/**
* Find a grid near the given one for an object to fall on
*
* We check several locations to see if we can find a location at which
* the object can combine, stack, or be placed. Artifacts will try very
* hard to be placed, including "teleporting" to a useful grid if needed.
*
* If no appropriate grid is found, the given grid is unchanged
*/
static void drop_find_grid(struct object *drop, int *y, int *x)
{
int best_score = -1;
int best_y = *y;
int best_x = *x;
int i, dy, dx;
struct object *obj;
/* Scan local grids */
for (dy = -3; dy <= 3; dy++) {
for (dx = -3; dx <= 3; dx++) {
bool combine = false;
int dist = (dy * dy) + (dx * dx);
int ty = *y + dy;
int tx = *x + dx;
int num_shown = 0;
int num_ignored = 0;
int score;
/* Lots of reasons to say no */
if ((dist > 10) ||
!square_in_bounds_fully(cave, ty, tx) ||
!los(cave, *y, *x, ty, tx) ||
!square_isfloor(cave, ty, tx) ||
square_isplayertrap(cave, ty, tx) ||
square_iswarded(cave, ty, tx))
continue;
/* Analyse the grid for carrying the new object */
for (obj = square_object(cave, ty, tx); obj; obj = obj->next) {
/* Check for possible combination */
if (object_similar(obj, drop, OSTACK_FLOOR))
combine = true;
/* Count objects */
if (!ignore_item_ok(obj))
num_shown++;
else
num_ignored++;
}
if (!combine)
num_shown++;
/* Disallow if the stack size is too big */
if ((OPT(player, birth_stacking) && (num_shown > 1)) ||
((num_shown + num_ignored) > z_info->floor_size &&
!floor_get_oldest_ignored(ty, tx)))
continue;
/* Score the location based on how close and how full the grid is */
score = 1000 - (dist + num_shown * 5);
if ((score < best_score) || ((score == best_score) && one_in_(2)))
continue;
best_score = score;
best_y = ty;
best_x = tx;
}
}
/* Return if we have a score, otherwise fail or try harder for artifacts */
if (best_score >= 0) {
*y = best_y;
*x = best_x;
return;
} else if (!drop->artifact) {
return;
}
for (i = 0; i < 2000; i++) {
/* Start bouncing from grid to grid, stopping if we find an empty one */
if (i < 1000) {
best_y = rand_spread(best_y, 1);
best_x = rand_spread(best_x, 1);
} else {
/* Now go to purely random locations */
best_y = randint0(cave->height);
best_x = randint0(cave->width);
}
if (square_canputitem(cave, best_y, best_x)) {
*y = best_y;
*x = best_x;
return;
}
}
}
/**
* Place random stairs at (x, y).
* \param c current chunk
* \param y co-ordinates
* \param x co-ordinates
*/
void place_random_stairs(struct chunk *c, int y, int x)
{
int feat = randint0(100) < 50 ? FEAT_LESS : FEAT_MORE;
if (square_canputitem(c, y, x))
place_stairs(c, y, x, feat);
}
/**
* Let an object fall to the ground at or near a location.
*
* The initial location is assumed to be "square_in_bounds_fully(cave, )".
*
* This function takes a parameter "chance". This is the percentage
* chance that the item will "disappear" instead of drop. If the object
* has been thrown, then this is the chance of disappearance on contact.
*
* This function will produce a description of a drop event under the player
* when "verbose" is true.
*
* We check several locations to see if we can find a location at which
* the object can combine, stack, or be placed. Artifacts will try very
* hard to be placed, including "teleporting" to a useful grid if needed.
*
* Objects which fail to be carried by the floor are deleted. This function
* attempts to add successfully dropped objects to, and to remove failures
* from, the object list (as dropped items may or may not be already listed).
