1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include <array>
9
10#include "src/sfnt/SkOTUtils.h"
11
12#include "include/core/SkData.h"
13#include "include/core/SkStream.h"
14#include "include/private/SkTo.h"
15#include "src/core/SkAdvancedTypefaceMetrics.h"
16#include "src/core/SkEndian.h"
17#include "src/sfnt/SkOTTableTypes.h"
18#include "src/sfnt/SkOTTable_head.h"
19#include "src/sfnt/SkOTTable_name.h"
20#include "src/sfnt/SkSFNTHeader.h"
21
22extern const uint8_t SK_OT_GlyphData_NoOutline[] = {
23 0x0,0x0, //SkOTTableGlyphData::numberOfContours
24 0x0,0x0, //SkOTTableGlyphData::xMin
25 0x0,0x0, //SkOTTableGlyphData::yMin
26 0x0,0x0, //SkOTTableGlyphData::xMax
27 0x0,0x0, //SkOTTableGlyphData::yMax
28
29 0x0,0x0, //SkOTTableGlyphDataInstructions::length
30};
31
32uint32_t SkOTUtils::CalcTableChecksum(SK_OT_ULONG *data, size_t length) {
33 uint32_t sum = 0;
34 SK_OT_ULONG *dataEnd = data + ((length + 3) & ~3) / sizeof(SK_OT_ULONG);
35 for (; data < dataEnd; ++data) {
36 sum += SkEndian_SwapBE32(*data);
37 }
38 return sum;
39}
40
41SkData* SkOTUtils::RenameFont(SkStreamAsset* fontData, const char* fontName, int fontNameLen) {
42
43 // Get the sfnt header.
44 SkSFNTHeader sfntHeader;
45 if (fontData->read(&sfntHeader, sizeof(sfntHeader)) < sizeof(sfntHeader)) {
46 return nullptr;
47 }
48
49 // Find the existing 'name' table.
50 int tableIndex;
51 SkSFNTHeader::TableDirectoryEntry tableEntry;
52 int numTables = SkEndian_SwapBE16(sfntHeader.numTables);
53 for (tableIndex = 0; tableIndex < numTables; ++tableIndex) {
54 if (fontData->read(&tableEntry, sizeof(tableEntry)) < sizeof(tableEntry)) {
55 return nullptr;
56 }
57 if (SkOTTableName::TAG == tableEntry.tag) {
58 break;
59 }
60 }
61 if (tableIndex == numTables) {
62 return nullptr;
63 }
64
65 if (!fontData->rewind()) {
66 return nullptr;
67 }
68
69 // The required 'name' record types: Family, Style, Unique, Full and PostScript.
70 static constexpr std::array<SkOTTableName::Record::NameID::Predefined::Value, 5> names{{
71 SkOTTableName::Record::NameID::Predefined::FontFamilyName,
72 SkOTTableName::Record::NameID::Predefined::FontSubfamilyName,
73 SkOTTableName::Record::NameID::Predefined::UniqueFontIdentifier,
74 SkOTTableName::Record::NameID::Predefined::FullFontName,
75 SkOTTableName::Record::NameID::Predefined::PostscriptName,
76 }};
77
78 // GDI will not use a Symbol cmap table if there is no Symbol encoded name.
79 static constexpr std::array<SkOTTableName::Record::EncodingID::Windows::Value, 2> encodings{{
80 SkOTTableName::Record::EncodingID::Windows::Symbol,
81 SkOTTableName::Record::EncodingID::Windows::UnicodeBMPUCS2,
82 }};
83
84 // Copy the data, leaving out the old name table.
85 // In theory, we could also remove the DSIG table if it exists.
86 size_t nameTableLogicalSize = sizeof(SkOTTableName)
87 + (encodings.size() * names.size() * sizeof(SkOTTableName::Record))
88 + (fontNameLen * sizeof(SK_OT_USHORT));
89 size_t nameTablePhysicalSize = (nameTableLogicalSize + 3) & ~3; // Rounded up to a multiple of 4.
