/*
* memory_open
*
* Begin output redirection to the memory of the Z-machine.
*
*/
internal static void MemoryOpen(zword table, zword xsize, bool buffering)
{
if (++depth < MAX_NESTING)
{
if (!buffering)
{
xsize = 0xffff;
}
if (buffering && (short)xsize <= 0)
{
xsize = Screen.GetMaxWidth((zword)(-(short)xsize));
}
FastMem.StoreW(table, 0);
redirect[depth].Table = table;
redirect[depth].Width = 0;
redirect[depth].Total = 0;
redirect[depth].XSize = xsize;
Main.ostream_memory = true;
}
else
{
Err.RuntimeError(ErrorCodes.ERR_STR3_NESTING);
}
}/* memory_open */
}/* z_get_sibling */
/*
* z_insert_obj, make an object the first child of another object.
*
* Process.zargs[0] = object to be moved
* Process.zargs[1] = destination object
*
*/
internal static void ZInsertObj()
{
zword obj1 = Process.zargs[0];
zword obj2 = Process.zargs[1];
zword obj1_addr;
zword obj2_addr;
/* If we are monitoring object movements display a short note */
if (Main.option_object_movement == true)
{
Stream.StreamMssgOn();
Text.PrintString("@move_obj ");
Text.PrintObject(obj1);
Text.PrintString(" ");
Text.PrintObject(obj2);
Stream.StreamMssgOff();
}
if (obj1 == 0)
{
Err.RuntimeError(ErrorCodes.ERR_MOVE_OBJECT_0);
return;
}
if (obj2 == 0)
{
Err.RuntimeError(ErrorCodes.ERR_MOVE_OBJECT_TO_0);
return;
}
/* Get addresses of both objects */
obj1_addr = ObjectAddress(obj1);
obj2_addr = ObjectAddress(obj2);
/* Remove object 1 from current parent */
UnlinkObject(obj1);
/* Make object 1 first child of object 2 */
if (Main.h_version <= ZMachine.V3)
{
obj1_addr += O1_PARENT;
FastMem.SetByte(obj1_addr, (zbyte)obj2);
obj2_addr += O1_CHILD;
FastMem.LowByte(obj2_addr, out byte child);
FastMem.SetByte(obj2_addr, (zbyte)obj1);
obj1_addr += (zword)(O1_SIBLING - O1_PARENT);
FastMem.SetByte(obj1_addr, child);
}
else
{
obj1_addr += O4_PARENT;
FastMem.SetWord(obj1_addr, obj2);
obj2_addr += O4_CHILD;
FastMem.LowWord(obj2_addr, out ushort child);
FastMem.SetWord(obj2_addr, obj1);
obj1_addr += (zword)(O4_SIBLING - O4_PARENT);
FastMem.SetWord(obj1_addr, child);
}
}/* z_insert_obj */
}/* z_get_parent */
/*
* z_get_prop, store the value of an object property.
*
* Process.zargs[0] = object
* Process.zargs[1] = number of property to be examined
*
*/
internal static void ZGetProp()
{
zword prop_addr;
zword wprop_val;
zbyte value;
zbyte mask;
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_PROP_0);
Process.Store(0);
return;
}
/* Property id is in bottom five (six) bits */
mask = (zbyte)((Main.h_version <= ZMachine.V3) ? 0x1f : 0x3f);
/* Load address of first property */
prop_addr = FirstProperty(Process.zargs[0]);
/* Scan down the property list */
for (; ;)
{
FastMem.LowByte(prop_addr, out value);
if ((value & mask) <= Process.zargs[1])
{
break;
}
prop_addr = NextProperty(prop_addr);
}
if ((value & mask) == Process.zargs[1])
{ /* property found */
/* Load property (byte or word sized) */
prop_addr++;
if ((Main.h_version <= ZMachine.V3 && !((value & 0xe0) > 0)) || (Main.h_version >= ZMachine.V4 && !((value & 0xc0) > 0)))
{
FastMem.LowByte(prop_addr, out zbyte bprop_val);
wprop_val = bprop_val;
}
else
{
FastMem.LowWord(prop_addr, out wprop_val);
}
}
else
{ /* property not found */
/* Load default value */
prop_addr = (zword)(Main.h_objects + 2 * (Process.zargs[1] - 1));
FastMem.LowWord(prop_addr, out wprop_val);
}
/* Store the property value */
Process.Store(wprop_val);
}/* z_get_prop */
}/* z_art_shift */
/*
* z_div, signed 16bit division.
