Changed requirements for auto-identification of equipped

items, specifically jewellery and randarts. The goal of 
this change was to clear up the identification rules and
apply them consistently. It was inspired by FR 1788698.

* Like the ring of teleportation, =lev and "rage now only
  autoID if you do not wear/wield a randart with the same
  property.
* Stat changes caused by randarts always give a message.
* Other "obvious" changes give a message only if the 
  randart has not been identified, to avoid message spam.
  (Obvious refers to attributes that would cause the item
   to be autoID'd if it were the appropriate sub type.)
* Randarts do NOT autoID anymore just because you recognize
  the base type.

On the whole, autoidentification becomes much rarer (thus 
both the scroll and the spell become more valuable). Yes,
this might be too harsh. On the upside, the player is told 
about properties such as stat changes (including AC and EV) 
and all evokable abilities. 
We might even include information about items hindering or 
preventing spellcasting and teleportation, respectively, 
under the assumption that skilled spellcasters and chars 
with teleportitis or teleport control would notice.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@2067 c06c8d41-db1a-0410-9941-cceddc491573

4 files changed, 152 insertions, 25 deletions

diff --git a/crawl-ref/source/it_use2.cc b/crawl-ref/source/it_use2.cc
index c6cac55f36..955bd69e98 100644
--- a/crawl-ref/source/it_use2.cc
+++ b/crawl-ref/source/it_use2.cc
@@ -593,19 +593,35 @@ void unuse_randart(const item_def &item)
 {
     ASSERT( is_random_artefact( item ) );
 
+    const bool ident = fully_identified(item);
+
     randart_properties_t proprt;
     randart_wpn_properties( item, proprt );
 
     if (proprt[RAP_AC])
+    {
         you.redraw_armour_class = 1;
+        if (!ident)
+        {
+            mprf("You feel less %s.",
+            proprt[RAP_AC] > 0? "well-protected" : "vulnerable");
+        }
+    }
 
     if (proprt[RAP_EVASION])
+    {
         you.redraw_evasion = 1;
+        if (!ident)
+        {
+            mprf("You feel less %s.",
+                 proprt[RAP_EVASION] > 0? "nimble" : "awkward");
+        }
+    }
 
-    // modify ability scores
-    modify_stat( STAT_STRENGTH,     -proprt[RAP_STRENGTH],     true );
-    modify_stat( STAT_INTELLIGENCE, -proprt[RAP_INTELLIGENCE], true );
-    modify_stat( STAT_DEXTERITY,    -proprt[RAP_DEXTERITY],    true );
+    // modify ability scores, always output messages
+    modify_stat( STAT_STRENGTH,     -proprt[RAP_STRENGTH],     false );
+    modify_stat( STAT_INTELLIGENCE, -proprt[RAP_INTELLIGENCE], false );
+    modify_stat( STAT_DEXTERITY,    -proprt[RAP_DEXTERITY],    false );
 
     if (proprt[RAP_NOISES] != 0)
         you.special_wield = SPWLD_NONE;
diff --git a/crawl-ref/source/item_use.cc b/crawl-ref/source/item_use.cc
index a16b8c6e88..5988e2c255 100644
--- a/crawl-ref/source/item_use.cc
+++ b/crawl-ref/source/item_use.cc
@@ -2239,6 +2239,12 @@ void jewellery_wear_effects(item_def &item)
 {
     item_type_id_state_type ident = ID_TRIED_TYPE;
 
+    // Randart jewellery shouldn't auto-ID just because the 
+    // base type is known. Somehow the player should still 
+    // be told, preferably by message. (jpeg)
+    const bool artefact = is_random_artefact( item );
+    const bool identified = fully_identified( item );
+
     switch (item.sub_type)
     {
     case RING_FIRE:
@@ -2261,63 +2267,86 @@ void jewellery_wear_effects(item_def &item)
     case RING_PROTECTION:
         you.redraw_armour_class = 1;
         if (item.plus != 0)
-            ident = ID_KNOWN_TYPE;
+        {
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
+            else if (!identified)
+            {
+                mprf("You feel %s.", item.plus > 0?
+                     "well-protected" : "more vulnerable");
+            }
+        }
         break;
 