90
91 size_t oldNameTablePhysicalSize = (SkEndian_SwapBE32(tableEntry.logicalLength) + 3) & ~3; // Rounded up to a multiple of 4.
92 size_t oldNameTableOffset = SkEndian_SwapBE32(tableEntry.offset);
93
94 //originalDataSize is the size of the original data without the name table.
95 size_t originalDataSize = fontData->getLength() - oldNameTablePhysicalSize;
96 size_t newDataSize = originalDataSize + nameTablePhysicalSize;
97
98 auto rewrittenFontData = SkData::MakeUninitialized(newDataSize);
99 SK_OT_BYTE* data = static_cast<SK_OT_BYTE*>(rewrittenFontData->writable_data());
100
101 if (fontData->read(data, oldNameTableOffset) < oldNameTableOffset) {
102 return nullptr;
103 }
104 if (fontData->skip(oldNameTablePhysicalSize) < oldNameTablePhysicalSize) {
105 return nullptr;
106 }
107 if (fontData->read(data + oldNameTableOffset, originalDataSize - oldNameTableOffset) < originalDataSize - oldNameTableOffset) {
108 return nullptr;
109 }
110
111 //Fix up the offsets of the directory entries after the old 'name' table entry.
112 SkSFNTHeader::TableDirectoryEntry* currentEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader));
113 SkSFNTHeader::TableDirectoryEntry* endEntry = currentEntry + numTables;
114 SkSFNTHeader::TableDirectoryEntry* headTableEntry = nullptr;
115 for (; currentEntry < endEntry; ++currentEntry) {
116 uint32_t oldOffset = SkEndian_SwapBE32(currentEntry->offset);
117 if (oldOffset > oldNameTableOffset) {
118 currentEntry->offset = SkEndian_SwapBE32(SkToU32(oldOffset - oldNameTablePhysicalSize));
119 }
120
121 if (SkOTTableHead::TAG == currentEntry->tag) {
122 headTableEntry = currentEntry;
123 }
124 }
125
126 // Make the table directory entry point to the new 'name' table.
127 SkSFNTHeader::TableDirectoryEntry* nameTableEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader)) + tableIndex;
128 nameTableEntry->logicalLength = SkEndian_SwapBE32(SkToU32(nameTableLogicalSize));
129 nameTableEntry->offset = SkEndian_SwapBE32(SkToU32(originalDataSize));
130
131 // Write the new 'name' table after the original font data.
132 SkOTTableName* nameTable = reinterpret_cast<SkOTTableName*>(data + originalDataSize);
133 unsigned short stringOffset = sizeof(SkOTTableName) + (encodings.size() * names.size() * sizeof(SkOTTableName::Record));
134 nameTable->format = SkOTTableName::format_0;
135 nameTable->count = SkEndian_SwapBE16(encodings.size() * names.size());
136 nameTable->stringOffset = SkEndian_SwapBE16(stringOffset);
137
138 SkOTTableName::Record* nameRecord = reinterpret_cast<SkOTTableName::Record*>(data + originalDataSize + sizeof(SkOTTableName));
139 for (const auto& encoding : encodings) {
140 for (const auto& name : names) {
141 nameRecord->platformID.value = SkOTTableName::Record::PlatformID::Windows;
142 nameRecord->encodingID.windows.value = encoding;
143 nameRecord->languageID.windows.value = SkOTTableName::Record::LanguageID::Windows::English_UnitedStates;
144 nameRecord->nameID.predefined.value = name;
145 nameRecord->offset = SkEndian_SwapBE16(0);
146 nameRecord->length = SkEndian_SwapBE16(SkToU16(fontNameLen * sizeof(SK_OT_USHORT)));
147 ++nameRecord;
148 }
149 }
150
151 SK_OT_USHORT* nameString = reinterpret_cast<SK_OT_USHORT*>(data + originalDataSize + stringOffset);
152 for (int i = 0; i < fontNameLen; ++i) {
153 nameString[i] = SkEndian_SwapBE16(fontName[i]);
154 }
155
156 unsigned char* logical = data + originalDataSize + nameTableLogicalSize;
157 unsigned char* physical = data + originalDataSize + nameTablePhysicalSize;
158 for (; logical < physical; ++logical) {
159 *logical = 0;
160 }
161
162 // Update the table checksum in the directory entry.
