After discussion with dpeg, added a Scroll of Antimagic,

taking probability (equal to ?oHolyWord) from the ?oPaper.

Effects apply to all creatures within LOS, including you,
with no magic resistance check:
- Remove all magical enchantments (e.g. Haste, but not Poison)
- Cut magic resistance in half for 40 turns. (This does not
  affect magic-immunes.)

Balance testing, etc., needed.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@7211 c06c8d41-db1a-0410-9941-cceddc491573

10 files changed, 146 insertions, 96 deletions

diff --git a/crawl-ref/source/acr.cc b/crawl-ref/source/acr.cc
index a81e3b017d..0d8d9afdee 100644
--- a/crawl-ref/source/acr.cc
+++ b/crawl-ref/source/acr.cc
@@ -2750,6 +2750,7 @@ static void _decrement_durations()
 
     _decrement_a_duration(DUR_BARGAIN, "You feel less charismatic.");
     _decrement_a_duration(DUR_CONF, "You feel less confused.");
+    _decrement_a_duration(DUR_LOWERED_MR, "You feel more resistant to magic.");
 
     if (you.duration[DUR_PARALYSIS] || you.duration[DUR_PETRIFIED])
     {
diff --git a/crawl-ref/source/enum.h b/crawl-ref/source/enum.h
index 13acab5ed4..6856219604 100644
--- a/crawl-ref/source/enum.h
+++ b/crawl-ref/source/enum.h
@@ -1129,6 +1129,7 @@ enum duration_type
     DUR_SAGE,
     DUR_TELEPATHY,
     DUR_PETRIFIED,
+    DUR_LOWERED_MR,
 
     NUM_DURATIONS
 };
@@ -1166,6 +1167,7 @@ enum enchant_type
     ENCH_NEUTRAL,
     ENCH_PETRIFYING,
     ENCH_PETRIFIED,
+    ENCH_LOWERED_MR,
 
     // Update enchantment names in mon-util.cc when adding or removing
     // enchantments.
diff --git a/crawl-ref/source/item_use.cc b/crawl-ref/source/item_use.cc
index 8ae9be4044..a63819553e 100644
--- a/crawl-ref/source/item_use.cc
+++ b/crawl-ref/source/item_use.cc
@@ -4271,17 +4271,50 @@ static bool _scroll_modify_item(item_def scroll)
     return (false);
 }
 
-void read_scroll( int slot )
+static void _antimagic_scroll()
 {
-    int affected = 0;
-    int i;
-    int count;
-    int nthing;
-    struct bolt beam;
+    // First cast antimagic on yourself.
+    antimagic();
+
+    const enchant_type lost_enchantments[] = {
+        ENCH_SLOW,
+        ENCH_HASTE,
+        ENCH_FEAR,
+        ENCH_CONFUSION,
+        ENCH_INVIS,
+        ENCH_BACKLIGHT,
+        ENCH_CHARM,
+        ENCH_PARALYSIS,
+        ENCH_PETRIFYING,
+        ENCH_PETRIFIED
+    };
+
+    mon_enchant lowered_mr(ENCH_LOWERED_MR, 1, KC_YOU, 40);
+
+    // All nearby creatures lose all magical enchantments, and halve
+    // their MR halved (if they're not magic-immune.)
+    for (radius_iterator ri(you.pos(), LOS_RADIUS); ri; ++ri)
+    {
+        const unsigned short targ_monst = env.mgrid(*ri);
+        if (targ_monst != NON_MONSTER)
+        {
+            monsters& mon = menv[targ_monst];
+            for (unsigned int i = 0; i < ARRAYSZ(lost_enchantments); ++i)
+                mon.del_ench(lost_enchantments[i], true, true);
+            
+            mon.add_ench(lowered_mr);
+            
+            // Annoying but not enough to turn friendlies against you.
+            behaviour_event(&mon, ME_ANNOY, MHITYOU);
+        }
+    }
 
-    // added: scroll effects are never tracers.
-    beam.is_tracer = false;
+    you.duration[DUR_LOWERED_MR] = 40;
+    mpr("Magic dampens around you!");
+}
 
