Unify picking crawl goodpos

include/extern.h

@@ -2785,6 +2785,7 @@ extern boolean lava_damage(struct obj *, coordxy, coordxy);
 extern void acid_damage(struct obj *);
 extern int water_damage(struct obj *, const char *, boolean);
 extern void water_damage_chain(struct obj *, boolean);
+extern boolean rnd_nextto_goodpos(coordxy *, coordxy *, struct monst *);
 extern boolean drown(void);
 extern void drain_en(int);
 extern int dountrap(void);

src/trap.c

@@ -4297,6 +4297,36 @@ emergency_disrobe(boolean *lostsome)
     return TRUE;
 }
 
+/* pick a random goodpos() next to x,y for monster mtmp.
+   mtmp could be &g.youmonst, uses then crawl_destination().
+   returns TRUE if any good position found, with the coord in x,y */
+boolean
+rnd_nextto_goodpos(coordxy *x, coordxy *y, struct monst *mtmp)
+{
+    int i, j, k, dirs[N_DIRS];
+    boolean is_u = (mtmp == &g.youmonst);
+    coordxy nx, ny;
+
+    for (i = 0; i < N_DIRS; ++i)
+        dirs[i] = i;
+    for (i = N_DIRS; i > 0; --i) {
+        j = rn2(i);
+        k = dirs[j];
+        dirs[j] = dirs[i - 1];
+        dirs[i - 1] = k;
+    }
+    for (i = 0; i < N_DIRS; ++i) {
+        nx = *x + xdir[dirs[i]];
+        ny = *y + ydir[dirs[i]];
+        /* crawl_destination and goodpos both include an isok() check */
+        if (is_u ? crawl_destination(nx, ny) : goodpos(nx, ny, mtmp, 0)) {
+            *x = nx;
+            *y = ny;
+            return TRUE;
+        }
+    }
+    return FALSE;
+}
 
 /*  return TRUE iff player relocated */
 boolean
@@ -4394,48 +4424,9 @@ drown(void)
     /* can't crawl if unable to move (crawl_ok flag stays false) */
     if (g.multi < 0 || (Upolyd && !g.youmonst.data->mmove))
         goto crawl;
-    /* look around for a place to crawl to */
+    x = u.ux, y = u.uy;
-#if 0
+    if (rnd_nextto_goodpos(&x, &y, &g.youmonst))
-    for (i = 0; i < 100; i++) {
+        crawl_ok = TRUE;
-        x = rn1(3, u.ux - 1);
-        y = rn1(3, u.uy - 1);
-        if (crawl_destination(x, y)) {
-            crawl_ok = TRUE;
-            goto crawl;
-        }
-    }
-    /* one more scan */
-    for (x = u.ux - 1; x <= u.ux + 1; x++)
-        for (y = u.uy - 1; y <= u.uy + 1; y++)
-            if (crawl_destination(x, y)) {
-                crawl_ok = TRUE;
-                goto crawl;
-            }
-#else
-    {
-        int j, k, dirs[N_DIRS];
-
-        /* instead of picking a random direction up to 100 times, try each
-           of the eight directions at most once after shuffling their order */
-        for (i = 0; i < N_DIRS; ++i)
-            dirs[i] = i;
-        for (i = N_DIRS; i > 0; --i) {
-            j = rn2(i);
-            k = dirs[j];
-            dirs[j] = dirs[i - 1];
-            dirs[i - 1] = k;
-        }
-        for (i = 0; i < N_DIRS; ++i) {
-            x = u.ux + xdir[dirs[i]];
-            y = u.uy + ydir[dirs[i]];
-            /* note: crawl_dest calls goodpos() which performs isok() check */
-            if (crawl_destination(x, y)) {
-                crawl_ok = TRUE;
-                break;
-            }
-        }
-    }
-#endif
  crawl:
     if (crawl_ok) {
         boolean lost = FALSE;

src/worm.c

@@ -776,39 +776,9 @@ place_worm_tail_randomly(struct monst *worm, coordxy x, coordxy y)
     new_tail->wy = y;
 
     while (curr) {
-        int nx = 0, ny = 0;
+        coordxy nx = ox, ny = oy;
-#if 0   /* old code */
-        int trycnt = 0;
 
-        /* pick a random direction from x, y and test for goodpos() */
+        if (rnd_nextto_goodpos(&nx, &ny, worm)) {
-        do {
-            random_dir(ox, oy, &nx, &ny);
-        } while (!goodpos(nx, ny, worm, 0) && ++tryct <= 50);
-
-        if (tryct <= 50)
-#else   /* new code */
-        int i, j, k, dirs[N_DIRS];
-
-        /* instead of picking a random direction up to 50 times, try each
-           of the eight directions at most once after shuffling their order */
-        for (i = 0; i < N_DIRS; ++i)
-            dirs[i] = i;
-        for (i = N_DIRS; i > 0; --i) {
-            j = rn2(i);
-            k = dirs[j];
-            dirs[j] = dirs[i - 1];
-            dirs[i - 1] = k;
-        }
-        for (i = 0; i < N_DIRS; ++i) {
-            nx = ox + xdir[dirs[i]];
-            ny = oy + ydir[dirs[i]];
-            if (goodpos(nx, ny, worm, 0)) /* includes an isok() check */
-                break;
-        }
-
-        if (i < N_DIRS)
-#endif
-        {
             place_worm_seg(worm, nx, ny);
             curr->wx = (coordxy) (ox = nx);
             curr->wy = (coordxy) (oy = ny);