/*
* z_copy_table, copy a table or fill it with zeroes.
*
* zargs[0] = address of table
* zargs[1] = destination address or 0 for fill
* zargs[2] = size of table
*
* Note: Copying is safe even when source and destination overlap; but
* if zargs[1] is negative the table _must_ be copied forwards.
*
*/
internal static void ZCopyTable()
{
zword addr;
zword size = Process.zargs[2];
zbyte value;
int i;
if (Process.zargs[1] == 0) /* zero table */
{
for (i = 0; i < size; i++)
{
FastMem.StoreB((zword)(Process.zargs[0] + i), 0);
}
}
else if ((short)size < 0 || Process.zargs[0] > Process.zargs[1]) /* copy forwards */
{
for (i = 0; i < (((short)size < 0) ? -(short)size : size); i++)
{
addr = (zword)(Process.zargs[0] + i);
FastMem.LowByte(addr, out value);
FastMem.StoreB((zword)(Process.zargs[1] + i), value);
}
}
else /* copy backwards */
{
for (i = size - 1; i >= 0; i--)
{
addr = (zword)(Process.zargs[0] + i);
FastMem.LowByte(addr, out value);
FastMem.StoreB((zword)(Process.zargs[1] + i), value);
}
}
} /* z_copy_table */
}/* memory_new_line */
/*
* memory_word
*
* Redirect a string of characters to the memory of the Z-machine.
*
*/
internal static void MemoryWord(ReadOnlySpan <zword> s)
{
zword addr;
zword c;
int pos = 0;
if (Main.h_version == ZMachine.V6)
{
int width = OS.StringWidth(s);
if (redirect[depth].XSize != 0xffff)
{
if (redirect[depth].Width + width > redirect[depth].XSize)
{
if (s[pos] is ' ' or CharCodes.ZC_INDENT or CharCodes.ZC_GAP)
{
width = OS.StringWidth(s.Slice(++pos));
}
MemoryNewline();
}
}
redirect[depth].Width += (zword)width;
}
addr = redirect[depth].Table;
FastMem.LowWord(addr, out zword size);
addr += 2;
while ((c = s[pos++]) != 0)
{
FastMem.StoreB((zword)(addr + (size++)), Text.TranslateToZscii(c));
}
FastMem.StoreW(redirect[depth].Table, size);
}/* memory_word */
}/* memory_open */
/*
* memory_new_line
*
* Redirect a newline to the memory of the Z-machine.
*
*/
internal static void MemoryNewline()
{
zword addr;
redirect[depth].Total += redirect[depth].Width;
redirect[depth].Width = 0;
addr = redirect[depth].Table;
FastMem.LowWord(addr, out zword size);
addr += 2;
if (redirect[depth].XSize != 0xffff)
{
redirect[depth].Table = (zword)(addr + size);
size = 0;
}
else
{
FastMem.StoreB((zword)(addr + (size++)), 13);
}
FastMem.StoreW(redirect[depth].Table, size);
}/* memory_new_line */
}/* z_scan_table */
/*
* z_storeb, write a byte into a table of bytes.
*
* zargs[0] = address of table
* zargs[1] = index of table entry
* zargs[2] = value to be written
*
*/
internal static void ZStoreB()
{
FastMem.StoreB((zword)(Process.zargs[0] + Process.zargs[1]), (byte)Process.zargs[2]);
} /* z_storeb */
