wmud/old-codebase/src/graph.c
2012-03-07 16:24:50 +01:00

250 lines
6.6 KiB
C

/* ************************************************************************
* File: graph.c Part of CircleMUD *
* Usage: various graph algorithms *
* *
* All rights reserved. See license.doc for complete information. *
* *
* Copyright (C) 1993, 94 by the Trustees of the Johns Hopkins University *
* CircleMUD is based on DikuMUD, Copyright (C) 1990, 1991. *
************************************************************************ */
#include "conf.h"
#include "sysdep.h"
#include "structs.h"
#include "utils.h"
#include "comm.h"
#include "interpreter.h"
#include "handler.h"
#include "db.h"
#include "spells.h"
/* external functions */
ACMD(do_say);
/* external variables */
extern const char *dirs[];
extern int track_through_doors;
/* local functions */
int VALID_EDGE(room_rnum x, int y);
void bfs_enqueue(room_rnum room, int dir);
void bfs_dequeue(void);
void bfs_clear_queue(void);
int find_first_step(room_rnum src, room_rnum target);
ACMD(do_track);
void hunt_victim(struct char_data *ch);
struct bfs_queue_struct {
room_rnum room;
char dir;
struct bfs_queue_struct *next;
};
static struct bfs_queue_struct *queue_head = 0, *queue_tail = 0;
/* Utility macros */
#define MARK(room) (SET_BIT(ROOM_FLAGS(room), ROOM_BFS_MARK))
#define UNMARK(room) (REMOVE_BIT(ROOM_FLAGS(room), ROOM_BFS_MARK))
#define IS_MARKED(room) (ROOM_FLAGGED(room, ROOM_BFS_MARK))
#define TOROOM(x, y) (world[(x)].dir_option[(y)]->to_room)
#define IS_CLOSED(x, y) (EXIT_FLAGGED(world[(x)].dir_option[(y)], EX_CLOSED))
int VALID_EDGE(room_rnum x, int y)
{
if (world[x].dir_option[y] == NULL || TOROOM(x, y) == NOWHERE)
return 0;
if (track_through_doors == FALSE && IS_CLOSED(x, y))
return 0;
if (ROOM_FLAGGED(TOROOM(x, y), ROOM_NOTRACK) || IS_MARKED(TOROOM(x, y)))
return 0;
return 1;
}
void bfs_enqueue(room_rnum room, int dir)
{
struct bfs_queue_struct *curr;
CREATE(curr, struct bfs_queue_struct, 1);
curr->room = room;
curr->dir = dir;
curr->next = 0;
if (queue_tail) {
queue_tail->next = curr;
queue_tail = curr;
} else
queue_head = queue_tail = curr;
}
void bfs_dequeue(void)
{
struct bfs_queue_struct *curr;
curr = queue_head;
if (!(queue_head = queue_head->next))
queue_tail = 0;
free(curr);
}
void bfs_clear_queue(void)
{
while (queue_head)
bfs_dequeue();
}
/*
* find_first_step: given a source room and a target room, find the first
* step on the shortest path from the source to the target.
*
* Intended usage: in mobile_activity, give a mob a dir to go if they're
* tracking another mob or a PC. Or, a 'track' skill for PCs.
