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/* Copyright 2013 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* 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;
// If we've seen this tag/offset before, pointer to the first time we saw it
// If this is the first time we've seen this table, NULL
// Intended use is to bypass re-processing tables
Font::Table* reuse_of;
uint8_t flag_byte;
// Is this table reused by a TTC
bool IsReused() const;
};
std::map<uint32_t, Table> tables;
std::vector<uint32_t> OutputOrderedTags() const;
Table* FindTable(uint32_t tag);
const Table* FindTable(uint32_t tag) const;
};
// Accomodates both singular (OTF, TTF) and collection (TTC) fonts
struct FontCollection {
uint32_t flavor;
uint32_t header_version;
// (offset, first use of table*) pairs
std::map<uint32_t, Font::Table*> tables;
std::vector<Font> fonts;
};
// 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. Does NOT support collections.
bool ReadFont(const uint8_t* data, size_t len, Font* font);
// 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. Supports collections.
bool ReadFontCollection(const uint8_t* data, size_t len, FontCollection* fonts);
// Returns the file size of the font.
size_t FontFileSize(const Font& font);
size_t FontCollectionFileSize(const FontCollection& 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);
// Write the font at a specific offset
bool WriteFont(const Font& font, size_t* offset, uint8_t* dst, size_t dst_size);
bool WriteFontCollection(const FontCollection& font_collection, 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_
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