843 lines
31 KiB
C++
843 lines
31 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 "gpos.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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// GPOS - The Glyph Positioning Table
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// http://www.microsoft.com/typography/otspec/gpos.htm
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#define TABLE_NAME "GPOS"
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namespace {
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enum GPOS_TYPE {
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GPOS_TYPE_SINGLE_ADJUSTMENT = 1,
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GPOS_TYPE_PAIR_ADJUSTMENT = 2,
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GPOS_TYPE_CURSIVE_ATTACHMENT = 3,
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GPOS_TYPE_MARK_TO_BASE_ATTACHMENT = 4,
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GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT = 5,
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GPOS_TYPE_MARK_TO_MARK_ATTACHMENT = 6,
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GPOS_TYPE_CONTEXT_POSITIONING = 7,
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GPOS_TYPE_CHAINED_CONTEXT_POSITIONING = 8,
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GPOS_TYPE_EXTENSION_POSITIONING = 9,
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GPOS_TYPE_RESERVED = 10
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};
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// The size of gpos header, version 1.0.
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const unsigned kGposHeaderSize_1_0 = 10;
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// The size of gpos header, version 1.1.
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const unsigned kGposHeaderSize_1_1 = 14;
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// The maximum format number for anchor tables.
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const uint16_t kMaxAnchorFormat = 3;
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// Lookup type parsers.
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bool ParseSingleAdjustment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParsePairAdjustment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseCursiveAttachment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseMarkToBaseAttachment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseMarkToLigatureAttachment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseMarkToMarkAttachment(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseContextPositioning(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseChainedContextPositioning(const ots::Font *font,
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const uint8_t *data, const size_t length);
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bool ParseExtensionPositioning(const ots::Font *font,
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const uint8_t *data, const size_t length);
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const ots::LookupSubtableParser::TypeParser kGposTypeParsers[] = {
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{GPOS_TYPE_SINGLE_ADJUSTMENT, ParseSingleAdjustment},
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{GPOS_TYPE_PAIR_ADJUSTMENT, ParsePairAdjustment},
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{GPOS_TYPE_CURSIVE_ATTACHMENT, ParseCursiveAttachment},
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{GPOS_TYPE_MARK_TO_BASE_ATTACHMENT, ParseMarkToBaseAttachment},
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{GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT, ParseMarkToLigatureAttachment},
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{GPOS_TYPE_MARK_TO_MARK_ATTACHMENT, ParseMarkToMarkAttachment},
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{GPOS_TYPE_CONTEXT_POSITIONING, ParseContextPositioning},
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{GPOS_TYPE_CHAINED_CONTEXT_POSITIONING, ParseChainedContextPositioning},
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{GPOS_TYPE_EXTENSION_POSITIONING, ParseExtensionPositioning}
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};
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const ots::LookupSubtableParser kGposLookupSubtableParser = {
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arraysize(kGposTypeParsers),
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GPOS_TYPE_EXTENSION_POSITIONING, kGposTypeParsers
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};
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// Shared Tables: ValueRecord, Anchor Table, and MarkArray
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size_t CalcValueRecordSize(const uint16_t value_format) {
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size_t size = 0;
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for (unsigned i = 0; i < 8; ++i) {
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if ((value_format >> i) & 0x1) {
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size += 2;
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}
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}
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return size;
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}
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bool ParseValueRecord(const ots::Font *font,
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ots::Buffer* subtable,
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const uint16_t value_format) {
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const uint8_t *data = subtable->buffer();
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const size_t length = subtable->length();
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// Check existence of adjustment fields.
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for (unsigned i = 0; i < 4; ++i) {
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if ((value_format >> i) & 0x1) {
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// Just read the field since these fileds could take an arbitrary values.
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if (!subtable->Skip(2)) {
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return OTS_FAILURE_MSG("Failed to read value reacord component");
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}
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}
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}
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// Check existence of offsets to device table.
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for (unsigned i = 0; i < 4; ++i) {
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if ((value_format >> (i + 4)) & 0x1) {
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uint16_t offset = 0;
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if (!subtable->ReadU16(&offset)) {
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return OTS_FAILURE_MSG("Failed to read value record offset");
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}
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if (offset) {
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// TODO(bashi): Is it possible that device tables locate before
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// this record? No fonts contain such offset AKAIF.
