uint16_t padding; |
| if (!subtable.ReadU16(&padding)) { |
| return OTS_FAILURE_MSG("Failed to read cmap subtable segment padding"); |
| } |
| if (padding) { |
| return OTS_FAILURE_MSG("Non zero cmap subtable segment padding (%d)", padding); |
| } |
| |
| for (unsigned i = 0; i < segcount; ++i) { |
| if (!subtable.ReadU16(&ranges[i].start_range)) { |
| return OTS_FAILURE_MSG("Failed to read segment start range %d", i); |
| } |
| } |
| for (unsigned i = 0; i < segcount; ++i) { |
| if (!subtable.ReadS16(&ranges[i].id_delta)) { |
| return OTS_FAILURE_MSG("Failed to read segment delta %d", i); |
| } |
| } |
| for (unsigned i = 0; i < segcount; ++i) { |
| ranges[i].id_range_offset_offset = subtable.offset(); |
| if (!subtable.ReadU16(&ranges[i].id_range_offset)) { |
| return OTS_FAILURE_MSG("Failed to read segment range offset %d", i); |
| } |
| |
| if (ranges[i].id_range_offset & 1) { |
| // Some font generators seem to put 65535 on id_range_offset |
| // for 0xFFFF-0xFFFF range. |
| // (e.g., many fonts in http://www.princexml.com/fonts/) |
| if (i == segcount - 1u) { |
| OTS_WARNING("bad id_range_offset"); |
| ranges[i].id_range_offset = 0; |
| // The id_range_offset value in the transcoded font will not change |
| // since this table is not actually "transcoded" yet. |
| } else { |
| return OTS_FAILURE_MSG("Bad segment offset (%d)", ranges[i].id_range_offset); |
| } |
| } |
| } |
| |
| // ranges must be ascending order, based on the end_code. Ranges may not |
| // overlap. |
| for (unsigned i = 1; i < segcount; ++i) { |
| if ((i == segcount - 1u) && |
| (ranges[i - 1].start_range == 0xffff) && |
| (ranges[i - 1].end_range == 0xffff) && |
| (ranges[i].start_range == 0xffff) && |
| (ranges[i].end_range == 0xffff)) { |
| // Some fonts (e.g., Germania.ttf) have multiple 0xffff terminators. |
| // We'll accept them as an exception. |
| OTS_WARNING("multiple 0xffff terminators found"); |
| continue; |
| } |
| |
| // Note: some Linux fonts (e.g., LucidaSansOblique.ttf, bsmi00lp.ttf) have |
| // unsorted table... |
| if (ranges[i].end_range <= ranges[i - 1].end_range) { |
| return OTS_FAILURE_MSG("Out of order end range (%d <= %d)", ranges[i].end_range, ranges[i-1].end_range); |
| } |
| if (ranges[i].start_range <= ranges[i - 1].end_range) { |
| return OTS_FAILURE_MSG("out of order start range (%d <= %d)", ranges[i].start_range, ranges[i-1].end_range); |
| } |
| |
| // On many fonts, the value of {first, last}_char_index are incorrect. |
| // Fix them. |
| if (file->os2->first_char_index != 0xFFFF && |
| ranges[i].start_range != 0xFFFF && |
| file->os2->first_char_index > ranges[i].start_range) { |
| file->os2->first_char_index = ranges[i].start_range; |
| } |
| if (file->os2->last_char_index != 0xFFFF && |
| ranges[i].end_range != 0xFFFF && |
| file->os2->last_char_index < ranges[i].end_range) { |
| file->os2->last_char_index = ranges[i].end_range; |
| } |
| } |
| |
| // The last range must end at 0xffff |
| if (ranges[segcount - 1].start_range != 0xffff || ranges[segcount - 1].end_range != 0xffff) { |
| return OTS_FAILURE_MSG("Final segment start and end must be 0xFFFF (0x%04X-0x%04X)", |
| ranges[segcount - 1].start_range, ranges[segcount - 1].end_range); |
| } |
| |
| // A format 4 CMAP subtable is complex. To be safe we simulate a lookup of |
| // each code-point defined in the table and make sure that they are all valid |
| // glyphs and that we don't access anything out-of-bounds. |
| for (unsigned i = 0; i < segcount; ++i) { |
| for (unsigned cp = ranges[i].start_range; cp <= ranges[i].end_range; ++cp) { |
| const uint16_t code_point = static_cast<uint16_t>(cp); |
| if (ranges[i].id_range_offset == 0) { |
| // this is explictly allowed to overflow in the spec |
| const uint16_t glyph = code_point + ranges[i].id_delta; |
| if (glyph >= num_glyphs) { |
| return OTS_FAILURE_MSG("Range glyph reference too high (%d > %d)", glyph, num_glyphs - 1); |
| } |
| } else { |
| const uint16_t range_delta = code_point - ranges[i].start_range; |
| // this might seem odd, but it's true. The offset is relative to the |
| // location of the offset value itself. |
| const uint32_t glyph_id_offset = ranges[i].id_range_offset_offset + |
| ranges[i].id_range_offset + |
| range_delta * 2; |
| // We need to be able to access a 16-bit value from this offset |
| if (glyph_id_offset + 1 >= length) { |