+void read_scroll(int slot)
+{
     if (you.duration[DUR_BERSERKER])
     {
         canned_msg(MSG_TOO_BERSERK);
@@ -4461,16 +4494,20 @@ void read_scroll( int slot )
         break;
 
     case SCR_IMMOLATION:
+    {
         mpr("The scroll explodes in your hands!");
         // We do this here to prevent it from blowing itself up.
         set_ident_type( scroll, ID_KNOWN_TYPE );
         dec_inv_item_quantity( item_slot, 1 );
 
-        // unsure about this    // BEAM_EXPLOSION instead? {dlb}
-        beam.flavour      = BEAM_FIRE;
+        bolt beam;
+
+        beam.is_tracer = false;
 
+        // unsure about this: BEAM_EXPLOSION instead? {dlb}
+        beam.flavour      = BEAM_FIRE;
         beam.type         = dchar_glyph(DCHAR_FIRED_BURST);
-        beam.damage       = dice_def( 3, 10 );
+        beam.damage       = dice_def(3, 10);
         beam.target       = you.pos();
         beam.name         = "fiery explosion";
         beam.colour       = RED;
@@ -4485,21 +4522,20 @@ void read_scroll( int slot )
 
         explosion(beam, false, false, true, true, true, false);
         break;
+    }
 
     case SCR_CURSE_WEAPON:
-        nthing = you.equip[EQ_WEAPON];
-
-        if (nthing == -1
-            || you.inv[nthing].base_type != OBJ_WEAPONS
-            || item_cursed( you.inv[nthing] ))
+        if (!you.weapon()
+            || you.weapon()->base_type != OBJ_WEAPONS
+            || item_cursed(*you.weapon()))
         {
             canned_msg(MSG_NOTHING_HAPPENS);
             id_the_scroll = false;
         }
         else
-        {
+        {             
             // Also sets wield_change.
-            do_curse_item( you.inv[nthing], false );
+            do_curse_item( *you.weapon(), false );
             learned_something_new(TUT_YOU_CURSED);
         }
         break;
@@ -4566,15 +4602,16 @@ void read_scroll( int slot )
         break;
 
     case SCR_CURSE_ARMOUR:
+    {
         // make sure there's something to curse first
-        count = 0;
-        affected = EQ_WEAPON;
-        for (i = EQ_CLOAK; i <= EQ_BODY_ARMOUR; i++)
+        int count = 0;
+        int affected = EQ_WEAPON;
+        for (int i = EQ_CLOAK; i <= EQ_BODY_ARMOUR; i++)
         {
-            if (you.equip[i] != -1 && !item_cursed( you.inv[you.equip[i]] ))
+            if (you.equip[i] != -1 && !item_cursed(you.inv[you.equip[i]]))
             {
                 count++;
-                if (one_chance_in( count ))
+                if (one_chance_in(count))
                     affected = i;
             }
         }
@@ -4590,6 +4627,7 @@ void read_scroll( int slot )
         do_curse_item( you.inv[you.equip[affected]], false );
         learned_something_new(TUT_YOU_CURSED);
         break;
+    }
 
     case SCR_HOLY_WORD:
     {
@@ -4625,6 +4663,10 @@ void read_scroll( int slot )
         break;
     }
 
+    case SCR_ANTIMAGIC:
+        _antimagic_scroll();
+        break;
+
     default:
         mpr("Read a buggy scroll, please report this.");
         break;
@@ -4649,7 +4691,7 @@ void read_scroll( int slot )
          // a dangerous monster nearby...
         xom_is_stimulated(255);
     }
-}                               // end read_scroll()
+}
 
 void examine_object(void)
 {
diff --git a/crawl-ref/source/itemname.cc b/crawl-ref/source/itemname.cc
index 3a7d4f05c2..fd6dcb96fb 100644
--- a/crawl-ref/source/itemname.cc
+++ b/crawl-ref/source/itemname.cc
@@ -551,6 +551,7 @@ static const char* scroll_type_name(int scrolltype)
     case SCR_RECHARGING:         return "recharging";
     case SCR_ENCHANT_WEAPON_III: return "enchant weapon III";
     case SCR_HOLY_WORD:          return "holy word";
+    case SCR_ANTIMAGIC:          return "antimagic";
     default:                     return "bugginess";
     }
 }
diff --git a/crawl-ref/source/itemprop.h b/crawl-ref/source/itemprop.h
index 65ff241f7b..aae23b1768 100644
--- a/crawl-ref/source/itemprop.h
+++ b/crawl-ref/source/itemprop.h
@@ -318,6 +318,7 @@ enum scroll_type
     SCR_RECHARGING,
     SCR_ENCHANT_WEAPON_III,
     SCR_HOLY_WORD,
+    SCR_ANTIMAGIC,
     NUM_SCROLLS
 };
 
