private int stackPtr; //Pointer to next address to write to
#endregion Fields
#region Constructors
/// <summary>
/// Creates a new z processor
/// </summary>
/// <param name="buf">memory buffer</param>
/// <param name="ui">interface with the rest of the world</param>
protected ZProcessor(MemoryBuffer buf, IUserInterface ui)
{
//Validate params
if (buf == null)
{
throw new ArgumentNullException("buf");
}
else if (ui == null)
{
throw new ArgumentNullException("ui");
}
//Cache global vars offset
globalVarsOffset = buf.GetUShort(0xC) - 0x10;
//Globals vars must be higher than the header (security)
if (globalVarsOffset + 0x10 < 64)
{
throw new ZMachineException("global variables table must not reside in the header");
}
//Set dynamic limit
buf.DynamicLimit = Math.Min((int) buf.GetUShort(0xE), 64);
//Store memory buffer and ui
memBuf = buf;
zUi = ui;
//Create encoder and object tree
zEncoder = new ZTextEncoder(buf);
objectTree = new ZObjectTree(buf);
}
/// <summary>
/// Creates a new version 1 z processor
/// </summary>
/// <param name="buf">memory buffer</param>
/// <param name="ui">interface with the rest of the world</param>
public MachineV1(MemoryBuffer buf, IUserInterface ui)
: base(buf, ui)
{
InstructionFunc[] ops;
//2OP instructions
ops = Instructions2OP;
ops[0x1] = Je;
ops[0x2] = Jl;
ops[0x3] = Jg;
ops[0x4] = DecChk;
ops[0x5] = IncChk;
ops[0x6] = Jin;
ops[0x7] = Test;
ops[0x8] = Or;
ops[0x9] = And;
ops[0xA] = TestAttr;
ops[0xB] = SetAttr;
ops[0xC] = ClearAttr;
ops[0xD] = Store;
ops[0xE] = InsertObj;
ops[0xF] = LoadW;
ops[0x10] = LoadB;
ops[0x11] = GetProp;
ops[0x12] = GetPropAddr;
ops[0x13] = GetNextProp;
ops[0x14] = Add;
ops[0x15] = Sub;
ops[0x16] = Mul;
ops[0x17] = Div;
ops[0x18] = Mod;
//1OP Instructions
ops = Instructions1OP;
ops[0x0] = Jz;
ops[0x1] = GetSibling;
ops[0x2] = GetChild;
ops[0x3] = GetParent;
ops[0x4] = GetPropLen;
ops[0x5] = Inc;
ops[0x6] = Dec;
ops[0x7] = PrintAddr;
ops[0x9] = RemoveObj;
ops[0xA] = PrintObj;
ops[0xB] = Ret;
ops[0xC] = Jump;
ops[0xD] = PrintPAddr;
ops[0xE] = Load;
ops[0xF] = Not;
//0OP Instructions
ops = Instructions0OP;
ops[0x0] = RTrue;
ops[0x1] = RFalse;
ops[0x2] = Print;
ops[0x3] = PrintRet;
ops[0x4] = Nop;
ops[0x5] = Save;
ops[0x6] = Restore;
ops[0x7] = Restart;
ops[0x8] = RetPopped;
ops[0x9] = Pop;
ops[0xA] = Quit;
ops[0xB] = NewLine;
//VAR Instructions
ops = InstructionsVAR;
ops[0x0] = GenericCall;
ops[0x0] = StoreW;
ops[0x0] = StoreB;
ops[0x0] = PutProp;
ops[0x0] = Read;
ops[0x0] = PrintChar;
ops[0x0] = PrintNum;
ops[0x0] = RandomFunc;
ops[0x0] = Push;
ops[0x0] = Pull;
}
/// <summary>
/// Creates a new z machine character encoder
/// </summary>
/// <param name="buf">game memory buffer</param>
public ZTextEncoder(MemoryBuffer buf)
{
//Store buffer
this.buf = buf;
//Get version
this.machineVersion = buf.GetByte(0);
//Find unicode table address
int unicodeTable = 0;
if (machineVersion >= 5)
{
//Search the extension header table
ushort extensionHdr = buf.GetUShort(0x36);
if (extensionHdr != 0 && buf.GetUShort(extensionHdr) >= 3)
{
unicodeTable = buf.GetUShort(extensionHdr + 6);
}
}
//Create unicode cache
this.unicodeCache = CreateUnicodeCache(unicodeTable);
//Create reverse cache
// Go in reverse so that ASCII takes priority over custom unicode
for(int i = 255; i > 0; i--)
{
//Add character
if (unicodeCache[i] != InvalidChar)
{
reverseUnicodeCache[unicodeCache[i]] = (byte) i;
}
}
//Create alphabet cache
if (machineVersion >= 5 && buf.GetUShort(0x34) != 0)
{
this.alphabetCache = CreateAlphabetCache(buf.GetUShort(0x34));
}
else
{
//Use default alphabet
this.alphabetCache = machineVersion == 1 ? DEFAULT_ALPHABET_TABLE_V1 : DEFAULT_ALPHABET_TABLE;
}
//Create reverse alphabet cache
for (int i = 0; i < 78; i++)
{
reverseAlphabetCache[reverseUnicodeCache[alphabetCache[i]]] = (byte) (i + 1);
}
//Create abbreviation cache
if (machineVersion >= 2 && buf.GetUShort(0x18) != 0)
{
this.abbreviationCache = CreateAbbreviationCache(buf.GetUShort(0x18));
}
//Cache dictionary information
mainDictionaryAddress = buf.GetUShort(0x8);
mainDictionary = GetDictionaryInfo(mainDictionaryAddress);
}