*
* zargs[0] = first value
* zargs[1] = second value
*
*/
internal static void ZDiv()
{
if (Process.zargs[1] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_DIV_ZERO);
}
Process.Store((zword)((short)Process.zargs[0] / (short)Process.zargs[1]));
}/* z_div */
internal static void PrintChar(zword c)
{
if (Main.message || Main.ostream_memory || Main.enable_buffering)
{
if (!PrintCharFlag)
{
/* Characters 0 and ZC_RETURN are special cases */
if (c == CharCodes.ZC_RETURN)
{
NewLine(); return;
}
if (c == 0)
{
return;
}
/* Flush the buffer before a whitespace or after a hyphen */
if ((c is ' ' or CharCodes.ZC_INDENT or CharCodes.ZC_GAP) || (prev_c == '-' && c != '-'))
{
FlushBuffer();
}
/* Set the flag if this is part one of a style or font change */
if (c is CharCodes.ZC_NEW_FONT or CharCodes.ZC_NEW_STYLE)
{
PrintCharFlag = true;
}
/* Remember the current character code */
prev_c = c;
}
else
{
PrintCharFlag = false;
}
/* Insert the character into the buffer */
buffer_var[bufpos++] = c;
if (bufpos == General.TEXT_BUFFER_SIZE)
{
Err.RuntimeError(ErrorCodes.ERR_TEXT_BUF_OVF);
}
}
else
{
Stream.StreamChar(c);
}
}/* print_char */
}/* z_get_prop */
/*
* z_get_prop_addr, store the address of an object property.
*
* Process.zargs[0] = object
* Process.zargs[1] = number of property to be examined
*
*/
internal static void ZGetPropAddr()
{
zword prop_addr;
zbyte value;
zbyte mask;
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_PROP_ADDR_0);
Process.Store(0);
return;
}
if (Main.StoryId == Story.BEYOND_ZORK && Process.zargs[0] > MAX_OBJECT)
{
Process.Store(0);
return;
}
/* Property id is in bottom five (six) bits */
mask = (zbyte)((Main.h_version <= ZMachine.V3) ? 0x1f : 0x3f);
/* Load address of first property */
prop_addr = FirstProperty(Process.zargs[0]);
/* Scan down the property list */
for (; ;)
{
FastMem.LowByte(prop_addr, out value);
if ((value & mask) <= Process.zargs[1])
{
break;
}
prop_addr = NextProperty(prop_addr);
}
/* Calculate the property address or return zero */
if ((value & mask) == Process.zargs[1])
{
if (Main.h_version >= ZMachine.V4 && (value & 0x80) > 0)
{
prop_addr++;
}
Process.Store((zword)(prop_addr + 1));
}
else
{
Process.Store(0);
}
}/* z_get_prop_addr */
}/* z_insert_obj */
/*
* z_put_prop, set the value of an object property.
