1 files changed, 458 insertions, 0 deletions
diff --git a/modules/woff2/src/woff2_enc.cc b/modules/woff2/src/woff2_enc.cc
new file mode 100644
index 0000000000..f3f46e5759
--- /dev/null
+++ b/modules/woff2/src/woff2_enc.cc
@@ -0,0 +1,458 @@
+/* Copyright 2014 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Library for converting TTF format font files to their WOFF2 versions. */
+
+#include <woff2/encode.h>
+
+#include <stdlib.h>
+#include <complex>
+#include <cstring>
+#include <limits>
+#include <string>
+#include <vector>
+
+#include <brotli/encode.h>
+#include "./buffer.h"
+#include "./font.h"
+#include "./normalize.h"
+#include "./round.h"
+#include "./store_bytes.h"
+#include "./table_tags.h"
+#include "./transform.h"
+#include "./variable_length.h"
+#include "./woff2_common.h"
+
+namespace woff2 {
+
+
+namespace {
+
+const size_t kWoff2HeaderSize = 48;
+const size_t kWoff2EntrySize = 20;
+
+bool Compress(const uint8_t* data, const size_t len, uint8_t* result,
+              uint32_t* result_len, BrotliEncoderMode mode, int quality) {
+  size_t compressed_len = *result_len;
+  if (BrotliEncoderCompress(quality, BROTLI_DEFAULT_WINDOW, mode, len, data,
+                            &compressed_len, result) == 0) {
+    return false;
+  }
+  *result_len = compressed_len;
+  return true;
+}
+
+bool Woff2Compress(const uint8_t* data, const size_t len,
+                   uint8_t* result, uint32_t* result_len,
+                   int quality) {
+  return Compress(data, len, result, result_len,
+                  BROTLI_MODE_FONT, quality);
+}
+
+bool TextCompress(const uint8_t* data, const size_t len,
+                  uint8_t* result, uint32_t* result_len,
+                  int quality) {
+  return Compress(data, len, result, result_len,
+                  BROTLI_MODE_TEXT, quality);
+}
+
+int KnownTableIndex(uint32_t tag) {
+  for (int i = 0; i < 63; ++i) {
+    if (tag == kKnownTags[i]) return i;
+  }
+  return 63;
+}
+
+void StoreTableEntry(const Table& table, size_t* offset, uint8_t* dst) {
+  uint8_t flag_byte = (table.flags & 0xC0) | KnownTableIndex(table.tag);
+  dst[(*offset)++] = flag_byte;
+  // The index here is treated as a set of flag bytes because
+  // bits 6 and 7 of the byte are reserved for future use as flags.
+  // 0x3f or 63 means an arbitrary table tag.
+  if ((flag_byte & 0x3f) == 0x3f) {
+    StoreU32(table.tag, offset, dst);
+  }
+  StoreBase128(table.src_length, offset, dst);
+  if ((table.flags & kWoff2FlagsTransform) != 0) {
+    StoreBase128(table.transform_length, offset, dst);
+  }
+}
+
+size_t TableEntrySize(const Table& table) {
+  uint8_t flag_byte = KnownTableIndex(table.tag);
+  size_t size = ((flag_byte & 0x3f) != 0x3f) ? 1 : 5;
+  size += Base128Size(table.src_length);
+  if ((table.flags & kWoff2FlagsTransform) != 0) {
+     size += Base128Size(table.transform_length);
+  }
+  return size;
+}
+
+size_t ComputeWoff2Length(const FontCollection& font_collection,
+                          const std::vector<Table>& tables,
+                          std::map<std::pair<uint32_t, uint32_t>, uint16_t>
+                            index_by_tag_offset,
+                          size_t compressed_data_length,
+                          size_t extended_metadata_length) {
+  size_t size = kWoff2HeaderSize;
+
+  for (const auto& table : tables) {
+    size += TableEntrySize(table);
+  }
+
+  // for collections only, collection tables
+  if (font_collection.flavor == kTtcFontFlavor) {
+    size += 4;  // UInt32 Version of TTC Header
+    size += Size255UShort(font_collection.fonts.size());  // 255UInt16 numFonts
+
+    size += 4 * font_collection.fonts.size();  // UInt32 flavor for each
+
+    for (const auto& font : font_collection.fonts) {
+      size += Size255UShort(font.tables.size());  // 255UInt16 numTables
+      for (const auto& entry : font.tables) {
+        const Font::Table& table = entry.second;
+        // no collection entry for xform table
+        if (table.tag & 0x80808080) continue;
+
+        std::pair<uint32_t, uint32_t> tag_offset(table.tag, table.offset);
+        uint16_t table_index = index_by_tag_offset[tag_offset];
