UpVal *luaF_findupval (lua_State *L, StkId level) {
global_State *g = G(L);
GCObject **pp = &L->openupval;
UpVal *p;
UpVal *uv;
while (*pp != NULL && (p = gco2uv(*pp))->v >= level) {
GCObject *o = obj2gco(p);
lua_assert(p->v != &p->u.value);
lua_assert(!isold(o) || isold(obj2gco(L)));
if (p->v == level) { /* found a corresponding upvalue? */
if (isdead(g, o)) /* is it dead? */
changewhite(o); /* resurrect it */
return p;
}
pp = &p->next;
}
/* not found: create a new one */
uv = &luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal), pp, 0)->uv;
uv->v = level; /* current value lives in the stack */
uv->u.l.prev = &g->uvhead; /* double link it in `uvhead' list */
uv->u.l.next = g->uvhead.u.l.next;
uv->u.l.next->u.l.prev = uv;
g->uvhead.u.l.next = uv;
lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
return uv;
}
/*
* Move to a particular position and see if we hit a mine.
* If not, then count the number of mines adjacent to us so it can be seen.
* If we are stepping onto a location where we remembered a mine is at,
* then don't do it. Moving is only allowed to old locations, or to
* locations adjacent to old ones.
*/
static void
movetopos(POS newpos)
{
POS fixpos; /* position to fix up */
CELL cell; /* current cell */
GR_COUNT count; /* count of cells */
GR_COUNT i; /* index for neighbors */
if ((newpos < 0) || (newpos >= (FULLSIZE * FULLSIZE)) || !playing)
return;
cell = board[newpos];
if (isedge(cell) || (isseen(cell)) || isold(cell))
return;
count = isold(cell);
for (i = 0; i < 8; i++)
if (isold(board[newpos + steptable[i]]))
count++;
if (count <= 0)
return;
cell = (cell & F_FLAGS) | F_OLD;
steps++;
PRINTSTEPS;
if (ismine(cell)) { /* we hit a mine */
legs--;
board[newpos] = (F_REMEMBER | F_MINE);
cell = (F_EMPTY | F_OLD);
board[newpos] = cell;
drawbomb(newpos, redgc, GR_TRUE);
clearcell(newpos);
setcursor();
for (i = 0; i < 8; i++) {
fixpos = newpos + steptable[i];
if (isold(board[fixpos])) {
board[fixpos]--;
drawcell(fixpos);
}
}
drawstatus();
}
count = 0;
for (i = 0; i < 8; i++)
if (ismine(board[newpos + steptable[i]]))
count++;
board[newpos] = cell | (count + '0');
drawcell(newpos);
if ((legs <= 0) || (newpos == boardpos(size,size)))
gameover();
}
/*
* Draw a cell on the board.
*/
static void
drawcell(POS pos)
{
GR_COORD x;
GR_COORD y;
GR_SIZE chwidth;
GR_SIZE chheight;
GR_SIZE chbase;
CELL cell;
GR_CHAR ch;
cell = board[pos];
if (!isknown(cell))
return;
ch = displaychar(cell);
if (ch == F_WRONG) {
drawbomb(pos, greengc, GR_FALSE);
return;
}
if (isold(cell)) {
clearcell(pos);
cellcenter(pos, &x, &y);
GrGetGCTextSize(boardgc, &ch, 1, GR_TFASCII, &chwidth,
&chheight, &chbase);
GrText(boardwid, boardgc, x - chwidth / 2 + 1,
y + chheight / 2, &ch, 1, GR_TFBOTTOM);
return;
}
drawbomb(pos, redgc, GR_FALSE);
}
static GCObject *udata2finalize (global_State *g) {
GCObject *o = g->tobefnz; /* get first element */
lua_assert(isfinalized(o));
g->tobefnz = gch(o)->next; /* remove it from 'tobefnz' list */
gch(o)->next = g->allgc; /* return it to 'allgc' list */
g->allgc = o;
resetbit(gch(o)->marked, SEPARATED); /* mark that it is not in 'tobefnz' */
lua_assert(!isold(o)); /* see MOVE OLD rule */
if (!keepinvariantout(g)) /* not keeping invariant? */
makewhite(g, o); /* "sweep" object */
return o;
}