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if (offset >= length) {
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return OTS_FAILURE_MSG("Value record offset too high %d >= %ld", offset, length);
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}
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if (!ots::ParseDeviceTable(font, data + offset, length - offset)) {
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return OTS_FAILURE_MSG("Failed to parse device table in value record");
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}
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}
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}
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}
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return true;
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}
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bool ParseAnchorTable(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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// Read format and skip 2 2-byte fields that could be arbitrary values.
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if (!subtable.ReadU16(&format) ||
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!subtable.Skip(4)) {
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return OTS_FAILURE_MSG("Faled to read anchor table");
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}
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if (format == 0 || format > kMaxAnchorFormat) {
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return OTS_FAILURE_MSG("Bad Anchor table format %d", format);
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}
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// Format 2 and 3 has additional fields.
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if (format == 2) {
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// Format 2 provides an index to a glyph contour point, which will take
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// arbitrary value.
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uint16_t anchor_point = 0;
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if (!subtable.ReadU16(&anchor_point)) {
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return OTS_FAILURE_MSG("Failed to read anchor point in format 2 Anchor Table");
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}
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} else if (format == 3) {
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uint16_t offset_x_device = 0;
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uint16_t offset_y_device = 0;
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if (!subtable.ReadU16(&offset_x_device) ||
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!subtable.ReadU16(&offset_y_device)) {
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return OTS_FAILURE_MSG("Failed to read device table offsets in format 3 anchor table");
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}
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const unsigned format_end = static_cast<unsigned>(10);
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if (offset_x_device) {
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if (offset_x_device < format_end || offset_x_device >= length) {
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return OTS_FAILURE_MSG("Bad x device table offset %d", offset_x_device);
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}
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if (!ots::ParseDeviceTable(font, data + offset_x_device,
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length - offset_x_device)) {
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return OTS_FAILURE_MSG("Failed to parse device table in anchor table");
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}
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}
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if (offset_y_device) {
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if (offset_y_device < format_end || offset_y_device >= length) {
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return OTS_FAILURE_MSG("Bad y device table offset %d", offset_y_device);
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}
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if (!ots::ParseDeviceTable(font, data + offset_y_device,
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length - offset_y_device)) {
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return OTS_FAILURE_MSG("Failed to parse device table in anchor table");
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}
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}
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}
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return true;
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}
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bool ParseMarkArrayTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t class_count) {
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ots::Buffer subtable(data, length);
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uint16_t mark_count = 0;
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if (!subtable.ReadU16(&mark_count)) {
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return OTS_FAILURE_MSG("Can't read mark table length");
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}
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// MarkRecord consists of 4-bytes.
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const unsigned mark_records_end = 4 * static_cast<unsigned>(mark_count) + 2;
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if (mark_records_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad mark table length");
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}
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for (unsigned i = 0; i < mark_count; ++i) {
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uint16_t class_value = 0;
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uint16_t offset_mark_anchor = 0;
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if (!subtable.ReadU16(&class_value) ||
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!subtable.ReadU16(&offset_mark_anchor)) {
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return OTS_FAILURE_MSG("Can't read mark table %d", i);
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}
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// |class_value| may take arbitrary values including 0 here so we don't
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// check the value.
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if (offset_mark_anchor < mark_records_end ||
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offset_mark_anchor >= length) {
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return OTS_FAILURE_MSG("Bad mark anchor offset %d for mark table %d", offset_mark_anchor, i);
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}
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if (!ParseAnchorTable(font, data + offset_mark_anchor,
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length - offset_mark_anchor)) {
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return OTS_FAILURE_MSG("Faled to parse anchor table for mark table %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 1:
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// Single Adjustment Positioning Subtable
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bool ParseSingleAdjustment(const ots::Font *font, const uint8_t *data,
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const size_t length) {
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ots::Buffer subtable(data, 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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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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uint16_t value_format = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage) ||
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!subtable.ReadU16(&value_format)) {
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return OTS_FAILURE_MSG("Can't read single adjustment information");
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}
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if (format == 1) {
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// Format 1 exactly one value record.
