676 lines
24 KiB
C++
676 lines
24 KiB
C++
// Copyright (c) 2011-2017 The OTS Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include "gsub.h"
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#include <limits>
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#include <vector>
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#include "layout.h"
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#include "maxp.h"
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// GSUB - The Glyph Substitution Table
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// http://www.microsoft.com/typography/otspec/gsub.htm
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#define TABLE_NAME "GSUB"
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namespace {
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// The GSUB header size for table version 1.0
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const size_t kGsubHeaderSize_1_0 = 4 + 3 * 2;
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// GSUB header size v1.1
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const size_t kGsubHeaderSize_1_1 = 4 + 3 * 2 + 4;
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enum GSUB_TYPE {
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GSUB_TYPE_SINGLE = 1,
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GSUB_TYPE_MULTIPLE = 2,
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GSUB_TYPE_ALTERNATE = 3,
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GSUB_TYPE_LIGATURE = 4,
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GSUB_TYPE_CONTEXT = 5,
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GSUB_TYPE_CHANGING_CONTEXT = 6,
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GSUB_TYPE_EXTENSION_SUBSTITUTION = 7,
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GSUB_TYPE_REVERSE_CHAINING_CONTEXT_SINGLE = 8,
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GSUB_TYPE_RESERVED = 9
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};
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// Lookup type parsers.
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bool ParseSingleSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseMutipleSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseAlternateSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseLigatureSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseContextSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseChainingContextSubstitution(const ots::Font *font,
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const uint8_t *data,
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const size_t length);
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bool ParseExtensionSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseReverseChainingContextSingleSubstitution(
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const ots::Font *font, const uint8_t *data, const size_t length);
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const ots::LookupSubtableParser::TypeParser kGsubTypeParsers[] = {
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{GSUB_TYPE_SINGLE, ParseSingleSubstitution},
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{GSUB_TYPE_MULTIPLE, ParseMutipleSubstitution},
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{GSUB_TYPE_ALTERNATE, ParseAlternateSubstitution},
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{GSUB_TYPE_LIGATURE, ParseLigatureSubstitution},
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{GSUB_TYPE_CONTEXT, ParseContextSubstitution},
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{GSUB_TYPE_CHANGING_CONTEXT, ParseChainingContextSubstitution},
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{GSUB_TYPE_EXTENSION_SUBSTITUTION, ParseExtensionSubstitution},
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{GSUB_TYPE_REVERSE_CHAINING_CONTEXT_SINGLE,
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ParseReverseChainingContextSingleSubstitution}
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};
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const ots::LookupSubtableParser kGsubLookupSubtableParser = {
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arraysize(kGsubTypeParsers),
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GSUB_TYPE_EXTENSION_SUBSTITUTION, kGsubTypeParsers
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};
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// Lookup Type 1:
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// Single Substitution Subtable
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bool ParseSingleSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length) {
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ots::Buffer subtable(data, length);
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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage)) {
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return OTS_FAILURE_MSG("Failed to read single subst table header");
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}
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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const uint16_t num_glyphs = maxp->num_glyphs;
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if (format == 1) {
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// Parse SingleSubstFormat1
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int16_t delta_glyph_id = 0;
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if (!subtable.ReadS16(&delta_glyph_id)) {
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return OTS_FAILURE_MSG("Failed to read glyph shift from format 1 single subst table");
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}
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if (std::abs(delta_glyph_id) >= num_glyphs) {
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return OTS_FAILURE_MSG("bad glyph shift of %d in format 1 single subst table", delta_glyph_id);
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}
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} else if (format == 2) {
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// Parse SingleSubstFormat2
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uint16_t glyph_count = 0;
