1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkData.h"
#include "SkEndian.h"
#include "SkSFNTHeader.h"
#include "SkStream.h"
#include "SkOTTable_head.h"
#include "SkOTTable_name.h"
#include "SkOTTableTypes.h"
#include "SkOTUtils.h"
extern const uint8_t SK_OT_GlyphData_NoOutline[] = {
0x0,0x0, //SkOTTableGlyphData::numberOfContours
0x0,0x0, //SkOTTableGlyphData::xMin
0x0,0x0, //SkOTTableGlyphData::yMin
0x0,0x0, //SkOTTableGlyphData::xMax
0x0,0x0, //SkOTTableGlyphData::yMax
0x0,0x0, //SkOTTableGlyphDataInstructions::length
};
uint32_t SkOTUtils::CalcTableChecksum(SK_OT_ULONG *data, size_t length) {
uint32_t sum = 0;
SK_OT_ULONG *dataEnd = data + ((length + 3) & ~3) / sizeof(SK_OT_ULONG);
for (; data < dataEnd; ++data) {
sum += SkEndian_SwapBE32(*data);
}
return sum;
}
SkData* SkOTUtils::RenameFont(SkStream* fontData, const char* fontName, int fontNameLen) {
// Get the sfnt header.
SkSFNTHeader sfntHeader;
if (fontData->read(&sfntHeader, sizeof(sfntHeader)) < sizeof(sfntHeader)) {
return NULL;
}
// Find the existing 'name' table.
int tableIndex;
SkSFNTHeader::TableDirectoryEntry tableEntry;
int numTables = SkEndian_SwapBE16(sfntHeader.numTables);
for (tableIndex = 0; tableIndex < numTables; ++tableIndex) {
if (fontData->read(&tableEntry, sizeof(tableEntry)) < sizeof(tableEntry)) {
return NULL;
}
if (SkOTTableName::TAG == tableEntry.tag) {
break;
}
}
if (tableIndex == numTables) {
return NULL;
}
if (!fontData->rewind()) {
return NULL;
}
// The required 'name' record types: Family, Style, Unique, Full and PostScript.
const SkOTTableName::Record::NameID::Predefined::Value namesToCreate[] = {
SkOTTableName::Record::NameID::Predefined::FontFamilyName,
SkOTTableName::Record::NameID::Predefined::FontSubfamilyName,
SkOTTableName::Record::NameID::Predefined::UniqueFontIdentifier,
SkOTTableName::Record::NameID::Predefined::FullFontName,
SkOTTableName::Record::NameID::Predefined::PostscriptName,
};
const int namesCount = SK_ARRAY_COUNT(namesToCreate);
// Copy the data, leaving out the old name table.
// In theory, we could also remove the DSIG table if it exists.
size_t nameTableLogicalSize = sizeof(SkOTTableName) + (namesCount * sizeof(SkOTTableName::Record)) + (fontNameLen * sizeof(wchar_t));
size_t nameTablePhysicalSize = (nameTableLogicalSize + 3) & ~3; // Rounded up to a multiple of 4.
size_t oldNameTablePhysicalSize = (SkEndian_SwapBE32(tableEntry.logicalLength) + 3) & ~3; // Rounded up to a multiple of 4.
size_t oldNameTableOffset = SkEndian_SwapBE32(tableEntry.offset);
//originalDataSize is the size of the original data without the name table.
size_t originalDataSize = fontData->getLength() - oldNameTablePhysicalSize;
size_t newDataSize = originalDataSize + nameTablePhysicalSize;
SK_OT_BYTE* data = static_cast<SK_OT_BYTE*>(sk_malloc_throw(newDataSize));
SkAutoTUnref<SkData> rewrittenFontData(SkData::NewFromMalloc(data, newDataSize));
if (fontData->read(data, oldNameTableOffset) < oldNameTableOffset) {
return NULL;
}
if (fontData->skip(oldNameTablePhysicalSize) < oldNameTablePhysicalSize) {
return NULL;
}
if (fontData->read(data + oldNameTableOffset, originalDataSize - oldNameTableOffset) < originalDataSize - oldNameTableOffset) {
return NULL;
}
//Fix up the offsets of the directory entries after the old 'name' table entry.