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if (!ParseValueRecord(font, &subtable, value_format)) {
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return OTS_FAILURE_MSG("Failed to parse format 1 single adjustment table");
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}
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} else if (format == 2) {
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uint16_t value_count = 0;
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if (!subtable.ReadU16(&value_count)) {
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return OTS_FAILURE_MSG("Failed to parse format 2 single adjustment table");
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}
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for (unsigned i = 0; i < value_count; ++i) {
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if (!ParseValueRecord(font, &subtable, value_format)) {
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return OTS_FAILURE_MSG("Failed to parse value record %d in format 2 single adjustment table", i);
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}
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}
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} else {
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return OTS_FAILURE_MSG("Bad format %d in single adjustment table", 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 %d in single adjustment table", offset_coverage);
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}
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if (!ots::ParseCoverageTable(font, data + offset_coverage,
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length - offset_coverage,
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maxp->num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse coverage table in single adjustment table");
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}
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return true;
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}
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bool ParsePairSetTable(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t value_format1,
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const uint16_t value_format2,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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uint16_t value_count = 0;
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if (!subtable.ReadU16(&value_count)) {
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return OTS_FAILURE_MSG("Failed to read pair set table structure");
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}
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for (unsigned i = 0; i < value_count; ++i) {
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// Check pair value record.
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uint16_t glyph_id = 0;
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if (!subtable.ReadU16(&glyph_id)) {
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return OTS_FAILURE_MSG("Failed to read glyph in pair value record %d", i);
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}
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if (glyph_id >= num_glyphs) {
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return OTS_FAILURE_MSG("glyph id %d too high >= %d", glyph_id, num_glyphs);
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}
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if (!ParseValueRecord(font, &subtable, value_format1)) {
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return OTS_FAILURE_MSG("Failed to parse value record in format 1 pair set table");
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}
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if (!ParseValueRecord(font, &subtable, value_format2)) {
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return OTS_FAILURE_MSG("Failed to parse value record in format 2 pair set table");
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}
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}
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return true;
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}
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bool ParsePairPosFormat1(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t value_format1,
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const uint16_t value_format2,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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// Skip 8 bytes that are already read before.
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if (!subtable.Skip(8)) {
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return OTS_FAILURE_MSG("Failed to read pair pos table structure");
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}
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uint16_t pair_set_count = 0;
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if (!subtable.ReadU16(&pair_set_count)) {
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return OTS_FAILURE_MSG("Failed to read pair pos set count");
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}
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const unsigned pair_pos_end = 2 * static_cast<unsigned>(pair_set_count) + 10;
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if (pair_pos_end > std::numeric_limits<uint16_t>::max()) {
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return OTS_FAILURE_MSG("Bad pair set length %d", pair_pos_end);
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}
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for (unsigned i = 0; i < pair_set_count; ++i) {
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uint16_t pair_set_offset = 0;
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if (!subtable.ReadU16(&pair_set_offset)) {
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return OTS_FAILURE_MSG("Failed to read pair set offset for pair set %d", i);
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}
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if (pair_set_offset < pair_pos_end || pair_set_offset >= length) {
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return OTS_FAILURE_MSG("Bad pair set offset %d for pair set %d", pair_set_offset, i);
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}
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// Check pair set tables
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if (!ParsePairSetTable(font, data + pair_set_offset, length - pair_set_offset,
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value_format1, value_format2,
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num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse pair set table %d", i);
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}
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}
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return true;
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}
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bool ParsePairPosFormat2(const ots::Font *font,
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const uint8_t *data, const size_t length,
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const uint16_t value_format1,
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const uint16_t value_format2,
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const uint16_t num_glyphs) {
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ots::Buffer subtable(data, length);
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// Skip 8 bytes that are already read before.
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if (!subtable.Skip(8)) {
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return OTS_FAILURE_MSG("Failed to read pair pos format 2 structure");
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}
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uint16_t offset_class_def1 = 0;
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uint16_t offset_class_def2 = 0;
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uint16_t class1_count = 0;
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uint16_t class2_count = 0;
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if (!subtable.ReadU16(&offset_class_def1) ||
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!subtable.ReadU16(&offset_class_def2) ||
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!subtable.ReadU16(&class1_count) ||
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!subtable.ReadU16(&class2_count)) {
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return OTS_FAILURE_MSG("Failed to read pair pos format 2 data");
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}
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size_t value_record1_size = CalcValueRecordSize(value_format1);
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size_t value_record2_size = CalcValueRecordSize(value_format2);
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size_t value_records_size = size_t(class1_count) * size_t(class2_count) *
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(value_record1_size + value_record2_size);
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// Check the validity of class definition offsets.