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if (!subtable.ReadU16(&glyph_count)) {
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return OTS_FAILURE_MSG("Failed to read glyph cound in format 2 single subst table");
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}
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if (glyph_count > num_glyphs) {
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return OTS_FAILURE_MSG("Bad glyph count %d > %d in format 2 single subst table", glyph_count, num_glyphs);
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}
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for (unsigned i = 0; i < glyph_count; ++i) {
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uint16_t substitute = 0;
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if (!subtable.ReadU16(&substitute)) {
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return OTS_FAILURE_MSG("Failed to read substitution %d in format 2 single subst table", i);
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}
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if (substitute >= num_glyphs) {
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return OTS_FAILURE_MSG("too large substitute: %u", substitute);
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}
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}
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} else {
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return OTS_FAILURE_MSG("Bad single subst table format %d", format);
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}
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if (offset_coverage < subtable.offset() || offset_coverage >= length) {
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return OTS_FAILURE_MSG("Bad coverage offset %x", offset_coverage);
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}
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if (!ots::ParseCoverageTable(font, data + offset_coverage,
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length - offset_coverage, num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse coverage table");
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}
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return true;
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}
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bool ParseSequenceTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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uint16_t glyph_count = 0;
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if (!subtable.ReadU16(&glyph_count)) {
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return OTS_FAILURE_MSG("Failed to read glyph count in sequence table");
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}
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if (glyph_count > num_glyphs) {
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return OTS_FAILURE_MSG("bad glyph count %d > %d", glyph_count, num_glyphs);
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}
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for (unsigned i = 0; i < glyph_count; ++i) {
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uint16_t substitute = 0;
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if (!subtable.ReadU16(&substitute)) {
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return OTS_FAILURE_MSG("Failedt o read substitution %d in sequence table", i);
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}
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if (substitute >= num_glyphs) {
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return OTS_FAILURE_MSG("Bad subsitution (%d) %d > %d", i, substitute, num_glyphs);
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}
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}
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return true;
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}
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// Lookup Type 2:
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// Multiple Substitution Subtable
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bool ParseMutipleSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length) {
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ots::Buffer subtable(data, length);
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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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uint16_t sequence_count = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage) ||
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!subtable.ReadU16(&sequence_count)) {
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return OTS_FAILURE_MSG("Can't read header of multiple subst table");
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}
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if (format != 1) {
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return OTS_FAILURE_MSG("Bad multiple subst table format %d", format);
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}
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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const uint16_t num_glyphs = maxp->num_glyphs;
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const unsigned sequence_end = static_cast<unsigned>(6) +
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sequence_count * 2;
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if (sequence_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad segence end %d, in multiple subst", sequence_end);
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}
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for (unsigned i = 0; i < sequence_count; ++i) {
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uint16_t offset_sequence = 0;
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if (!subtable.ReadU16(&offset_sequence)) {
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return OTS_FAILURE_MSG("Failed to read sequence offset for sequence %d", i);
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}
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if (offset_sequence < sequence_end || offset_sequence >= length) {