*/
int find_first_step(room_rnum src, room_rnum target)
{
int curr_dir;
room_rnum curr_room;
if (src == NOWHERE || target == NOWHERE || src > top_of_world || target > top_of_world) {
log("SYSERR: Illegal value %d or %d passed to find_first_step. (%s)", src, target, __FILE__);
return (BFS_ERROR);
}
if (src == target)
return (BFS_ALREADY_THERE);
/* clear marks first, some OLC systems will save the mark. */
for (curr_room = 0; curr_room <= top_of_world; curr_room++)
UNMARK(curr_room);
MARK(src);
/* first, enqueue the first steps, saving which direction we're going. */
for (curr_dir = 0; curr_dir < NUM_OF_DIRS; curr_dir++)
if (VALID_EDGE(src, curr_dir)) {
MARK(TOROOM(src, curr_dir));
bfs_enqueue(TOROOM(src, curr_dir), curr_dir);
}
/* now, do the classic BFS. */
while (queue_head) {
if (queue_head->room == target) {
curr_dir = queue_head->dir;
bfs_clear_queue();
return (curr_dir);
} else {
for (curr_dir = 0; curr_dir < NUM_OF_DIRS; curr_dir++)
if (VALID_EDGE(queue_head->room, curr_dir)) {
MARK(TOROOM(queue_head->room, curr_dir));
bfs_enqueue(TOROOM(queue_head->room, curr_dir), queue_head->dir);
}
bfs_dequeue();
}
}
return (BFS_NO_PATH);
}
/********************************************************
* Functions and Commands which use the above functions. *
********************************************************/
ACMD(do_track)
{
char arg[MAX_INPUT_LENGTH];
struct char_data *vict;
int dir;
/* The character must have the track skill. */
if (IS_NPC(ch) || !GET_SKILL(ch, SKILL_TRACK)) {
send_to_char(ch, "You have no idea how.\r\n");
return;
}
one_argument(argument, arg);
if (!*arg) {
send_to_char(ch, "Whom are you trying to track?\r\n");
return;
}
/* The person can't see the victim. */
if (!(vict = get_char_vis(ch, arg, NULL, FIND_CHAR_WORLD))) {
send_to_char(ch, "No one is around by that name.\r\n");
return;
}
/* We can't track the victim. */
if (AFF_FLAGGED(vict, AFF_NOTRACK)) {
send_to_char(ch, "You sense no trail.\r\n");
return;
}
/* 101 is a complete failure, no matter what the proficiency. */
if (rand_number(0, 101) >= GET_SKILL(ch, SKILL_TRACK)) {
int tries = 10;
/* Find a random direction. :) */
do {
dir = rand_number(0, NUM_OF_DIRS - 1);
} while (!CAN_GO(ch, dir) && --tries);
send_to_char(ch, "You sense a trail %s from here!\r\n", dirs[dir]);
return;
}
/* They passed the skill check. */
dir = find_first_step(IN_ROOM(ch), IN_ROOM(vict));
switch (dir) {
case BFS_ERROR:
send_to_char(ch, "Hmm.. something seems to be wrong.\r\n");
break;
case BFS_ALREADY_THERE:
send_to_char(ch, "You're already in the same room!!\r\n");
break;
case BFS_NO_PATH:
send_to_char(ch, "You can't sense a trail to %s from here.\r\n", HMHR(vict));
break;
default: /* Success! */
send_to_char(ch, "You sense a trail %s from here!\r\n", dirs[dir]);
break;
}
}
void hunt_victim(struct char_data *ch)
{
int dir;
byte found;
struct char_data *tmp;
if (!ch || !HUNTING(ch) || FIGHTING(ch))
return;
/* make sure the char still exists */
for (found = FALSE, tmp = character_list; tmp && !found; tmp = tmp->next)
if (HUNTING(ch) == tmp)
found = TRUE;
if (!found) {
char actbuf[MAX_INPUT_LENGTH] = "Damn! My prey is gone!!";
do_say(ch, actbuf, 0, 0);
HUNTING(ch) = NULL;
return;
}
if ((dir = find_first_step(IN_ROOM(ch), IN_ROOM(HUNTING(ch)))) < 0) {
char buf[MAX_INPUT_LENGTH];
snprintf(buf, sizeof(buf), "Damn! I lost %s!", HMHR(HUNTING(ch)));
do_say(ch, buf, 0, 0);
HUNTING(ch) = NULL;
} else {
perform_move(ch, dir, 1);
if (IN_ROOM(ch) == IN_ROOM(HUNTING(ch)))
hit(ch, HUNTING(ch), TYPE_UNDEFINED);
}
}