ladybird/Userland/Libraries/LibPDF/Fonts/CFF.h

/*
 * Copyright (c) 2023, Rodrigo Tobar <rtobarc@gmail.com>.
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Tuple.h>
#include <AK/Types.h>
#include <LibPDF/Error.h>
#include <LibPDF/Fonts/Type1FontProgram.h>

namespace PDF {

class Reader;

class CFF : public Type1FontProgram {

private:
    // Table 9: Top DICT Operator Entries
    enum class TopDictOperator {
        Version = 0,
        Notice,
        FullName,
        FamilyName,
        Weight,
        FontBBox,
        // UniqueID = 13,
        // XUID,
        Charset = 15,
        Encoding,
        CharStrings,
        Private,
        // IsFixedPitch = (12 << 8 | 1),
        // ItalicAngle,
        // UnderlinePosition,
        // UnderlineThickness,
        // PaintType,
    };

    enum class PrivDictOperator {
        Subrs = 19,
        DefaultWidthX,
        NominalWidthX,
    };

public:
    static PDFErrorOr<NonnullRefPtr<CFF>> create(ReadonlyBytes const&, RefPtr<Encoding> encoding);

    // to private
    using Card8 = u8;
    using Card16 = u16;
    using Offset = i32;
    using OffSize = u8;
    using SID = u16;
    using DictOperand = Variant<int, float>;

    static int load_int_dict_operand(u8 b0, Reader&);
    static float load_float_dict_operand(Reader&);
    static PDFErrorOr<DictOperand> load_dict_operand(u8, Reader&);

    using IndexDataHandler = Function<PDFErrorOr<void>(ReadonlyBytes const&)>;
    static PDFErrorOr<void> parse_index(Reader& reader, IndexDataHandler&&);

    template<typename OffsetType>
    static PDFErrorOr<void> parse_index_data(Card16 count, Reader& reader, IndexDataHandler&);

    template<typename OperatorT>
    using DictEntryHandler = Function<PDFErrorOr<void>(OperatorT, Vector<DictOperand> const&)>;

    template<typename OperatorT>
    static PDFErrorOr<void> parse_dict(Reader& reader, DictEntryHandler<OperatorT>&& handler);

    template<typename OperatorT>
    static PDFErrorOr<OperatorT> parse_dict_operator(u8, Reader&);

    static PDFErrorOr<Vector<CFF::Glyph>> parse_charstrings(Reader&&, Vector<ByteBuffer> const& subroutines);

    static PDFErrorOr<Vector<DeprecatedFlyString>> parse_charset(Reader&&, size_t);
    static PDFErrorOr<Vector<u8>> parse_encoding(Reader&&);
};

}