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return OTS_FAILURE_MSG("Bad sequence offset %d for sequence %d", offset_sequence, i);
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}
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if (!ParseSequenceTable(font, data + offset_sequence, length - offset_sequence,
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num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse sequence table %d", i);
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}
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}
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if (offset_coverage < sequence_end || offset_coverage >= length) {
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return OTS_FAILURE_MSG("Bad coverage offset %d", offset_coverage);
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}
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if (!ots::ParseCoverageTable(font, data + offset_coverage,
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length - offset_coverage, num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse coverage table");
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}
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return true;
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}
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bool ParseAlternateSetTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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uint16_t glyph_count = 0;
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if (!subtable.ReadU16(&glyph_count)) {
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return OTS_FAILURE_MSG("Failed to read alternate set header");
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}
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if (glyph_count > num_glyphs) {
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return OTS_FAILURE_MSG("Bad glyph count %d > %d in alternate set table", glyph_count, num_glyphs);
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}
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for (unsigned i = 0; i < glyph_count; ++i) {
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uint16_t alternate = 0;
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if (!subtable.ReadU16(&alternate)) {
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return OTS_FAILURE_MSG("Can't read alternate %d", i);
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}
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if (alternate >= num_glyphs) {
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return OTS_FAILURE_MSG("Too large alternate: %u", alternate);
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}
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}
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return true;
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}
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// Lookup Type 3:
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// Alternate Substitution Subtable
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bool ParseAlternateSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length) {
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ots::Buffer subtable(data, length);
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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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uint16_t alternate_set_count = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage) ||
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!subtable.ReadU16(&alternate_set_count)) {
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return OTS_FAILURE_MSG("Can't read alternate subst header");
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}
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if (format != 1) {
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return OTS_FAILURE_MSG("Bad alternate subst table format %d", format);
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}
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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const uint16_t num_glyphs = maxp->num_glyphs;
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const unsigned alternate_set_end = static_cast<unsigned>(6) +
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alternate_set_count * 2;
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if (alternate_set_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad end of alternate set %d", alternate_set_end);
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}
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for (unsigned i = 0; i < alternate_set_count; ++i) {
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uint16_t offset_alternate_set = 0;
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if (!subtable.ReadU16(&offset_alternate_set)) {
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return OTS_FAILURE_MSG("Can't read alternate set offset for set %d", i);
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}
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if (offset_alternate_set < alternate_set_end ||
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offset_alternate_set >= length) {
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return OTS_FAILURE_MSG("Bad alternate set offset %d for set %d", offset_alternate_set, i);
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}
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if (!ParseAlternateSetTable(font, data + offset_alternate_set,
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length - offset_alternate_set,
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num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse alternate set");
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}
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}
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if (offset_coverage < alternate_set_end || offset_coverage >= length) {
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return OTS_FAILURE_MSG("Bad coverage offset %d", offset_coverage);
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}
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if (!ots::ParseCoverageTable(font, data + offset_coverage,