| return OTS_FAILURE_MSG("bad glyph id offset (%d > %ld)", glyph_id_offset, length); |
| } |
| uint16_t glyph; |
| std::memcpy(&glyph, data + glyph_id_offset, 2); |
| glyph = ntohs(glyph); |
| if (glyph >= num_glyphs) { |
| return OTS_FAILURE_MSG("Range glyph reference too high (%d > %d)", glyph, num_glyphs - 1); |
| } |
| } |
| } |
| } |
| |
| // We accept the table. |
| // TODO(yusukes): transcode the subtable. |
| if (platform == 3 && encoding == 0) { |
| file->cmap->subtable_3_0_4_data = data; |
| file->cmap->subtable_3_0_4_length = length; |
| } else if (platform == 3 && encoding == 1) { |
| file->cmap->subtable_3_1_4_data = data; |
| file->cmap->subtable_3_1_4_length = length; |
| } else if (platform == 0 && encoding == 3) { |
| file->cmap->subtable_0_3_4_data = data; |
| file->cmap->subtable_0_3_4_length = length; |
| } else { |
| return OTS_FAILURE_MSG("Unknown cmap subtable type (platform=%d, encoding=%d)", platform, encoding); |
| } |
| |
| return true; |
| } |
| |
| bool Parse31012(ots::OpenTypeFile *file, |
| const uint8_t *data, size_t length, uint16_t num_glyphs) { |
| ots::Buffer subtable(data, length); |
| |
| // Format 12 tables are simple. We parse these and fully serialise them |
| // later. |
| |
| if (!subtable.Skip(8)) { |
| return OTS_FAILURE_MSG("failed to skip the first 8 bytes of format 12 subtable"); |
| } |
| uint32_t language = 0; |
| if (!subtable.ReadU32(&language)) { |
| return OTS_FAILURE_MSG("can't read format 12 subtable language"); |
| } |
| if (language) { |
| return OTS_FAILURE_MSG("format 12 subtable language should be zero (%d)", language); |
| } |
| |
| uint32_t num_groups = 0; |
| if (!subtable.ReadU32(&num_groups)) { |
| return OTS_FAILURE_MSG("can't read number of format 12 subtable groups"); |
| } |
| if (num_groups == 0 || num_groups > kMaxCMAPGroups) { |
| return OTS_FAILURE_MSG("bad format 12 subtable group count %d", num_groups); |
| } |
| |
| std::vector<ots::OpenTypeCMAPSubtableRange> &groups |
| = file->cmap->subtable_3_10_12; |
| groups.resize(num_groups); |
| |
| for (unsigned i = 0; i < num_groups; ++i) { |
| if (!subtable.ReadU32(&groups[i].start_range) || |
| !subtable.ReadU32(&groups[i].end_range) || |
| !subtable.ReadU32(&groups[i].start_glyph_id)) { |
| return OTS_FAILURE_MSG("can't read format 12 subtable group"); |
| } |
| |
| if (groups[i].start_range > kUnicodeUpperLimit || |
| groups[i].end_range > kUnicodeUpperLimit || |
| groups[i].start_glyph_id > 0xFFFF) { |
| return OTS_FAILURE_MSG("bad format 12 subtable group (startCharCode=0x%4X, endCharCode=0x%4X, startGlyphID=%d)", |
| groups[i].start_range, groups[i].end_range, groups[i].start_glyph_id); |
| } |
| |
| // [0xD800, 0xDFFF] are surrogate code points. |
| if (groups[i].start_range >= 0xD800 && |
| groups[i].start_range <= 0xDFFF) { |
| return OTS_FAILURE_MSG("format 12 subtable out of range group startCharCode (0x%4X)", groups[i].start_range); |
| } |
| if (groups[i].end_range >= 0xD800 && |
| groups[i].end_range <= 0xDFFF) { |
| return OTS_FAILURE_MSG("format 12 subtable out of range group endCharCode (0x%4X)", groups[i].end_range); |
| } |
| if (groups[i].start_range < 0xD800 && |
| groups[i].end_range > 0xDFFF) { |
| return OTS_FAILURE_MSG("bad format 12 subtable group startCharCode (0x%4X) or endCharCode (0x%4X)", |
| groups[i].start_range, groups[i].end_range); |
| } |
| |
| // We assert that the glyph value is within range. Because of the range |
| // limits, above, we don't need to worry about overflow. |
| if (groups[i].end_range < groups[i].start_range) { |
| return OTS_FAILURE_MSG("format 12 subtable group endCharCode before startCharCode (0x%4X < 0x%4X)", |
| groups[i].end_range, groups[i].start_range); |
| } |
| if ((groups[i].end_range - groups[i].start_range) + |
| groups[i].start_glyph_id > num_glyphs) { |
| return OTS_FAILURE_MSG("bad format 12 subtable group startGlyphID (%d)", groups[i].start_glyph_id); |
| } |
| } |
| |
| // the groups must be sorted by start code and may not overlap |
| for (unsigned i = 1; i < num_groups; ++i) { |
| if (groups[i].start_range <= groups[i - 1].start_range) { |
| return OTS_FAILURE_MSG("out of order format 12 subtable group (startCharCode=0x%4X <= startCharCode=0x%4X of previous group)", |
| groups[i].start_range, groups[i-1].start_range); |
| } |
