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 "SkData.h"
9 #include "SkEndian.h"
10 #include "SkSFNTHeader.h"
11 #include "SkStream.h"
12 #include "SkOTTable_head.h"
13 #include "SkOTTable_name.h"
14 #include "SkOTTableTypes.h"
15 #include "SkOTUtils.h"
16
17 extern const uint8_t SK_OT_GlyphData_NoOutline[] = {
18 0x0,0x0, //SkOTTableGlyphData::numberOfContours
19 0x0,0x0, //SkOTTableGlyphData::xMin
20 0x0,0x0, //SkOTTableGlyphData::yMin
21 0x0,0x0, //SkOTTableGlyphData::xMax
22 0x0,0x0, //SkOTTableGlyphData::yMax
23
24 0x0,0x0, //SkOTTableGlyphDataInstructions::length
25 };
26
CalcTableChecksum(SK_OT_ULONG * data,size_t length)27 uint32_t SkOTUtils::CalcTableChecksum(SK_OT_ULONG *data, size_t length) {
28 uint32_t sum = 0;
29 SK_OT_ULONG *dataEnd = data + ((length + 3) & ~3) / sizeof(SK_OT_ULONG);
30 for (; data < dataEnd; ++data) {
31 sum += SkEndian_SwapBE32(*data);
32 }
33 return sum;
34 }
35
RenameFont(SkStreamAsset * fontData,const char * fontName,int fontNameLen)36 SkData* SkOTUtils::RenameFont(SkStreamAsset* fontData, const char* fontName, int fontNameLen) {
37
38 // Get the sfnt header.
39 SkSFNTHeader sfntHeader;
40 if (fontData->read(&sfntHeader, sizeof(sfntHeader)) < sizeof(sfntHeader)) {
41 return nullptr;
42 }
43
44 // Find the existing 'name' table.
45 int tableIndex;
46 SkSFNTHeader::TableDirectoryEntry tableEntry;
47 int numTables = SkEndian_SwapBE16(sfntHeader.numTables);
48 for (tableIndex = 0; tableIndex < numTables; ++tableIndex) {
49 if (fontData->read(&tableEntry, sizeof(tableEntry)) < sizeof(tableEntry)) {
50 return nullptr;
51 }
52 if (SkOTTableName::TAG == tableEntry.tag) {
53 break;
54 }
55 }
56 if (tableIndex == numTables) {
57 return nullptr;
58 }
59
60 if (!fontData->rewind()) {
61 return nullptr;
62 }
63
64 // The required 'name' record types: Family, Style, Unique, Full and PostScript.
65 const SkOTTableName::Record::NameID::Predefined::Value namesToCreate[] = {
66 SkOTTableName::Record::NameID::Predefined::FontFamilyName,
67 SkOTTableName::Record::NameID::Predefined::FontSubfamilyName,
68 SkOTTableName::Record::NameID::Predefined::UniqueFontIdentifier,
69 SkOTTableName::Record::NameID::Predefined::FullFontName,
70 SkOTTableName::Record::NameID::Predefined::PostscriptName,
71 };
72 const int namesCount = SK_ARRAY_COUNT(namesToCreate);
73
74 // Copy the data, leaving out the old name table.
75 // In theory, we could also remove the DSIG table if it exists.
76 size_t nameTableLogicalSize = sizeof(SkOTTableName) + (namesCount * sizeof(SkOTTableName::Record)) + (fontNameLen * sizeof(wchar_t));
77 size_t nameTablePhysicalSize = (nameTableLogicalSize + 3) & ~3; // Rounded up to a multiple of 4.
78
79 size_t oldNameTablePhysicalSize = (SkEndian_SwapBE32(tableEntry.logicalLength) + 3) & ~3; // Rounded up to a multiple of 4.
80 size_t oldNameTableOffset = SkEndian_SwapBE32(tableEntry.offset);
81
82 //originalDataSize is the size of the original data without the name table.
83 size_t originalDataSize = fontData->getLength() - oldNameTablePhysicalSize;
84 size_t newDataSize = originalDataSize + nameTablePhysicalSize;
85
86 SkAutoTUnref<SkData> rewrittenFontData(SkData::NewUninitialized(newDataSize));
87 SK_OT_BYTE* data = static_cast<SK_OT_BYTE*>(rewrittenFontData->writable_data());
88
89 if (fontData->read(data, oldNameTableOffset) < oldNameTableOffset) {
90 return nullptr;
91 }
92 if (fontData->skip(oldNameTablePhysicalSize) < oldNameTablePhysicalSize) {
93 return nullptr;
94 }
95 if (fontData->read(data + oldNameTableOffset, originalDataSize - oldNameTableOffset) < originalDataSize - oldNameTableOffset) {
96 return nullptr;
97 }
98
99 //Fix up the offsets of the directory entries after the old 'name' table entry.
100 SkSFNTHeader::TableDirectoryEntry* currentEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader));
101 SkSFNTHeader::TableDirectoryEntry* endEntry = currentEntry + numTables;
102 SkSFNTHeader::TableDirectoryEntry* headTableEntry = nullptr;
103 for (; currentEntry < endEntry; ++currentEntry) {
104 uint32_t oldOffset = SkEndian_SwapBE32(currentEntry->offset);
105 if (oldOffset > oldNameTableOffset) {
106 currentEntry->offset = SkEndian_SwapBE32(SkToU32(oldOffset - oldNameTablePhysicalSize));
107 }
108 if (SkOTTableHead::TAG == currentEntry->tag) {
109 headTableEntry = currentEntry;
110 }
111 }
112
113 // Make the table directory entry point to the new 'name' table.
