Improved OnItemRoll hook

Now you can change the chance temporary and dinamically

src/game/Loot/LootMgr.cpp

@@ -84,7 +84,7 @@ class LootTemplate::LootGroup                               // A set of loot def
         bool HasQuestDrop() const;                          // True if group includes at least 1 quest drop entry
         bool HasQuestDropForPlayer(Player const* player) const;
                                                             // The same for active quests of the player
-        void Process(Loot& loot, uint16 lootMode) const;    // Rolls an item from the group (if any) and adds the item to the loot
+        void Process(Loot& loot, Player const *player, LootStore const& lootstore, uint16 lootMode) const;    // Rolls an item from the group (if any) and adds the item to the loot
         float RawTotalChance() const;                       // Overall chance for the group (without equal chanced items)
         float TotalChance() const;                          // Overall chance for the group
 
@@ -98,7 +98,7 @@ class LootTemplate::LootGroup                               // A set of loot def
         LootStoreItemList ExplicitlyChanced;                // Entries with chances defined in DB
         LootStoreItemList EqualChanced;                     // Zero chances - every entry takes the same chance
 
-        LootStoreItem const* Roll(Loot& loot, uint16 lootMode) const;   // Rolls an item from the group, returns NULL if all miss their chances
+        LootStoreItem const* Roll(Loot& loot, Player const *player, LootStore const& store, uint16 lootMode) const;   // Rolls an item from the group, returns NULL if all miss their chances
 
         // This class must never be copied - storing pointers
         LootGroup(LootGroup const&);
@@ -279,19 +279,23 @@ void LootStore::ReportNotExistedId(uint32 id) const
 
 // Checks if the entry (quest, non-quest, reference) takes it's chance (at loot generation)
 // RATE_DROP_ITEMS is no longer used for all types of entries
-bool LootStoreItem::Roll(bool rate) const
+bool LootStoreItem::Roll(bool rate, Player const *player, Loot& loot, LootStore const& store) const
 {
-    if (chance >= 100.0f)
+    float _chance = chance;
+
+    sScriptMgr->OnItemRoll(player, this, _chance, loot, store);
+
+    if (_chance >= 100.0f)
         return true;
 
     if (mincountOrRef < 0)                                   // reference case
-        return roll_chance_f(chance* (rate ? sWorld->getRate(RATE_DROP_ITEM_REFERENCED) : 1.0f));
+        return roll_chance_f(_chance* (rate ? sWorld->getRate(RATE_DROP_ITEM_REFERENCED) : 1.0f));
 
     ItemTemplate const* pProto = sObjectMgr->GetItemTemplate(itemid);
 
     float qualityModifier = pProto && rate ? sWorld->getRate(qualityToRate[pProto->Quality]) : 1.0f;
 
-    return roll_chance_f(chance*qualityModifier);
+    return roll_chance_f(_chance*qualityModifier);
 }
 
 // Checks correctness of values
@@ -1102,7 +1106,7 @@ void LootTemplate::LootGroup::AddEntry(LootStoreItem* item)
 }
 
 // Rolls an item from the group, returns NULL if all miss their chances
-LootStoreItem const* LootTemplate::LootGroup::Roll(Loot& loot, uint16 lootMode) const
+LootStoreItem const* LootTemplate::LootGroup::Roll(Loot& loot, Player const *player, LootStore const& store, uint16 lootMode) const
 {
     LootStoreItemList possibleLoot = ExplicitlyChanced;
     possibleLoot.remove_if(LootGroupInvalidSelector(loot, lootMode));
@@ -1114,10 +1118,14 @@ LootStoreItem const* LootTemplate::LootGroup::Roll(Loot& loot, uint16 lootMode)
         for (LootStoreItemList::const_iterator itr = possibleLoot.begin(); itr != possibleLoot.end(); ++itr)   // check each explicitly chanced entry in the template and modify its chance based on quality.
         {
             LootStoreItem* item = *itr;
-            if (item->chance >= 100.0f)
+            float chance = item->chance;
+ 
+            sScriptMgr->OnItemRoll(player, item, chance, loot, store);
+
+            if (chance >= 100.0f)
                 return item;
 
-            roll -= item->chance;
+            roll -= chance;
             if (roll < 0)
                 return item;
         }
@@ -1169,9 +1177,9 @@ void LootTemplate::LootGroup::CopyConditions(ConditionList /*conditions*/)
 }
 
 // Rolls an item from the group (if any takes its chance) and adds the item to the loot
-void LootTemplate::LootGroup::Process(Loot& loot, uint16 lootMode) const
+void LootTemplate::LootGroup::Process(Loot& loot, Player const *player, LootStore const& store, uint16 lootMode) const
 {
-    if (LootStoreItem const* item = Roll(loot, lootMode))
+    if (LootStoreItem const* item = Roll(loot, player, store, lootMode))
         loot.AddItem(*item);
 }
 
@@ -1309,7 +1317,7 @@ void LootTemplate::Process(Loot& loot, LootStore const& store, uint16 lootMode,
         if (!Groups[groupId - 1])
             return;
 
-        Groups[groupId-1]->Process(loot, lootMode);
+        Groups[groupId-1]->Process(loot, player, store, lootMode);
         return;
     }
 
