/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2000, Dave Pare, Jeff Bailey, Thomas Ruschak,
- * Ken Stevens, Steve McClure
+ * Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ * Ken Stevens, Steve McClure, Markus Armbruster
*
- * This program is free software; you can redistribute it and/or modify
+ * Empire is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* ---
*
- * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
- * related information and legal notices. It is expected that any future
- * projects/authors will amend these files as needed.
+ * See files README, COPYING and CREDITS in the root of the source
+ * tree for related information and legal notices. It is expected
+ * that future projects/authors will amend these files as needed.
*
* ---
*
- * path.c: Empire/A* Interface code. Provides callbacks for A* code and
- * a sector cache to speed things up. Define BP_STATS for sector
- * cache statistics, AS_STATS for A* statistics.
- *
+ * path.c: Path finding interface code
+ *
* Known contributors to this file:
* Phil Lapsley, 1991
* Dave Pare, 1991
* Thomas Ruschak, 1993
* Steve McClure, 1997
+ * Markus Armbruster, 2011
*/
-#include <stdio.h>
-#include <stdlib.h>
-#include "../as/as.h"
-#include "misc.h"
-#include "path.h"
-#include "xy.h"
-#include "sect.h"
+#include <config.h>
+
+#include <string.h>
#include "file.h"
-#include "common.h"
-#include "gen.h"
#include "optlist.h"
+#include "path.h"
+#include "sect.h"
+#include "xy.h"
-/* STM - The server is now reliant on the sector file being
- * memory mapped for other things. So, this code has been
- * setup to have the sector hashing #ifdef'd instead so that
- * we don't have to do runtime checking. If someone moves
- * the sector file to me non-memory mapped, they have larger
- * problems than this, and can just turn this back on. Then
- * again, their performance will be so bad going to a file
- * all the time, it won't matter. */
-
-/*#define DO_EFF_MEM_CHECKING*/
-
-
-/* XXX won't need sector hash when sect file is memory mapped */
-
-#define BP_SCTHASHSIZE 128 /* sector cache hash table size */
-#define BP_ASHASHSIZE 128 /* A* queue hash table size */
-#define BP_NEIGHBORS 6 /* max number of neighbors */
-
-struct sctcache {
- coord x, y;
- struct sctstr *sp;
- struct sctcache *next;
-};
-
-struct bestp {
- struct sctcache *sctcachetab[BP_SCTHASHSIZE];
- int sctcache_hits;
- int sctcache_misses;
- int bp_mobtype;
- struct as_data *adp;
-};
-
-#ifdef DO_EFF_MEM_CHECKING
-
-static struct sctstr *bp_getsect(struct bestp *bp, coord x, coord y);
-static struct sctstr *bp_sctcache_get(struct bestp *bp, coord x, coord y);
-static void bp_sctcache_set(struct bestp *bp, coord x, coord y, struct sctstr *sp);
-static void bp_sctcache_zap(struct bestp *bp);
-
-#endif /* DO_EFF_MEM_CHECKING */
-
-static int bp_path(struct as_path *pp, s_char *buf);
-static int bp_neighbors(struct as_coord c, struct as_coord *cp, s_char *pp);
-static double bp_lbcost(struct as_coord from, struct as_coord to, s_char *pp);
-static double bp_realcost(struct as_coord from, struct as_coord to, s_char *pp);
-static double bp_seccost(struct as_coord from, struct as_coord to, s_char *pp);
-static int bp_coord_hash(struct as_coord c);
-
-struct empfile *ep;
-
-/* We use this for caching neighbors. It never changes except
- * at reboot time (maybe) so we never need to free it */
-struct sctstr **neighsects = (struct sctstr **)0;
-
-s_char *
-bp_init(void)
-{
- struct bestp *bp;
-
- ep = &empfile[EF_SECTOR];
-
- bp = (struct bestp *) malloc(sizeof(*bp));
- bzero((s_char *)bp, sizeof(*bp));
- bp->adp = as_init(BP_NEIGHBORS, BP_ASHASHSIZE, bp_coord_hash,
- bp_neighbors, bp_lbcost, bp_realcost,
- bp_seccost, (s_char *)bp);
-
- if (bp->adp == NULL)
- return NULL;
-
- if (neighsects == (struct sctstr **)0)
- neighsects = (struct sctstr **)calloc(1, (sizeof(struct sctstr *) *
- ((WORLD_X * WORLD_Y)/2)*6));
-
- return (s_char *) bp;
-}
-
-/*
- * Find the best path from sector to to sector, and put the Empire movement
- * string in path. Return 0 on success, -1 on error.