*
* Process.zargs[0] = object
* Process.zargs[1] = number of property to set
* Process.zargs[2] = value to set property to
*
*/
internal static void ZPutProp()
{
zword prop_addr;
zbyte value;
zbyte mask;
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_PUT_PROP_0);
return;
}
/* Property id is in bottom five or six bits */
mask = (zbyte)((Main.h_version <= ZMachine.V3) ? 0x1f : 0x3f);
/* Load address of first property */
prop_addr = FirstProperty(Process.zargs[0]);
/* Scan down the property list */
for (; ;)
{
FastMem.LowByte(prop_addr, out value);
if ((value & mask) <= Process.zargs[1])
{
break;
}
prop_addr = NextProperty(prop_addr);
}
/* Exit if the property does not exist */
if ((value & mask) != Process.zargs[1])
{
Err.RuntimeError(ErrorCodes.ERR_NO_PROP);
}
/* Store the new property value (byte or word sized) */
prop_addr++;
if ((Main.h_version <= ZMachine.V3 && !((value & 0xe0) > 0)) || (Main.h_version >= ZMachine.V4 && !((value & 0xc0) > 0)))
{
zbyte v = (zbyte)Process.zargs[2];
FastMem.SetByte(prop_addr, v);
}
else
{
zword v = Process.zargs[2];
FastMem.SetWord(prop_addr, v);
}
}/* z_put_prop */
}/* z_remove_obj */
/*
* z_set_attr, set an object attribute.
*
* Process.zargs[0] = object
* Process.zargs[1] = number of attribute to set
*
*/
internal static void ZSetAttr()
{
zword obj_addr;
if (Main.StoryId == Story.SHERLOCK)
{
if (Process.zargs[1] == 48)
{
return;
}
}
if (Process.zargs[1] > ((Main.h_version <= ZMachine.V3) ? 31 : 47))
{
Err.RuntimeError(ErrorCodes.ERR_ILL_ATTR);
}
/* If we are monitoring attribute assignment display a short note */
if (Main.option_attribute_assignment == true)
{
Stream.StreamMssgOn();
Text.PrintString("@set_attr ");
Text.PrintObject(Process.zargs[0]);
Text.PrintString(" ");
Text.PrintNum(Process.zargs[1]);
Stream.StreamMssgOff();
}
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_SET_ATTR_0);
return;
}
/* Get attribute address */
obj_addr = (zword)(ObjectAddress(Process.zargs[0]) + Process.zargs[1] / 8);
/* Load attribute byte */
FastMem.LowByte(obj_addr, out zbyte value);
/* Set attribute bit */
value |= (zbyte)(0x80 >> (Process.zargs[1] & 7));
/* Store attribute byte */
FastMem.SetByte(obj_addr, value);
}/* z_set_attr */
}/* z_clear_attr */
/*
* z_jin, branch if the first object is inside the second.
*
* Process.zargs[0] = first object
* Process.zargs[1] = second object
*
*/
internal static void ZJin()
{
zword obj_addr;
/* If we are monitoring object locating display a short note */
if (Main.option_object_locating)
{
Stream.StreamMssgOn();
Text.PrintString("@jin ");
Text.PrintObject(Process.zargs[0]);
Text.PrintString(" ");
Text.PrintObject(Process.zargs[1]);
Stream.StreamMssgOff();
}
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_JIN_0);
Process.Branch(0 == Process.zargs[1]);
return;
}
obj_addr = ObjectAddress(Process.zargs[0]);
if (Main.h_version <= ZMachine.V3)
{
/* Get parent id from object */
obj_addr += O1_PARENT;
FastMem.LowByte(obj_addr, out zbyte parent);
/* Branch if the parent is obj2 */
Process.Branch(parent == Process.zargs[1]);
}
else
{
/* Get parent id from object */
obj_addr += O4_PARENT;
FastMem.LowWord(obj_addr, out zword parent);
/* Branch if the parent is obj2 */
Process.Branch(parent == Process.zargs[1]);
}
}/* z_jin */
}/* z_get_next_prop */
/*
* z_get_parent, store the parent of an object.
