Add a blessing to improve AC by enchanting armor or shields by one or

two points, or at least uncursing them (5% chance, to discourage 
killings for armor; the probability of healing has been dropped to 90%).  
In the process, split out and generalize the code to enchant armor to 
not be so player-specific; now, handle_enchant_armour() contains the 
player-specific portion, and enchant_armour() contains the rest.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@3798 c06c8d41-db1a-0410-9941-cceddc491573

3 files changed, 109 insertions, 50 deletions

diff --git a/crawl-ref/source/item_use.cc b/crawl-ref/source/item_use.cc
index d843830b9d..a3206ca0a6 100644
--- a/crawl-ref/source/item_use.cc
+++ b/crawl-ref/source/item_use.cc
@@ -81,7 +81,7 @@
 #include "xom.h"
 
 static bool drink_fountain();
-static bool enchant_armour(int item_slot = -1);
+static bool handle_enchant_armour( int item_slot = -1 );
 
 static int  _fire_prompt_for_item(std::string& err);
 static bool _fire_validate_item(int selected, std::string& err);
@@ -3915,51 +3915,31 @@ bool enchant_weapon( enchant_stat_type which_stat, bool quiet, int wpn )
     return (true);
 }
 
-static bool enchant_armour( int item_slot )
+bool enchant_armour( int &ac_change, bool quiet, item_def &arm )
 {
-    if (item_slot == -1)
-        item_slot = prompt_invent_item( "Enchant which item?", MT_INVLIST,
-                                        OSEL_ENCH_ARM, true, true, false );
-
-    if (item_slot == PROMPT_ABORT)
-    {
-        canned_msg( MSG_OK );
-        return (false);
-    }
-
-    item_def& arm(you.inv[item_slot]);
+    ac_change = 0;
 
     // cannot be enchanted nor uncursed
     if (!is_enchantable_armour(arm, true))
-    {
-        canned_msg( MSG_NOTHING_HAPPENS );
         return (false);
-    }
 
     bool is_cursed = item_cursed(arm);
-                
+
     // Turn hides into mails where applicable.
     // NOTE: It is assumed that armour which changes in this way does
     // not change into a form of armour with a different evasion modifier.
-    if (arm.sub_type == ARM_DRAGON_HIDE
-        || arm.sub_type == ARM_ICE_DRAGON_HIDE
-        || arm.sub_type == ARM_STEAM_DRAGON_HIDE
-        || arm.sub_type == ARM_MOTTLED_DRAGON_HIDE
-        || arm.sub_type == ARM_STORM_DRAGON_HIDE
-        || arm.sub_type == ARM_GOLD_DRAGON_HIDE
-        || arm.sub_type == ARM_SWAMP_DRAGON_HIDE
-        || arm.sub_type == ARM_TROLL_HIDE)
+    if (armour_is_hide(arm, false))
     {
         mprf("%s glows purple and changes!",
              arm.name(DESC_CAP_YOUR).c_str());
-             
+
+        ac_change = arm.plus;
         hide2armour(arm);
+        ac_change = arm.plus - ac_change;
 
         if (is_cursed)
             do_uncurse_item( arm );
 
-        you.redraw_armour_class = 1;
-
         // no additional enchantment
         return (true);
     }
@@ -3970,33 +3950,61 @@ static bool enchant_armour( int item_slot )
     {
         if (is_cursed)
         {
-            mprf("%s glows silver for a moment.",
-                 arm.name(DESC_CAP_YOUR).c_str());
-                 
+            if (!quiet)
+            {
+                mprf("%s glows silver for a moment.",
+                     arm.name(DESC_CAP_YOUR).c_str());
+            }
+
             do_uncurse_item( arm );
             return (true);
         }
         else
-        {
-            canned_msg( MSG_NOTHING_HAPPENS );
             return (false);
-        }
     }
 
     // output message before changing enchantment and curse status
-    mprf("%s glows green for a moment.",
-         arm.name(DESC_CAP_YOUR).c_str());
+    if (!quiet)
+    {
+        mprf("%s glows green for a moment.",
+             arm.name(DESC_CAP_YOUR).c_str());
+    }
 
     arm.plus++;
+    ac_change++;
 
     if (is_cursed)
         do_uncurse_item( arm );
-        
-    you.redraw_armour_class = 1;
+
     xom_is_stimulated(16);
     return (true);
 }
 
+static bool handle_enchant_armour( int item_slot )
+{
+    if (item_slot == -1)
+        item_slot = prompt_invent_item( "Enchant which item?", MT_INVLIST,
+                                        OSEL_ENCH_ARM, true, true, false );
+
+    if (item_slot == PROMPT_ABORT)
+    {
+        canned_msg( MSG_OK );
+        return (false);
+    }
+
+    item_def& arm(you.inv[item_slot]);
+
+    int ac_change;
+    bool result = enchant_armour(ac_change, false, arm);
+
+    if (!result)
+        canned_msg( MSG_NOTHING_HAPPENS );
+    else if (ac_change)
+        you.redraw_armour_class = true;
+
+    return result;
+}
+
 static void handle_read_book( int item_slot )
 {
     item_def& book(you.inv[item_slot]);
@@ -4047,7 +4055,7 @@ static bool scroll_modify_item(const scroll_type scroll)
 {
      int item_slot = prompt_invent_item( "Use on which item?", MT_INVLIST,
                                           OSEL_ANY, true, true, false );
-                                          
+
      if (item_slot == PROMPT_ABORT)
      {
          canned_msg( MSG_OK );
@@ -4055,7 +4063,7 @@ static bool scroll_modify_item(const scroll_type scroll)
      }
 