- */
-int
-best_path(struct sctstr *from, struct sctstr *to, s_char *path, int mob_type)
-{
- static struct bestp *mybestpath;
- struct as_data *adp;
- struct as_path *ap;
-
- if (mybestpath == 0)
- mybestpath = (struct bestp *)bp_init();
- adp = mybestpath->adp;
-#ifdef DO_EFF_MEM_CHECKING
- bp_sctcache_zap(mybestpath);
-#endif
- ap = as_find_cachepath(from->sct_x, from->sct_y, to->sct_x, to->sct_y);
- if (ap == NULL) {
- adp->from.x = from->sct_x;
- adp->from.y = from->sct_y;
- adp->to.x = to->sct_x;
- adp->to.y = to->sct_y;
- mybestpath->bp_mobtype = mob_type;
-
- if (as_search(adp) < 0)
- return -1;
- ap = adp->path;
- }
-
- if (bp_path(ap, path) < 0)
- return -1;
-
-#ifdef AS_STATS
- as_stats(adp, stderr);
-#endif /* AS_STATS */
-#ifdef BP_STATS
- fprintf(stderr, "best path %s\n", path);
- fprintf(stderr, "cache hits/misses: %d/%d\n",
- bp->sctcache_hits, bp->sctcache_misses);
-#endif /* BP_STATS */
- return 0;
-}
-
-/*
- * Translate an A* path into an empire movement string. Return 0 on
- * success, -1 on failure.
- */
-static int
-bp_path(struct as_path *pp, s_char *buf)
-{
- struct as_path *np;
- s_char *cp = buf;
- int dx, dy;
- int n;
-
- np = pp->next;
- while (np) {
- dx = np->c.x - pp->c.x;
- /* deal with wraparound from non-neg coords */
- if (dx < -2)
- dx += WORLD_X;
- else if (dx > 2)
- dx -= WORLD_X;
- dy = np->c.y - pp->c.y;
- if (dy < -1)
- dy += WORLD_Y;
- else if (dy > 1)
- dy -= WORLD_Y;
- for (n=1;n<=6;n++)
- if (dx == diroff[n][0] && dy == diroff[n][1])
- break;
- if (n > 6)
- return -1;
-
- *cp++ = dirch[n];
- pp = np;
- np = np->next;
- }
- *cp = '\0';
- return 0;
-}
-
-/*
- * Find coords neighboring this sector; return number of such
- * coords, and coordinartes themselves in an array pointed
- * to by *cpp.
- * XXX need to check ownership, sector types, etc.
- */
-static int
-bp_neighbors(struct as_coord c, struct as_coord *cp, s_char *pp)
-{
-#ifdef DO_EFF_MEM_CHECKING
- struct bestp *bp = (struct bestp *) pp;
-#endif /* DO_EFF_MEM_CHECKING */
- coord x, y;
- coord nx, ny;
- int n = 0, q;
- struct sctstr *sp, *from, **ssp;
- /* Six pointers, just in case our cache isn't there */
- struct sctstr *tsp[] = { 0, 0, 0, 0, 0, 0 };
- int sx, sy, offset;
-
- x = c.x;
- y = c.y;
-#ifdef DO_EFF_MEM_CHECKING
- if ((ep->flags & EFF_MEM) == 0) {
- from = bp_getsect(bp, x, y);
- } else {
-#endif /* DO_EFF_MEM_CHECKING */
- sx = XNORM(x);
- sy = YNORM(y);
- offset = (sy * WORLD_X + sx) / 2;
- from = (struct sctstr *) (ep->cache + ep->size * offset);
-#ifdef DO_EFF_MEM_CHECKING
- }
-#endif /* DO_EFF_MEM_CHECKING */
-
- if (neighsects == (struct sctstr **)0)
- ssp = (struct sctstr **)&tsp[0];
- else
- ssp = (struct sctstr **)&neighsects[offset * 6];
- for (q = 1; q <= 6; q++, ssp++) {
- if (*ssp == (struct sctstr *)0) {
- /* We haven't cached this neighbor yet */
- nx = x + diroff[q][0];
- ny = y + diroff[q][1];
- sx = XNORM(nx);
- sy = YNORM(ny);
-#ifdef DO_EFF_MEM_CHECKING
- if ((ep->flags & EFF_MEM) == 0) {
- sp = bp_getsect(bp, nx, ny);
- } else {
-#endif /* DO_EFF_MEM_CHECKING */
- offset = (sy * WORLD_X + sx) / 2;
- sp = (struct sctstr *) (ep->cache + ep->size * offset);
- /* We can only save in our neighbor cache if the
- sector file is in memory */
- *ssp = sp;
-#ifdef DO_EFF_MEM_CHECKING
- }
-#endif /* DO_EFF_MEM_CHECKING */
- } else {
- sp = *ssp;
- sx = XNORM(sp->sct_x);
- sy = YNORM(sp->sct_y);
- }
- /* No need to calculate cost each time, just make sure we can
- move through it. We calculate it later. */
- if (dchr[sp->sct_type].d_mcst == 0)
- continue;
- if (sp->sct_own != from->sct_own)
- continue;
- cp[n].x = sx;
- cp[n].y = sy;
- n++;
- }
- return (n);
-}
-
-/*
- * Compute a lower-bound on the cost from "from" to "to".