*
* Process.zargs[0] = object
*
*/
internal static void ZGetParent()
{
zword obj_addr;
/* If we are monitoring object locating display a short note */
if (Main.option_object_locating)
{
Stream.StreamMssgOn();
Text.PrintString("@get_parent ");
Text.PrintObject(Process.zargs[0]);
Stream.StreamMssgOff();
}
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_PARENT_0);
Process.Store(0);
return;
}
obj_addr = ObjectAddress(Process.zargs[0]);
if (Main.h_version <= ZMachine.V3)
{
/* Get parent id from object */
obj_addr += O1_PARENT;
FastMem.LowByte(obj_addr, out zbyte parent);
/* Store parent */
Process.Store(parent);
}
else
{
/* Get parent id from object */
obj_addr += O4_PARENT;
FastMem.LowWord(obj_addr, out zword parent);
/* Store parent */
Process.Store(parent);
}
}/* z_get_parent */
}/* z_jin */
/*
* z_get_child, store the child of an object.
*
* Process.zargs[0] = object
*
*/
internal static void ZGetChild()
{
zword obj_addr;
/* If we are monitoring object locating display a short note */
if (Main.option_object_locating)
{
Stream.StreamMssgOn();
Text.PrintString("@get_child ");
Text.PrintObject(Process.zargs[0]);
Stream.StreamMssgOff();
}
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_CHILD_0);
Process.Store(0);
Process.Branch(false);
return;
}
obj_addr = ObjectAddress(Process.zargs[0]);
if (Main.h_version <= ZMachine.V3)
{
/* Get child id from object */
obj_addr += O1_CHILD;
FastMem.LowByte(obj_addr, out zbyte child);
/* Store child id and branch */
Process.Store(child);
Process.Branch(child > 0);
}
else
{
/* Get child id from object */
obj_addr += O4_CHILD;
FastMem.LowWord(obj_addr, out zword child);
/* Store child id and branch */
Process.Store(child);
Process.Branch(child > 0);
}
}/* z_get_child */
}/* alphabet */
/*
* find_resolution
*
* Find the number of bytes used for dictionary resolution.
*
*/
internal static void FindResolution()
{
zword dct = Main.h_dictionary;
FastMem.LowByte(dct, out zbyte sep_count);
dct += (zword)(1 + sep_count); /* skip word separators */
FastMem.LowByte(dct, out zbyte entry_len);
Resolution = (Main.h_version <= ZMachine.V3) ? 2 : 3;
if (2 * Resolution > entry_len)
{
Err.RuntimeError(ErrorCodes.ERR_DICT_LEN);
}
Decoded = new zword[3 * Resolution + 1];
Encoded = new zword[Resolution];
}/* find_resolution */
}/* z_get_child */
/*
* z_get_next_prop, store the number of the first or next property.
*
* Process.zargs[0] = object
* Process.zargs[1] = address of current property (0 gets the first property)
*
*/
internal static void ZGetNextProp()
{
zbyte value;
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_NEXT_PROP_0);
Process.Store(0);
return;
}
/* Property id is in bottom five (six) bits */
zbyte mask = (zbyte)((Main.h_version <= ZMachine.V3) ? 0x1f : 0x3f);
/* Load address of first property */
zword prop_addr = FirstProperty(Process.zargs[0]);
if (Process.zargs[1] != 0)
{
/* Scan down the property list */
do
{
FastMem.LowByte(prop_addr, out value);
prop_addr = NextProperty(prop_addr);
} while ((value & mask) > Process.zargs[1]);
/* Exit if the property does not exist */
if ((value & mask) != Process.zargs[1])
{
Err.RuntimeError(ErrorCodes.ERR_NO_PROP);
}
}
/* Return the property id */
FastMem.LowByte(prop_addr, out value);
Process.Store((zword)(value & mask));
}/* z_get_next_prop */
}/* z_get_prop_len */
/*
* z_get_sibling, store the sibling of an object.
*
* Process.zargs[0] = object
*
*/
internal static void ZGetSibling()
{
zword obj_addr;
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_GET_SIBLING_0);
Process.Store(0);
Process.Branch(false);
return;
}
obj_addr = ObjectAddress(Process.zargs[0]);
if (Main.h_version <= ZMachine.V3)
{
/* Get sibling id from object */
obj_addr += O1_SIBLING;
FastMem.LowByte(obj_addr, out byte sibling);
/* Store sibling and branch */
Process.Store(sibling);
Process.Branch(sibling > 0); // TODO I'm not sure about this logic Process.branch (sibling);
// I think it means if the sibling isn't zero, jump..