diff --git a/crawl-ref/source/makeitem.cc b/crawl-ref/source/makeitem.cc
index d4dcf01cfa..cedc817167 100644
--- a/crawl-ref/source/makeitem.cc
+++ b/crawl-ref/source/makeitem.cc
@@ -2374,72 +2374,57 @@ static void _generate_scroll_item(item_def& item, int force_type,
         item.sub_type = force_type;
     else
     {
-        // only used in certain cases {dlb}
         const int depth_mod = random2(1 + item_level);
-        const int temp_rand = random2(935);
 
-        item.sub_type =
-            ((temp_rand > 766) ? SCR_IDENTIFY :          // 17.97%
-             (temp_rand > 644) ? SCR_REMOVE_CURSE :      // 13.05%
-             (temp_rand > 569) ? SCR_TELEPORTATION :     //  8.02%
-             (temp_rand > 509) ? SCR_DETECT_CURSE :      //  6.42%
-             (temp_rand > 479) ? SCR_FEAR :              //  3.21%
-             (temp_rand > 449) ? SCR_NOISE :             //  3.21%
-             (temp_rand > 419) ? SCR_MAGIC_MAPPING :     //  3.21%
-             (temp_rand > 389) ? SCR_FOG :               //  3.21%
-             (temp_rand > 359) ? SCR_RANDOM_USELESSNESS ://  3.21%
-             (temp_rand > 329) ? SCR_CURSE_WEAPON :      //  3.21%
-             (temp_rand > 299) ? SCR_CURSE_ARMOUR :      //  3.21%
-             (temp_rand > 269) ? SCR_RECHARGING :        //  3.21%
-             (temp_rand > 239) ? SCR_BLINKING :          //  3.21%
-             (temp_rand > 209) ? SCR_PAPER :             //  3.21%
-             (temp_rand > 179) ? SCR_ENCHANT_ARMOUR :    //  3.21%
-             (temp_rand > 149) ? SCR_ENCHANT_WEAPON_I :  //  3.21%
-             (temp_rand > 119) ? SCR_ENCHANT_WEAPON_II : //  3.21%
-
-             // Crawl is kind to newbie adventurers {dlb}:
-             // yes -- these five are messy {dlb}:
-             // yes they are a hellish mess of tri-ops and long lines,
-             // this formating is somewhat better -- bwr
-             (temp_rand > 89) ?
-              ((item_level < 4) ? SCR_TELEPORTATION
-                                : SCR_IMMOLATION) :    //  3.21%
-             (temp_rand > 74) ?
-              ((depth_mod < 4) ? SCR_TELEPORTATION
-                               : SCR_ACQUIREMENT) :    //  1.60%
-             (temp_rand > 59) ?
-              ((depth_mod < 4) ? SCR_DETECT_CURSE
-                               : SCR_SUMMONING) :      //  1.60%
-             (temp_rand > 44) ?
-              ((depth_mod < 4) ? SCR_TELEPORTATION     //  1.60%
-                               : SCR_ENCHANT_WEAPON_III) :
-             (temp_rand > 29) ?
-              ((depth_mod < 7) ? SCR_DETECT_CURSE
-                               : SCR_TORMENT) :        //  1.60%
-             (temp_rand > 14) ?
-              ((depth_mod < 7) ? SCR_DETECT_CURSE
-                               : SCR_HOLY_WORD) :      //  1.60%
-             // default:
-              ((depth_mod < 7) ? SCR_TELEPORTATION     //  1.60%
-                               : SCR_VORPALISE_WEAPON));
+        // total weight: 10000
+        item.sub_type = random_choose_weighted(
+            1797, SCR_IDENTIFY,
+            1305, SCR_REMOVE_CURSE,
+            802, SCR_TELEPORTATION,
+            642, SCR_DETECT_CURSE,
+            321, SCR_FEAR,
+            321, SCR_NOISE,
+            321, SCR_MAGIC_MAPPING,
+            321, SCR_FOG,
+            321, SCR_RANDOM_USELESSNESS,
+            321, SCR_CURSE_WEAPON,
+            321, SCR_CURSE_ARMOUR,
+            321, SCR_RECHARGING,
+            321, SCR_BLINKING,
+            161, SCR_PAPER,
+            321, SCR_ENCHANT_ARMOUR,
+            321, SCR_ENCHANT_WEAPON_I,
+            321, SCR_ENCHANT_WEAPON_II,
+
+            // Don't create ?oImmolation at low levels (encourage read-ID)
+            321, (item_level < 4 ? SCR_TELEPORTATION : SCR_IMMOLATION),
+
+            // Medium-level scrolls
+            160, (depth_mod < 4 ? SCR_TELEPORTATION : SCR_ACQUIREMENT),
+            160, (depth_mod < 4 ? SCR_TELEPORTATION : SCR_ENCHANT_WEAPON_III),
+            160, (depth_mod < 4 ? SCR_DETECT_CURSE  : SCR_SUMMONING),
+            160, (depth_mod < 4 ? SCR_PAPER :         SCR_ANTIMAGIC),
+
+            // High-level scrolls
+            160, (depth_mod < 7 ? SCR_TELEPORTATION : SCR_VORPALISE_WEAPON),
+            160, (depth_mod < 7 ? SCR_DETECT_CURSE  : SCR_TORMENT),
+            160, (depth_mod < 7 ? SCR_DETECT_CURSE  : SCR_HOLY_WORD),
+            0);
     }
 