+        size += Size255UShort(table_index);  // 255UInt16 index entry
+      }
+    }
+  }
+
+  // compressed data
+  size += compressed_data_length;
+  size = Round4(size);
+
+  size += extended_metadata_length;
+  return size;
+}
+
+size_t ComputeUncompressedLength(const Font& font) {
+  // sfnt header + offset table
+  size_t size = 12 + 16 * font.num_tables;
+  for (const auto& entry : font.tables) {
+    const Font::Table& table = entry.second;
+    if (table.tag & 0x80808080) continue;  // xform tables don't stay
+    if (table.IsReused()) continue;  // don't have to pay twice
+    size += Round4(table.length);
+  }
+  return size;
+}
+
+size_t ComputeUncompressedLength(const FontCollection& font_collection) {
+  if (font_collection.flavor != kTtcFontFlavor) {
+    return ComputeUncompressedLength(font_collection.fonts[0]);
+  }
+  size_t size = CollectionHeaderSize(font_collection.header_version,
+    font_collection.fonts.size());
+  for (const auto& font : font_collection.fonts) {
+    size += ComputeUncompressedLength(font);
+  }
+  return size;
+}
+
+size_t ComputeTotalTransformLength(const Font& font) {
+  size_t total = 0;
+  for (const auto& i : font.tables) {
+    const Font::Table& table = i.second;
+    if (table.IsReused()) {
+      continue;
+    }
+    if (table.tag & 0x80808080 || !font.FindTable(table.tag ^ 0x80808080)) {
+      // Count transformed tables and non-transformed tables that do not have
+      // transformed versions.
+      total += table.length;
+    }
+  }
+  return total;
+}
+
+}  // namespace
+
+size_t MaxWOFF2CompressedSize(const uint8_t* data, size_t length) {
+  return MaxWOFF2CompressedSize(data, length, "");
+}
+
+size_t MaxWOFF2CompressedSize(const uint8_t* data, size_t length,
+                              const std::string& extended_metadata) {
+  // Except for the header size, which is 32 bytes larger in woff2 format,
+  // all other parts should be smaller (table header in short format,
+  // transformations and compression). Just to be sure, we will give some
+  // headroom anyway.
+  return length + 1024 + extended_metadata.length();
+}
+
+uint32_t CompressedBufferSize(uint32_t original_size) {
+  return 1.2 * original_size + 10240;
+}
+
+bool TransformFontCollection(FontCollection* font_collection) {
+  for (auto& font : font_collection->fonts) {
+    if (!TransformGlyfAndLocaTables(&font)) {
+#ifdef FONT_COMPRESSION_BIN
+      fprintf(stderr, "glyf/loca transformation failed.\n");
+#endif
+      return FONT_COMPRESSION_FAILURE();
+    }
+  }
+
+  return true;
+}
+
+bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
+                       uint8_t *result, size_t *result_length) {
+  WOFF2Params params;
+  return ConvertTTFToWOFF2(data, length, result, result_length,
+                           params);
+}
+
+bool ConvertTTFToWOFF2(const uint8_t *data, size_t length,
+                       uint8_t *result, size_t *result_length,
+                       const WOFF2Params& params) {
+  FontCollection font_collection;
+  if (!ReadFontCollection(data, length, &font_collection)) {
+#ifdef FONT_COMPRESSION_BIN
+    fprintf(stderr, "Parsing of the input font failed.\n");
+#endif
+    return FONT_COMPRESSION_FAILURE();
+  }
+
+  if (!NormalizeFontCollection(&font_collection)) {
+    return FONT_COMPRESSION_FAILURE();
+  }
+
+  if (params.allow_transforms && !TransformFontCollection(&font_collection)) {
+    return FONT_COMPRESSION_FAILURE();
+  } else {
+    // glyf/loca use 11 to flag "not transformed"
+    for (auto& font : font_collection.fonts) {
+      Font::Table* glyf_table = font.FindTable(kGlyfTableTag);
+      Font::Table* loca_table = font.FindTable(kLocaTableTag);
+      if (glyf_table) {
+        glyf_table->flag_byte |= 0xc0;
+      }
+      if (loca_table) {
+        loca_table->flag_byte |= 0xc0;
+      }
+    }
+  }
+
+  // Although the compressed size of each table in the final woff2 file won't
+  // be larger than its transform_length, we have to allocate a large enough
+  // buffer for the compressor, since the compressor can potentially increase
+  // the size. If the compressor overflows this, it should return false and
+  // then this function will also return false.