}
else
{
/* Get sibling id from object */
obj_addr += O4_SIBLING;
FastMem.LowWord(obj_addr, out ushort sibling);
/* Store sibling and branch */
Process.Store(sibling);
Process.Branch(sibling > 0);
}
}/* z_get_sibling */
}/* z_set_attr */
/*
* z_test_attr, branch if an object attribute is set.
*
* Process.zargs[0] = object
* Process.zargs[1] = number of attribute to test
*
*/
internal static void ZTestAttr()
{
zword obj_addr;
if (Process.zargs[1] > ((Main.h_version <= ZMachine.V3) ? 31 : 47))
{
Err.RuntimeError(ErrorCodes.ERR_ILL_ATTR);
}
/* If we are monitoring attribute testing display a short note */
if (Main.option_attribute_testing == true)
{
Stream.StreamMssgOn();
Text.PrintString("@test_attr ");
Text.PrintObject(Process.zargs[0]);
Text.PrintString(" ");
Text.PrintNum(Process.zargs[1]);
Stream.StreamMssgOff();
}
if (Process.zargs[0] == 0)
{
Err.RuntimeError(ErrorCodes.ERR_TEST_ATTR_0);
Process.Branch(false);
return;
}
/* Get attribute address */
obj_addr = (zword)(ObjectAddress(Process.zargs[0]) + Process.zargs[1] / 8);
/* Load attribute byte */
FastMem.LowByte(obj_addr, out byte value);
/* Test attribute */
Process.Branch((value & (0x80 >> (Process.zargs[1] & 7))) > 0);
}/* z_test_attr */
/*
* object_address
*
* Calculate the address of an object.
*
*/
internal static zword ObjectAddress(zword obj)
{
/* Check object number */
if (obj > ((Main.h_version <= ZMachine.V3) ? 255 : MAX_OBJECT))
{
Text.PrintString("@Attempt to address illegal object ");
Text.PrintNum(obj);
Text.PrintString(". This is normally fatal.");
Buffer.NewLine();
Err.RuntimeError(ErrorCodes.ERR_ILL_OBJ);
}
/* Return object address */
if (Main.h_version <= ZMachine.V3)
{
return((zword)(Main.h_objects + ((obj - 1) * O1_SIZE + 62)));
}
else
{
return((zword)(Main.h_objects + ((obj - 1) * O4_SIZE + 126)));
}
}/* object_address */
/*
* Save a game using Quetzal format. Return 1 if OK, 0 if failed.
