Add woff2 to src/third_party

third_party/woff2/src/font.h

+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Data model for a font file in sfnt format, reading and writing functions and
+// accessors for the glyph data.
+
+#ifndef WOFF2_FONT_H_
+#define WOFF2_FONT_H_
+
+#include <stddef.h>
+#include <inttypes.h>
+#include <map>
+#include <vector>
+
+namespace woff2 {
+
+// Represents an sfnt font file. Only the table directory is parsed, for the
+// table data we only store a raw pointer, therefore a font object is valid only
+// as long the data from which it was parsed is around.
+struct Font {
+  uint32_t flavor;
+  uint16_t num_tables;
+
+  struct Table {
+    uint32_t tag;
+    uint32_t checksum;
+    uint32_t offset;
+    uint32_t length;
+    const uint8_t* data;
+
+    // Buffer used to mutate the data before writing out.
+    std::vector<uint8_t> buffer;
+  };
+  std::map<uint32_t, Table> tables;
+
+  Table* FindTable(uint32_t tag);
+  const Table* FindTable(uint32_t tag) const;
+};
+
+// Parses the font from the given data. Returns false on parsing failure or
+// buffer overflow. The font is valid only so long the input data pointer is
+// valid.
+bool ReadFont(const uint8_t* data, size_t len, Font* font);
+
+// Returns the file size of the font.
+size_t FontFileSize(const Font& font);
+
+// Writes the font into the specified dst buffer. The dst_size should be the
+// same as returned by FontFileSize(). Returns false upon buffer overflow (which
+// should not happen if dst_size was computed by FontFileSize()).
+bool WriteFont(const Font& font, uint8_t* dst, size_t dst_size);
+
+// Returns the number of glyphs in the font.
+// NOTE: Currently this works only for TrueType-flavored fonts, will return
+// zero for CFF-flavored fonts.
+int NumGlyphs(const Font& font);
+
+// Returns the index format of the font
+int IndexFormat(const Font& font);
+
+// Sets *glyph_data and *glyph_size to point to the location of the glyph data
+// with the given index. Returns false if the glyph is not found.
+bool GetGlyphData(const Font& font, int glyph_index,
+                  const uint8_t** glyph_data, size_t* glyph_size);
+
+// Removes the digital signature (DSIG) table
+bool RemoveDigitalSignature(Font* font);
+
+} // namespace woff2
+
+#endif  // WOFF2_FONT_H_