BM.ParseBitmap C# (CSharp) Method

    private void ParseBitmap(ByteStream stream, CreateArgs createArgs)
    {
        if ((stream.ReadString(3) != "BM ") || (stream.ReadByte() != 0x1e)){
            throw new InvalidDataException("Not a BM file.");
        }

        Header header = ReadHeader(stream, EHeaderType.FileHeader);
        DebugCheck.Assert(stream.Position == 32);

        if ((header.W == 1) && (header.H != 1)) {
            // multiple bitmaps in this file.
            _fps = stream.ReadByte();
            stream.Skip(1);

            long baseOfs = stream.Position;

            int[] offsets = new int[header.IY];
            for (int i = 0; i < offsets.Length; ++i) {
                offsets[i] = stream.ReadLittleInt32();
            }

            for (int i = 0; i < offsets.Length; ++i) {
                stream.SeekSet(offsets[i] + baseOfs);
                Header subHeader = ReadHeader(stream, EHeaderType.SubHeader);
                Frame frame = ReadColumns(stream, subHeader, null, createArgs);
                _frames.Add(frame);
            }
        } else {
            int[] columnOffsets = null;

            if (header.Compressed != 0) {
                // read column offsets.
                stream.SeekSet(header.DataSize);
                columnOffsets = new int[header.W];

                for (int i = 0; i < columnOffsets.Length; ++i) {
                    columnOffsets[i] = stream.ReadLittleInt32() + 32;
                }
            }

            Frame frame = ReadColumns(stream, header, columnOffsets, createArgs);
            _frames.Add(frame);
        }
    }