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if (offset_class_def1 < subtable.offset() + value_records_size ||
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offset_class_def2 < subtable.offset() + value_records_size ||
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offset_class_def1 >= length || offset_class_def2 >= length) {
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return OTS_FAILURE_MSG("Bad ParsePairPosFormat2 class definition offsets %d or %d", offset_class_def1, offset_class_def2);
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}
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// Check class 1 records.
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if (value_record1_size || value_record2_size) {
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for (unsigned i = 0; i < class1_count; ++i) {
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// Check class 2 records.
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for (unsigned j = 0; j < class2_count; ++j) {
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if (value_format1 && value_record2_size &&
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!ParseValueRecord(font, &subtable, value_format1)) {
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return OTS_FAILURE_MSG("Failed to parse value record 1 %d and %d", j, i);
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}
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if (value_format2 && value_record2_size &&
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!ParseValueRecord(font, &subtable, value_format2)) {
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return OTS_FAILURE_MSG("Falied to parse value record 2 %d and %d", j, i);
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}
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}
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}
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}
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// Check class definition tables.
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if (!ots::ParseClassDefTable(font, data + offset_class_def1,
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length - offset_class_def1,
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num_glyphs, ots::kMaxClassDefValue)) {
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return OTS_FAILURE_MSG("Failed to parse class definition table 1");
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}
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if (!ots::ParseClassDefTable(font, data + offset_class_def2,
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length - offset_class_def2,
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num_glyphs, ots::kMaxClassDefValue)) {
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return OTS_FAILURE_MSG("Failed to parse class definition table 2");
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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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// Pair Adjustment Positioning Subtable
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bool ParsePairAdjustment(const ots::Font *font, const uint8_t *data,
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const size_t length) {
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ots::Buffer subtable(data, 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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uint16_t format = 0;
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uint16_t offset_coverage = 0;
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uint16_t value_format1 = 0;
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uint16_t value_format2 = 0;
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if (!subtable.ReadU16(&format) ||
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!subtable.ReadU16(&offset_coverage) ||
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!subtable.ReadU16(&value_format1) ||
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!subtable.ReadU16(&value_format2)) {
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return OTS_FAILURE_MSG("Failed to read pair adjustment structure");
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}
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if (format == 1) {
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if (!ParsePairPosFormat1(font, data, length, value_format1, value_format2,
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maxp->num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse pair pos format 1");
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}
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} else if (format == 2) {
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if (!ParsePairPosFormat2(font, data, length, value_format1, value_format2,
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maxp->num_glyphs)) {
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return OTS_FAILURE_MSG("Failed to parse pair format 2");
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}
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} else {
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return OTS_FAILURE_MSG("Bad pos pair 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 pair pos offset coverage %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,
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maxp->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 3
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// Cursive Attachment Positioning Subtable
|
|
bool ParseCursiveAttachment(const ots::Font *font, const uint8_t *data,
|
|
const size_t length) {
|
|
ots::Buffer subtable(data, length);
|
|
|
|
ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
|
|
font->GetTypedTable(OTS_TAG_MAXP));
|
|
if (!maxp) {
|
|
return OTS_FAILURE_MSG("Required maxp table missing");
|
|
}
|
|
|
|
uint16_t format = 0;
|
|
uint16_t offset_coverage = 0;
|
|
uint16_t entry_exit_count = 0;
|
|
if (!subtable.ReadU16(&format) ||
|
|
!subtable.ReadU16(&offset_coverage) ||
|
|
!subtable.ReadU16(&entry_exit_count)) {
|
|
return OTS_FAILURE_MSG("Failed to read cursive attachment structure");
|
|
}
|
|
|
|
if (format != 1) {
|
|
return OTS_FAILURE_MSG("Bad cursive attachment format %d", format);
|
|
}
|
|
|
|
// Check entry exit records.