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length - offset_coverage, num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse coverage table");
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}
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return true;
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}
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bool ParseLigatureTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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uint16_t lig_glyph = 0;
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uint16_t comp_count = 0;
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if (!subtable.ReadU16(&lig_glyph) ||
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!subtable.ReadU16(&comp_count)) {
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return OTS_FAILURE_MSG("Failed to read ligatuer table header");
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}
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if (lig_glyph >= num_glyphs) {
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return OTS_FAILURE_MSG("too large lig_glyph: %u", lig_glyph);
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}
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if (comp_count == 0 || comp_count > num_glyphs) {
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return OTS_FAILURE_MSG("Bad component count of %d", comp_count);
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}
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for (unsigned i = 0; i < comp_count - static_cast<unsigned>(1); ++i) {
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uint16_t component = 0;
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if (!subtable.ReadU16(&component)) {
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return OTS_FAILURE_MSG("Can't read ligature component %d", i);
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}
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if (component >= num_glyphs) {
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return OTS_FAILURE_MSG("Bad ligature component %d of %d", i, component);
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}
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}
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return true;
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}
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bool ParseLigatureSetTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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uint16_t ligature_count = 0;
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if (!subtable.ReadU16(&ligature_count)) {
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return OTS_FAILURE_MSG("Can't read ligature count in ligature set");
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}
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const unsigned ligature_end = static_cast<unsigned>(2) + ligature_count * 2;
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if (ligature_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad end of ligature %d in ligature set", ligature_end);
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}
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for (unsigned i = 0; i < ligature_count; ++i) {
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uint16_t offset_ligature = 0;
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if (!subtable.ReadU16(&offset_ligature)) {
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return OTS_FAILURE_MSG("Failed to read ligature offset %d", i);
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}
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if (offset_ligature < ligature_end || offset_ligature >= length) {
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return OTS_FAILURE_MSG("Bad ligature offset %d for ligature %d", offset_ligature, i);
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}
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if (!ParseLigatureTable(font, data + offset_ligature, length - offset_ligature,
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num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse ligature %d", i);
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}
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}
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return true;
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}
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// Lookup Type 4:
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// Ligature Substitution Subtable
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bool ParseLigatureSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length) {
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ots::Buffer subtable(data, length);
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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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uint16_t lig_set_count = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage) ||
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!subtable.ReadU16(&lig_set_count)) {
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return OTS_FAILURE_MSG("Failed to read ligature substitution header");
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}
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if (format != 1) {
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return OTS_FAILURE_MSG("Bad ligature substitution table format %d", format);
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}
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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const uint16_t num_glyphs = maxp->num_glyphs;
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const unsigned ligature_set_end = static_cast<unsigned>(6) +
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lig_set_count * 2;
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if (ligature_set_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad end of ligature set %d in ligature substitution table", ligature_set_end);
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}
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for (unsigned i = 0; i < lig_set_count; ++i) {
