zfunctions

byte[] ROM_DATA;
List<byte> dataBuffer = new List<byte>();
public void Decompress(int apos)
{
    int pos = 0x08B800;
    bool done = false;

    while (done == false)
    {
        bool expand = false;
        byte b = ROM_DATA[pos];

        Console.WriteLine(b + " : " +((b >> 5) & 0x07));
        if (b == 0xFF)
        {
            done = true;
        }

        if (((b >> 5) & 0x07) == 7) //expanded command
        {
            expand = true;
        }
        byte cmd = 0;
        short length = 0;
        if (expand)
        {
            cmd = (byte)((b >> 2) & 0x07);
            length = BitConverter.ToInt16(new byte[] { (ROM_DATA[pos + 1]), (byte)(b & 0x03) }, 0);
            pos += 2;
        }
        else
        {
            cmd = (byte)((b >> 5) & 0x07);
            length = (byte)(b & 0x1F);
            pos += 1;
        }
        length += 1;
        if (cmd == 0)//000 Direct Copy Followed by (L+1) bytes of data
        {
            for(int i = 0;i<length;i++)
            {
                dataBuffer.Add(ROM_DATA[pos]);
                pos++;
            }
        }

        if (cmd == 1)//001 "Byte Fill" Followed by one byte to be repeated (L + 1) times
        {
            byte copiedByte = ROM_DATA[pos];
            pos++;
            for (int i = 0; i < length; i++)
            {
                dataBuffer.Add(copiedByte);
            }
            //pos++;
        }

        if (cmd == 2)//010    "Word Fill" Followed by two bytes. Output first byte, then second, then first,then second, etc. until (L+1) bytes has been outputted
        {
            byte copiedByte = ROM_DATA[pos];
            byte copiedByte2 = ROM_DATA[pos+1];
            pos += 2;
            int j = 0;
            for (int i = 0; i < length; i++)
            {
                if (j == 0)
                {
                    dataBuffer.Add(copiedByte);
                    j = 1;
                }
                else
                {
                    dataBuffer.Add(copiedByte2);
                    j = 0;
                }
            }
        }

        if (cmd == 3)//"Increasing Fill" Followed by one byte to be repeated (L + 1) times, but the byte is increased by 1 after each write
        {
            byte copiedByte = ROM_DATA[pos];
            pos += 1;
            for (int i = 0; i < length ; i++)
            {
                dataBuffer.Add((byte)(copiedByte +i));
            }
        }

        if (cmd == 4)//"Repeat" Followed by two bytes (ABCD byte order) containing address (in the output buffer) to copy (L + 1) bytes from
        {
            byte copiedByte = ROM_DATA[pos];
            byte copiedByte2 = ROM_DATA[pos+1];
            int pos2 = BitConverter.ToInt16(new byte[] { copiedByte, copiedByte2 }, 0);
            pos += 2;
            for (int i = 0; i < length; i++)
            {
                dataBuffer.Add(dataBuffer[pos2]);
                pos2++;
            }
        }
    }
    FileStream fs = new FileStream("gfx.bin", FileMode.OpenOrCreate, FileAccess.Write);
    fs.Write(dataBuffer.ToArray(), 0, dataBuffer.Count);
    fs.Close();
}





//Convert Snes Address in PC Address - Mirrored Format
public int snestopc(int addr)
{
    int temp = (addr & 0x7FFF) + ((addr / 2) & 0xFF8000);
    return (temp);
}



//Convert PC Address to Snes Address
public int pctosnes(int addr)
{
    byte[] b = BitConverter.GetBytes(addr);
    b[2] = (byte)(b[2] * 2);
    if (b[1] >= 0x80)
        b[2] += 1;
    else
        b[1] += 0x80;

    return BitConverter.ToInt32(b, 0);
}