Unify getting terrain under drawbridge

include/extern.h

@@ -222,6 +222,7 @@ E boolean FDECL(is_lava, (int,int));
 E boolean FDECL(is_pool_or_lava, (int,int));
 E boolean FDECL(is_ice, (int,int));
 E boolean FDECL(is_moat, (int,int));
+E schar FDECL(db_under_typ, (int));
 E int FDECL(is_drawbridge_wall, (int,int));
 E boolean FDECL(is_db_wall, (int,int));
 E boolean FDECL(find_drawbridge, (int *,int*));

src/dbridge.c

@@ -103,6 +103,18 @@ int x, y;
     return FALSE;
 }
 
+schar
+db_under_typ(mask)
+int mask;
+{
+    switch (mask & DB_UNDER) {
+    case DB_ICE:  return ICE; break;
+    case DB_LAVA: return LAVAPOOL; break;
+    case DB_MOAT: return MOAT; break;
+    default:      return STONE; break;
+    }
+}
+
 /*
  * We want to know whether a wall (or a door) is the portcullis (passageway)
  * of an eventual drawbridge.

src/dungeon.c

@@ -2207,12 +2207,7 @@ recalc_mapseen()
 	    if (cansee(x, y) || (x == u.ux && y == u.uy && !Levitation)) {
 		ltyp = levl[x][y].typ;
 		if (ltyp == DRAWBRIDGE_UP)
-		    switch (levl[x][y].drawbridgemask & DB_UNDER) {
+		    ltyp = db_under_typ(levl[x][y].drawbridgemask);
-			case DB_ICE:  ltyp = ICE; break;
-			case DB_LAVA: ltyp = LAVAPOOL; break;
-			case DB_MOAT: ltyp = MOAT; break;
-			default:      ltyp = STONE; break;
-		    }
 		if ((mtmp = m_at(x, y)) != 0 &&
 			mtmp->m_ap_type == M_AP_FURNITURE && canseemon(mtmp))
 		    ltyp = cmap_to_type(mtmp->mappearance);

src/mkmaze.c

@@ -1157,12 +1157,7 @@ xchar x,y;
 	lev = &levl[x][y];
 	ltyp = lev->typ;
 	if (ltyp == DRAWBRIDGE_UP)
-	    switch (lev->drawbridgemask & DB_UNDER) {
+	    ltyp = db_under_typ(lev->drawbridgemask);
-	    case DB_ICE:  ltyp = ICE; break;
-	    case DB_LAVA: ltyp = LAVAPOOL; break;
-	    case DB_MOAT: ltyp = MOAT; break;
-	    default:      ltyp = STONE; break;
-	    }
 
 	if (ltyp == LAVAPOOL)
 		return "lava";

src/monmove.c

@@ -1305,15 +1305,10 @@ register int x, y;
 {
 	int levtyp = levl[x][y].typ;
 
-	if (levtyp == DRAWBRIDGE_UP) {
+	/* use underlying terrain in front of closed drawbridge */
-	    /* use underlying terrain in front of closed drawbridge */
+	if (levtyp == DRAWBRIDGE_UP)
-	    switch (levl[x][y].drawbridgemask & DB_UNDER) {
+	    levtyp = db_under_typ(levl[x][y].drawbridgemask);
-	    case DB_MOAT:  levtyp = MOAT; break;
+
-	    case DB_LAVA:  levtyp = LAVAPOOL; break;
-	    case DB_ICE:   levtyp = ICE; break;
-	    case DB_FLOOR: levtyp = ROOM; break;
-	    }
-	}
 	return (boolean)(ACCESSIBLE(levtyp) && !closed_door(x, y));
 }