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uint16_t offset_ligature_set = 0;
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if (!subtable.ReadU16(&offset_ligature_set)) {
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return OTS_FAILURE_MSG("Can't read ligature set offset %d", i);
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}
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if (offset_ligature_set < ligature_set_end ||
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offset_ligature_set >= length) {
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return OTS_FAILURE_MSG("Bad ligature set offset %d for set %d", offset_ligature_set, i);
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}
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if (!ParseLigatureSetTable(font, data + offset_ligature_set,
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length - offset_ligature_set, num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse ligature set %d", i);
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}
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}
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if (offset_coverage < ligature_set_end || offset_coverage >= length) {
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return OTS_FAILURE_MSG("Bad coverage offset %d", offset_coverage);
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}
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if (!ots::ParseCoverageTable(font, data + offset_coverage,
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length - offset_coverage, num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse coverage table");
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}
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return true;
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}
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// Lookup Type 5:
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// Contextual Substitution Subtable
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bool ParseContextSubstitution(const ots::Font *font,
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const uint8_t *data, const size_t length) {
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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ots::OpenTypeGSUB *gsub = static_cast<ots::OpenTypeGSUB*>(
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font->GetTypedTable(OTS_TAG_GSUB));
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if (!gsub) {
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return OTS_FAILURE_MSG("Internal error!");
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}
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return ots::ParseContextSubtable(font, data, length, maxp->num_glyphs,
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gsub->num_lookups);
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}
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// Lookup Type 6:
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// Chaining Contextual Substitution Subtable
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bool ParseChainingContextSubstitution(const ots::Font *font,
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const uint8_t *data,
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const size_t length) {
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ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
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font->GetTypedTable(OTS_TAG_MAXP));
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if (!maxp) {
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return OTS_FAILURE_MSG("Required maxp table missing");
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}
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ots::OpenTypeGSUB *gsub = static_cast<ots::OpenTypeGSUB*>(
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font->GetTypedTable(OTS_TAG_GSUB));
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if (!gsub) {
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return OTS_FAILURE_MSG("Internal error!");
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}
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return ots::ParseChainingContextSubtable(font, data, length,
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maxp->num_glyphs,
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gsub->num_lookups);
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}
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// Lookup Type 7:
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// Extension Substition
|
|
bool ParseExtensionSubstitution(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
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return ots::ParseExtensionSubtable(font, data, length,
|
|
&kGsubLookupSubtableParser);
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|
}
|
|
|
|
// Lookup Type 8:
|
|
// Reverse Chaining Contexual Single Substitution Subtable
|
|
bool ParseReverseChainingContextSingleSubstitution(
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const ots::Font *font, const uint8_t *data, const size_t length) {
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ots::Buffer subtable(data, length);
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|
|
|
uint16_t format = 0;
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|
uint16_t offset_coverage = 0;
|
|
|
|
if (!subtable.ReadU16(&format) ||
|
|
!subtable.ReadU16(&offset_coverage)) {
|
|
return OTS_FAILURE_MSG("Failed to read reverse chaining header");
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|
}
|
|
|
|
ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
|
|
font->GetTypedTable(OTS_TAG_MAXP));
|
|
if (!maxp) {
|
|
return OTS_FAILURE_MSG("Required maxp table missing");
|
|
}
|
|
const uint16_t num_glyphs = maxp->num_glyphs;
|
|
|
|
uint16_t backtrack_glyph_count = 0;
|
|
if (!subtable.ReadU16(&backtrack_glyph_count)) {
|
|
return OTS_FAILURE_MSG("Failed to read backtrack glyph count in reverse chaining table");
|
|
}
|
|
if (backtrack_glyph_count > num_glyphs) {
|
|
return OTS_FAILURE_MSG("Bad backtrack glyph count of %d", backtrack_glyph_count);
|
|
}