163 nameTableEntry->checksum = SkEndian_SwapBE32(SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(nameTable), nameTableLogicalSize));
164
165 // Update the checksum adjustment in the head table.
166 if (headTableEntry) {
167 size_t headTableOffset = SkEndian_SwapBE32(headTableEntry->offset);
168 if (headTableOffset + sizeof(SkOTTableHead) < originalDataSize) {
169 SkOTTableHead* headTable = reinterpret_cast<SkOTTableHead*>(data + headTableOffset);
170 headTable->checksumAdjustment = SkEndian_SwapBE32(0);
171 uint32_t unadjustedFontChecksum = SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(data), originalDataSize + nameTablePhysicalSize);
172 headTable->checksumAdjustment = SkEndian_SwapBE32(SkOTTableHead::fontChecksum - unadjustedFontChecksum);
173 }
174 }
175
176 return rewrittenFontData.release();
177}
178
179sk_sp<SkOTUtils::LocalizedStrings_NameTable>
180SkOTUtils::LocalizedStrings_NameTable::Make(const SkTypeface& typeface,
181 SK_OT_USHORT types[],
182 int typesCount)
183{
184 static const SkFontTableTag nameTag = SkSetFourByteTag('n','a','m','e');
185 size_t nameTableSize = typeface.getTableSize(nameTag);
186 if (0 == nameTableSize) {
187 return nullptr;
188 }
189 std::unique_ptr<uint8_t[]> nameTableData(new uint8_t[nameTableSize]);
190 size_t copied = typeface.getTableData(nameTag, 0, nameTableSize, nameTableData.get());
191 if (copied != nameTableSize) {
192 return nullptr;
193 }
194
195 return sk_sp<SkOTUtils::LocalizedStrings_NameTable>(
196 new SkOTUtils::LocalizedStrings_NameTable(std::move(nameTableData), nameTableSize,
197 types, typesCount));
198}
199
200sk_sp<SkOTUtils::LocalizedStrings_NameTable>
201SkOTUtils::LocalizedStrings_NameTable::MakeForFamilyNames(const SkTypeface& typeface) {
202 return Make(typeface,
203 SkOTUtils::LocalizedStrings_NameTable::familyNameTypes,
204 SK_ARRAY_COUNT(SkOTUtils::LocalizedStrings_NameTable::familyNameTypes));
205}
206
207bool SkOTUtils::LocalizedStrings_NameTable::next(SkTypeface::LocalizedString* localizedString) {
208 do {
209 SkOTTableName::Iterator::Record record;
210 if (fFamilyNameIter.next(record)) {
211 localizedString->fString = record.name;
212 localizedString->fLanguage = record.language;
213 return true;
214 }
215 if (fTypesCount == fTypesIndex + 1) {
216 return false;
217 }
218 ++fTypesIndex;
219 fFamilyNameIter.reset(fTypes[fTypesIndex]);
220 } while (true);
221}
222
223SK_OT_USHORT SkOTUtils::LocalizedStrings_NameTable::familyNameTypes[3] = {
224 SkOTTableName::Record::NameID::Predefined::FontFamilyName,
225 SkOTTableName::Record::NameID::Predefined::PreferredFamily,
226 SkOTTableName::Record::NameID::Predefined::WWSFamilyName,
227};
228
229void SkOTUtils::SetAdvancedTypefaceFlags(SkOTTableOS2_V4::Type fsType,
230 SkAdvancedTypefaceMetrics* info) {
231 SkASSERT(info);
232 // The logic should be identical to SkTypeface_FreeType::onGetAdvancedMetrics().
233 if (fsType.raw.value != 0) {
234 if (SkToBool(fsType.field.Restricted) || SkToBool(fsType.field.Bitmap)) {
235 info->fFlags |= SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag;
236 }
237 if (SkToBool(fsType.field.NoSubsetting)) {
238 info->fFlags |= SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag;
239 }
240 }
241}
242