Instructions for adding semi-intelligent mob use of weapons. By Mark Garringer
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The idea here is that mobs should try to make use of better weapons they are
carrying around in their inventories. Rather than continuing to wield a dagger
it was loaded with, if it finds a long sword for example. There are some changes
that have been made to my code base that are no standard to Circle. 

First and foremost, I have made changes in mobact.c to allow aggressive mobs to
fight with each other instead of just with PCs. In mobile_activity look for
/* Aggressive Mobs */ and change the line: 
if (IS_NPC(vict) || !CAN_SEE(ch, vict) || PRF_FLAGGED(vict, PRF_NOHASSLE)) to:
if (!CAN_SEE(ch, vict) || (!IS_NPC(vict) && PRF_FLAGGED(vict, PRF_NOHASSLE))) 
you should also add this: 
if (vict == ch)
  continue;
Below so that aggressive mobs will not try to kill themselves.

Ok, now you are off and running. Mobs are fighting each other! You might also 
want to add something near your AUTOLOOT/AUTOGOLD checks so that mobs are doing
corpse looting of their own. (Usually in fight.c) My own code base allows for
mobs defined as race types considered to be humanoid to loot corpses. (Thus
animals, snakes, fish, insects etc, are not trying to get stuff they have
no logical use for.) Of course my mobs are all loaded with a race and class
as well, but that is something else entirely.

So given this, you now have mobs fighting each other, collecting equipment and
looting the corpse of players they have killed. (This pisses off players to no
end, especially since shortly we are going to allow mobs to start using better
equipment they find.)

Towards the end of mobile_activity it says to /* Add new mobile actions here */
Insert the following:

if (IS_HUMANOID(ch) && ((ch)->mob_specials.newitem != 0) && ! (mob_index[GET_MOB_RNUM(ch)].func == shop_keeper) ) {
    if (IS_WIELDING(ch)) {
      wield_obj = ch->equipment[WEAR_WIELD];
      best_obj = wield_obj;
      for (i = 0; i < MAX_OBJ_AFFECT; i++) {
        if (wield_obj->affected[i].location == APPLY_DAMROLL)
          a1 = wield_obj->affected[i].modifier;
      }
      max =(((GET_OBJ_VAL(wield_obj, 2)+a1+1)/2.0) * GET_OBJ_VAL(wield_obj, 1));      } else {
      wield_obj = NULL;
      best_obj = NULL;
      max = 1;
    }
    a1 = 0;
    a2 = 0;
    for (obj = ch->carrying; obj; obj = obj-> next_content) {
      if (GET_OBJ_TYPE(obj) == ITEM_WEAPON) {
        for (i = 0; i < MAX_OBJ_AFFECT; i++) {
          if (obj->affected[i].location == APPLY_DAMROLL)
            a2 = obj->affected[i].modifier;
        }
        dam2 =(((GET_OBJ_VAL(obj, 2)+a2+ 1) / 2.0) * GET_OBJ_VAL(obj, 1));
        if (dam2 > max) {
          if (!invalid_align(ch, obj) && !invalid_class(ch, obj)) {
            best_obj = obj;
            for (i = 0; i < MAX_OBJ_AFFECT; i++) {
              if (best_obj->affected[i].location == APPLY_DAMROLL)
                a2 = best_obj->affected[i].modifier;
            }
            max=(((GET_OBJ_VAL(best_obj,2)+a2+1)/2.0)*GET_OBJ_VAL(best_obj, 1));          }
        } else (ch)->mob_specials.newitem = 0;
      }
    }
    if (IS_WIELDING(ch)) {
      if (wield_obj != best_obj) {
        perform_remove(ch, WEAR_WIELD);
        perform_wear(ch, best_obj, WEAR_WIELD);
        (ch)->mob_specials.newitem = 0;
      }
    } else {
       if (best_obj != NULL)
         perform_wear(ch, best_obj, WEAR_WIELD);
        (ch)->mob_specials.newitem = 0;
    }
  }

You will need to add the following to the top of mobact.c:
void perform_wear(struct char_data * ch, struct obj_data * obj, int where);
void perform_remove(struct char_data * ch, int pos);
int invalid_class(struct char_data *ch, struct obj_data *obj);
SPECIAL(shop_keeper);

*Note* You only need to add invalid_class if you are using classes for your mobs
which I highly recommend.

You will also have to add these to mobile_activity: (can be appended to other 
defines of the same types)
	struct obj_data *wield_obj;
	int i, a1 = 0, a2 = 0;
	float max, dam2; /* Thanks to Chet Kress for fixing this! */

You might be saying to yourself at this point, where the hell did 
mob_specials.newitem come from and what is it for? Well, this is to limit the
looping of mobs checking their inventory to see if they should change weapons.

In structs.h add the following of mob_special_data:
int newitem;                 /* Check if mob has new inv item       */

You also need to make some change to act.item.c so when I mob gets or is given a
weapon it changes the value of newitem so it then knows it is ok to see if it
now has a better weapon. In perform_get_from_room add:
if (IS_NPC(ch) && GET_OBJ_TYPE(obj) == ITEM_WEAPON) 
      (ch)->mob_specials.newitem = 1;
After the two act statements will be just fine.
Still in act.item.c in perform_give add:
if (IS_NPC(vict) && GET_OBJ_TYPE(obj) == ITEM_WEAPON)
    (vict)->mob_specials.newitem = 1;
Again, after the act statements is fine.
Finally (I think) you should initialize newitem to 0 when the mobs are loaded in
db.c add:
mob_proto[i].mob_specials.newitem = 0;
After where it sets weight and height for mobs is fine.

If you have questions or even modifications/bug reports for this code please
send them to me. If you have problems I can try to help you, but my C is
not that hot so my support is limited.

I think this is all. My MUD had quite a few non-standard modifications so if
this does not plug right in I am sorry. I have spent a lot of time on this code,
and even though it is ugly in some spots it seems to work VERY well. If you use
it, please give me some props in your credits file or something:
Zizazat Lazuras (zizazat@hotmail.com)