|
|
std::vector<uint16_t> offsets_backtrack;
|
|
offsets_backtrack.reserve(backtrack_glyph_count);
|
|
for (unsigned i = 0; i < backtrack_glyph_count; ++i) {
|
|
uint16_t offset = 0;
|
|
if (!subtable.ReadU16(&offset)) {
|
|
return OTS_FAILURE_MSG("Failed to read backtrack offset %d", i);
|
|
}
|
|
offsets_backtrack.push_back(offset);
|
|
}
|
|
|
|
uint16_t lookahead_glyph_count = 0;
|
|
if (!subtable.ReadU16(&lookahead_glyph_count)) {
|
|
return OTS_FAILURE_MSG("Failed to read look ahead glyph count");
|
|
}
|
|
if (lookahead_glyph_count > num_glyphs) {
|
|
return OTS_FAILURE_MSG("Bad look ahead glyph count %d", lookahead_glyph_count);
|
|
}
|
|
std::vector<uint16_t> offsets_lookahead;
|
|
offsets_lookahead.reserve(lookahead_glyph_count);
|
|
for (unsigned i = 0; i < lookahead_glyph_count; ++i) {
|
|
uint16_t offset = 0;
|
|
if (!subtable.ReadU16(&offset)) {
|
|
return OTS_FAILURE_MSG("Can't read look ahead offset %d", i);
|
|
}
|
|
offsets_lookahead.push_back(offset);
|
|
}
|
|
|
|
uint16_t glyph_count = 0;
|
|
if (!subtable.ReadU16(&glyph_count)) {
|
|
return OTS_FAILURE_MSG("Can't read glyph count in reverse chaining table");
|
|
}
|
|
if (glyph_count > num_glyphs) {
|
|
return OTS_FAILURE_MSG("Bad glyph count of %d", glyph_count);
|
|
}
|
|
for (unsigned i = 0; i < glyph_count; ++i) {
|
|
uint16_t substitute = 0;
|
|
if (!subtable.ReadU16(&substitute)) {
|
|
return OTS_FAILURE_MSG("Failed to read substitution %d reverse chaining table", i);
|
|
}
|
|
if (substitute >= num_glyphs) {
|
|
return OTS_FAILURE_MSG("Bad substitute glyph %d in reverse chaining table substitution %d", substitute, i);
|
|
}
|
|
}
|
|
|
|
const unsigned substitute_end = static_cast<unsigned>(10) +
|
|
(backtrack_glyph_count + lookahead_glyph_count + glyph_count) * 2;
|
|
if (substitute_end > std::numeric_limits<uint16_t>::max()) {
|
|
return OTS_FAILURE_MSG("Bad substitute end offset in reverse chaining table");
|
|
}
|
|
|
|
if (offset_coverage < substitute_end || offset_coverage >= length) {
|
|
return OTS_FAILURE_MSG("Bad coverage offset %d in reverse chaining table", offset_coverage);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offset_coverage,
|
|
length - offset_coverage, num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse coverage table in reverse chaining table");
|
|
}
|
|
|
|
for (unsigned i = 0; i < backtrack_glyph_count; ++i) {
|
|
if (offsets_backtrack[i] < substitute_end ||
|
|
offsets_backtrack[i] >= length) {
|
|
return OTS_FAILURE_MSG("Bad backtrack offset %d for backtrack %d in reverse chaining table", offsets_backtrack[i], i);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offsets_backtrack[i],
|
|
length - offsets_backtrack[i], num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse coverage table for backtrack %d in reverse chaining table", i);
|
|
}
|
|
}
|
|
|
|
for (unsigned i = 0; i < lookahead_glyph_count; ++i) {
|
|
if (offsets_lookahead[i] < substitute_end ||
|
|
offsets_lookahead[i] >= length) {
|
|
return OTS_FAILURE_MSG("Bad lookahead offset %d for lookahead %d in reverse chaining table", offsets_lookahead[i], i);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offsets_lookahead[i],
|
|
length - offsets_lookahead[i], num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse lookahead coverage table %d in reverse chaining table", i);
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
namespace ots {
|
|
|
|
bool OpenTypeGSUB::Parse(const uint8_t *data, size_t length) {
|
|
// Parsing gsub table requires |maxp->num_glyphs|
|
|
Font *font = GetFont();
|
|
Buffer table(data, length);
|
|
|
|
uint16_t version_major = 0, version_minor = 0;
|
|
uint16_t offset_script_list = 0;
|
|
uint16_t offset_feature_list = 0;
|
|
uint16_t offset_lookup_list = 0;
|
|
uint32_t offset_feature_variations = 0;
|
|
if (!table.ReadU16(&version_major) ||
|
|
!table.ReadU16(&version_minor) ||
|
|
!table.ReadU16(&offset_script_list) ||
|
|
!table.ReadU16(&offset_feature_list) ||
|
|
!table.ReadU16(&offset_lookup_list)) {
|
|
return Error("Incomplete table");
|
|
}
|
|
|
|
if (version_major != 1 || version_minor > 1) {
|
|
return Error("Bad version");
|
|
}
|
|
|
|
if (version_minor > 0) {
|
|
if (!table.ReadU32(&offset_feature_variations)) {
|
|
return Error("Incomplete table");
|
|
}
|
|
}
|
|
|
|
const size_t header_size =
|
|
(version_minor == 0) ? kGsubHeaderSize_1_0 : kGsubHeaderSize_1_1;
|
|
|
|
if (offset_lookup_list) {
|
|
if (offset_lookup_list < header_size || offset_lookup_list >= length) {
|
|
return Error("Bad lookup list offset in table header");
|
|
}
|
|
|
|
if (!ParseLookupListTable(font, data + offset_lookup_list,
|
|
length - offset_lookup_list,
|
|
&kGsubLookupSubtableParser,
|
|
&this->num_lookups)) {
|
|
return Error("Failed to parse lookup list table");
|
|
}
|
|
}
|
|
|
|
uint16_t num_features = 0;
|
|
if (offset_feature_list) {
|
|
if (offset_feature_list < header_size || offset_feature_list >= length) {
|
|
return Error("Bad feature list offset in table header");
|
|
}
|
|
|
|
if (!ParseFeatureListTable(font, data + offset_feature_list,
|
|
length - offset_feature_list, this->num_lookups,
|
|
&num_features)) {
|
|
return Error("Failed to parse feature list table");
|
|
}
|
|
}
|
|
|
|
if (offset_script_list) {
|
|
if (offset_script_list < header_size || offset_script_list >= length) {
|
|
return Error("Bad script list offset in table header");
|
|
}
|
|
|
|
if (!ParseScriptListTable(font, data + offset_script_list,
|
|
length - offset_script_list, num_features)) {
|
|
return Error("Failed to parse script list table");
|
|
}
|
|
}
|
|
|
|
if (offset_feature_variations) {
|
|
if (offset_feature_variations < header_size || offset_feature_variations >= length) {
|
|
return Error("Bad feature variations offset in table header");
|
|
}
|
|
|
|
if (!ParseFeatureVariationsTable(font, data + offset_feature_variations,
|
|
length - offset_feature_variations,
|
|
this->num_lookups)) {
|
|
return Error("Failed to parse feature variations table");
|
|
}
|
|
}
|
|
|
|
this->m_data = data;
|
|
this->m_length = length;
|
|
return true;
|
|
}
|
|
|
|
bool OpenTypeGSUB::Serialize(OTSStream *out) {
|
|
if (!out->Write(this->m_data, this->m_length)) {
|
|
return Error("Failed to write GSUB table");
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace ots
|
|
|
|
#undef TABLE_NAME
|