SkSFNTHeader::TableDirectoryEntry* currentEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader));
SkSFNTHeader::TableDirectoryEntry* endEntry = currentEntry + numTables;
SkSFNTHeader::TableDirectoryEntry* headTableEntry = NULL;
for (; currentEntry < endEntry; ++currentEntry) {
uint32_t oldOffset = SkEndian_SwapBE32(currentEntry->offset);
if (oldOffset > oldNameTableOffset) {
currentEntry->offset = SkEndian_SwapBE32(oldOffset - oldNameTablePhysicalSize);
}
if (SkOTTableHead::TAG == currentEntry->tag) {
headTableEntry = currentEntry;
}
}
// Make the table directory entry point to the new 'name' table.
SkSFNTHeader::TableDirectoryEntry* nameTableEntry = reinterpret_cast<SkSFNTHeader::TableDirectoryEntry*>(data + sizeof(SkSFNTHeader)) + tableIndex;
nameTableEntry->logicalLength = SkEndian_SwapBE32(nameTableLogicalSize);
nameTableEntry->offset = SkEndian_SwapBE32(originalDataSize);
// Write the new 'name' table after the original font data.
SkOTTableName* nameTable = reinterpret_cast<SkOTTableName*>(data + originalDataSize);
unsigned short stringOffset = sizeof(SkOTTableName) + (namesCount * sizeof(SkOTTableName::Record));
nameTable->format = SkOTTableName::format_0;
nameTable->count = SkEndian_SwapBE16(namesCount);
nameTable->stringOffset = SkEndian_SwapBE16(stringOffset);
SkOTTableName::Record* nameRecords = reinterpret_cast<SkOTTableName::Record*>(data + originalDataSize + sizeof(SkOTTableName));
for (int i = 0; i < namesCount; ++i) {
nameRecords[i].platformID.value = SkOTTableName::Record::PlatformID::Windows;
nameRecords[i].encodingID.windows.value = SkOTTableName::Record::EncodingID::Windows::UnicodeBMPUCS2;
nameRecords[i].languageID.windows.value = SkOTTableName::Record::LanguageID::Windows::English_UnitedStates;
nameRecords[i].nameID.predefined.value = namesToCreate[i];
nameRecords[i].offset = SkEndian_SwapBE16(0);
nameRecords[i].length = SkEndian_SwapBE16(fontNameLen * sizeof(wchar_t));
}
SK_OT_USHORT* nameString = reinterpret_cast<SK_OT_USHORT*>(data + originalDataSize + stringOffset);
for (int i = 0; i < fontNameLen; ++i) {
nameString[i] = SkEndian_SwapBE16(fontName[i]);
}
unsigned char* logical = data + originalDataSize + nameTableLogicalSize;
unsigned char* physical = data + originalDataSize + nameTablePhysicalSize;
for (; logical < physical; ++logical) {
*logical = 0;
}
// Update the table checksum in the directory entry.
nameTableEntry->checksum = SkEndian_SwapBE32(SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(nameTable), nameTableLogicalSize));
// Update the checksum adjustment in the head table.
if (headTableEntry) {
size_t headTableOffset = SkEndian_SwapBE32(headTableEntry->offset);
if (headTableOffset + sizeof(SkOTTableHead) < originalDataSize) {
SkOTTableHead* headTable = reinterpret_cast<SkOTTableHead*>(data + headTableOffset);
headTable->checksumAdjustment = SkEndian_SwapBE32(0);
uint32_t unadjustedFontChecksum = SkOTUtils::CalcTableChecksum(reinterpret_cast<SK_OT_ULONG*>(data), originalDataSize + nameTablePhysicalSize);
headTable->checksumAdjustment = SkEndian_SwapBE32(SkOTTableHead::fontChecksum - unadjustedFontChecksum);
}
}
return rewrittenFontData.detach();
}
|
