void op_save_undo(void)
{
if(saveundo(TRUE)) {
mop_store_result(1);
} else {
mop_store_result(0);
}
}
void op_save4(void)
{
if(!savegame()) {
mop_store_result(0);
} else {
mop_store_result(1);
}
}
void op_pull(void)
{
if(zversion == 6) { /* v6 uses user stacks */
if(numoperands == 0 || operand[0] == 0)
mop_store_result(stack_pop());
else {
zword space = LOWORD(operand[0]) + 1; /* One more slot is free */
LOWORDwrite(operand[0], space);
mop_store_result(LOWORD(operand[0] + space * ZWORD_SIZE));
}
} else {
zword val = stack_pop();
set_var(operand[0], val);
}
}
void op_save5(void)
{
unsigned i;
char filename[256];
unsigned length;
strid_t file = NULL;
offset end;
switch(numoperands) {
case 0:
op_save4();
return;
case 1:
n_show_error(E_INSTR, "call save with bad number of operands", numoperands);
mop_store_result(0);
return;
case 2:
file = n_file_prompt(fileusage_Data | fileusage_BinaryMode,
filemode_Write);
break;
default:
length = LOBYTE(operand[2]);
if(length > 13)
n_show_port(E_INSTR, "save with filename > 13 characters", length);
for(i = 0; i < length; i++)
filename[i] = glk_char_to_upper(LOBYTE(operand[2] + 1 + i));
filename[length] = 0;
file = n_file_name(fileusage_Data | fileusage_BinaryMode,
filemode_Write, filename);
break;
}
if(!file) {
mop_store_result(0);
return;
}
end = ((offset) operand[0]) + operand[1];
if(end > 65535 || end > total_size) {
n_show_error(E_MEMORY, "attempt to save data out of range", end);
mop_store_result(0);
return;
}
w_glk_put_buffer_stream(file, (char *) z_memory + operand[0], operand[1]);
glk_stream_close(file, NULL);
mop_store_result(1);
}
/* Just like restoreundo, but the opposite ;)
The idea is to go to the @save_undo location, but return 0 instead of 2
so the game thinks it just successfully saved the game. For games which
don't contain @save_undo, jumps to right after the @read instruction. */
BOOL restoreredo(void)
{
strid_t stack;
int i;
glui32 wid, hei;
stream_result_t poo;
move_difference *p = movelist;
if(!p || move_index <= 0)
return FALSE;
move_index--;
for(i = 0; i < move_index; i++) {
p=p->next;
if(!p)
return FALSE;
}
quetzal_undiff(prevstate, dynamic_size, p->delta, p->deltalength, TRUE);
n_memcpy(z_memory, prevstate, dynamic_size);
stack = glk_stream_open_memory((char *) p->stackchunk, p->stacklength,
filemode_Read, 0);
quetzal_stack_restore(stack, p->stacklength);
glk_stream_close(stack, &poo);
if(poo.readcount != p->stacklength) {
n_show_error(E_SAVE, "incorrect stack size assessment", poo.readcount);
return FALSE;
}
if(p->PC_in_instruction) {
PC = p->PC;
mop_store_result(0);
false_undo = FALSE;
} else {
PC = p->PC;
false_undo = FALSE;
}
has_done_save_undo = TRUE;
z_find_size(&wid, &hei);
set_header(wid, hei);
return TRUE;
}
BOOL restoreundo(void)
{
strid_t stack;
int i;
glui32 wid, hei;
move_difference *p = movelist;
if(!p || move_index < 0)
return FALSE;
for(i = 0; i < move_index; i++) {
p=p->next;
if(!p)
return FALSE;
}
move_index++;
n_memcpy(z_memory, prevstate, dynamic_size);
quetzal_undiff(prevstate, dynamic_size, p->delta, p->deltalength, TRUE);
stack = glk_stream_open_memory((char *) p->stackchunk, p->stacklength,
filemode_Read, 0);
quetzal_stack_restore(stack, p->stacklength);
glk_stream_close(stack, NULL);
if(p->PC_in_instruction) {
PC = p->PC;
mop_store_result(2);
false_undo = FALSE;
} else {
PC = p->oldPC;
false_undo = TRUE;
}
has_done_save_undo = TRUE;
z_find_size(&wid, &hei);
set_header(wid, hei);
return TRUE;
}
void op_restore_undo(void)
{
if(!restoreundo())
mop_store_result(0);
}
void op_catch(void)
{
mop_store_result(frame_count);
}
