Implemented SE_AStacker, BStacker, CStacker, DStacker

Effects are buff stacking blockers.

zone/bonuses.cpp

@@ -2661,6 +2661,22 @@ void Mob::ApplySpellsBonuses(uint16 spell_id, uint8 casterlevel, StatBonuses* ne
 				}
 				break;
 
+			case SE_AStacker:
+				newbon->AStacker = true;
+				break;
+
+			case SE_BStacker:
+				newbon->BStacker = true;
+				break;
+
+			case SE_CStacker:
+				newbon->CStacker = true;
+				break;
+
+			case SE_DStacker:
+				newbon->DStacker = true;
+				break;
+
 			//Special custom cases for loading effects on to NPC from 'npc_spels_effects' table
 			if (IsAISpellEffect) {
 				

zone/common.h

@@ -350,6 +350,10 @@ struct StatBonuses {
 	bool	NegateIfCombat;						// Bool Drop buff if cast or melee
 	int8	Screech;							// -1 = Will be blocked if another Screech is +(1)
 	int16	AlterNPCLevel;						// amount of lvls +/-
+	bool	AStacker;							// For buff stack blocking
+	bool	BStacker;							// For buff stack blocking
+	bool	CStacker;							// For buff stack blocking
+	bool	DStacker;							// For buff stack blocking
 
 	// AAs
 	int8	Packrat;							//weight reduction for items, 1 point = 10%

zone/mob.h

@@ -800,7 +800,7 @@ public:
 	uint16 GetInstrumentMod(uint16 spell_id) const;
 	int CalcSpellEffectValue(uint16 spell_id, int effect_id, int caster_level = 1, Mob *caster = nullptr, int ticsremaining = 0);
 	int CalcSpellEffectValue_formula(int formula, int base, int max, int caster_level, uint16 spell_id, int ticsremaining = 0);
-	virtual int CheckStackConflict(uint16 spellid1, int caster_level1, uint16 spellid2, int caster_level2, Mob* caster1 = nullptr, Mob* caster2 = nullptr);
+	virtual int CheckStackConflict(uint16 spellid1, int caster_level1, uint16 spellid2, int caster_level2, Mob* caster1 = nullptr, Mob* caster2 = nullptr, int buffslot = -1);
 	uint32 GetCastedSpellInvSlot() const { return casting_spell_inventory_slot; }
 
 	// HP Event

zone/spell_effects.cpp

@@ -2886,6 +2886,10 @@ bool Mob::SpellEffect(Mob* caster, uint16 spell_id, float partial)
 			case SE_LimitCastTimeMax:
 			case SE_TriggerOnReqCaster:
 			case SE_FrenziedDevastation:
+			case SE_AStacker:						
+			case SE_BStacker:						
+			case SE_CStacker:						
+			case SE_DStacker:	
 			{
 				break;
 			}

zone/spells.cpp

@@ -2542,7 +2542,7 @@ int CalcBuffDuration_formula(int level, int formula, int duration)
 // -1 if they can't stack and spellid2 should be stopped
 //currently, a spell will not land if it would overwrite a better spell on any effect
 //if all effects are better or the same, we overwrite, else we do nothing
-int Mob::CheckStackConflict(uint16 spellid1, int caster_level1, uint16 spellid2, int caster_level2, Mob* caster1, Mob* caster2)
+int Mob::CheckStackConflict(uint16 spellid1, int caster_level1, uint16 spellid2, int caster_level2, Mob* caster1, Mob* caster2, int buffslot)
 {
 	const SPDat_Spell_Struct &sp1 = spells[spellid1];
 	const SPDat_Spell_Struct &sp2 = spells[spellid2];
@@ -2621,6 +2621,24 @@ int Mob::CheckStackConflict(uint16 spellid1, int caster_level1, uint16 spellid2,
 				}
 			}
 
+			/*Buff stacking prevention spell effects (446 - 449) works as follows... If B prevent A, if C prevent B, if D prevent C.
+			Special check is added to make sure the buffs stack properly when applied from fade on duration effect, since the buff
+			is not fully removed at the time of the trgger*/
+			if (spellbonuses.BStacker) {
+				if ((effect2 == SE_AStacker) && (!IsCastonFadeDurationSpell(spellid1) && buffs[buffslot].ticsremaining != 1 && IsEffectInSpell(spellid1, SE_BStacker)))
+					return -1;
+			}
+
+			if (spellbonuses.CStacker) {
+				if ((effect2 == SE_BStacker) && (!IsCastonFadeDurationSpell(spellid1) && buffs[buffslot].ticsremaining != 1 && IsEffectInSpell(spellid1, SE_CStacker)))
+					return -1;
+			}
+						
+			if (spellbonuses.DStacker) {
+				if ((effect2 == SE_CStacker) && (!IsCastonFadeDurationSpell(spellid1) && buffs[buffslot].ticsremaining != 1 && IsEffectInSpell(spellid1, SE_DStacker)))
+					return -1;
+			}
+
 			if(effect2 == SE_StackingCommand_Overwrite)
 			{
 				overwrite_effect = sp2.base[i];
@@ -2901,7 +2919,7 @@ int Mob::AddBuff(Mob *caster, uint16 spell_id, int duration, int32 level_overrid
 		if (curbuf.spellid != SPELL_UNKNOWN) {
 			// there's a buff in this slot
 			ret = CheckStackConflict(curbuf.spellid, curbuf.casterlevel, spell_id,
-					caster_level, entity_list.GetMobID(curbuf.casterid), caster);
+					caster_level, entity_list.GetMobID(curbuf.casterid), caster, buffslot);
 			if (ret == -1) {	// stop the spell
 				mlog(SPELLS__BUFFS, "Adding buff %d failed: stacking prevented by spell %d in slot %d with caster level %d",
 						spell_id, curbuf.spellid, buffslot, curbuf.casterlevel);
@@ -3047,7 +3065,7 @@ int Mob::CanBuffStack(uint16 spellid, uint8 caster_level, bool iFailIfOverwrite)
 			return(-1);	//do not recast a buff we already have on, we recast fast enough that we dont need to refresh our buffs
 
 		// there's a buff in this slot
-		ret = CheckStackConflict(curbuf.spellid, curbuf.casterlevel, spellid, caster_level);
+		ret = CheckStackConflict(curbuf.spellid, curbuf.casterlevel, spellid, caster_level, nullptr, nullptr, i);
 		if(ret == 1) {
 			// should overwrite current slot
 			if(iFailIfOverwrite) {