|
|
const unsigned entry_exit_records_end =
|
|
2 * static_cast<unsigned>(entry_exit_count) + 6;
|
|
if (entry_exit_records_end > std::numeric_limits<uint16_t>::max()) {
|
|
return OTS_FAILURE_MSG("Bad entry exit record end %d", entry_exit_records_end);
|
|
}
|
|
for (unsigned i = 0; i < entry_exit_count; ++i) {
|
|
uint16_t offset_entry_anchor = 0;
|
|
uint16_t offset_exit_anchor = 0;
|
|
if (!subtable.ReadU16(&offset_entry_anchor) ||
|
|
!subtable.ReadU16(&offset_exit_anchor)) {
|
|
return OTS_FAILURE_MSG("Can't read entry exit record %d", i);
|
|
}
|
|
// These offsets could be NULL.
|
|
if (offset_entry_anchor) {
|
|
if (offset_entry_anchor < entry_exit_records_end ||
|
|
offset_entry_anchor >= length) {
|
|
return OTS_FAILURE_MSG("Bad entry anchor offset %d in entry exit record %d", offset_entry_anchor, i);
|
|
}
|
|
if (!ParseAnchorTable(font, data + offset_entry_anchor,
|
|
length - offset_entry_anchor)) {
|
|
return OTS_FAILURE_MSG("Failed to parse entry anchor table in entry exit record %d", i);
|
|
}
|
|
}
|
|
if (offset_exit_anchor) {
|
|
if (offset_exit_anchor < entry_exit_records_end ||
|
|
offset_exit_anchor >= length) {
|
|
return OTS_FAILURE_MSG("Bad exit anchor offset %d in entry exit record %d", offset_exit_anchor, i);
|
|
}
|
|
if (!ParseAnchorTable(font, data + offset_exit_anchor,
|
|
length - offset_exit_anchor)) {
|
|
return OTS_FAILURE_MSG("Failed to parse exit anchor table in entry exit record %d", i);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (offset_coverage < subtable.offset() || offset_coverage >= length) {
|
|
return OTS_FAILURE_MSG("Bad coverage offset in cursive attachment %d", offset_coverage);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offset_coverage,
|
|
length - offset_coverage,
|
|
maxp->num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse coverage table in cursive attachment");
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ParseAnchorArrayTable(const ots::Font *font,
|
|
const uint8_t *data, const size_t length,
|
|
const uint16_t class_count) {
|
|
ots::Buffer subtable(data, length);
|
|
|
|
uint16_t record_count = 0;
|
|
if (!subtable.ReadU16(&record_count)) {
|
|
return OTS_FAILURE_MSG("Can't read anchor array length");
|
|
}
|
|
|
|
const unsigned anchor_array_end = 2 * static_cast<unsigned>(record_count) *
|
|
static_cast<unsigned>(class_count) + 2;
|
|
if (anchor_array_end > std::numeric_limits<uint16_t>::max()) {
|
|
return OTS_FAILURE_MSG("Bad end of anchor array %d", anchor_array_end);
|
|
}
|
|
for (unsigned i = 0; i < record_count; ++i) {
|
|
for (unsigned j = 0; j < class_count; ++j) {
|
|
uint16_t offset_record = 0;
|
|
if (!subtable.ReadU16(&offset_record)) {
|
|
return OTS_FAILURE_MSG("Can't read anchor array record offset for class %d and record %d", j, i);
|
|
}
|
|
// |offset_record| could be NULL.