- */
-/*ARGSUSED*/
-static double
-bp_lbcost(struct as_coord from, struct as_coord to, s_char *pp)
-{
- struct bestp *bp = (struct bestp *) pp;
- struct sctstr *ts;
- float cost;
- int x, y, sx, sy, offset;
-
-#ifdef DO_EFF_MEM_CHECKING
- if ((ep->flags & EFF_MEM) == 0) {
- ts = bp_getsect(bp, (coord)to.x, (coord)to.y);
- } else {
-#endif /* DO_EFF_MEM_CHECKING */
- x = to.x;
- y = to.y;
- sx = XNORM(x);
- sy = YNORM(y);
- offset = (sy * WORLD_X + sx) / 2;
- ts = (struct sctstr *)(ep->cache + ep->size * offset);
-#ifdef DO_EFF_MEM_CHECKING
- }
-#endif /* DO_EFF_MEM_CHECKING */
- cost = sector_mcost(ts, bp->bp_mobtype);
- return (cost);
-}
-
-/*
- * Compute the real cost to move from "from" to "to".
- */
-static double
-bp_realcost(struct as_coord from, struct as_coord to, s_char *pp)
-{
- return (bp_lbcost(from, to, pp));
-}
-
-/*
- * Tie breaker secondary metric (only used when lower bound costs
- * are equal).
- */
-/*ARGSUSED*/
-static double
-bp_seccost(struct as_coord from, struct as_coord to, s_char *pp)
-{
- return ((double) mapdist((coord)from.x, (coord)from.y,
- (coord)to.x, (coord)to.y));
-}
-
-#ifdef DO_EFF_MEM_CHECKING
-
-/*
- * Get a sector from the cache. If it's not in the cache,
- * get it from disk and add it to the cache.
- */
-static struct sctstr *
-bp_getsect(struct bestp *bp, coord x, coord y)
-{
- struct sctstr *sp;
-
- sp = bp_sctcache_get(bp, x, y);
- if (sp == NULL) {
- sp = (struct sctstr *) malloc(sizeof(*sp));
- getsect(x, y, sp);
- bp_sctcache_set(bp, x, y, sp);
- bp->sctcache_misses++;
- } else {
- bp->sctcache_hits++;
- }
- return (sp);
-}
-
-/*
- * Get a sector from the cache; return NULL if it's not there.
- */
-static struct sctstr *
-bp_sctcache_get(struct bestp *bp, coord x, coord y)
-{
- int hashval;
- struct as_coord c;
- struct sctcache *hp;
-
- c.x = x;
- c.y = y;
- hashval = bp_coord_hash(c) % BP_SCTHASHSIZE;
- for (hp = bp->sctcachetab[hashval]; hp; hp = hp->next) {
- if (hp->x == x && hp->y == y)
- return (hp->sp);
- }
- return (NULL);
-}
-
-/*
- * Put a sector in the cache.
- */
-static void
-bp_sctcache_set(struct bestp *bp, coord x, coord y, struct sctstr *sp)
-{
- int hashval;
- struct as_coord c;
- struct sctcache *hp;
-
- hp = (struct sctcache *) calloc(1, sizeof(*hp));
- hp->x = x;
- hp->y = y;
- hp->sp = sp;
- c.x = x;
- c.y = y;
- hashval = bp_coord_hash(c) % BP_SCTHASHSIZE;
- hp->next = bp->sctcachetab[hashval];
- bp->sctcachetab[hashval] = hp;
-}
-
-/*
- * Zap the cache and reset statistics.
- */
-static void
-bp_sctcache_zap(struct bestp *bp)
-{
- register struct sctcache *hp;
- register struct sctcache *np;
- register int i;
-
- for (i = 0; i < BP_SCTHASHSIZE; i++) {
- for (hp = bp->sctcachetab[i]; hp; hp = np) {
- np = hp->next;
- free(hp->sp);
- free(hp);
- }
- bp->sctcachetab[i] = NULL;
- }
- bp->sctcache_hits = 0;
- bp->sctcache_misses = 0;
-}
-
-#endif /* DO_EFF_MEM_CHECKING */
-
-/*
- * Hash a coordinate into an integer.