114 SkSFNTHeader::TableDirectoryEntry* nameTableEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader)) + tableIndex;
115 nameTableEntry->logicalLength = SkEndian_SwapBE32(SkToU32(nameTableLogicalSize));
116 nameTableEntry->offset = SkEndian_SwapBE32(SkToU32(originalDataSize));
117
118 // Write the new 'name' table after the original font data.
119 SkOTTableName* nameTable = reinterpret_cast<SkOTTableName*>(data + originalDataSize);
120 unsigned short stringOffset = sizeof(SkOTTableName) + (namesCount * sizeof(SkOTTableName::Record));
121 nameTable->format = SkOTTableName::format_0;
122 nameTable->count = SkEndian_SwapBE16(namesCount);
123 nameTable->stringOffset = SkEndian_SwapBE16(stringOffset);
124
125 SkOTTableName::Record* nameRecords = reinterpret_cast<SkOTTableName::Record*>(data + originalDataSize + sizeof(SkOTTableName));
126 for (int i = 0; i < namesCount; ++i) {
127 nameRecords[i].platformID.value = SkOTTableName::Record::PlatformID::Windows;
128 nameRecords[i].encodingID.windows.value = SkOTTableName::Record::EncodingID::Windows::UnicodeBMPUCS2;
129 nameRecords[i].languageID.windows.value = SkOTTableName::Record::LanguageID::Windows::English_UnitedStates;
130 nameRecords[i].nameID.predefined.value = namesToCreate[i];
131 nameRecords[i].offset = SkEndian_SwapBE16(0);
132 nameRecords[i].length = SkEndian_SwapBE16(SkToU16(fontNameLen * sizeof(wchar_t)));
133 }
134
135 SK_OT_USHORT* nameString = reinterpret_cast<SK_OT_USHORT*>(data + originalDataSize + stringOffset);
136 for (int i = 0; i < fontNameLen; ++i) {
137 nameString[i] = SkEndian_SwapBE16(fontName[i]);
138 }
139
140 unsigned char* logical = data + originalDataSize + nameTableLogicalSize;
141 unsigned char* physical = data + originalDataSize + nameTablePhysicalSize;
142 for (; logical < physical; ++logical) {
143 *logical = 0;
144 }
145
146 // Update the table checksum in the directory entry.
147 nameTableEntry->checksum = SkEndian_SwapBE32(SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(nameTable), nameTableLogicalSize));
148
149 // Update the checksum adjustment in the head table.
150 if (headTableEntry) {
151 size_t headTableOffset = SkEndian_SwapBE32(headTableEntry->offset);
152 if (headTableOffset + sizeof(SkOTTableHead) < originalDataSize) {
153 SkOTTableHead* headTable = reinterpret_cast<SkOTTableHead*>(data + headTableOffset);
154 headTable->checksumAdjustment = SkEndian_SwapBE32(0);
155 uint32_t unadjustedFontChecksum = SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(data), originalDataSize + nameTablePhysicalSize);
156 headTable->checksumAdjustment = SkEndian_SwapBE32(SkOTTableHead::fontChecksum - unadjustedFontChecksum);
157 }
158 }
159
160 return rewrittenFontData.detach();
161 }
162
163
164 SkOTUtils::LocalizedStrings_NameTable*
CreateForFamilyNames(const SkTypeface & typeface)165 SkOTUtils::LocalizedStrings_NameTable::CreateForFamilyNames(const SkTypeface& typeface) {
166 static const SkFontTableTag nameTag = SkSetFourByteTag('n','a','m','e');
167 size_t nameTableSize = typeface.getTableSize(nameTag);
168 if (0 == nameTableSize) {
169 return nullptr;
170 }
171 SkAutoTDeleteArray<uint8_t> nameTableData(new uint8_t[nameTableSize]);
172 size_t copied = typeface.getTableData(nameTag, 0, nameTableSize, nameTableData.get());
173 if (copied != nameTableSize) {
174 return nullptr;
175 }
176
177 return new SkOTUtils::LocalizedStrings_NameTable((SkOTTableName*)nameTableData.detach(),
178 SkOTUtils::LocalizedStrings_NameTable::familyNameTypes,
179 SK_ARRAY_COUNT(SkOTUtils::LocalizedStrings_NameTable::familyNameTypes));
180 }
181
next(SkTypeface::LocalizedString * localizedString)182 bool SkOTUtils::LocalizedStrings_NameTable::next(SkTypeface::LocalizedString* localizedString) {
183 do {
184 SkOTTableName::Iterator::Record record;
185 if (fFamilyNameIter.next(record)) {
186 localizedString->fString = record.name;
187 localizedString->fLanguage = record.language;
188 return true;
189 }
190 if (fTypesCount == fTypesIndex + 1) {
191 return false;
192 }
193 ++fTypesIndex;
194 fFamilyNameIter.reset(fTypes[fTypesIndex]);
195 } while (true);
196 }
197
198 SkOTTableName::Record::NameID::Predefined::Value
199 SkOTUtils::LocalizedStrings_NameTable::familyNameTypes[3] = {
200 SkOTTableName::Record::NameID::Predefined::FontFamilyName,
201 SkOTTableName::Record::NameID::Predefined::PreferredFamily,
202 SkOTTableName::Record::NameID::Predefined::WWSFamilyName,
203 };
204