|
|
if (offset_record) {
|
|
if (offset_record < anchor_array_end || offset_record >= length) {
|
|
return OTS_FAILURE_MSG("Bad record offset %d in class %d, record %d", offset_record, j, i);
|
|
}
|
|
if (!ParseAnchorTable(font, data + offset_record,
|
|
length - offset_record)) {
|
|
return OTS_FAILURE_MSG("Failed to parse anchor table for class %d, record %d", j, i);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool ParseLigatureArrayTable(const ots::Font *font,
|
|
const uint8_t *data, const size_t length,
|
|
const uint16_t class_count) {
|
|
ots::Buffer subtable(data, length);
|
|
|
|
uint16_t ligature_count = 0;
|
|
if (!subtable.ReadU16(&ligature_count)) {
|
|
return OTS_FAILURE_MSG("Failed to read ligature count");
|
|
}
|
|
for (unsigned i = 0; i < ligature_count; ++i) {
|
|
uint16_t offset_ligature_attach = 0;
|
|
if (!subtable.ReadU16(&offset_ligature_attach)) {
|
|
return OTS_FAILURE_MSG("Can't read ligature offset %d", i);
|
|
}
|
|
if (offset_ligature_attach < 2 || offset_ligature_attach >= length) {
|
|
return OTS_FAILURE_MSG("Bad ligature attachment offset %d in ligature %d", offset_ligature_attach, i);
|
|
}
|
|
if (!ParseAnchorArrayTable(font, data + offset_ligature_attach,
|
|
length - offset_ligature_attach, class_count)) {
|
|
return OTS_FAILURE_MSG("Failed to parse anchor table for ligature %d", i);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Common parser for Lookup Type 4, 5 and 6.
|
|
bool ParseMarkToAttachmentSubtables(const ots::Font *font,
|
|
const uint8_t *data, const size_t length,
|
|
const GPOS_TYPE type) {
|
|
ots::Buffer subtable(data, length);
|
|
|
|
ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
|
|
font->GetTypedTable(OTS_TAG_MAXP));
|
|
if (!maxp) {
|
|
return OTS_FAILURE_MSG("Required maxp table missing");
|
|
}
|
|
|
|
uint16_t format = 0;
|
|
uint16_t offset_coverage1 = 0;
|
|
uint16_t offset_coverage2 = 0;
|
|
uint16_t class_count = 0;
|
|
uint16_t offset_mark_array = 0;
|
|
uint16_t offset_type_specific_array = 0;
|
|
if (!subtable.ReadU16(&format) ||
|
|
!subtable.ReadU16(&offset_coverage1) ||
|
|
!subtable.ReadU16(&offset_coverage2) ||
|
|
!subtable.ReadU16(&class_count) ||
|
|
!subtable.ReadU16(&offset_mark_array) ||
|
|
!subtable.ReadU16(&offset_type_specific_array)) {
|
|
return OTS_FAILURE_MSG("Failed to read mark attachment subtable header");
|
|
}
|
|
|
|
if (format != 1) {
|
|
return OTS_FAILURE_MSG("bad mark attachment subtable format %d", format);
|
|
}
|
|
|
|
const unsigned header_end = static_cast<unsigned>(subtable.offset());
|
|
if (header_end > std::numeric_limits<uint16_t>::max()) {
|
|
return OTS_FAILURE_MSG("Bad mark attachment subtable size ending at %d", header_end);
|
|
}
|
|
if (offset_coverage1 < header_end || offset_coverage1 >= length) {
|
|
return OTS_FAILURE_MSG("Bad coverage 1 offset %d", offset_coverage1);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offset_coverage1,
|
|
length - offset_coverage1,
|
|
maxp->num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse converge 1 table");
|
|
}
|
|
if (offset_coverage2 < header_end || offset_coverage2 >= length) {
|
|
return OTS_FAILURE_MSG("Bad coverage 2 offset %d", offset_coverage2);
|
|
}
|
|
if (!ots::ParseCoverageTable(font, data + offset_coverage2,
|
|
length - offset_coverage2,
|
|
maxp->num_glyphs)) {
|
|
return OTS_FAILURE_MSG("Failed to parse coverage table 2");
|
|
}
|
|
|
|
if (offset_mark_array < header_end || offset_mark_array >= length) {
|
|
return OTS_FAILURE_MSG("Bad mark array offset %d", offset_mark_array);
|
|
}
|
|
if (!ParseMarkArrayTable(font, data + offset_mark_array,
|
|
length - offset_mark_array, class_count)) {
|
|
return OTS_FAILURE_MSG("Failed to parse mark array");
|
|
}
|
|
|
|