| if (groups[i].start_range <= groups[i - 1].end_range) { |
| return OTS_FAILURE_MSG("overlapping format 12 subtable groups (startCharCode=0x%4X <= endCharCode=0x%4X of previous group)", |
| groups[i].start_range, groups[i-1].end_range); |
| } |
| } |
| |
| return true; |
| } |
| |
| bool Parse31013(ots::OpenTypeFile *file, |
| const uint8_t *data, size_t length, uint16_t num_glyphs) { |
| ots::Buffer subtable(data, length); |
| |
| // Format 13 tables are simple. We parse these and fully serialise them |
| // later. |
| |
| if (!subtable.Skip(8)) { |
| return OTS_FAILURE_MSG("Bad cmap subtable length"); |
| } |
| uint32_t language = 0; |
| if (!subtable.ReadU32(&language)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable language"); |
| } |
| if (language) { |
| return OTS_FAILURE_MSG("Cmap subtable language should be zero but is %d", language); |
| } |
| |
| uint32_t num_groups = 0; |
| if (!subtable.ReadU32(&num_groups)) { |
| return OTS_FAILURE_MSG("Can't read number of groups in a cmap subtable"); |
| } |
| |
| // We limit the number of groups in the same way as in 3.10.12 tables. See |
| // the comment there in |
| if (num_groups == 0 || num_groups > kMaxCMAPGroups) { |
| return OTS_FAILURE_MSG("Bad number of groups (%d) in a cmap subtable", num_groups); |
| } |
| |
| std::vector<ots::OpenTypeCMAPSubtableRange> &groups |
| = file->cmap->subtable_3_10_13; |
| groups.resize(num_groups); |
| |
| for (unsigned i = 0; i < num_groups; ++i) { |
| if (!subtable.ReadU32(&groups[i].start_range) || |
| !subtable.ReadU32(&groups[i].end_range) || |
| !subtable.ReadU32(&groups[i].start_glyph_id)) { |
| return OTS_FAILURE_MSG("Can't read subrange structure in a cmap subtable"); |
| } |
| |
| // We conservatively limit all of the values to protect some parsers from |
| // overflows |
| if (groups[i].start_range > kUnicodeUpperLimit || |
| groups[i].end_range > kUnicodeUpperLimit || |
| groups[i].start_glyph_id > 0xFFFF) { |
| return OTS_FAILURE_MSG("Bad subrange with start_range=%d, end_range=%d, start_glyph_id=%d", groups[i].start_range, groups[i].end_range, groups[i].start_glyph_id); |
| } |
| |
| if (groups[i].start_glyph_id >= num_glyphs) { |
| return OTS_FAILURE_MSG("Subrange starting glyph id too high (%d > %d)", groups[i].start_glyph_id, num_glyphs); |
| } |
| } |
| |
| // the groups must be sorted by start code and may not overlap |
| for (unsigned i = 1; i < num_groups; ++i) { |
| if (groups[i].start_range <= groups[i - 1].start_range) { |
| return OTS_FAILURE_MSG("Overlapping subrange starts (%d >= %d)", groups[i]. start_range, groups[i-1].start_range); |
| } |
| if (groups[i].start_range <= groups[i - 1].end_range) { |
| return OTS_FAILURE_MSG("Overlapping subranges (%d <= %d)", groups[i].start_range, groups[i-1].end_range); |
| } |
| } |
| |
| return true; |
| } |
| |
| bool Parse0514(ots::OpenTypeFile *file, |
| const uint8_t *data, size_t length, uint16_t num_glyphs) { |
| // Unicode Variation Selector table |
| ots::Buffer subtable(data, length); |
| |
| // Format 14 tables are simple. We parse these and fully serialise them |
| // later. |
| |
| // Skip format (USHORT) and length (ULONG) |
| if (!subtable.Skip(6)) { |
| return OTS_FAILURE_MSG("Can't read start of cmap subtable"); |
| } |
| |
| uint32_t num_records = 0; |
| if (!subtable.ReadU32(&num_records)) { |
| return OTS_FAILURE_MSG("Can't read number of records in cmap subtable"); |
| } |
| if (num_records == 0 || num_records > kMaxCMAPSelectorRecords) { |
| return OTS_FAILURE_MSG("Bad number of records (%d) in cmap subtable", num_records); |
| } |
| |
| std::vector<ots::OpenTypeCMAPSubtableVSRecord>& records |
| = file->cmap->subtable_0_5_14; |
| records.resize(num_records); |
| |
| for (unsigned i = 0; i < num_records; ++i) { |
| if (!subtable.ReadU24(&records[i].var_selector) || |
| !subtable.ReadU32(&records[i].default_offset) || |
| !subtable.ReadU32(&records[i].non_default_offset)) { |
| return OTS_FAILURE_MSG("Can't read record structure of record %d in cmap subtale", i); |
| } |
| // Checks the value of variation selector |
| if (!((records[i].var_selector >= kMongolianVSStart && |
| records[i].var_selector <= kMongolianVSEnd) || |
| (records[i].var_selector >= kVSStart && |
| records[i].var_selector <= kVSEnd) || |
| (records[i].var_selector >= kIVSStart && |
| records[i].var_selector <= kIVSEnd))) { |
