(fuel, load, shp_check_nav, retreat_ship1, shp_nav_one_sector)

(shp_check_nav, sail_nav_fleet, bigcity_dchr[], sector_navigation[])
(d_navigation): Add a NEW d_navigation enum NAV_CANAL to
indicate that a sector has canal capability. Add canal determination
logic to shp_check_nav(). Update sector_navigation[] with new
canal navigation enum.  Use shp_check_nav() to determine the
sector can be navigated.

include/prototypes.h

@@ -684,7 +684,7 @@ extern int shp_sweep(struct emp_qelem *, int, natid);
 extern s_char *shp_path(int, struct shpstr *, s_char *);
 extern void shp_put(struct emp_qelem *, natid);
 extern void shp_list(struct emp_qelem *);
-extern int shp_check_nav(struct sctstr *);
+extern int shp_check_nav(struct sctstr *, struct shpstr *);
 extern int sect_has_dock(struct sctstr *);
 extern int shp_hardtarget(struct shpstr *);
 extern void shp_view(struct emp_qelem *);

include/sect.h

@@ -93,6 +93,7 @@ typedef enum {
     NAV_NONE,	/* ships can't navigate */
     NAVOK,	/* ships can always navigate */
     NAV_02,	/* requires 2% effic to navigate */
+    NAV_CANAL,	/* requires 2% effic to navigate and M_CANAL capability */
     NAV_60	/* requires 60% effic to navigate */
 } d_navigation;
 

src/lib/commands/fuel.c

@@ -121,13 +121,9 @@ fuel(void)
 	    if (!item.ship.shp_own)
 		continue;
 
-	    if ((sect.sct_type != SCT_HARBR)
+	    if (shp_check_nav(&sect, &item.ship) == CN_LANDLOCKED) {
-		&& (sect.sct_type != SCT_WATER)
+		pr("%s is landlocked and cannot be fueled.\n",
-		&& (sect.sct_type != SCT_BSPAN)
+		   prship(&item.ship));
-		&& (!IS_BIG_CITY(sect.sct_type))) {
-		pr("Sector %s is not a harbor, bridge span, or sea.\n",
-		   xyas(item.ship.shp_x, item.ship.shp_y,
-			item.ship.shp_own));
 		continue;
 	    }
 

src/lib/commands/load.c

@@ -153,8 +153,8 @@ load(void)
 	    if (noisy)
 		pr("Sector %s is not a harbor%s%s.\n",
 		   xyas(ship.shp_x, ship.shp_y, player->cnum),
-		   dchr[SCT_CAPIT].d_nav == NAV_02 ? " or a " : "",
+		   dchr[SCT_CAPIT].d_nav == NAV_CANAL ? " or a " : "",
-		   dchr[SCT_CAPIT].d_nav == NAV_02 ?
+		   dchr[SCT_CAPIT].d_nav == NAV_CANAL ?
 		    dchr[SCT_CAPIT].d_name : "");
 	    continue;
 	}

src/lib/global/nsc.c

@@ -787,6 +787,7 @@ struct symbol sector_navigation[] = { /* for d_nav */
     {NAV_NONE, "land"},
     {NAVOK, "sea"},
     {NAV_02, "harbor"},
+    {NAV_CANAL, "canal"},
     {NAV_60, "bridge"},
     {0, NULL}
 };

src/lib/global/sect.c

@@ -44,7 +44,7 @@
 #include "product.h"
 
 struct dchrstr bigcity_dchr = {
-    SCT_CAPIT,   'c',       0, 2,  NAV_02,   UPKG, 1.0, 2.0,   30, 0, 10, 1, 2, 999, "city"
+    SCT_CAPIT,   'c',       0, 2, NAV_CANAL, UPKG, 1.0, 2.0,   30, 0, 10, 1, 2, 999, "city"
 };
 
 struct dchrstr dchr[] = {

src/lib/subs/retreat.c

@@ -188,7 +188,7 @@ retreat_ship1(struct shpstr *sp, s_char code, int orig)
     }
 
     getsect(sp->shp_x, sp->shp_y, &sect);
-    switch (shp_check_nav(&sect)) {
+    switch (shp_check_nav(&sect, sp)) {
     case CN_CONSTRUCTION:
 	wu(0, sp->shp_own,
 	   "%s %s,\nbut was caught in a construction zone, and couldn't retreat!\n",
@@ -262,7 +262,7 @@ retreat_ship1(struct shpstr *sp, s_char code, int orig)
 	mobcost = 480.0 / (mobcost + techfact(sp->shp_tech, mobcost));
 
 	getsect(newx, newy, &sect);
-	if (shp_check_nav(&sect) != CN_NAVIGABLE ||
+	if (shp_check_nav(&sect, sp) != CN_NAVIGABLE ||
 	    (sect.sct_own && !player->owner &&
 	     getrel(getnatp(sect.sct_own), sp->shp_own) < FRIENDLY)) {
 	    wu(0, sp->shp_own, "%s %s,\nbut could not retreat to %s!\n",

src/lib/subs/shpsub.c

@@ -156,7 +156,7 @@ shp_nav(struct emp_qelem *list, double *minmobp, double *maxmobp,
 	    shp_mess("was sucked into the sky by a strange looking spaceship", mlp);	/* heh -KHS */
 	    continue;
 	}
-	switch (shp_check_nav(&sect)) {
+	switch (shp_check_nav(&sect, &ship)) {
 	case CN_CONSTRUCTION:
 	    shp_mess("is caught in a construction zone", mlp);
 	    continue;
@@ -368,12 +368,18 @@ shp_mess(s_char *str, struct mlist *mlp)
 }
 