@@ -1320,9 +1328,7 @@ void LootTemplate::Process(Loot& loot, LootStore const& store, uint16 lootMode,
         if (!(item->lootmode & lootMode))                         // Do not add if mode mismatch
             continue;
 
-        sScriptMgr->OnBeforeItemRoll(player, loot, rate, lootMode, item, store);
+        if (!item->Roll(rate, player, loot, store))
-
-        if (!item->Roll(rate))
             continue;                                           // Bad luck for the entry
 
         if (item->mincountOrRef < 0)                            // References processing
@@ -1345,7 +1351,7 @@ void LootTemplate::Process(Loot& loot, LootStore const& store, uint16 lootMode,
     // Now processing groups
     for (LootGroups::const_iterator i = Groups.begin(); i != Groups.end(); ++i)
         if (LootGroup* group = *i)
-            group->Process(loot, lootMode);
+            group->Process(loot, player, store, lootMode);
 }
 
 // True if template includes at least 1 quest drop entry

src/game/Loot/LootMgr.h

@@ -110,6 +110,7 @@ enum LootSlotType
 class Player;
 class LootStore;
 class ConditionMgr;
+struct Loot;
 
 struct LootStoreItem
 {
@@ -129,7 +130,7 @@ struct LootStoreItem
         group(_group), needs_quest(_chanceOrQuestChance < 0), maxcount(_maxcount)
          {}
 
-    bool Roll(bool rate) const;                             // Checks if the entry takes it's chance (at loot generation)
+    bool Roll(bool rate, Player const *player, Loot& loot, LootStore const& store) const;                             // Checks if the entry takes it's chance (at loot generation)
     bool IsValid(LootStore const& store, uint32 entry) const;
                                                             // Checks correctness of values
 };
@@ -178,7 +179,6 @@ struct QuestItem
         : index(_index), is_looted(_islooted) {}
 };
 
-struct Loot;
 class LootTemplate;
 
 typedef std::vector<QuestItem> QuestItemList;

src/game/Scripting/ScriptMgr.cpp

@@ -1519,8 +1519,8 @@ void ScriptMgr::OnBeforeDropAddItem(Player const* player, Loot& loot, bool canRa
     FOREACH_SCRIPT(GlobalScript)->OnBeforeDropAddItem(player, loot, canRate, lootMode, LootStoreItem, store);
 }
 
-void ScriptMgr::OnBeforeItemRoll(Player const* player, Loot& loot, bool canRate, uint16 lootMode, LootStoreItem* LootStoreItem, LootStore const& store) {
+void ScriptMgr::OnItemRoll(Player const* player, LootStoreItem const* LootStoreItem, float &chance, Loot& loot, LootStore const& store) {
-    FOREACH_SCRIPT(GlobalScript)->OnBeforeItemRoll(player, loot, canRate, lootMode, LootStoreItem, store);
+    FOREACH_SCRIPT(GlobalScript)->OnItemRoll(player, LootStoreItem,  chance, loot, store);
 }
 
 void ScriptMgr::OnInitializeLockedDungeons(Player* player, uint8& level, uint32& lockData)

src/game/Scripting/ScriptMgr.h

@@ -1008,7 +1008,7 @@ class GlobalScript : public ScriptObject
         // loot
         virtual void OnAfterRefCount(Player const* /*player*/, LootStoreItem* /*LootStoreItem*/, Loot& /*loot*/, bool /*canRate*/, uint16 /*lootMode*/, uint32& /*maxcount*/, LootStore const& /*store*/) { }
         virtual void OnBeforeDropAddItem(Player const* /*player*/, Loot& /*loot*/, bool /*canRate*/, uint16 /*lootMode*/, LootStoreItem* /*LootStoreItem*/, LootStore const& /*store*/) { }
-        virtual void OnBeforeItemRoll(Player const* /*player*/, Loot& /*loot*/, bool /*canRate*/, uint16 /*lootMode*/, LootStoreItem* /*LootStoreItem*/, LootStore const& /*store*/) { };
+        virtual void OnItemRoll(Player const* /*player*/, LootStoreItem const* /*LootStoreItem*/, float& /*chance*/, Loot& /*loot*/, LootStore const& /*store*/) { };
 
         virtual void OnInitializeLockedDungeons(Player* /*player*/, uint8& /*level*/, uint32& /*lockData*/) { }
         virtual void OnAfterInitializeLockedDungeons(Player* /*player*/) { }
@@ -1281,7 +1281,7 @@ class ScriptMgr
         void OnBeforeUpdateArenaPoints(ArenaTeam* at, std::map<uint32, uint32> &ap);
         void OnAfterRefCount(Player const* player, Loot& loot, bool canRate, uint16 lootMode, LootStoreItem* LootStoreItem, uint32 &maxcount, LootStore const& store);
         void OnBeforeDropAddItem(Player const* player, Loot& loot, bool canRate, uint16 lootMode, LootStoreItem* LootStoreItem, LootStore const& store);
-        void OnBeforeItemRoll(Player const* player, Loot& loot, bool canRate, uint16 lootMode, LootStoreItem* LootStoreItem, LootStore const& store);
+        void OnItemRoll(Player const* player, LootStoreItem const* LootStoreItem, float &chance, Loot& loot, LootStore const& store);
         void OnInitializeLockedDungeons(Player* player, uint8& level, uint32& lockData);
         void OnAfterInitializeLockedDungeons(Player* player);