Designate high altars with dedicated altarmask bit

High altars and normal temple altars had identical altarmasks, so
there was no way to distinguish between the two based on the altarmask
alone.  Instead, anywhere it was necessary to determine whether an altar
was a high altar included a check whether the hero was currently the
Astral Plane or Moloch's Sanctum, and assumed any temple altar was the
high altar.

Since there's an extra, unused bit in altarmask anyway, use it to
explicitly mark high altars -- the lua level files already distinguish
between normal temple altars and so-called 'sanctum' altars anyway, so
rather than throwing away this distinction when generating the level,
keep it in the altarmask and use it in place of various u.uz checks.

I think this would require incrementing EDITLEVEL again...

include/align.h

@@ -34,11 +34,13 @@ typedef struct align { /* alignment & record */
 /* Some altars are considered shrines, add a flag for that
    for the altarmask field of struct rm. */
 #define AM_SHRINE       0x08
+/* High altar on Astral plane or Moloch's sanctum */
+#define AM_SANCTUM      0x10
 
 /* special level flags, gone by the time the level has been loaded */
-#define AM_SPLEV_CO     0x10 /* co-aligned: force alignment to match hero's  */
-#define AM_SPLEV_NONCO  0x20 /* non-co-aligned: force alignment to not match */
-#define AM_SPLEV_RANDOM 0x40
+#define AM_SPLEV_CO     0x20 /* co-aligned: force alignment to match hero's  */
+#define AM_SPLEV_NONCO  0x40 /* non-co-aligned: force alignment to not match */
+#define AM_SPLEV_RANDOM 0x80
 
 #define Amask2align(x) \
     ((aligntyp) ((((x) & AM_MASK) == 0) ? A_NONE                \

include/display.h

@@ -544,10 +544,9 @@ enum glyph_offsets {
             (((mon)->female == 0) ? GLYPH_PET_MALE_OFF : GLYPH_PET_FEM_OFF))
 
 #define altar_to_glyph(amsk) \
-    (((amsk & (AM_MASK | AM_SHRINE)) == AM_NONE)               \
+    (((amsk & (AM_MASK | AM_SHRINE | AM_SANCTUM)) == AM_NONE)  \
        ? (GLYPH_ALTAR_OFF + altar_unaligned)                   \
-       : (((amsk & AM_SHRINE) == AM_SHRINE)                    \
-          && (Is_astralevel(&u.uz) || Is_sanctum(&u.uz)))      \
+       : ((amsk & AM_SANCTUM) == AM_SANCTUM)                   \
           ? (GLYPH_ALTAR_OFF + altar_other)                    \
           : ((amsk & AM_MASK) == AM_CHAOTIC)                   \
             ? (GLYPH_ALTAR_OFF + altar_chaotic)                \

src/invent.c

@@ -3989,10 +3989,7 @@ dfeature_at(int x, int y, char *buf)
         cmap = S_sink; /* "sink" */
     else if (IS_ALTAR(ltyp)) {
         Sprintf(altbuf, "%saltar to %s (%s)",
-                ((lev->altarmask & AM_SHRINE)
-                 && (Is_astralevel(&u.uz) || Is_sanctum(&u.uz)))
-                    ? "high "
-                    : "",
+                (lev->altarmask & AM_SANCTUM) ? "high " : "",
                 a_gname(),
                 align_str(Amask2align(lev->altarmask & ~AM_SHRINE)));
         dfeature = altbuf;

src/music.c

@@ -292,12 +292,10 @@ do_earthquake(int force)
                     pline_The("kitchen sink falls%s.", into_a_chasm);
                 goto do_pit;
             case ALTAR:
-                /* always preserve the high altars */
-                if (Is_astralevel(&u.uz) || Is_sanctum(&u.uz))
-                    break;
-                /* no need to check for high altar here; we've just
-                   excluded those */
                 amsk = altarmask_at(x, y);
+                /* always preserve the high altars */
+                if ((amsk & AM_SANCTUM) != 0)
+                    break;
                 algn = Amask2align(amsk & AM_MASK);
                 if (cansee(x, y))
                     pline_The("%s altar falls%s.",

src/pager.c

@@ -619,13 +619,11 @@ lookat(int x, int y, char *buf, char *monbuf)
             Sprintf(buf, "%s %saltar",
                     /* like endgame high priests, endgame high altars
                        are only recognizable when immediately adjacent */
-                    (Is_astralevel(&u.uz) && !next2u(x, y))
+                    (Is_astralevel(&u.uz) && !next2u(x, y)
+                     && (amsk & AM_SANCTUM))
                         ? "aligned"
                         : align_str(algn),
-                    ((amsk & AM_SHRINE) != 0
-                     && (Is_astralevel(&u.uz) || Is_sanctum(&u.uz)))
-                        ? "high "
-                        : "");
+                    (amsk & AM_SANCTUM) ? "high " : "");
             break;
         case S_ndoor:
             if (is_drawbridge_wall(x, y) >= 0)

src/pray.c

@@ -1468,8 +1468,7 @@ dosacrifice(void)
         You("are not standing on an altar.");
         return ECMD_OK;
     }
-    highaltar = ((Is_astralevel(&u.uz) || Is_sanctum(&u.uz))
-                 && (levl[u.ux][u.uy].altarmask & AM_SHRINE));
+    highaltar = (levl[u.ux][u.uy].altarmask & AM_SANCTUM);
 
     otmp = floorfood("sacrifice", 1);
     if (!otmp)

src/sp_lev.c

@@ -2330,6 +2330,8 @@ create_altar(altar* a, struct mkroom* croom)
     if (a->shrine) { /* Is it a shrine  or sanctum? */
         priestini(&u.uz, croom, x, y, (a->shrine > 1));
         levl[x][y].altarmask |= AM_SHRINE;
+        if (a->shrine == 2) /* high altar or sanctum */
+            levl[x][y].altarmask |= AM_SANCTUM;
         g.level.flags.has_temple = TRUE;
     }
 }