 int
-shp_check_nav(struct sctstr *sect)
+shp_check_nav(struct sctstr *sect, struct shpstr *shp)
 {
     switch (dchr[sect->sct_type].d_nav) {
     case NAVOK:
 	break;
-
+    case NAV_CANAL:
+	if (mchr[(int)shp->shp_type].m_flags & M_CANAL == M_CANAL) {
+	    if (sect->sct_effic < 2)
+		return CN_CONSTRUCTION;
+	} else
+	    return CN_LANDLOCKED;
+	break;
     case NAV_02:
 	if (sect->sct_effic < 2)
 	    return CN_CONSTRUCTION;
@@ -821,6 +827,7 @@ shp_nav_one_sector(struct emp_qelem *list, int dir, natid actor,
     double tech;		/* for mapping */
     double tf;			/* for mapping */
     s_char dp[80];
+    int navigate;
 
     if (dir <= DIR_STOP || dir >= DIR_VIEW) {
 	shp_put(list, actor);
@@ -834,27 +841,27 @@ shp_nav_one_sector(struct emp_qelem *list, int dir, natid actor,
 	newx = xnorm(mlp->ship.shp_x + dx);
 	newy = ynorm(mlp->ship.shp_y + dy);
 	getsect(newx, newy, &sect);
-	if (shp_check_nav(&sect) != CN_NAVIGABLE ||
+	navigate = shp_check_nav(&sect, &mlp->ship);
+	if (navigate != CN_NAVIGABLE ||
 	    (sect.sct_own && actor != sect.sct_own &&
 	     getrel(getnatp(sect.sct_own), actor) < FRIENDLY)) {
-	    if (together) {
+	    if (dchr[sect.sct_type].d_nav == NAV_CANAL &&
-		mpr(actor, "can't go to %s\n", xyas(newx, newy, actor));
+		!(mlp->mcp->m_flags & M_CANAL) &&
-		return 2;
+		navigate == CN_LANDLOCKED)
-	    } else {
-		sprintf(dp, "can't go to %s", xyas(newx, newy, actor));
-		shp_mess(dp, mlp);
-		continue;
-	    }
-	}
-	if (IS_BIG_CITY(sect.sct_type)) {
-	    if (!(mlp->mcp->m_flags & M_CANAL)) {
 		sprintf(dp,
 			"is too large to fit into the canal system at %s",
 			xyas(newx, newy, actor));
+	    else
+		sprintf(dp, "can't go to %s", xyas(newx, newy, actor));
+	    if (together) {
+		mpr(actor, "%s\n", dp);
+		return 2;
+	    } else {
 		shp_mess(dp, mlp);
 		continue;
 	    }
 	}
+
 	if (mlp->mobil <= 0.0) {
 	    shp_mess("is out of mobility", mlp);
 	    continue;

src/lib/update/sail.c

@@ -216,7 +216,6 @@ sail_nav_fleet(struct fltheadstr *fltp)
     natid own;
     struct emp_qelem ship_list;
     int dir;
-    int canal = 1;
 
 #ifdef SAILDEBUG
     switch (fltp->real_q) {
@@ -239,6 +238,7 @@ sail_nav_fleet(struct fltheadstr *fltp)
 	wu(0, fltp->own, " %d", fe->num);
     wu(0, fltp->own, "\n");
 #endif
+    sectp = getsectp(fltp->x, fltp->y);
     for (fe = fltp->head; fe; fe = fe->next) {
 	sp = getshipp(fe->num);
 	if (sp->shp_item[I_MILIT] == 0 && sp->shp_item[I_CIVIL] == 0) {
@@ -246,28 +246,22 @@ sail_nav_fleet(struct fltheadstr *fltp)
 	       "   ship #%d (%s) is crewless and can't go on\n",
 	       fe->num, cname(fe->own));
 	    error = 1;
-	} else if (!(mchr[sp->shp_type].m_flags & M_CANAL))
+	}
-	    canal = 0;
+        if ((shp_check_nav(sectp, sp) == CN_LANDLOCKED) &&
+	    (dchr[sectp->sct_type].d_nav == NAV_CANAL)) {
+	    wu(0, fltp->own,
+	       "Your ship #%d (%s) is too big to fit through the canal.\n",
+	       fe->num, cname(fe->own));
+	    error = 1;
+	}
     }
     if (error)
 	return 0;
+    sp = getshipp(fltp->leader);
     sectp = getsectp(fltp->x, fltp->y);
-    switch (shp_check_nav(sectp)) {
+    if (shp_check_nav(sectp, sp) != CN_NAVIGABLE)
-    case CN_NAVIGABLE:
-	if (IS_BIG_CITY(sectp->sct_type) && !canal) {
-	    wu(0, fltp->own,
-	       "Your fleet lead by %d is too big to fit through the canal.\n",
-	       fltp->leader);
-	    return 0;
-	}
-	break;
-    case CN_CONSTRUCTION:
-    case CN_LANDLOCKED:
-    default:
 	wu(0, fltp->own, "Your fleet lead by %d is trapped by land.\n",
 	   fltp->leader);
-	return 0;
-    }
     sp = getshipp(fltp->leader);
     own = sp->shp_own;
     fltp_to_list(fltp, &ship_list);	/* hack -KHS 1995 */