| return OTS_FAILURE_MSG("Bad record variation selector (%04X) in record %i", records[i].var_selector, i); |
| } |
| if (i > 0 && |
| records[i-1].var_selector >= records[i].var_selector) { |
| return OTS_FAILURE_MSG("Out of order variation selector (%04X >= %04X) in record %d", records[i-1].var_selector, records[i].var_selector, i); |
| } |
| |
| // Checks offsets |
| if (!records[i].default_offset && !records[i].non_default_offset) { |
| return OTS_FAILURE_MSG("No default aoffset in variation selector record %d", i); |
| } |
| if (records[i].default_offset && |
| records[i].default_offset >= length) { |
| return OTS_FAILURE_MSG("Default offset too high (%d >= %ld) in record %d", records[i].default_offset, length, i); |
| } |
| if (records[i].non_default_offset && |
| records[i].non_default_offset >= length) { |
| return OTS_FAILURE_MSG("Non default offset too high (%d >= %ld) in record %d", records[i].non_default_offset, length, i); |
| } |
| } |
| |
| for (unsigned i = 0; i < num_records; ++i) { |
| // Checks default UVS table |
| if (records[i].default_offset) { |
| subtable.set_offset(records[i].default_offset); |
| uint32_t num_ranges = 0; |
| if (!subtable.ReadU32(&num_ranges)) { |
| return OTS_FAILURE_MSG("Can't read number of ranges in record %d", i); |
| } |
| if (!num_ranges || num_ranges > kMaxCMAPGroups) { |
| return OTS_FAILURE_MSG("number of ranges too high (%d > %d) in record %d", num_ranges, kMaxCMAPGroups, i); |
| } |
| |
| uint32_t last_unicode_value = 0; |
| std::vector<ots::OpenTypeCMAPSubtableVSRange>& ranges |
| = records[i].ranges; |
| ranges.resize(num_ranges); |
| |
| for (unsigned j = 0; j < num_ranges; ++j) { |
| if (!subtable.ReadU24(&ranges[j].unicode_value) || |
| !subtable.ReadU8(&ranges[j].additional_count)) { |
| return OTS_FAILURE_MSG("Can't read range info in variation selector record %d", i); |
| } |
| const uint32_t check_value = |
| ranges[j].unicode_value + ranges[j].additional_count; |
| if (ranges[j].unicode_value == 0 || |
| ranges[j].unicode_value > kUnicodeUpperLimit || |
| check_value > kUVSUpperLimit || |
| (last_unicode_value && |
| ranges[j].unicode_value <= last_unicode_value)) { |
| return OTS_FAILURE_MSG("Bad Unicode value *%04X) in variation selector range %d record %d", ranges[j].unicode_value, j, i); |
| } |
| last_unicode_value = check_value; |
| } |
| } |
| |
| // Checks non default UVS table |
| if (records[i].non_default_offset) { |
| subtable.set_offset(records[i].non_default_offset); |
| uint32_t num_mappings = 0; |
| if (!subtable.ReadU32(&num_mappings)) { |
| return OTS_FAILURE_MSG("Can't read number of mappings in variation selector record %d", i); |
| } |
| if (!num_mappings || num_mappings > kMaxCMAPGroups) { |
| return OTS_FAILURE_MSG("Number of mappings too high (%d) in variation selector record %d", num_mappings, i); |
| } |
| |
| uint32_t last_unicode_value = 0; |
| std::vector<ots::OpenTypeCMAPSubtableVSMapping>& mappings |
| = records[i].mappings; |
| mappings.resize(num_mappings); |
| |
| for (unsigned j = 0; j < num_mappings; ++j) { |
| if (!subtable.ReadU24(&mappings[j].unicode_value) || |
| !subtable.ReadU16(&mappings[j].glyph_id)) { |
| return OTS_FAILURE_MSG("Can't read mapping %d in variation selector record %d", j, i); |
| } |
| if (mappings[j].glyph_id == 0 || |
| mappings[j].unicode_value == 0 || |
| mappings[j].unicode_value > kUnicodeUpperLimit || |
| (last_unicode_value && |
| mappings[j].unicode_value <= last_unicode_value)) { |
| return OTS_FAILURE_MSG("Bad mapping (%04X -> %d) in mapping %d of variation selector %d", mappings[j].unicode_value, mappings[j].glyph_id, j, i); |
| } |
| last_unicode_value = mappings[j].unicode_value; |
| } |
| } |
| } |
| |
| if (subtable.offset() != length) { |
| return OTS_FAILURE_MSG("Bad subtable offset (%ld != %ld)", subtable.offset(), length); |
| } |
| file->cmap->subtable_0_5_14_length = subtable.offset(); |
| return true; |
| } |
| |
| bool Parse100(ots::OpenTypeFile *file, const uint8_t *data, size_t length) { |
| // Mac Roman table |
| ots::Buffer subtable(data, length); |
| |
| if (!subtable.Skip(4)) { |
| return OTS_FAILURE_MSG("Bad cmap subtable"); |
| } |
| uint16_t language = 0; |
| if (!subtable.ReadU16(&language)) { |
| return OTS_FAILURE_MSG("Can't read language in cmap subtable"); |
| } |
| if (language) { |