     case RING_INVISIBILITY:
         if (!you.duration[DUR_INVIS])
         {
             mpr("You become transparent for a moment.");
-            ident = ID_KNOWN_TYPE;
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
         }
         break;
 
     case RING_EVASION:
         you.redraw_evasion = 1;
         if (item.plus != 0)
-            ident = ID_KNOWN_TYPE;
+        {
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
+            else if (!identified)
+                mprf("You feel %s.", item.plus > 0? "nimbler" : "more awkward");
+        }
         break;
 
     case RING_STRENGTH:
-        modify_stat(STAT_STRENGTH, item.plus, true);
-        if (item.plus != 0)
+        modify_stat(STAT_STRENGTH, item.plus, !artefact);
+        if (item.plus != 0 && !artefact)
             ident = ID_KNOWN_TYPE;
         break;
 
     case RING_DEXTERITY:
-        modify_stat(STAT_DEXTERITY, item.plus, true);
-        if (item.plus != 0)
+        modify_stat(STAT_DEXTERITY, item.plus, !artefact);
+        if (item.plus != 0 && !artefact)
             ident = ID_KNOWN_TYPE;
         break;
 
     case RING_INTELLIGENCE:
-        modify_stat(STAT_INTELLIGENCE, item.plus, true);
-        if (item.plus != 0)
+        modify_stat(STAT_INTELLIGENCE, item.plus, !artefact);
+        if (item.plus != 0 && !artefact)
             ident = ID_KNOWN_TYPE;
         break;
 
     case RING_MAGICAL_POWER:
         calc_mp();
-        ident = ID_KNOWN_TYPE;
+        if (!artefact)
+            ident = ID_KNOWN_TYPE;
         break;
 
     case RING_LEVITATION:
-        mpr("You feel buoyant.");
-        ident = ID_KNOWN_TYPE;
+        if (!scan_randarts( RAP_LEVITATE ))
+        {
+            mpr("You feel buoyant.");
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
+        }
         break;
 
     case RING_TELEPORTATION:
         if (!scan_randarts( RAP_CAN_TELEPORT ))
         {
             mpr("You feel slightly jumpy.");
-            ident = ID_KNOWN_TYPE;
-            break;
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
         }
         break;
         
     case AMU_RAGE:
-        mpr("You feel a brief urge to hack something to bits.");
-        ident = ID_KNOWN_TYPE;
+        if (!scan_randarts( RAP_BERSERK ))
+        {
+            mpr("You feel a brief urge to hack something to bits.");
+            if (!artefact)
+                ident = ID_KNOWN_TYPE;
+        }
         break;
 
     case AMU_THE_GOURMAND:
@@ -2327,7 +2356,7 @@ void jewellery_wear_effects(item_def &item)
 
     // Artefacts have completely different appearance than base types
     // so we don't allow them to make the base types known
-    if (is_random_artefact( item ))
+    if (artefact)
         use_randart(item);
     else
         set_ident_type( item.base_type, item.sub_type, ident );
@@ -3852,21 +3881,56 @@ void use_randart(const item_def &item)
 
     const bool alreadyknown = item_type_known(item);
     const bool dangerous = player_in_a_dangerous_place();
+    const bool ident = fully_identified(item);
 
     randart_properties_t proprt;
     randart_wpn_properties( item, proprt );
 
+    // Give messages for stat changes, possibly only if !identified
     if (proprt[RAP_AC])
+    {
         you.redraw_armour_class = 1;
+        if (!ident)
+        {
+            mprf("You feel %s.", proprt[RAP_AC] > 0?
+                 "well-protected" : "more vulnerable");
+        }
+    }
 
     if (proprt[RAP_EVASION])
+    {
         you.redraw_evasion = 1;
+        if (!ident)
+        {
+            mprf("You feel somewhat %s.", proprt[RAP_EVASION] > 0?
+                 "nimbler" : "more awkward");
+        }
+    }
 
     // modify ability scores
-    modify_stat( STAT_STRENGTH,     proprt[RAP_STRENGTH],     true );
-    modify_stat( STAT_INTELLIGENCE, proprt[RAP_INTELLIGENCE], true );
-    modify_stat( STAT_DEXTERITY,    proprt[RAP_DEXTERITY],    true );
+    // output result even when identified (because of potential fatality)
+    modify_stat( STAT_STRENGTH,     proprt[RAP_STRENGTH],     false );
+    modify_stat( STAT_INTELLIGENCE, proprt[RAP_INTELLIGENCE], false );
+    modify_stat( STAT_DEXTERITY,    proprt[RAP_DEXTERITY],    false );
+
 
