blob: ed2dac471393334f4acf4df04c4e0d1da6b809d8 [file] [log] [blame]
/*
* 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 <array>
#include "src/sfnt/SkOTUtils.h"
#include "include/core/SkData.h"
#include "include/core/SkStream.h"
#include "include/private/base/SkTo.h"
#include "src/core/SkAdvancedTypefaceMetrics.h"
#include "src/core/SkEndian.h"
#include "src/sfnt/SkOTTableTypes.h"
#include "src/sfnt/SkOTTable_head.h"
#include "src/sfnt/SkOTTable_name.h"
#include "src/sfnt/SkSFNTHeader.h"
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(SkStreamAsset* fontData, const char* fontName, int fontNameLen) {
// Get the sfnt header.
SkSFNTHeader sfntHeader;
if (fontData->read(&sfntHeader, sizeof(sfntHeader)) < sizeof(sfntHeader)) {
return nullptr;
}
// 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 nullptr;
}
if (SkOTTableName::TAG == tableEntry.tag) {
break;
}
}
if (tableIndex == numTables) {
return nullptr;
}
if (!fontData->rewind()) {
return nullptr;
}
// The required 'name' record types: Family, Style, Unique, Full and PostScript.
static constexpr std::array<SkOTTableName::Record::NameID::Predefined::Value, 5> names{{
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,
}};
// GDI will not use a Symbol cmap table if there is no Symbol encoded name.
static constexpr std::array<SkOTTableName::Record::EncodingID::Windows::Value, 2> encodings{{
SkOTTableName::Record::EncodingID::Windows::Symbol,
SkOTTableName::Record::EncodingID::Windows::UnicodeBMPUCS2,
}};
// 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)
+ (encodings.size() * names.size() * sizeof(SkOTTableName::Record))
+ (fontNameLen * sizeof(SK_OT_USHORT));
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;
auto rewrittenFontData = SkData::MakeUninitialized(newDataSize);
SK_OT_BYTE* data = static_cast<SK_OT_BYTE*>(rewrittenFontData->writable_data());
if (fontData->read(data, oldNameTableOffset) < oldNameTableOffset) {
return nullptr;
}
if (fontData->skip(oldNameTablePhysicalSize) < oldNameTablePhysicalSize) {
return nullptr;
}
if (fontData->read(data + oldNameTableOffset, originalDataSize - oldNameTableOffset) < originalDataSize - oldNameTableOffset) {
return nullptr;
}
//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 = nullptr;
for (; currentEntry < endEntry; ++currentEntry) {
uint32_t oldOffset = SkEndian_SwapBE32(currentEntry->offset);
if (oldOffset > oldNameTableOffset) {
currentEntry->offset = SkEndian_SwapBE32(SkToU32(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(SkToU32(nameTableLogicalSize));
nameTableEntry->offset = SkEndian_SwapBE32(SkToU32(originalDataSize));
// Write the new 'name' table after the original font data.
SkOTTableName* nameTable = reinterpret_cast<SkOTTableName*>(data + originalDataSize);
unsigned short stringOffset = sizeof(SkOTTableName) + (encodings.size() * names.size() * sizeof(SkOTTableName::Record));
nameTable->format = SkOTTableName::format_0;
nameTable->count = SkEndian_SwapBE16(encodings.size() * names.size());
nameTable->stringOffset = SkEndian_SwapBE16(stringOffset);
SkOTTableName::Record* nameRecord = reinterpret_cast<SkOTTableName::Record*>(data + originalDataSize + sizeof(SkOTTableName));
for (const auto& encoding : encodings) {
for (const auto& name : names) {
nameRecord->platformID.value = SkOTTableName::Record::PlatformID::Windows;
nameRecord->encodingID.windows.value = encoding;
nameRecord->languageID.windows.value = SkOTTableName::Record::LanguageID::Windows::English_UnitedStates;
nameRecord->nameID.predefined.value = name;
nameRecord->offset = SkEndian_SwapBE16(0);
nameRecord->length = SkEndian_SwapBE16(SkToU16(fontNameLen * sizeof(SK_OT_USHORT)));
++nameRecord;
}
}
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.release();
}
sk_sp<SkOTUtils::LocalizedStrings_NameTable>
SkOTUtils::LocalizedStrings_NameTable::Make(const SkTypeface& typeface,
SK_OT_USHORT types[],
int typesCount)
{
static const SkFontTableTag nameTag = SkSetFourByteTag('n','a','m','e');
size_t nameTableSize = typeface.getTableSize(nameTag);
if (0 == nameTableSize) {
return nullptr;
}
std::unique_ptr<uint8_t[]> nameTableData(new uint8_t[nameTableSize]);
size_t copied = typeface.getTableData(nameTag, 0, nameTableSize, nameTableData.get());
if (copied != nameTableSize) {
return nullptr;
}
return sk_sp<SkOTUtils::LocalizedStrings_NameTable>(
new SkOTUtils::LocalizedStrings_NameTable(std::move(nameTableData), nameTableSize,
types, typesCount));
}
sk_sp<SkOTUtils::LocalizedStrings_NameTable>
SkOTUtils::LocalizedStrings_NameTable::MakeForFamilyNames(const SkTypeface& typeface) {
return Make(typeface,
SkOTUtils::LocalizedStrings_NameTable::familyNameTypes,
std::size(SkOTUtils::LocalizedStrings_NameTable::familyNameTypes));
}
bool SkOTUtils::LocalizedStrings_NameTable::next(SkTypeface::LocalizedString* localizedString) {
do {
SkOTTableName::Iterator::Record record;
if (fFamilyNameIter.next(record)) {
localizedString->fString = record.name;
localizedString->fLanguage = record.language;
return true;
}
if (fTypesCount == fTypesIndex + 1) {
return false;
}
++fTypesIndex;
fFamilyNameIter.reset(fTypes[fTypesIndex]);
} while (true);
}
SK_OT_USHORT SkOTUtils::LocalizedStrings_NameTable::familyNameTypes[3] = {
SkOTTableName::Record::NameID::Predefined::FontFamilyName,
SkOTTableName::Record::NameID::Predefined::PreferredFamily,
SkOTTableName::Record::NameID::Predefined::WWSFamilyName,
};
void SkOTUtils::SetAdvancedTypefaceFlags(SkOTTableOS2_V4::Type fsType,
SkAdvancedTypefaceMetrics* info) {
SkASSERT(info);
// The logic should be identical to SkTypeface_FreeType::onGetAdvancedMetrics().
if (fsType.raw.value != 0) {
if (SkToBool(fsType.field.Restricted) || SkToBool(fsType.field.Bitmap)) {
info->fFlags |= SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag;
}
if (SkToBool(fsType.field.NoSubsetting)) {
info->fFlags |= SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag;
}
}
}