/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=8 sts=2 et sw=2 tw=80: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "SFNTData.h" #include <algorithm> #include "BigEndianInts.h" #include "Logging.h" #include "mozilla/HashFunctions.h" #include "SFNTNameTable.h" namespace mozilla { namespace gfx { #define TRUETYPE_TAG(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d)) #pragma pack(push, 1) struct TTCHeader { BigEndianUint32 ttcTag; // Always 'ttcf' BigEndianUint32 version; // Fixed, 0x00010000 BigEndianUint32 numFonts; }; struct OffsetTable { BigEndianUint32 sfntVersion; // Fixed, 0x00010000 for version 1.0. BigEndianUint16 numTables; BigEndianUint16 searchRange; // (Maximum power of 2 <= numTables) x 16. BigEndianUint16 entrySelector; // Log2(maximum power of 2 <= numTables). BigEndianUint16 rangeShift; // NumTables x 16-searchRange. }; struct TableDirEntry { BigEndianUint32 tag; // 4 -byte identifier. BigEndianUint32 checkSum; // CheckSum for this table. BigEndianUint32 offset; // Offset from beginning of TrueType font file. BigEndianUint32 length; // Length of this table. friend bool operator<(const TableDirEntry& lhs, const uint32_t aTag) { return lhs.tag < aTag; } }; #pragma pack(pop) class SFNTData::Font { public: Font(const OffsetTable *aOffsetTable, const uint8_t *aFontData, uint32_t aDataLength) : mFontData(aFontData) , mFirstDirEntry(reinterpret_cast<const TableDirEntry*>(aOffsetTable + 1)) , mEndOfDirEntries(mFirstDirEntry + aOffsetTable->numTables) , mDataLength(aDataLength) { } bool GetU16FullName(mozilla::u16string& aU16FullName) { const TableDirEntry* dirEntry = GetDirEntry(TRUETYPE_TAG('n', 'a', 'm', 'e')); if (!dirEntry) { gfxWarning() << "Name table entry not found."; return false; } UniquePtr<SFNTNameTable> nameTable = SFNTNameTable::Create((mFontData + dirEntry->offset), dirEntry->length); if (!nameTable) { return false; } return nameTable->GetU16FullName(aU16FullName); } private: const TableDirEntry* GetDirEntry(const uint32_t aTag) { const TableDirEntry* foundDirEntry = std::lower_bound(mFirstDirEntry, mEndOfDirEntries, aTag); if (foundDirEntry == mEndOfDirEntries || foundDirEntry->tag != aTag) { gfxWarning() << "Font data does not contain tag."; return nullptr; } if (mDataLength < (foundDirEntry->offset + foundDirEntry->length)) { gfxWarning() << "Font data too short to contain table."; return nullptr; } return foundDirEntry; } const uint8_t *mFontData; const TableDirEntry *mFirstDirEntry; const TableDirEntry *mEndOfDirEntries; uint32_t mDataLength; }; /* static */ UniquePtr<SFNTData> SFNTData::Create(const uint8_t *aFontData, uint32_t aDataLength) { MOZ_ASSERT(aFontData); // Check to see if this is a font collection. if (aDataLength < sizeof(TTCHeader)) { gfxWarning() << "Font data too short."; return nullptr; } const TTCHeader *ttcHeader = reinterpret_cast<const TTCHeader*>(aFontData); if (ttcHeader->ttcTag == TRUETYPE_TAG('t', 't', 'c', 'f')) { uint32_t numFonts = ttcHeader->numFonts; if (aDataLength < sizeof(TTCHeader) + (numFonts * sizeof(BigEndianUint32))) { gfxWarning() << "Font data too short to contain full TTC Header."; return nullptr; } UniquePtr<SFNTData> sfntData(new SFNTData); const BigEndianUint32* offset = reinterpret_cast<const BigEndianUint32*>(aFontData + sizeof(TTCHeader)); const BigEndianUint32* endOfOffsets = offset + numFonts; while (offset != endOfOffsets) { if (!sfntData->AddFont(aFontData, aDataLength, *offset)) { return nullptr; } ++offset; } return Move(sfntData); } UniquePtr<SFNTData> sfntData(new SFNTData); if (!sfntData->AddFont(aFontData, aDataLength, 0)) { return nullptr; } return Move(sfntData); } /* static */ uint64_t SFNTData::GetUniqueKey(const uint8_t *aFontData, uint32_t aDataLength) { uint64_t hash; UniquePtr<SFNTData> sfntData = SFNTData::Create(aFontData, aDataLength); mozilla::u16string firstName; if (sfntData && sfntData->GetU16FullName(0, firstName)) { hash = HashString(firstName.c_str(), firstName.length()); } else { gfxWarning() << "Failed to get name from font data hashing whole font."; hash = HashString(aFontData, aDataLength); } return hash << 32 | aDataLength;; } SFNTData::~SFNTData() { for (size_t i = 0; i < mFonts.length(); ++i) { delete mFonts[i]; } } bool SFNTData::GetU16FullName(uint32_t aIndex, mozilla::u16string& aU16FullName) { if (aIndex >= mFonts.length()) { gfxWarning() << "aIndex to font data too high."; return false; } return mFonts[aIndex]->GetU16FullName(aU16FullName); } bool SFNTData::GetU16FullNames(Vector<mozilla::u16string>& aU16FullNames) { bool fontFound = false; for (size_t i = 0; i < mFonts.length(); ++i) { mozilla::u16string name; if (mFonts[i]->GetU16FullName(name)) { fontFound = true; } if (!aU16FullNames.append(Move(name))) { return false; } } return fontFound; } bool SFNTData::GetIndexForU16Name(const mozilla::u16string& aU16FullName, uint32_t* aIndex, size_t aTruncatedLen) { for (size_t i = 0; i < mFonts.length(); ++i) { mozilla::u16string name; if (!mFonts[i]->GetU16FullName(name)) { continue; } if (aTruncatedLen) { MOZ_ASSERT(aU16FullName.length() <= aTruncatedLen); name = name.substr(0, aTruncatedLen); } if (name == aU16FullName) { *aIndex = i; return true; } } return false; } bool SFNTData::AddFont(const uint8_t *aFontData, uint32_t aDataLength, uint32_t aOffset) { uint32_t remainingLength = aDataLength - aOffset; if (remainingLength < sizeof(OffsetTable)) { gfxWarning() << "Font data too short to contain OffsetTable " << aOffset; return false; } const OffsetTable *offsetTable = reinterpret_cast<const OffsetTable*>(aFontData + aOffset); if (remainingLength < sizeof(OffsetTable) + (offsetTable->numTables * sizeof(TableDirEntry))) { gfxWarning() << "Font data too short to contain tables."; return false; } return mFonts.append(new Font(offsetTable, aFontData, aDataLength)); } } // gfx } // mozilla