public static ushort GetFirstProperty(this ZMachine aMachine, ushort aObject)
{
ushort xObjectAddress = aMachine.GetObjectAddress(aObject);
aMachine.Memory.GetWord(xObjectAddress + 7, out ushort propTable);
aMachine.Memory.GetByte(propTable, out byte nameSize);
propTable += (ushort)(2 * nameSize + 1);
return(propTable);
}
public static string GetObjectName(this ZMachine aMachine, ushort aObject)
{
ushort objAddress = aMachine.GetObjectAddress(aObject);
if (aMachine.Story.Header.Version <= FileVersion.V3)
{
objAddress += O1_PROPERTY_OFFSET;
}
else
{
objAddress += O4_PROPERTY_OFFSET;
}
aMachine.Memory.GetWord(objAddress, out ushort nameAddress);
return(ZText.DecodeString((ushort)(nameAddress + 1)));
}
public static void UnlinkObject(this ZMachine aMachine, ushort aObject)
{
if (aObject == 0)
{
return;
}
ushort xObjectAddress = aMachine.GetObjectAddress(aObject);
if (aMachine.Story.Header.Version <= FileVersion.V3)
{
byte zero = 0;
xObjectAddress += O1_PARENT;
aMachine.Memory.GetByte(xObjectAddress, out byte xParentObject);
if (xParentObject == 0)
{
return;
}
aMachine.Memory.SetByte(xObjectAddress, zero);
xObjectAddress += O1_SIBLING - O1_PARENT;
aMachine.Memory.GetByte(xObjectAddress, out byte xOlderSibling);
aMachine.Memory.SetByte(xObjectAddress, zero);
ushort xParentAddress = (ushort)(aMachine.GetObjectAddress(xParentObject) + O1_CHILD);
aMachine.Memory.GetByte(xParentAddress, out byte xYoungerSibling);
if (xYoungerSibling == aObject)
{
aMachine.Memory.SetByte(xParentAddress, xOlderSibling);
}
else
{
ushort xSiblingAddress;
do
{
xSiblingAddress = (ushort)(aMachine.GetObjectAddress(xYoungerSibling) + O1_SIBLING);
aMachine.Memory.GetByte(xSiblingAddress, out xYoungerSibling);
} while (xYoungerSibling != aObject);
aMachine.Memory.SetByte(xSiblingAddress, xOlderSibling);
}
}
else
{
ushort zero = 0;
xObjectAddress += O4_PARENT;
aMachine.Memory.GetWord(xObjectAddress, out ushort xParentObject);
if (xParentObject == 0)
{
return;
}
aMachine.Memory.SetWord(xObjectAddress, zero);
xObjectAddress += O4_SIBLING - O4_PARENT;
aMachine.Memory.GetWord(xObjectAddress, out ushort xOlderSibling);
aMachine.Memory.SetWord(xObjectAddress, zero);
ushort xParentAddress = (ushort)(aMachine.GetObjectAddress(xParentObject) + O4_CHILD);
aMachine.Memory.GetWord(xParentAddress, out ushort xYoungerSibling);
if (xYoungerSibling == aObject)
{
aMachine.Memory.SetWord(xParentAddress, xOlderSibling);
}
else
{
ushort xSiblingAddress;
do
{
xSiblingAddress = (ushort)(aMachine.GetObjectAddress(xYoungerSibling) + O4_SIBLING);
aMachine.Memory.GetWord(xYoungerSibling, out xYoungerSibling);
} while (xYoungerSibling != aObject);
aMachine.Memory.SetWord(xSiblingAddress, xOlderSibling);
}
}
}