*/
void drop_near(struct chunk *c, struct object *dropped, int chance, int y,
int x, bool verbose)
{
int i, k, n, d, s;
int bs, bn;
int by, bx;
int dy, dx;
int ty, tx;
struct object *obj;
char o_name[80];
bool flag = false;
/* Only called in the current level */
assert(c == cave);
/* Describe object */
object_desc(o_name, sizeof(o_name), dropped, ODESC_BASE);
/* Handle normal "breakage" */
if (!dropped->artifact && (randint0(100) < chance)) {
/* Message */
msg("The %s %s.", o_name,
VERB_AGREEMENT(dropped->number, "breaks", "break"));
/* Failure */
if (dropped->known) {
delist_object(cave_k, dropped->known);
object_delete(&dropped->known);
}
delist_object(c, dropped);
object_delete(&dropped);
return;
}
/* Score */
bs = -1;
/* Picker */
bn = 0;
/* Default */
by = y;
bx = x;
/* Scan local grids */
for (dy = -3; dy <= 3; dy++) {
for (dx = -3; dx <= 3; dx++) {
bool comb = false;
/* Calculate actual distance */
d = (dy * dy) + (dx * dx);
/* Ignore distant grids */
if (d > 10) continue;
/* Location */
ty = y + dy;
tx = x + dx;
/* Skip illegal grids */
if (!square_in_bounds_fully(c, ty, tx)) continue;
/* Require line of sight */
if (!los(c, y, x, ty, tx)) continue;
/* Require floor space */
if (!square_isfloor(c, ty, tx)) continue;
/* Require no trap or rune */
if (square_isplayertrap(c, ty, tx) ||
square_iswarded(c, ty, tx))
continue;
/* No objects */
k = 0;
n = 0;
/* Scan objects in that grid */
for (obj = square_object(c, ty, tx); obj; obj = obj->next) {
/* Check for possible combination */
if (object_similar(obj, dropped, OSTACK_FLOOR))
comb = true;
/* Count objects */
if (!ignore_item_ok(obj))
k++;
else
n++;
}
/* Add new object */
if (!comb) k++;
/* Option -- disallow stacking */
if (OPT(birth_no_stacking) && (k > 1)) continue;
/* Paranoia? */
if ((k + n) > z_info->floor_size &&
!floor_get_oldest_ignored(ty, tx)) continue;
/* Calculate score */
s = 1000 - (d + k * 5);
/* Skip bad values */
if (s < bs) continue;
/* New best value */
if (s > bs) bn = 0;
/* Apply the randomizer to equivalent values */
if ((++bn >= 2) && (randint0(bn) != 0)) continue;
/* Keep score */
bs = s;
/* Track it */
by = ty;
bx = tx;
/* Okay */
flag = true;
}
}
/* Handle lack of space */
if (!flag && !dropped->artifact) {
/* Message */
msg("The %s %s.", o_name,
VERB_AGREEMENT(dropped->number, "disappears", "disappear"));
/* Debug */
if (player->wizard) msg("Breakage (no floor space).");
/* Failure */
if (dropped->known) {
delist_object(cave_k, dropped->known);
object_delete(&dropped->known);
}
delist_object(c, dropped);
object_delete(&dropped);
return;
}
/* Find a grid */
for (i = 0; !flag; i++) {
/* Bounce around */
if (i < 1000) {
ty = rand_spread(by, 1);
tx = rand_spread(bx, 1);
} else {
/* Random locations */
ty = randint0(c->height);
tx = randint0(c->width);
}
/* Require floor space */
if (!square_canputitem(c, ty, tx)) continue;
/* Bounce to that location */
by = ty;
bx = tx;
/* Okay */
flag = true;
}
/* Give it to the floor */
if (!floor_carry(c, by, bx, dropped, false)) {
/* Message */
msg("The %s %s.", o_name,
VERB_AGREEMENT(dropped->number, "disappears", "disappear"));
/* Debug */
if (player->wizard) msg("Breakage (too many objects).");
if (dropped->artifact) dropped->artifact->created = false;
/* Failure */
if (dropped->known) {
delist_object(cave_k, dropped->known);
object_delete(&dropped->known);
}
delist_object(c, dropped);
object_delete(&dropped);
return;
}
/* Sound */
sound(MSG_DROP);
/* Message when an object falls under the player */
if (verbose && (c->squares[by][bx].mon < 0))
/* Check the item still exists and isn't ignored */
if (c->objects[dropped->oidx] && !ignore_item_ok(dropped))
msg("You feel something roll beneath your feet.");
}
