From: The Arrow <pt94jpi@student.hk-r.se>
Subject: Room affections

Now that room affections have been dragged into the light (by some
strange coincidence by me :), here are my solution to room affections
with a timer (including the fabled 'wall of fog' spell :) on a clean 3.0
patchlevel 11:

(Warning: This isn't a pretty patch, but this is what I did, and it works! :)

In the file db.c, after the line:
   int top_of_world = 0;

/* ref to top element of world
 */
add this line:
   struct raff_node *raff_list = NULL;  /* list of room affections */

In the file utils.h, after the line:
  #define ROOM_FLAGS(loc) (world[(loc)].room_flags)
add the following two lines:
  #define ROOM_AFFECTIONS(loc)    (world[(loc)].room_affections)
  #define ROOM_AFFECTED(loc, aff) (IS_SET(ROOM_AFFECTIONS(loc), (aff)))

in the file structs.h, after the room_direction_data structure,
add the followin structure:
struct raff_node {

room_num room;        /* location in the world[] array of the room */

int      timer;       /* how many ticks this affection lasts */

long     affection;   /* which affection does this room have */

int      spell;       /* the spell number */


struct raff_node *next; /* link to the next node */
};

also in the structs.h file, at the end of the room_data structure,
add the followin line:

long  room_affections;    /* bitvector for spells/skills */

At the top of the file structs.h, after the room flag defines, this lines
was added:
  /* Room affections */
  #define RAFF_FOG        (1 << 0)

In the file constants.h, after the room_bits[] array, add this array:
const char *room_affections[] = {

"FOG",

"\n"
};

And in the spell_wear_off_msg[] array, before the "!UNUSED!" line, add:

"The fog seams to clear out.",


Now to the file act.informative.c, in the function look_at_room()
(preferably after the AFF_BLIND check) add:

if (ROOM_AFFECTED(ch->in_room, RAFF_FOG)) {


/* NOTE: you might wish to change so that wizards,


 * or the use of some 'see through fog' makes you see


 * through the fog


 */


send_to_char("Your view is obscured by a thick fog.\r\n", ch);


return;

}


In act.wizard.c, the function do_stat_room(), at the top add the following:

extern char *room_affections[];

and after it prints out spec-func and room flags add:
  sprintbit((long) rm->room_affections, room_affections, buf2);
  sprintf(buf, "Room affections: %s\r\n", buf2);
  send_to_char(buf, ch);


In class.c, somewhere in the init_spell_levels() function, add this line:
  spell_level(SPELL_WALL_OF_FOG, CLASS_CLERIC, 20);


In the spells.h file, at the top, after
  #define MAG_MANUAL
(1 << 10)
add this line:
  #define MAG_ROOM     (1 << 11)

and after
  /* Insert new spells here, up to MAX_SPELLS */
add this line:
  #define SPELL_WALL_OF_FOG      52

also, after the mag_creations() prototypem add this prototype:
  void mag_room(int level, struct char_data * ch, int spellnum);


In the file spell_parser.c, replace the first "!UNUSED!" after
"waterwalk" with: "wall of fog"

In the call_magic() function, before the calls of manual spells, add:
  if (IS_SET(SINFO.routines, MAG_ROOM))
    mag_room(level, caster, spellnum);

and somewhere in the mag_assign_spells() function add:

spello(SPELL_WALL_OF_FOG, 50, 25, 5, POS_STANDING,


 TAR_CHAR_ROOM | TAR_SELF_ONLY, FALSE, MAG_ROOM);


In the file magic.c, in the function affect_update(), at the top add:

extern struct raff_node *raff_list;

struct raff_node *raff, *next_raff, *temp;
and at the end of the function add:

/* update the room affections */

for (raff = raff_list; raff; raff = next_raff) {


next_raff = raff->next;



raff->timer--;



if (raff->timer <= 0) {



/* this room affection has expired */



send_to_room(spell_wear_off_msg[raff->spell],




raff->room);



send_to_room("\r\n", raff->room);




/* remove the affection */



REMOVE_BIT(world[(int)raff->room].room_affections,




raff->affection);



REMOVE_FROM_LIST(raff, raff_list, next)



free(raff);


}

}


aaand finaly, this function should be added at the bottom of magic.c
void mag_room(int level, struct char_data * ch, int spellnum)
{

long aff; /* what affection */

int ticks; /* how many ticks this spell lasts */

char *to_char = NULL;

char *to_room = NULL;

struct raff_node *raff;


extern struct raff_node *raff_list;


aff = ticks =0;


if (ch == NULL)


return;

level = MAX(MIN(level, LVL_IMPL), 1);


switch (spellnum) {

case SPELL_WALL_OF_FOG:


to_char = "You create a fog out of nowhere.";


to_room = "%n creates a fog out of nowhere.";


aff = RAFF_FOG;


ticks = 1; /* this spell lasts one tick */


break;


/* add more room spells here */


default:


sprintf(buf, "SYSERR: unknown spellnum %d " \


"passed to mag_unaffects", spellnum);


log(buf);


break;

}


/* create, initialize, and link a room-affection node */

CREATE(raff, struct raff_node, 1);

raff->room = ch->in_room;

raff->timer = ticks;

raff->affection = aff;

raff->spell = spellnum;

raff->next = raff_list;

raff_list = raff;


/* set the affection */

SET_BIT(ROOM_AFFECTIONS(raff->room), aff);


if (to_char == NULL)


send_to_char(NOEFFECT, ch);

else


act(to_char, TRUE, ch, 0, 0, TO_CHAR);


if (to_room != NULL)


act(to_room, TRUE, ch, 0, 0, TO_ROOM);

else if (to_char != NULL)


act(to_char, TRUE, ch, 0, 0, TO_ROOM);
}



Btw, if there is someone who wants it, I could put together some code so
that you can define room affections in the world files.