     // determine quantity
-    if ( item.sub_type == SCR_VORPALISE_WEAPON
-         || item.sub_type == SCR_ENCHANT_WEAPON_III
-         || item.sub_type == SCR_ACQUIREMENT
-         || item.sub_type == SCR_TORMENT
-         || item.sub_type == SCR_HOLY_WORD )
+    if (item.sub_type == SCR_VORPALISE_WEAPON
+        || item.sub_type == SCR_ENCHANT_WEAPON_III
+        || item.sub_type == SCR_ACQUIREMENT
+        || item.sub_type == SCR_TORMENT
+        || item.sub_type == SCR_HOLY_WORD)
     {
         item.quantity = 1;
     }
     else
     {
-        const int tmp = random2(48);
-        if ( tmp == 1 )
-            item.quantity = 2;
-        else if ( tmp == 0 )
-            item.quantity = 3;
+        if (one_chance_in(24))
+            item.quantity = (coinflip() ? 2 : 3);
         else
             item.quantity = 1;
     }
diff --git a/crawl-ref/source/misc.cc b/crawl-ref/source/misc.cc
index c55e4573b2..b411f205c7 100644
--- a/crawl-ref/source/misc.cc
+++ b/crawl-ref/source/misc.cc
@@ -2388,25 +2388,22 @@ std::vector<monsters*> get_nearby_monsters(bool want_move,
 
     std::vector<monsters*> mons;
 
-    // Sweep every square within range.
+    // Sweep every visible square within range.
     for ( radius_iterator ri(you.pos(), range); ri; ++ri )
     {
         const unsigned short targ_monst = env.mgrid(*ri);
         if (targ_monst != NON_MONSTER)
         {
-            if (see_grid(*ri))
+            monsters *mon = &menv[targ_monst];
+            if (mon->alive()
+                && (!require_visible || player_monster_visible(mon))
+                && !mons_is_submerged(mon)
+                && (!mons_is_mimic(mon->type) || mons_is_known_mimic(mon))
+                && (!dangerous_only || !mons_is_safe(mon, want_move)))
             {
-                monsters *mon = &menv[targ_monst];
-                if (mon->alive()
-                    && (!require_visible || player_monster_visible(mon))
-                    && !mons_is_submerged(mon)
-                    && (!mons_is_mimic(mon->type) || mons_is_known_mimic(mon))
-                    && (!dangerous_only || !mons_is_safe(mon, want_move)))
-                {
-                    mons.push_back(mon);
-                    if (just_check) // stop once you find one
-                        return mons;
-                }
+                mons.push_back(mon);
+                if (just_check) // stop once you find one
+                    return mons;
             }
         }
     }
diff --git a/crawl-ref/source/mon-util.cc b/crawl-ref/source/mon-util.cc
index 5c70b00cb2..d15988d629 100644
--- a/crawl-ref/source/mon-util.cc
+++ b/crawl-ref/source/mon-util.cc
@@ -936,6 +936,9 @@ int mons_resist_magic( const monsters *mon )
         u += 30;
     }
 
