Method encode

arch/c64/encoder.cc:158–204

public:
    std::unique_ptr<Fluxmap> encode(const LogicalTrackLayout& ltl,
        const std::vector<std::shared_ptr<const Sector>>& sectors,
        const Image& image) override
    {
        /* The format ID Character # 1 and # 2 are in the .d64 image only
         * present in track 18 sector zero which contains the BAM info in byte
         * 162 and 163. it is written in every header of every sector and track.
         * headers are not stored in a d64 disk image so we have to get it from
         * track 18 which contains the BAM.
         */

        const auto& sectorData = image.get(
            C64_BAM_TRACK, 0, 0); // Read de BAM to get the DISK ID bytes
        if (sectorData)
        {
            ByteReader br(sectorData->data);
            br.seek(162); // goto position of the first Disk ID Byte
            _formatByte1 = br.read_8();
            _formatByte2 = br.read_8();
        }
        else
            _formatByte1 = _formatByte2 = 0;

        double clockRateUs = clockPeriodForC64Track(ltl.logicalCylinder);
        int bitsPerRevolution = 200000.0 / clockRateUs;

        std::vector<bool> bits(bitsPerRevolution);
        unsigned cursor = 0;

        fillBitmapTo(bits,
            cursor,
            _config.post_index_gap_us() / clockRateUs,
            {true, false});
        lastBit = false;

        for (const auto& sector : sectors)
            writeSector(bits, cursor, sector);

        if (cursor >= bits.size())
            error("track data overrun by {} bits", cursor - bits.size());
        fillBitmapTo(bits, cursor, bits.size(), {true, false});

        std::unique_ptr<Fluxmap> fluxmap(new Fluxmap);
        fluxmap->appendBits(
            bits, calculatePhysicalClockPeriod(clockRateUs * 1e3, 200e6));
        return fluxmap;
    }

private:
    void writeSector(std::vector<bool>& bits,