+
+  size_t total_transform_length = 0;
+  for (const auto& font : font_collection.fonts) {
+    total_transform_length += ComputeTotalTransformLength(font);
+  }
+  size_t compression_buffer_size = CompressedBufferSize(total_transform_length);
+  std::vector<uint8_t> compression_buf(compression_buffer_size);
+  uint32_t total_compressed_length = compression_buffer_size;
+
+  // Collect all transformed data into one place in output order.
+  std::vector<uint8_t> transform_buf(total_transform_length);
+  size_t transform_offset = 0;
+  for (const auto& font : font_collection.fonts) {
+    for (const auto tag : font.OutputOrderedTags()) {
+      const Font::Table& original = font.tables.at(tag);
+      if (original.IsReused()) continue;
+      if (tag & 0x80808080) continue;
+      const Font::Table* table_to_store = font.FindTable(tag ^ 0x80808080);
+      if (table_to_store == NULL) table_to_store = &original;
+
+      StoreBytes(table_to_store->data, table_to_store->length,
+                 &transform_offset, &transform_buf[0]);
+    }
+  }
+
+  // Compress all transformed data in one stream.
+  if (!Woff2Compress(transform_buf.data(), total_transform_length,
+                     &compression_buf[0],
+                     &total_compressed_length,
+                     params.brotli_quality)) {
+#ifdef FONT_COMPRESSION_BIN
+    fprintf(stderr, "Compression of combined table failed.\n");
+#endif
+    return FONT_COMPRESSION_FAILURE();
+  }
+
+#ifdef FONT_COMPRESSION_BIN
+  fprintf(stderr, "Compressed %zu to %u.\n", total_transform_length,
+          total_compressed_length);
+#endif
+
+  // Compress the extended metadata
+  // TODO(user): how does this apply to collections
+  uint32_t compressed_metadata_buf_length =
+    CompressedBufferSize(params.extended_metadata.length());
+  std::vector<uint8_t> compressed_metadata_buf(compressed_metadata_buf_length);
+
+  if (params.extended_metadata.length() > 0) {
+    if (!TextCompress((const uint8_t*)params.extended_metadata.data(),
+                      params.extended_metadata.length(),
+                      compressed_metadata_buf.data(),
+                      &compressed_metadata_buf_length,
+                      params.brotli_quality)) {
+#ifdef FONT_COMPRESSION_BIN
+      fprintf(stderr, "Compression of extended metadata failed.\n");
+#endif
+      return FONT_COMPRESSION_FAILURE();
+    }
+  } else {
+    compressed_metadata_buf_length = 0;
+  }
+
+  std::vector<Table> tables;
+  std::map<std::pair<uint32_t, uint32_t>, uint16_t> index_by_tag_offset;
+
+  for (const auto& font : font_collection.fonts) {
+
+    for (const auto tag : font.OutputOrderedTags()) {
+      const Font::Table& src_table = font.tables.at(tag);
+      if (src_table.IsReused()) {
+        continue;
+      }
+
+      std::pair<uint32_t, uint32_t> tag_offset(src_table.tag, src_table.offset);
+      if (index_by_tag_offset.find(tag_offset) == index_by_tag_offset.end()) {
+        index_by_tag_offset[tag_offset] = tables.size();
+      } else {
+        return false;
+      }
+
+      Table table;
+      table.tag = src_table.tag;
+      table.flags = src_table.flag_byte;
+      table.src_length = src_table.length;
+      table.transform_length = src_table.length;
+      const uint8_t* transformed_data = src_table.data;
+      const Font::Table* transformed_table =
+          font.FindTable(src_table.tag ^ 0x80808080);
+      if (transformed_table != NULL) {
+        table.flags = transformed_table->flag_byte;
+        table.flags |= kWoff2FlagsTransform;
+        table.transform_length = transformed_table->length;
+        transformed_data = transformed_table->data;
+
+      }
+      tables.push_back(table);
+    }
+  }
+
+  size_t woff2_length = ComputeWoff2Length(font_collection, tables,
+      index_by_tag_offset, total_compressed_length,
+      compressed_metadata_buf_length);
+  if (woff2_length > *result_length) {