*/
internal static zword SaveQuetzal(FileStream svf, System.IO.Stream stf)
{
zlong stkslen = 0;
zword i, j, n;
int nvars, nargs, nstk, p;
zbyte var;
long cmempos, stkspos;
int c;
/* Write `IFZS' header. */
if (!WriteChunk(svf, ID_FORM, 0))
{
return(0);
}
if (!WriteLong(svf, ID_IFZS))
{
return(0);
}
/* Write `IFhd' chunk. */
FastMem.GetPc(out long pc);
if (!WriteChunk(svf, ID_IFhd, 13))
{
return(0);
}
if (!WriteWord(svf, Main.h_release))
{
return(0);
}
for (i = ZMachine.H_SERIAL; i < ZMachine.H_SERIAL + 6; ++i)
{
if (!WriteByte(svf, FastMem.ZMData[FastMem.Zmp + i]))
{
return(0);
}
}
if (!WriteWord(svf, Main.h_checksum))
{
return(0);
}
if (!WriteLong(svf, pc << 8)) /* Includes pad. */ return {
(0);
}
/* Write `CMem' chunk. */
if ((cmempos = svf.Position) < 0)
{
return(0);
}
if (!WriteChunk(svf, ID_CMem, 0))
{
return(0);
}
// (void) fseek (stf, 0, SEEK_SET);
stf.Position = 0;
uint cmemlen;
/* j holds current run length. */
for (i = 0, j = 0, cmemlen = 0; i < Main.h_dynamic_size; ++i)
{
if ((c = stf.ReadByte()) == -1)
{
return(0);
}
c ^= FastMem.ZMData[i];
if (c == 0)
{
++j; /* It's a run of equal bytes. */
}
else
{
/* Write out any run there may be. */
if (j > 0)
{
for (; j > 0x100; j -= 0x100)
{
if (!WriteRun(svf, 0xFF))
{
return(0);
}
cmemlen += 2;
}
if (!WriteRun(svf, (byte)(j - 1)))
{
return(0);
}
cmemlen += 2;
j = 0;
}
/* Any runs are now written. Write this (nonzero) byte. */
if (!WriteByte(svf, (zbyte)c))
{
return(0);
}
++cmemlen;
}
}
/*
* Reached end of dynamic memory. We ignore any unwritten run there may be
* at this point.
*/
if ((cmemlen & 1) > 0) /* Chunk length must be even. */
{
if (!WriteByte(svf, 0))
{
return(0);
}
}
/* Write `Stks' chunk. You are not expected to understand this. ;) */
if ((stkspos = svf.Position) < 0)
{
return(0);
}
if (!WriteChunk(svf, ID_Stks, 0))
{
return(0);
}
using var buffer = SpanOwner <zword> .Allocate(General.STACK_SIZE / 4 + 1);
var frames = buffer.Span;
/*
* We construct a list of frame indices, most recent first, in `frames'.
* These indices are the offsets into the `stack' array of the word before
* the first word pushed in each frame.
*/
frames[0] = (zword)Main.sp; /* The frame we'd get by doing a call now. */
for (i = (zword)(Main.fp + 4), n = 0; i < General.STACK_SIZE + 4; i = (zword)(Main.Stack[i - 3] + 5))
{
frames[++n] = i;
}
/*
* All versions other than V6 can use evaluation stack outside a function
* context. We write a faked stack frame (most fields zero) to cater for
* this.
*/
if (Main.h_version != ZMachine.V6)
{
for (i = 0; i < 6; ++i)
{
if (!WriteByte(svf, 0))
{
return(0);
}
}
nstk = General.STACK_SIZE - frames[n];
if (!WriteWord(svf, nstk))
{
return(0);
}
for (j = General.STACK_SIZE - 1; j >= frames[n]; --j)
{
if (!WriteWord(svf, Main.Stack[j]))
{
return(0);
}
}
stkslen = (zword)(8 + 2 * nstk);
}
/* Write out the rest of the stack frames. */
for (i = n; i > 0; --i)
{
p = frames[i] - 4; // p = stack + frames[i] - 4; /* Points to call frame. */
nvars = (Main.Stack[p] & 0x0F00) >> 8;
nargs = Main.Stack[p] & 0x00FF;
nstk = (zword)(frames[i] - frames[i - 1] - nvars - 4);
pc = ((zlong)Main.Stack[p + 3] << 9) | Main.Stack[p + 2];
switch (Main.Stack[p] & 0xF000) /* Check type of call. */
{
case 0x0000: /* Function. */
var = FastMem.ZMData[FastMem.Zmp + pc];
pc = ((pc + 1) << 8) | (zlong)nvars;
break;
case 0x1000: /* Procedure. */