| // simsun.ttf has non-zero language id. |
| OTS_WARNING("language id should be zero: %u", language); |
| } |
| |
| file->cmap->subtable_1_0_0.reserve(kFormat0ArraySize); |
| for (size_t i = 0; i < kFormat0ArraySize; ++i) { |
| uint8_t glyph_id = 0; |
| if (!subtable.ReadU8(&glyph_id)) { |
| return OTS_FAILURE_MSG("Can't read glyph id at array[%ld] in cmap subtable", i); |
| } |
| file->cmap->subtable_1_0_0.push_back(glyph_id); |
| } |
| |
| return true; |
| } |
| |
| } // namespace |
| |
| namespace ots { |
| |
| bool ots_cmap_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| Buffer table(data, length); |
| file->cmap = new OpenTypeCMAP; |
| |
| uint16_t version = 0; |
| uint16_t num_tables = 0; |
| if (!table.ReadU16(&version) || |
| !table.ReadU16(&num_tables)) { |
| return OTS_FAILURE_MSG("Can't read structure of cmap"); |
| } |
| |
| if (version != 0) { |
| return OTS_FAILURE_MSG("Non zero cmap version (%d)", version); |
| } |
| if (!num_tables) { |
| return OTS_FAILURE_MSG("No subtables in cmap!"); |
| } |
| |
| std::vector<CMAPSubtableHeader> subtable_headers; |
| |
| // read the subtable headers |
| subtable_headers.reserve(num_tables); |
| for (unsigned i = 0; i < num_tables; ++i) { |
| CMAPSubtableHeader subt; |
| |
| if (!table.ReadU16(&subt.platform) || |
| !table.ReadU16(&subt.encoding) || |
| !table.ReadU32(&subt.offset)) { |
| return OTS_FAILURE_MSG("Can't read subtable information cmap subtable %d", i); |
| } |
| |
| subtable_headers.push_back(subt); |
| } |
| |
| const size_t data_offset = table.offset(); |
| |
| // make sure that all the offsets are valid. |
| for (unsigned i = 0; i < num_tables; ++i) { |
| if (subtable_headers[i].offset > 1024 * 1024 * 1024) { |
| return OTS_FAILURE_MSG("Bad subtable offset in cmap subtable %d", i); |
| } |
| if (subtable_headers[i].offset < data_offset || |
| subtable_headers[i].offset >= length) { |
| return OTS_FAILURE_MSG("Bad subtable offset (%d) in cmap subtable %d", subtable_headers[i].offset, i); |
| } |
| } |
| |
| // the format of the table is the first couple of bytes in the table. The |
| // length of the table is stored in a format-specific way. |
| for (unsigned i = 0; i < num_tables; ++i) { |
| table.set_offset(subtable_headers[i].offset); |
| if (!table.ReadU16(&subtable_headers[i].format)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable header format %d", i); |
| } |
| |
| uint16_t len = 0; |
| uint16_t lang = 0; |
| switch (subtable_headers[i].format) { |
| case 0: |
| case 4: |
| if (!table.ReadU16(&len)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable %d length", i); |
| } |
| if (!table.ReadU16(&lang)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable %d language", i); |
| } |
| subtable_headers[i].length = len; |
| subtable_headers[i].language = lang; |
| break; |
| case 12: |
| case 13: |
| if (!table.Skip(2)) { |
| return OTS_FAILURE_MSG("Bad cmap subtable %d structure", i); |
| } |
| if (!table.ReadU32(&subtable_headers[i].length)) { |
| return OTS_FAILURE_MSG("Can read cmap subtable %d length", i); |
| } |
| if (!table.ReadU32(&subtable_headers[i].language)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable %d language", i); |
| } |
| break; |
| case 14: |
| if (!table.ReadU32(&subtable_headers[i].length)) { |
| return OTS_FAILURE_MSG("Can't read cmap subtable %d length", i); |
| } |
| subtable_headers[i].language = 0; |
| break; |
| default: |
| subtable_headers[i].length = 0; |
| subtable_headers[i].language = 0; |
| break; |
| } |
| } |
| |
| // check if the table is sorted first by platform ID, then by encoding ID. |
| uint32_t last_id = 0; |
| for (unsigned i = 0; i < num_tables; ++i) { |
| uint32_t current_id |
| = (subtable_headers[i].platform << 24) |
| + (subtable_headers[i].encoding << 16) |
| + subtable_headers[i].language; |
| if ((i != 0) && (last_id >= current_id)) { |
| OTS_WARNING("subtable %d with platform ID %d, encoding ID %d, language ID %d " |
| "following subtable with platform ID %d, encoding ID %d, language ID %d", |
| i, |
| (uint8_t)(current_id >> 24), (uint8_t)(current_id >> 16), (uint8_t)(current_id), |
| (uint8_t)(last_id >> 24), (uint8_t)(last_id >> 16), (uint8_t)(last_id)); |
| } |
| last_id = current_id; |
| } |
| |
| // Now, verify that all the lengths are sane |
| for (unsigned i = 0; i < num_tables; ++i) { |
