// 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;
};
// 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::Font *font, 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 (!font->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 (font->os2->first_char_index != 0xFFFF &&
ranges[i].start_range != 0xFFFF &&
font->os2->first_char_index > ranges[i].start_range) {
font->os2->first_char_index = ranges[i].start_range;
}
if (font->os2->last_char_index != 0xFFFF &&
ranges[i].end_range != 0xFFFF &&
font->os2->last_char_index < ranges[i].end_range) {
font->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) {
font->cmap->subtable_3_0_4_data = data;
font->cmap->subtable_3_0_4_length = length;
} else if (platform == 3 && encoding == 1) {
font->cmap->subtable_3_1_4_data = data;
font->cmap->subtable_3_1_4_length = length;
} else if (platform == 0 && encoding == 3) {
font->cmap->subtable_0_3_4_data = data;
font->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::Font *font,
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 || subtable.remaining() / 12 < num_groups) {
return OTS_FAILURE_MSG("Bad format 12 subtable group count %d", num_groups);
}
std::vector<ots::OpenTypeCMAPSubtableRange> &groups
= font->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);
}
// 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::Font *font,
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 || subtable.remaining() / 12 < num_groups) {
return OTS_FAILURE_MSG("Bad format 13 subtable group count %d", num_groups);
}
std::vector<ots::OpenTypeCMAPSubtableRange> &groups
= font->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::Font *font,
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 format 14 subtable records count %d", num_records);
}
std::vector<ots::OpenTypeCMAPSubtableVSRecord>& records
= font->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 == 0 || subtable.remaining() / 4 < num_ranges) {
return OTS_FAILURE_MSG("Bad number of ranges (%d) in record %d", num_ranges, 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 == 0 || subtable.remaining() / 5 < num_mappings) {
return OTS_FAILURE_MSG("Bad number of mappings (%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);
}
font->cmap->subtable_0_5_14_length = subtable.offset();
return true;
}
bool Parse100(ots::Font *font, 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);
}
font->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);
}
font->cmap->subtable_1_0_0.push_back(glyph_id);
}
return true;
}
} // namespace
namespace ots {
bool ots_cmap_parse(Font *font, const uint8_t *data, size_t length) {
Buffer table(data, length);
font->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.
for (unsigned i = 1; i < num_tables; ++i) {
if (subtable_headers[i - 1].platform > subtable_headers[i].platform ||
(subtable_headers[i - 1].platform == subtable_headers[i].platform &&
(subtable_headers[i - 1].encoding > subtable_headers[i].encoding ||
(subtable_headers[i - 1].encoding == subtable_headers[i].encoding &&
subtable_headers[i - 1].language > subtable_headers[i].language))))
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,
subtable_headers[i].platform,
subtable_headers[i].encoding,
subtable_headers[i].language,
subtable_headers[i - 1].platform,
subtable_headers[i - 1].encoding,
subtable_headers[i - 1].language);
}
// 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 (!font->maxp) {
return OTS_FAILURE_MSG("No maxp table in font! Needed by cmap.");
}
const uint16_t num_glyphs = font->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(font, 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(font, 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(font, 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(font, 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(font, 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(font, 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) {
font->cmap->subtable_3_10_12.clear();
if (!Parse31012(font, data + subtable_headers[i].offset,
subtable_headers[i].length, num_glyphs)) {
return OTS_FAILURE();
}
} else if (subtable_headers[i].format == 13) {
font->cmap->subtable_3_10_13.clear();
if (!Parse31013(font, data + subtable_headers[i].offset,
subtable_headers[i].length, num_glyphs)) {
return OTS_FAILURE();
}
}
break;
}
}
}
return true;
}
bool ots_cmap_should_serialise(Font *font) {
return font->cmap != NULL;
}
bool ots_cmap_serialise(OTSStream *out, Font *font) {
const bool have_034 = font->cmap->subtable_0_3_4_data != NULL;
const bool have_0514 = font->cmap->subtable_0_5_14.size() != 0;
const bool have_100 = font->cmap->subtable_1_0_0.size() != 0;
const bool have_304 = font->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) && font->cmap->subtable_3_1_4_data;
const bool have_31012 = font->cmap->subtable_3_10_12.size() != 0;
const bool have_31013 = font->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(font->cmap->subtable_0_3_4_data,
font->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
= font->cmap->subtable_0_5_14;
const unsigned num_records = records.size();
if (!out->WriteU16(14) ||
!out->WriteU32(font->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(&(font->cmap->subtable_1_0_0[0]), kFormat0ArraySize)) {
return OTS_FAILURE();
}
}
const off_t offset_304 = out->Tell();
if (have_304) {
if (!out->Write(font->cmap->subtable_3_0_4_data,
font->cmap->subtable_3_0_4_length)) {
return OTS_FAILURE();
}
}
const off_t offset_314 = out->Tell();
if (have_314) {
if (!out->Write(font->cmap->subtable_3_1_4_data,
font->cmap->subtable_3_1_4_length)) {
return OTS_FAILURE();
}
}
const off_t offset_31012 = out->Tell();
if (have_31012) {
std::vector<OpenTypeCMAPSubtableRange> &groups
= font->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
= font->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();
// 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();
}
return true;
}
void ots_cmap_reuse(Font *font, Font *other) {
font->cmap = other->cmap;
font->cmap_reused = true;
}
void ots_cmap_free(Font *font) {
delete font->cmap;
}
} // namespace ots
#undef TABLE_NAME