      item_def &item = you.inv[item_slot];
-                                          
+
      switch (scroll)
      {
      case SCR_IDENTIFY:
@@ -4080,7 +4088,7 @@ static bool scroll_modify_item(const scroll_type scroll)
         if (is_enchantable_armour(item, true))
         {
             // might still fail because of already high enchantment
-            if (enchant_armour(item_slot))
+            if (handle_enchant_armour(item_slot))
                 return (true);
             return (false);
         }
@@ -4418,7 +4426,7 @@ void read_scroll( int slot )
         if ( !item_type_known(scroll) )
              id_the_scroll = scroll_modify_item(which_scroll);
         else
-             enchant_armour(-1);
+             handle_enchant_armour(-1);
         break;
 
     case SCR_CURSE_ARMOUR:
diff --git a/crawl-ref/source/item_use.h b/crawl-ref/source/item_use.h
index 64d33e00e2..1c79a93ecc 100644
--- a/crawl-ref/source/item_use.h
+++ b/crawl-ref/source/item_use.h
@@ -162,6 +162,7 @@ bool puton_item(int slot, bool prompt_finger = true);
 
 bool enchant_weapon( enchant_stat_type which_stat, bool quiet = false,
                      int wpn = -1 );
+bool enchant_armour( int &ac_change, bool quiet, item_def &arm );
 
 bool throw_it(bolt &pbolt, int throw_2, bool teleport=false, int acc_bonus=0,
               dist *target = NULL);
diff --git a/crawl-ref/source/religion.cc b/crawl-ref/source/religion.cc
index 7cff471e50..6c2bcb33c5 100644
--- a/crawl-ref/source/religion.cc
+++ b/crawl-ref/source/religion.cc
@@ -754,7 +754,7 @@ static void give_nemelex_gift()
     }
 }
 
-static bool promote_to_priest(monsters* mon)
+static bool blessing_priesthood(monsters* mon)
 {
     monster_type priest_type = MONS_PROGRAM_BUG;
 
@@ -775,6 +775,32 @@ static bool promote_to_priest(monsters* mon)
     return false;
 }
 
+static bool blessing_ac(monsters* mon)
+{
+    // Pick either the armour or the shield.
+    const int armour = mon->inv[MSLOT_ARMOUR];
+    const int shield = mon->inv[MSLOT_SHIELD];
+
+    if (armour == NON_ITEM && shield == NON_ITEM)
+        return false;
+
+    int slot;
+
+    if (armour == NON_ITEM)
+        slot = shield;
+    else if (shield == NON_ITEM)
+        slot = armour;
+    else
+        slot = (coinflip()) ? armour : shield;
+
+    item_def& arm(mitm[slot]);
+
+    int ac_change;
+
+    // And enchant it.
+    return enchant_armour(ac_change, true, arm);
+}
+
 void bless_follower(god_type god,
                     bool (*suitable)(const monsters* mon))
 {
@@ -792,13 +818,38 @@ void bless_follower(god_type god,
 
     // 5% chance: Turn a monster into a priestly monster, if possible.
     // This is currently only used for Beogh and ordinary orcs.
-    if (god == GOD_BEOGH && one_chance_in(20) && mon->type == MONS_ORC)
+    if (one_chance_in(20))
+    {
+        if (god == GOD_BEOGH && mon->type == MONS_ORC
+            && blessing_priesthood(mon))
+        {
+            result = "priesthood";
+            goto blessing_done;
+        }
+    }
+
+    // 5% chance: Enchant a monster's armour or shield by one or two
+    // points, or at least uncurse it, if possible.  The message doesn't
+    // make a distinction.
+    if (one_chance_in(20))
     {
-        promote_to_priest(mon);
-        result = "priesthood";
+        bool ac_effect = blessing_ac(mon);
+
+        if (!ac_effect || coinflip())
+        {
+            if (blessing_ac(mon))
+                ac_effect = true;
+        }
+
+        if (ac_effect)
+        {
+            result = "extra defence";
+            goto blessing_done;
+        }
     }
-    // 95% chance: full healing.
-    else
+
+    // 90% chance: full healing, optionally adding one or two extra hit
+    // points.
     {
         bool healing = false;
         bool vigour = true;
@@ -807,11 +858,9 @@ void bless_follower(god_type god,
 
         if (!healing || coinflip())
         {
-            // Full healing, plus one added hit point.
             heal_monster(mon, mon->max_hit_points, true);
 
             if (coinflip())
-                // Full healing, plus another added hit point.
                 heal_monster(mon, mon->max_hit_points, true);
 
             vigour = true;
@@ -825,6 +874,7 @@ void bless_follower(god_type god,
             result = "extra vigour";
     }
 
+blessing_done:
     mprf(MSGCH_GOD, "%s blesses %s with %s.", god_name(god).c_str(),
         blessed, result);
 }