| if (!subtable_headers[i].length) continue; |
| if (subtable_headers[i].length > 1024 * 1024 * 1024) { |
| return OTS_FAILURE_MSG("Bad cmap subtable %d length", i); |
| } |
| // We know that both the offset and length are < 1GB, so the following |
| // addition doesn't overflow |
| const uint32_t end_byte |
| = subtable_headers[i].offset + subtable_headers[i].length; |
| if (end_byte > length) { |
| return OTS_FAILURE_MSG("Over long cmap subtable %d @ %d for %d", i, subtable_headers[i].offset, subtable_headers[i].length); |
| } |
| } |
| |
| // check that the cmap subtables are not overlapping. |
| std::set<std::pair<uint32_t, uint32_t> > uniq_checker; |
| std::vector<std::pair<uint32_t, uint8_t> > overlap_checker; |
| for (unsigned i = 0; i < num_tables; ++i) { |
| const uint32_t end_byte |
| = subtable_headers[i].offset + subtable_headers[i].length; |
| |
| if (!uniq_checker.insert(std::make_pair(subtable_headers[i].offset, |
| end_byte)).second) { |
| // Sometimes Unicode table and MS table share exactly the same data. |
| // We'll allow this. |
| continue; |
| } |
| overlap_checker.push_back( |
| std::make_pair(subtable_headers[i].offset, |
| static_cast<uint8_t>(1) /* start */)); |
| overlap_checker.push_back( |
| std::make_pair(end_byte, static_cast<uint8_t>(0) /* end */)); |
| } |
| std::sort(overlap_checker.begin(), overlap_checker.end()); |
| int overlap_count = 0; |
| for (unsigned i = 0; i < overlap_checker.size(); ++i) { |
| overlap_count += (overlap_checker[i].second ? 1 : -1); |
| if (overlap_count > 1) { |
| return OTS_FAILURE_MSG("Excessive overlap count %d", overlap_count); |
| } |
| } |
| |
| // we grab the number of glyphs in the file from the maxp table to make sure |
| // that the character map isn't referencing anything beyound this range. |
| if (!file->maxp) { |
| return OTS_FAILURE_MSG("No maxp table in font! Needed by cmap."); |
| } |
| const uint16_t num_glyphs = file->maxp->num_glyphs; |
| |
| // We only support a subset of the possible character map tables. Microsoft |
| // 'strongly recommends' that everyone supports the Unicode BMP table with |
| // the UCS-4 table for non-BMP glyphs. We'll pass the following subtables: |
| // Platform ID Encoding ID Format |
| // 0 0 4 (Unicode Default) |
| // 0 1 4 (Unicode 1.1) |
| // 0 3 4 (Unicode BMP) |
| // 0 3 12 (Unicode UCS-4) |
| // 0 5 14 (Unicode Variation Sequences) |
| // 1 0 0 (Mac Roman) |
| // 3 0 4 (MS Symbol) |
| // 3 1 4 (MS Unicode BMP) |
| // 3 10 12 (MS Unicode UCS-4) |
| // 3 10 13 (MS UCS-4 Fallback mapping) |
| // |
| // Note: |
| // * 0-0-4 and 0-1-4 tables are (usually) written as a 3-1-4 table. If 3-1-4 table |
| // also exists, the 0-0-4 or 0-1-4 tables are ignored. |
| // * Unlike 0-0-4 table, 0-3-4 table is written as a 0-3-4 table. |
| // Some fonts which include 0-5-14 table seems to be required 0-3-4 |
| // table. The 0-3-4 table will be wriiten even if 3-1-4 table also exists. |
| // * 0-3-12 table is written as a 3-10-12 table. If 3-10-12 table also |
| // exists, the 0-3-12 table is ignored. |
| // |
| |
| for (unsigned i = 0; i < num_tables; ++i) { |
| if (subtable_headers[i].platform == 0) { |
| // Unicode platform |
| |
| if ((subtable_headers[i].encoding == 0 || subtable_headers[i].encoding == 1) && |
| (subtable_headers[i].format == 4)) { |
| // parse and output the 0-0-4 and 0-1-4 tables as 3-1-4 table. Sometimes the 0-0-4 |
| // table actually points to MS symbol data and thus should be parsed as |
| // 3-0-4 table (e.g., marqueem.ttf and quixotic.ttf). This error will be |
| // recovered in ots_cmap_serialise(). |
| if (!ParseFormat4(file, 3, 1, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE_MSG("Failed to parse format 4 cmap subtable %d", i); |
| } |
| } else if ((subtable_headers[i].encoding == 3) && |
| (subtable_headers[i].format == 4)) { |
| // parse and output the 0-3-4 table as 0-3-4 table. |
| if (!ParseFormat4(file, 0, 3, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE_MSG("Failed to parse format 4 cmap subtable %d", i); |
| } |
| } else if ((subtable_headers[i].encoding == 3) && |
| (subtable_headers[i].format == 12)) { |
| // parse and output the 0-3-12 table as 3-10-12 table. |
| if (!Parse31012(file, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE_MSG("Failed to parse format 12 cmap subtable %d", i); |
| } |