+    // For evokable stuff, check whether other equipped items yield
+    // the same ability. If not, give a message.
+    // Do NOT give all these messages if the randart is identified.
+    if (!ident)
+    {
+        if (proprt[RAP_LEVITATE] && !items_give_ability(item.link, RAP_LEVITATE))
+            mpr("You feel buoyant.");
+
+        if (proprt[RAP_INVISIBLE] && !you.duration[DUR_INVIS])
+            mpr("You become transparent for a moment.");
+
+        if (proprt[RAP_CAN_TELEPORT] && !items_give_ability(item.link, RAP_CAN_TELEPORT))
+            mpr("You feel slightly jumpy.");
+
+        if (proprt[RAP_BERSERK] && !items_give_ability(item.link, RAP_BERSERK))
+            mpr("You feel a brief urge to hack something to bits.");
+    }
     if (proprt[RAP_NOISES])
         you.special_wield = 50 + proprt[RAP_NOISES];
 
diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index 145a490d7f..7b2cab6c3a 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -3933,6 +3933,52 @@ int slaying_bonus(char which_affected)
     return (ret);
 }                               // end slaying_bonus()
 
+// Checks each equip slot for an evokable item (jewellery or randart).
+// Returns true if any of these has the same ability as the one handed in.
+bool items_give_ability(const int slot, char abil)
+{
+    for (int i = EQ_WEAPON; i < NUM_EQUIP; i++)
+    {
+        const int eq = you.equip[i];
+
+        if (eq == -1)
+            continue;
+
+        // skip item to compare with
+        if (eq == slot)
+            continue;
+
+        // only weapons give their effects when in our hands
+        if (i == EQ_WEAPON && you.inv[ eq ].base_type != OBJ_WEAPONS)
+            continue;
+            
+        if (eq == EQ_LEFT_RING || eq == EQ_RIGHT_RING)
+        {
+            if (abil == RAP_LEVITATE && you.inv[eq].sub_type == RING_LEVITATION)
+                return (true);
+            if (abil == RAP_CAN_TELEPORT && you.inv[eq].sub_type == RING_TELEPORTATION)
+                return (true);
+            if (abil == RAP_INVISIBLE && you.inv[eq].sub_type == RING_INVISIBILITY)
+                return (true);
+        }
+        else if (eq == EQ_AMULET)
+        {
+            if (abil == RAP_BERSERK && you.inv[eq].sub_type == AMU_RAGE)
+                return (true);
+        }
+
+        // other items are not evokable
+        if (!is_random_artefact( you.inv[ eq ] ))
+            continue;
+
+        if (randart_wpn_property(you.inv[ eq ], abil))
+            return (true);
+    }
+
+    // none of the equipped items possesses this ability
+    return (false);
+}                               // end scan_randarts()
+
 /* Checks each equip slot for a randart, and adds up all of those with
    a given property. Slow if any randarts are worn, so avoid where possible. */
 int scan_randarts(char which_property, bool calc_unid)
@@ -4012,7 +4058,7 @@ void modify_stat(stat_type which_stat, char amount, bool suppress_msg)
         break;
     }
 
-    if (!suppress_msg)
+    if (!suppress_msg && amount != 0)
         mpr( msg.c_str(), (amount > 0) ? MSGCH_INTRINSIC_GAIN : MSGCH_WARN );
 
     *ptr_stat += amount;
diff --git a/crawl-ref/source/player.h b/crawl-ref/source/player.h
index 7a87e5d676..a346cd9a38 100644
--- a/crawl-ref/source/player.h
+++ b/crawl-ref/source/player.h
@@ -233,6 +233,7 @@ int player_teleport(bool calc_unid = true);
 /* ***********************************************************************
  * called from: ability - acr - items - misc - spells1 - spells3
  * *********************************************************************** */
+bool items_give_ability(const int slot, char abil);
 int scan_randarts(char which_property, bool calc_unid = true);