if (offset_type_specific_array < header_end ||
|
|
offset_type_specific_array >= length) {
|
|
return OTS_FAILURE_MSG("Bad type specific array offset %d", offset_type_specific_array);
|
|
}
|
|
if (type == GPOS_TYPE_MARK_TO_BASE_ATTACHMENT ||
|
|
type == GPOS_TYPE_MARK_TO_MARK_ATTACHMENT) {
|
|
if (!ParseAnchorArrayTable(font, data + offset_type_specific_array,
|
|
length - offset_type_specific_array,
|
|
class_count)) {
|
|
return OTS_FAILURE_MSG("Failed to parse anchor array");
|
|
}
|
|
} else if (type == GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT) {
|
|
if (!ParseLigatureArrayTable(font, data + offset_type_specific_array,
|
|
length - offset_type_specific_array,
|
|
class_count)) {
|
|
return OTS_FAILURE_MSG("Failed to parse ligature array");
|
|
}
|
|
} else {
|
|
return OTS_FAILURE_MSG("Bad attachment type %d", type);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Lookup Type 4:
|
|
// MarkToBase Attachment Positioning Subtable
|
|
bool ParseMarkToBaseAttachment(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
return ParseMarkToAttachmentSubtables(font, data, length,
|
|
GPOS_TYPE_MARK_TO_BASE_ATTACHMENT);
|
|
}
|
|
|
|
// Lookup Type 5:
|
|
// MarkToLigature Attachment Positioning Subtable
|
|
bool ParseMarkToLigatureAttachment(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
return ParseMarkToAttachmentSubtables(font, data, length,
|
|
GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT);
|
|
}
|
|
|
|
// Lookup Type 6:
|
|
// MarkToMark Attachment Positioning Subtable
|
|
bool ParseMarkToMarkAttachment(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
return ParseMarkToAttachmentSubtables(font, data, length,
|
|
GPOS_TYPE_MARK_TO_MARK_ATTACHMENT);
|
|
}
|
|
|
|
// Lookup Type 7:
|
|
// Contextual Positioning Subtables
|
|
bool ParseContextPositioning(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
|
|
font->GetTypedTable(OTS_TAG_MAXP));
|
|
if (!maxp) {
|
|
return OTS_FAILURE_MSG("Required maxp table missing");
|
|
}
|
|
ots::OpenTypeGPOS *gpos = static_cast<ots::OpenTypeGPOS*>(
|
|
font->GetTypedTable(OTS_TAG_GPOS));
|
|
if (!gpos) {
|
|
return OTS_FAILURE_MSG("Internal error!");
|
|
}
|
|
return ots::ParseContextSubtable(font, data, length, maxp->num_glyphs,
|
|
gpos->num_lookups);
|
|
}
|
|
|
|
// Lookup Type 8:
|
|
// Chaining Contexual Positioning Subtable
|
|
bool ParseChainedContextPositioning(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
ots::OpenTypeMAXP *maxp = static_cast<ots::OpenTypeMAXP*>(
|
|
font->GetTypedTable(OTS_TAG_MAXP));
|
|
if (!maxp) {
|
|
return OTS_FAILURE_MSG("Required maxp table missing");
|
|
}
|
|
ots::OpenTypeGPOS *gpos = static_cast<ots::OpenTypeGPOS*>(
|
|
font->GetTypedTable(OTS_TAG_GPOS));
|
|
if (!gpos) {
|
|
return OTS_FAILURE_MSG("Internal error!");
|
|
}
|
|
return ots::ParseChainingContextSubtable(font, data, length,
|
|
maxp->num_glyphs,
|
|
gpos->num_lookups);
|
|
}
|
|
|
|
// Lookup Type 9:
|
|
// Extension Positioning
|
|
bool ParseExtensionPositioning(const ots::Font *font,
|
|
const uint8_t *data, const size_t length) {
|
|
return ots::ParseExtensionSubtable(font, data, length,
|
|
&kGposLookupSubtableParser);
|
|
}
|
|
|
|
} // namespace
|
|
|
|
namespace ots {
|
|
|
|
bool OpenTypeGPOS::Parse(const uint8_t *data, size_t length) {
|
|
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) ? kGposHeaderSize_1_0 : kGposHeaderSize_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,
|
|
&kGposLookupSubtableParser,
|
|
&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 OpenTypeGPOS::Serialize(OTSStream *out) {
|
|
if (!out->Write(this->m_data, this->m_length)) {
|
|
return Error("Failed to write GPOS table");
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace ots
|
|
|
|
#undef TABLE_NAME
|