| } else if ((subtable_headers[i].encoding == 5) && |
| (subtable_headers[i].format == 14)) { |
| if (!Parse0514(file, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE_MSG("Failed to parse format 14 cmap subtable %d", i); |
| } |
| } |
| } else if (subtable_headers[i].platform == 1) { |
| // Mac platform |
| |
| if ((subtable_headers[i].encoding == 0) && |
| (subtable_headers[i].format == 0)) { |
| // parse and output the 1-0-0 table. |
| if (!Parse100(file, data + subtable_headers[i].offset, |
| subtable_headers[i].length)) { |
| return OTS_FAILURE(); |
| } |
| } |
| } else if (subtable_headers[i].platform == 3) { |
| // MS platform |
| |
| switch (subtable_headers[i].encoding) { |
| case 0: |
| case 1: |
| if (subtable_headers[i].format == 4) { |
| // parse 3-0-4 or 3-1-4 table. |
| if (!ParseFormat4(file, subtable_headers[i].platform, |
| subtable_headers[i].encoding, |
| data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE(); |
| } |
| } |
| break; |
| case 10: |
| if (subtable_headers[i].format == 12) { |
| file->cmap->subtable_3_10_12.clear(); |
| if (!Parse31012(file, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE(); |
| } |
| } else if (subtable_headers[i].format == 13) { |
| file->cmap->subtable_3_10_13.clear(); |
| if (!Parse31013(file, data + subtable_headers[i].offset, |
| subtable_headers[i].length, num_glyphs)) { |
| return OTS_FAILURE(); |
| } |
| } |
| break; |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| bool ots_cmap_should_serialise(OpenTypeFile *file) { |
| return file->cmap != NULL; |
| } |
| |
| bool ots_cmap_serialise(OTSStream *out, OpenTypeFile *file) { |
| const bool have_034 = file->cmap->subtable_0_3_4_data != NULL; |
| const bool have_0514 = file->cmap->subtable_0_5_14.size() != 0; |
| const bool have_100 = file->cmap->subtable_1_0_0.size() != 0; |
| const bool have_304 = file->cmap->subtable_3_0_4_data != NULL; |
| // MS Symbol and MS Unicode tables should not co-exist. |
| // See the comment above in 0-0-4 parser. |
| const bool have_314 = (!have_304) && file->cmap->subtable_3_1_4_data; |
| const bool have_31012 = file->cmap->subtable_3_10_12.size() != 0; |
| const bool have_31013 = file->cmap->subtable_3_10_13.size() != 0; |
| const uint16_t num_subtables = static_cast<uint16_t>(have_034) + |
| static_cast<uint16_t>(have_0514) + |
| static_cast<uint16_t>(have_100) + |
| static_cast<uint16_t>(have_304) + |
| static_cast<uint16_t>(have_314) + |
| static_cast<uint16_t>(have_31012) + |
| static_cast<uint16_t>(have_31013); |
| const off_t table_start = out->Tell(); |
| |
| // Some fonts don't have 3-0-4 MS Symbol nor 3-1-4 Unicode BMP tables |
| // (e.g., old fonts for Mac). We don't support them. |
| if (!have_304 && !have_314 && !have_034 && !have_31012 && !have_31013) { |
| return OTS_FAILURE_MSG("no supported subtables were found"); |
| } |
| |
| if (!out->WriteU16(0) || |
| !out->WriteU16(num_subtables)) { |
| return OTS_FAILURE(); |
| } |
| |
| const off_t record_offset = out->Tell(); |
| if (!out->Pad(num_subtables * 8)) { |
| return OTS_FAILURE(); |
| } |
| |
| const off_t offset_034 = out->Tell(); |
| if (have_034) { |
| if (!out->Write(file->cmap->subtable_0_3_4_data, |
| file->cmap->subtable_0_3_4_length)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| const off_t offset_0514 = out->Tell(); |
| if (have_0514) { |
| const std::vector<ots::OpenTypeCMAPSubtableVSRecord> &records |
| = file->cmap->subtable_0_5_14; |
| const unsigned num_records = records.size(); |
| if (!out->WriteU16(14) || |
| !out->WriteU32(file->cmap->subtable_0_5_14_length) || |
| !out->WriteU32(num_records)) { |
| return OTS_FAILURE(); |
| } |
| for (unsigned i = 0; i < num_records; ++i) { |
| if (!out->WriteU24(records[i].var_selector) || |
| !out->WriteU32(records[i].default_offset) || |
| !out->WriteU32(records[i].non_default_offset)) { |
| return OTS_FAILURE(); |
| } |
| } |
| for (unsigned i = 0; i < num_records; ++i) { |
| if (records[i].default_offset) { |
| const std::vector<ots::OpenTypeCMAPSubtableVSRange> &ranges |
| = records[i].ranges; |
| const unsigned num_ranges = ranges.size(); |
| if (!out->Seek(records[i].default_offset + offset_0514) || |
| !out->WriteU32(num_ranges)) { |
| return OTS_FAILURE(); |
| } |
| for (unsigned j = 0; j < num_ranges; ++j) { |
| if (!out->WriteU24(ranges[j].unicode_value) || |