+    if (mon->has_ench(ENCH_LOWERED_MR))
+        u /= 2;
+
     return (u);
 }
 
@@ -5897,6 +5900,7 @@ void monsters::timeout_enchantments(int levels)
         case ENCH_SICK:  case ENCH_SLEEPY: case ENCH_PARALYSIS:
         case ENCH_PETRIFYING: case ENCH_PETRIFIED:
         case ENCH_BATTLE_FRENZY: case ENCH_NEUTRAL:
+        case ENCH_LOWERED_MR:
             lose_ench_levels(i->second, levels);
             break;
 
@@ -6029,6 +6033,7 @@ void monsters::apply_enchantment(const mon_enchant &me)
     case ENCH_ABJ:
     case ENCH_CHARM:
     case ENCH_SLEEP_WARY:
+    case ENCH_LOWERED_MR:
         decay_enchantment(me);
         break;
 
@@ -7004,7 +7009,8 @@ static const char *enchant_names[] =
     "rot", "summon", "abj", "backlit", "charm", "fire",
     "gloshifter", "shifter", "tp", "wary", "submerged",
     "short-lived", "paralysis", "sick", "sleep", "fatigue", "held",
-    "blood-lust", "neutral", "petrifying", "petrified", "bug"
+    "blood-lust", "neutral", "petrifying", "petrified", "magic-vulnerable",
+    "bug"
 };
 
 static const char *_mons_enchantment_name(enchant_type ench)
diff --git a/crawl-ref/source/output.cc b/crawl-ref/source/output.cc
index 27c83fefda..fd97e6a5ec 100644
--- a/crawl-ref/source/output.cc
+++ b/crawl-ref/source/output.cc
@@ -596,8 +596,10 @@ static void _get_status_lights(std::vector<status_light>& out)
 
     if (you.duration[DUR_REPEL_UNDEAD])
     {
-        int color = _dur_colour( LIGHTGREY, (you.duration[DUR_REPEL_UNDEAD] <= 4) );
-        out.push_back(status_light(color, "Holy"));
+        int colour = _dur_colour(LIGHTGREY,
+                                 (you.duration[DUR_REPEL_UNDEAD] <= 4));
+
+        out.push_back(status_light(colour, "Holy"));
     }
 
     if (you.duration[DUR_TELEPORT])
@@ -686,6 +688,11 @@ static void _get_status_lights(std::vector<status_light>& out)
         out.push_back(status_light(RED, "Conf"));
     }
 
+    if (you.duration[DUR_LOWERED_MR])
+    {
+        out.push_back(status_light(RED, "-MR"));
+    }
+
     if (you.duration[DUR_BEHELD])
     {
         out.push_back(status_light(RED, "Bhld"));
@@ -2117,6 +2124,10 @@ std::string _status_mut_abilities()
 //    if (you.duration[DUR_CONTROL_TELEPORT])
 //        text += "control teleport, ";
 
+// MR output already says so
+//    if (you.duration[DUR_LOWERED_MR])
+//        text += "vulnerable to magic, ";
+
     if (you.duration[DUR_DEATH_CHANNEL])
         text += "death channel, ";
 
diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index 8e61018fdc..cfec9d3b8a 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -1162,6 +1162,10 @@ int player_res_magic(void)
     if (you.attribute[ATTR_TRANSFORMATION] == TRAN_LICH)
         rm += 50;
 
+    // Enchantment effect
+    if (you.duration[DUR_LOWERED_MR])
+        rm /= 2;
+
     return rm;
 }