/**
* Chooses a monster race that seems "appropriate" to the given level
*
* This function uses the "prob2" field of the "monster allocation table",
* and various local information, to calculate the "prob3" field of the
* same table, which is then used to choose an "appropriate" monster, in
* a relatively efficient manner.
*
* Note that "town" monsters will *only* be created in the town, and
* "normal" monsters will *never* be created in the town, unless the
* "level" is "modified", for example, by polymorph or summoning.
*
* There is a small chance (1/50) of "boosting" the given depth by
* a small amount (up to four levels), except in the town.
*
* It is (slightly) more likely to acquire a monster of the given level
* than one of a lower level. This is done by choosing several monsters
* appropriate to the given level and keeping the "hardest" one.
*
* Note that if no monsters are "appropriate", then this function will
* fail, and return zero, but this should *almost* never happen.
*/
struct monster_race *get_mon_num(int level)
{
int i, p;
long total;
struct monster_race *race;
alloc_entry *table = alloc_race_table;
/* Occasionally produce a nastier monster in the dungeon */
if (level > 0 && one_in_(z_info->ood_monster_chance))
level += MIN(level / 4 + 2, z_info->ood_monster_amount);
total = 0L;
/* Process probabilities */
for (i = 0; i < alloc_race_size; i++) {
time_t cur_time = time(NULL);
struct tm *date = localtime(&cur_time);
/* Monsters are sorted by depth */
if (table[i].level > level) break;
/* Default */
table[i].prob3 = 0;
/* No town monsters in dungeon */
if ((level > 0) && (table[i].level <= 0)) continue;
/* Get the chosen monster */
race = &r_info[table[i].index];
/* No seasonal monsters outside of Christmas */
if (rf_has(race->flags, RF_SEASONAL) &&
!(date->tm_mon == 11 && date->tm_mday >= 24 && date->tm_mday <= 26))
continue;
/* Only one copy of a a unique must be around at the same time */
if (rf_has(race->flags, RF_UNIQUE) &&
race->cur_num >= race->max_num)
continue;
/* Some monsters never appear out of depth */
if (rf_has(race->flags, RF_FORCE_DEPTH) && race->level > player->depth)
continue;
/* Accept */
table[i].prob3 = table[i].prob2;
/* Total */
total += table[i].prob3;
}
/* No legal monsters */
if (total <= 0) return NULL;
/* Pick a monster */
race = get_mon_race_aux(total, table);
/* Try for a "harder" monster once (50%) or twice (10%) */
p = randint0(100);
if (p < 60) {
struct monster_race *old = race;
/* Pick a new monster */
race = get_mon_race_aux(total, table);
/* Keep the deepest one */
if (race->level < old->level) race = old;
}
/* Try for a "harder" monster twice (10%) */
if (p < 10) {
struct monster_race *old = race;
/* Pick a monster */
race = get_mon_race_aux(total, table);
/* Keep the deepest one */
if (race->level < old->level) race = old;
}
/* Result */
return race;
}
/**
* Chooses a monster race that seems "appropriate" to the given level
*
* This function uses the "prob2" field of the "monster allocation table",
* and various local information, to calculate the "prob3" field of the
* same table, which is then used to choose an "appropriate" monster, in
* a relatively efficient manner.
*
* Note that "town" monsters will *only* be created in the town, and
* "normal" monsters will *never* be created in the town, unless the
* "level" is "modified", for example, by polymorph or summoning.
*
* There is a small chance (1/50) of "boosting" the given depth by
* a small amount (up to four levels), except in the town.
*
* It is (slightly) more likely to acquire a monster of the given level
* than one of a lower level. This is done by choosing several monsters
* appropriate to the given level and keeping the "hardest" one.
*
* Note that if no monsters are "appropriate", then this function will
* fail, and return zero, but this should *almost* never happen.
*/
monster_race *get_mon_num(int level)
{
int i, p;
long total;
monster_race *race;
alloc_entry *table = alloc_race_table;
/* Occasionally produce a nastier monster in the dungeon */
if (level > 0 && one_in_(NASTY_MON))
level += MIN(level / 4 + 2, MON_OOD_MAX);
total = 0L;
/* Process probabilities */
for (i = 0; i < alloc_race_size; i++) {
/* Monsters are sorted by depth */
if (table[i].level > level) break;
/* Default */
table[i].prob3 = 0;
/* No town monsters in dungeon */
if ((level > 0) && (table[i].level <= 0)) continue;
/* Get the chosen monster */
race = &r_info[table[i].index];
/* Only one copy of a a unique must be around at the same time */
if (rf_has(race->flags, RF_UNIQUE) &&
race->cur_num >= race->max_num)
continue;
/* Some monsters never appear out of depth */
if (rf_has(race->flags, RF_FORCE_DEPTH) &&
race->level > p_ptr->depth)
continue;
/* Accept */
table[i].prob3 = table[i].prob2;
/* Total */
total += table[i].prob3;
}
/* No legal monsters */
if (total <= 0) return NULL;
/* Pick a monster */
race = get_mon_race_aux(total, table);
/* Try for a "harder" monster once (50%) or twice (10%) */
p = randint0(100);
if (p < 60) {
monster_race *old = race;
/* Pick a new monster */
race = get_mon_race_aux(total, table);
/* Keep the deepest one */
if (race->level < old->level) race = old;
}
/* Try for a "harder" monster twice (10%) */
if (p < 10) {
monster_race *old = race;
/* Pick a monster */
race = get_mon_race_aux(total, table);
/* Keep the deepest one */
if (race->level < old->level) race = old;
}
/* Result */
return race;
}