| !out->WriteU8(ranges[j].additional_count)) { |
| return OTS_FAILURE(); |
| } |
| } |
| } |
| if (records[i].non_default_offset) { |
| const std::vector<ots::OpenTypeCMAPSubtableVSMapping> &mappings |
| = records[i].mappings; |
| const unsigned num_mappings = mappings.size(); |
| if (!out->Seek(records[i].non_default_offset + offset_0514) || |
| !out->WriteU32(num_mappings)) { |
| return OTS_FAILURE(); |
| } |
| for (unsigned j = 0; j < num_mappings; ++j) { |
| if (!out->WriteU24(mappings[j].unicode_value) || |
| !out->WriteU16(mappings[j].glyph_id)) { |
| return OTS_FAILURE(); |
| } |
| } |
| } |
| } |
| } |
| |
| const off_t offset_100 = out->Tell(); |
| if (have_100) { |
| if (!out->WriteU16(0) || // format |
| !out->WriteU16(6 + kFormat0ArraySize) || // length |
| !out->WriteU16(0)) { // language |
| return OTS_FAILURE(); |
| } |
| if (!out->Write(&(file->cmap->subtable_1_0_0[0]), kFormat0ArraySize)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| const off_t offset_304 = out->Tell(); |
| if (have_304) { |
| if (!out->Write(file->cmap->subtable_3_0_4_data, |
| file->cmap->subtable_3_0_4_length)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| const off_t offset_314 = out->Tell(); |
| if (have_314) { |
| if (!out->Write(file->cmap->subtable_3_1_4_data, |
| file->cmap->subtable_3_1_4_length)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| const off_t offset_31012 = out->Tell(); |
| if (have_31012) { |
| std::vector<OpenTypeCMAPSubtableRange> &groups |
| = file->cmap->subtable_3_10_12; |
| const unsigned num_groups = groups.size(); |
| if (!out->WriteU16(12) || |
| !out->WriteU16(0) || |
| !out->WriteU32(num_groups * 12 + 16) || |
| !out->WriteU32(0) || |
| !out->WriteU32(num_groups)) { |
| return OTS_FAILURE(); |
| } |
| |
| for (unsigned i = 0; i < num_groups; ++i) { |
| if (!out->WriteU32(groups[i].start_range) || |
| !out->WriteU32(groups[i].end_range) || |
| !out->WriteU32(groups[i].start_glyph_id)) { |
| return OTS_FAILURE(); |
| } |
| } |
| } |
| |
| const off_t offset_31013 = out->Tell(); |
| if (have_31013) { |
| std::vector<OpenTypeCMAPSubtableRange> &groups |
| = file->cmap->subtable_3_10_13; |
| const unsigned num_groups = groups.size(); |
| if (!out->WriteU16(13) || |
| !out->WriteU16(0) || |
| !out->WriteU32(num_groups * 12 + 16) || |
| !out->WriteU32(0) || |
| !out->WriteU32(num_groups)) { |
| return OTS_FAILURE(); |
| } |
| |
| for (unsigned i = 0; i < num_groups; ++i) { |
| if (!out->WriteU32(groups[i].start_range) || |
| !out->WriteU32(groups[i].end_range) || |
| !out->WriteU32(groups[i].start_glyph_id)) { |
| return OTS_FAILURE(); |
| } |
| } |
| } |
| |
| const off_t table_end = out->Tell(); |
| // We might have hanging bytes from the above's checksum which the OTSStream |
| // then merges into the table of offsets. |
| OTSStream::ChecksumState saved_checksum = out->SaveChecksumState(); |
| out->ResetChecksum(); |
| |
| // Now seek back and write the table of offsets |
| if (!out->Seek(record_offset)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (have_034) { |
| if (!out->WriteU16(0) || |
| !out->WriteU16(3) || |
| !out->WriteU32(offset_034 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_0514) { |
| if (!out->WriteU16(0) || |
| !out->WriteU16(5) || |
| !out->WriteU32(offset_0514 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_100) { |
| if (!out->WriteU16(1) || |
| !out->WriteU16(0) || |
| !out->WriteU32(offset_100 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_304) { |
| if (!out->WriteU16(3) || |
| !out->WriteU16(0) || |
| !out->WriteU32(offset_304 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_314) { |
| if (!out->WriteU16(3) || |
| !out->WriteU16(1) || |
| !out->WriteU32(offset_314 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_31012) { |
| if (!out->WriteU16(3) || |
| !out->WriteU16(10) || |
| !out->WriteU32(offset_31012 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (have_31013) { |
| if (!out->WriteU16(3) || |
| !out->WriteU16(10) || |
| !out->WriteU32(offset_31013 - table_start)) { |
| return OTS_FAILURE(); |
| } |
| } |
| |
| if (!out->Seek(table_end)) { |
| return OTS_FAILURE(); |
| } |
| out->RestoreChecksum(saved_checksum); |
| |
| return true; |
| } |
| |
| void ots_cmap_free(OpenTypeFile *file) { |
| delete file->cmap; |
| } |
| |
| } // namespace ots |
| |
| #undef TABLE_NAME |