- */
-static int
-bp_coord_hash(struct as_coord c)
-{
- return ((abs(c.x) + 1) << 3) ^ abs(c.y);
-}
-
-void
-bp_enable_cachepath()
-{
- as_enable_cachepath();
-}
-
-void
-bp_disable_cachepath()
-{
- as_disable_cachepath();
-}
-
-void
-bp_clear_cachepath()
-{
- as_clear_cachepath();
-}
-
-double
-pathcost(struct sctstr *start, s_char *path, int mob_type)
+char *
+BestLandPath(char *path,
+ struct sctstr *from,
+ struct sctstr *to, double *cost, int mob_type)
{
- register int o;
- register int cx, cy;
- double cost = 0.0;
- struct sctstr *sp;
- int sx, sy, offset;
+ double c;
+ size_t len;
- cx = start->sct_x;
- cy = start->sct_y;
-
- while (*path) {
- if (*path == 'h') {
- path++;
- continue;
- }
- o = dirindex[(int)((*path) - 'a')];
- cx += diroff[o][0];
- cy += diroff[o][1];
- sx = XNORM(cx);
- sy = YNORM(cy);
- offset = (sy * WORLD_X + sx) / 2;
- sp = (struct sctstr *)(ep->cache + ep->size * offset);
- cost += sector_mcost(sp, mob_type);
- path++;
- }
+ *cost = 0.0;
+ *path = 0;
- return cost;
+ /*
+ * Note: passing from->sct_own for actor is funny, but works: its
+ * only effect is to confine the search to that nation's land. It
+ * doesn't affect mobility costs. The real actor is different for
+ * marching in allied land, and passing it would break path
+ * finding there.
+ */
+ c = path_find(from->sct_x, from->sct_y, to->sct_x, to->sct_y,
+ from->sct_own, mob_type);
+ if (c < 0)
+ return NULL;
+ len = path_find_route(path, 1024,
+ from->sct_x, from->sct_y,
+ to->sct_x, to->sct_y);
+ if (len + 1 >= 1024)
+ return NULL;
+ strcpy(path + len, "h");
+ *cost = c;
+ return path;
}
-s_char *
-BestDistPath(s_char *path,
+char *
+BestDistPath(char *path,
struct sctstr *from,
- struct sctstr *to,
- double *cost,
- int mob_type)
+ struct sctstr *to, double *cost)
{
- return BestLandPath(path, from, to, cost, mob_type);
+ return BestLandPath(path, from, to, cost, MOB_MOVE);
}
-s_char *
-BestLandPath(s_char *path,
- struct sctstr *from,
- struct sctstr *to,
- double *cost,
- int mob_type)
+char *
+BestShipPath(char *path, int fx, int fy, int tx, int ty, int owner)
{
- int length;
+ size_t len;
- *path = 0;
- *cost = 0.0;
- if (best_path(from, to, path, mob_type) < 0)
- return (s_char *)0;
- *cost = pathcost(from, path, mob_type);
- length = strlen(path);
- path[length] = 'h';
- path[length + 1] = '\0';
+ if (path_find(fx, fy, tx, ty, owner, MOB_SAIL) < 0)
+ return NULL;
+ len = path_find_route(path, 100, fx, fy, tx, ty);
+ if (len >= 100)
+ return NULL;
+ if (len == 0)
+ strcpy(path, "h");
return path;
}
-s_char *
-BestShipPath(s_char *path,
- int fx,
- int fy,
- int tx,
- int ty,
- int owner)
+char *
+BestAirPath(char *path, int fx, int fy, int tx, int ty)
{
- s_char *map;
-
- /* need to make sector database available to bestpath */
- map = ef_ptr(EF_BMAP, owner);
-
- return (bestownedpath(path, map, fx, fy, tx, ty, ".=h", owner));
-}
+ size_t len;
-s_char *
-BestAirPath(s_char *path,
- int fx,
- int fy,
- int tx,
- int ty)
-{
- return (bestownedpath(path, 0, fx, fy, tx, ty, "", -1));
- /* return (bestpath(path, fx, fy, tx, ty, ""));*/
+ if (path_find(fx, fy, tx, ty, 0, MOB_FLY) < 0)
+ return NULL;
+ len = path_find_route(path, 100, fx, fy, tx, ty);
+ if (len >= 100)
+ return NULL;
+ if (len == 0)
+ strcpy(path, "h");
+ return path;
}
-
projects / empserver / blobdiff