var = 0;
pc = (pc << 8) | 0x10 | (zlong)nvars; /* Set procedure flag. */
break;
/* case 0x2000: */
default:
Err.RuntimeError(ErrorCodes.ERR_SAVE_IN_INTER);
return(0);
}
if (nargs != 0)
{
nargs = (zword)((1 << nargs) - 1); /* Make args into bitmap. */
}
/* Write the main part of the frame... */
if (!WriteLong(svf, pc) ||
!WriteByte(svf, var) ||
!WriteByte(svf, (byte)nargs) ||
!WriteWord(svf, nstk))
{
return(0);
}
/* Write the variables and eval stack. */
for (j = 0, --p; j < nvars + nstk; ++j, --p)
{
if (!WriteWord(svf, Main.Stack[p]))
{
return(0);
}
}
/* Calculate length written thus far. */
stkslen += (zword)(8 + 2 * (nvars + nstk));
}
/* Fill in variable chunk lengths. */
uint ifzslen = 3 * 8 + 4 + 14 + cmemlen + stkslen;
if ((cmemlen & 1) > 0)
{
++ifzslen;
}
svf.Position = 4;
if (!WriteLong(svf, ifzslen))
{
return(0);
}
svf.Position = cmempos + 4;
if (!WriteLong(svf, cmemlen))
{
return(0);
}
svf.Position = stkspos + 4;
if (!WriteLong(svf, stkslen))
{
return(0);
}
/* After all that, still nothing went wrong! */
return(1);
}
}/* next_property */
/*
* unlink_object
*
* Unlink an object from its parent and siblings.
*
*/
private static void UnlinkObject(zword object_var)
{
zword parent_addr;
zword sibling_addr;
if (object_var == 0)
{
Err.RuntimeError(ErrorCodes.ERR_REMOVE_OBJECT_0);
return;
}
zword obj_addr = ObjectAddress(object_var);
if (Main.h_version <= ZMachine.V3)
{
zbyte zero = 0;
/* Get parent of object, and return if no parent */
obj_addr += O1_PARENT;
FastMem.LowByte(obj_addr, out byte parent);
if (parent == 0)
{
return;
}
/* Get (older) sibling of object and set both parent and sibling
* pointers to 0 */
FastMem.SetByte(obj_addr, zero);
obj_addr += (zword)(O1_SIBLING - O1_PARENT);
FastMem.LowByte(obj_addr, out byte older_sibling);
FastMem.SetByte(obj_addr, zero);
/* Get first child of parent (the youngest sibling of the object) */
parent_addr = (zword)(ObjectAddress(parent) + O1_CHILD);
FastMem.LowByte(parent_addr, out byte younger_sibling);
/* Remove object from the list of siblings */
if (younger_sibling == object_var)
{
FastMem.SetByte(parent_addr, older_sibling);
}
else
{
do
{
sibling_addr = (zword)(ObjectAddress(younger_sibling) + O1_SIBLING);
FastMem.LowByte(sibling_addr, out younger_sibling);
} while (younger_sibling != object_var);
FastMem.SetByte(sibling_addr, older_sibling);
}
}
else
{
zword zero = 0;
/* Get parent of object, and return if no parent */
obj_addr += O4_PARENT;
FastMem.LowWord(obj_addr, out zword parent);
if (parent == 0)
{
return;
}
/* Get (older) sibling of object and set both parent and sibling
* pointers to 0 */
FastMem.SetWord(obj_addr, zero);
obj_addr += (zword)(O4_SIBLING - O4_PARENT);
FastMem.LowWord(obj_addr, out ushort older_sibling);
FastMem.SetWord(obj_addr, zero);
/* Get first child of parent (the youngest sibling of the object) */
parent_addr = (zword)(ObjectAddress(parent) + O4_CHILD);
FastMem.LowWord(parent_addr, out ushort younger_sibling);
/* Remove object from the list of siblings */
if (younger_sibling == object_var)
{
FastMem.SetWord(parent_addr, older_sibling);
}
else
{
do
{
sibling_addr = (zword)(ObjectAddress(younger_sibling) + O4_SIBLING);
FastMem.LowWord(sibling_addr, out younger_sibling);
} while (younger_sibling != object_var);
FastMem.SetWord(sibling_addr, older_sibling);
}
}
}/* unlink_object */
