/**
* True if the square can hold a trap.
*/
bool square_istrappable(struct chunk *c, int y, int x)
{
return feat_is_trap_holding(c->squares[y][x].feat);
}
/**
* Instantiate a player trap
*/
static int pick_trap(struct chunk *c, int feat, int trap_level)
{
int i, pick;
int *trap_probs = NULL;
int trap_prob_max = 0;
/* Paranoia */
if (!feat_is_trap_holding(feat))
return -1;
/* No traps in town */
if (c->depth == 0)
return -1;
/* Get trap probabilities */
trap_probs = mem_zalloc(z_info->trap_max * sizeof(int));
for (i = 0; i < z_info->trap_max; i++) {
/* Get this trap */
struct trap_kind *kind = &trap_info[i];
trap_probs[i] = trap_prob_max;
/* Ensure that this is a valid player trap */
if (!kind->name) continue;
if (!kind->rarity) continue;
if (!trf_has(kind->flags, TRF_TRAP)) continue;
/* Require that trap_level not be too low */
if (kind->min_depth > trap_level) continue;
/* Floor? */
if (feat_is_floor(feat) && !trf_has(kind->flags, TRF_FLOOR))
continue;
/* Check legality of trapdoors. */
if (trf_has(kind->flags, TRF_DOWN)) {
/* No trap doors on quest levels */
if (is_quest(player->depth)) continue;
/* No trap doors on the deepest level */
if (player->depth >= z_info->max_depth - 1)
continue;
/* No trap doors with persistent levels (for now) */
if (OPT(player, birth_levels_persist))
continue;
}
/* Trap is okay, store the cumulative probability */
trap_probs[i] += (100 / kind->rarity);
trap_prob_max = trap_probs[i];
}
/* No valid trap */
if (trap_prob_max == 0) {
mem_free(trap_probs);
return -1;
}
/* Pick at random. */
pick = randint0(trap_prob_max);
for (i = 0; i < z_info->trap_max; i++) {
if (pick < trap_probs[i]) {
break;
}
}
mem_free(trap_probs);
/* Return our chosen trap */
return i < z_info->trap_max ? i : -1;
}
