1 files changed, 231 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/sfnt/SkOTUtils.cpp b/gfx/skia/skia/src/sfnt/SkOTUtils.cpp
new file mode 100644
index 0000000000..0dd44a079a
--- /dev/null
+++ b/gfx/skia/skia/src/sfnt/SkOTUtils.cpp
@@ -0,0 +1,231 @@
+/*
+ * 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/base/SkEndian.h"
+#include "src/core/SkAdvancedTypefaceMetrics.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;
+        }
+    }
+}