Method readImage

lib/imagereader/dimimagereader.cc:22–152

    DimImageReader(const ImageReaderProto& config): ImageReader(config) {}

    std::unique_ptr<Image> readImage() override
    {
        std::ifstream inputFile(
            _config.filename(), std::ios::in | std::ios::binary);
        if (!inputFile.is_open())
            error("cannot open input file");

        Bytes header(256);
        inputFile.read((char*)header.begin(), header.size());
        if (header.slice(0xAB, 13) != Bytes("DIFC HEADER  "))
            error("DIM: could not find DIM header, is this a DIM file?");

        // the DIM header technically has a bit field for sectors present,
        // however it is currently ignored by this reader

        char mediaByte = header[0];
        int tracks;
        int sectorsPerTrack;
        int sectorSize;
        switch (mediaByte)
        {
            case 0:
                tracks = 77;
                sectorsPerTrack = 8;
                sectorSize = 1024;
                break;
            case 1:
                tracks = 80;
                sectorsPerTrack = 9;
                sectorSize = 1024;
                break;
            case 2:
                tracks = 80;
                sectorsPerTrack = 15;
                sectorSize = 512;
                break;
            case 3:
                tracks = 80;
                sectorsPerTrack = 18;
                sectorSize = 512;
                break;
            default:
                error("DIM: unsupported media byte");
                break;
        }

        std::unique_ptr<Image> image(new Image);
        int trackCount = 0;
        for (int track = 0; track < tracks; track++)
        {
            if (inputFile.eof())
                break;

            for (int side = 0; side < 2; side++)
            {
                std::vector<unsigned> sectors;
                for (int i = 0; i < sectorsPerTrack; i++)
                    sectors.push_back(i + 1);