+#ifdef FONT_COMPRESSION_BIN
+    fprintf(stderr, "Result allocation was too small (%zd vs %zd bytes).\n",
+           *result_length, woff2_length);
+#endif
+    return FONT_COMPRESSION_FAILURE();
+  }
+  *result_length = woff2_length;
+
+  size_t offset = 0;
+
+  // start of woff2 header (http://www.w3.org/TR/WOFF2/#woff20Header)
+  StoreU32(kWoff2Signature, &offset, result);
+  if (font_collection.flavor != kTtcFontFlavor) {
+    StoreU32(font_collection.fonts[0].flavor, &offset, result);
+  } else {
+    StoreU32(kTtcFontFlavor, &offset, result);
+  }
+  StoreU32(woff2_length, &offset, result);
+  Store16(tables.size(), &offset, result);
+  Store16(0, &offset, result);  // reserved
+  // totalSfntSize
+  StoreU32(ComputeUncompressedLength(font_collection), &offset, result);
+  StoreU32(total_compressed_length, &offset, result);  // totalCompressedSize
+
+  // Let's just all be v1.0
+  Store16(1, &offset, result);  // majorVersion
+  Store16(0, &offset, result);  // minorVersion
+  if (compressed_metadata_buf_length > 0) {
+    StoreU32(woff2_length - compressed_metadata_buf_length,
+             &offset, result);  // metaOffset
+    StoreU32(compressed_metadata_buf_length, &offset, result);  // metaLength
+    StoreU32(params.extended_metadata.length(),
+             &offset, result);  // metaOrigLength
+  } else {
+    StoreU32(0, &offset, result);  // metaOffset
+    StoreU32(0, &offset, result);  // metaLength
+    StoreU32(0, &offset, result);  // metaOrigLength
+  }
+  StoreU32(0, &offset, result);  // privOffset
+  StoreU32(0, &offset, result);  // privLength
+  // end of woff2 header
+
+  // table directory (http://www.w3.org/TR/WOFF2/#table_dir_format)
+  for (const auto& table : tables) {
+    StoreTableEntry(table, &offset, result);
+  }
+
+  // for collections only, collection table directory
+  if (font_collection.flavor == kTtcFontFlavor) {
+    StoreU32(font_collection.header_version, &offset, result);
+    Store255UShort(font_collection.fonts.size(), &offset, result);
+    for (const Font& font : font_collection.fonts) {
+
+      uint16_t num_tables = 0;
+      for (const auto& entry : font.tables) {
+        const Font::Table& table = entry.second;
+        if (table.tag & 0x80808080) continue;  // don't write xform tables
+        num_tables++;
+      }
+      Store255UShort(num_tables, &offset, result);
+
+      StoreU32(font.flavor, &offset, result);
+      for (const auto& entry : font.tables) {
+        const Font::Table& table = entry.second;
+        if (table.tag & 0x80808080) continue;  // don't write xform tables
+
+        // for reused tables, only the original has an updated offset
+        uint32_t table_offset =
+          table.IsReused() ? table.reuse_of->offset : table.offset;
+        uint32_t table_length =
+          table.IsReused() ? table.reuse_of->length : table.length;
+        std::pair<uint32_t, uint32_t> tag_offset(table.tag, table_offset);
+        if (index_by_tag_offset.find(tag_offset) == index_by_tag_offset.end()) {
+#ifdef FONT_COMPRESSION_BIN
+fprintf(stderr, "Missing table index for offset 0x%08x\n",
+                  table_offset);
+#endif
+          return FONT_COMPRESSION_FAILURE();
+        }
+        uint16_t index = index_by_tag_offset[tag_offset];
+        Store255UShort(index, &offset, result);
+
+      }
+
+    }
+  }
+
+  // compressed data format (http://www.w3.org/TR/WOFF2/#table_format)
+
+  StoreBytes(&compression_buf[0], total_compressed_length, &offset, result);
+  offset = Round4(offset);
+
+  StoreBytes(compressed_metadata_buf.data(), compressed_metadata_buf_length,
+             &offset, result);
+
+  if (*result_length != offset) {
+#ifdef FONT_COMPRESSION_BIN
+    fprintf(stderr, "Mismatch between computed and actual length "
+            "(%zd vs %zd)\n", *result_length, offset);
+#endif
+    return FONT_COMPRESSION_FAILURE();
+  }
+  return true;
+}
+
+} // namespace woff2