[Merchants] Add New Classic Greed/Faction/Charisma Prices Rule (#4301)

* [Merchants] Add New Classic Greed/Faction/Charisma Prices Rule

* Fix size of greed field.

* Fix { formatting and add {} to one liners

* Fix return type of GetGreedPercent

* Remove code that slipped in from another patch

* Fix greed to be unsigned

* Update client.cpp

* Update client_packet.cpp

* Update client.cpp

Fix bad name in extra log message added manually from merge.

* Update client_packet.cpp

Spacing.

* Update client.cpp

---------

Co-authored-by: Kinglykrab <kinglykrab@gmail.com>

zone/client.cpp

@@ -3761,7 +3761,83 @@ void Client::Escape()
 	MessageString(Chat::Skills, ESCAPE);
 }
 
-float Client::CalcPriceMod(Mob* other, bool reverse)
+float Client::CalcClassicPriceMod(Mob* other, bool reverse) {
+	float price_multiplier = 0.8f;
+
+	if (other && other->IsNPC()) {
+		FACTION_VALUE faction_level = GetFactionLevel(CharacterID(), other->CastToNPC()->GetNPCTypeID(), GetRace(), GetClass(), GetDeity(), other->CastToNPC()->GetPrimaryFaction(), other);
+		int32 cha = GetCHA();
+
+		if (faction_level <= FACTION_AMIABLY) {
+			cha += 11;		// amiable faction grants a defacto 11 charisma bonus
+		}
+
+		uint8 greed = other->CastToNPC()->GetGreedPercent();
+
+		// Sony's precise algorithm is unknown, but this produces output that is virtually identical
+		if (faction_level <= FACTION_INDIFFERENTLY) {
+			if (cha > 75) {
+				if (greed) {
+					// this is derived from curve fitting to a lot of price data
+					price_multiplier = -0.2487768 + (1.599635 - -0.2487768) / (1 + pow((cha / 135.1495), 1.001983));
+					price_multiplier += (greed + 25u) / 100.0f;  // default vendor markup is 25%; anything above that is 'greedy'
+					price_multiplier = 1.0f / price_multiplier;
+				}
+				else {
+					// non-greedy merchants use a linear scale
+					price_multiplier = 1.0f - ((115.0f - cha) * 0.004f);
+				}
+			}
+			else if (cha > 60) {
+				price_multiplier = 1.0f / (1.25f + (greed / 100.0f));
+			}
+			else {
+				price_multiplier = 1.0f / ((1.0f - (cha - 120.0f) / 220.0f) + (greed / 100.0f));
+			}
+		}
+		else { // apprehensive
+			if (cha > 75) {
+				if (greed) {
+					// this is derived from curve fitting to a lot of price data
+					price_multiplier = -0.25f + (1.823662 - -0.25f) / (1 + (cha / 135.0f));
+					price_multiplier += (greed + 25u) / 100.0f;  // default vendor markup is 25%; anything above that is 'greedy'
+					price_multiplier = 1.0f / price_multiplier;
+				}
+				else {
+					price_multiplier = (100.0f - (145.0f - cha) / 2.8f) / 100.0f;
+				}
+			}
+			else if (cha > 60) {
+				price_multiplier = 1.0f / (1.4f + greed / 100.0f);
+			}
+			else {
+				price_multiplier = 1.0f / ((1.0f + (143.574 - cha) / 196.434) + (greed / 100.0f));
+			}
+		}
+
+		float maxResult = 1.0f / 1.05;		// price reduction caps at this amount
+		if (price_multiplier > maxResult) {
+			price_multiplier = maxResult;
+		}
+
+		if (!reverse) {
+			price_multiplier = 1.0f / price_multiplier;
+		}
+	}
+
+	LogMerchants(
+		"[{}] [{}] items at [{}] price multiplier [{}] [{}]",
+		other->GetName(),
+		reverse ? "buys" : "sells",
+		price_multiplier,
+		reverse ? "from" : "to",
+		GetName()
+	);
+
+	return price_multiplier;
+}
+
+float Client::CalcNewPriceMod(Mob* other, bool reverse)
 {
 	float chaformula = 0;
 	if (other)
@@ -3807,6 +3883,17 @@ float Client::CalcPriceMod(Mob* other, bool reverse)
 	return chaformula; //Returns 1.10, expensive stuff!
 }
 
+float Client::CalcPriceMod(Mob* other, bool reverse)
+{
+	float price_mod = CalcNewPriceMod(other, reverse);
+
+	if (RuleB(Merchant, UseClassicPriceMod)) {
+		price_mod = CalcClassicPriceMod(other, reverse);
+	}
+
+	return price_mod;
+}
+
 void Client::GetGroupAAs(GroupLeadershipAA_Struct *into) const {
 	memcpy(into, &m_pp.leader_abilities.group, sizeof(GroupLeadershipAA_Struct));
 }
@@ -12474,4 +12561,4 @@ void Client::RemoveItemBySerialNumber(uint32 serial_number, uint32 quantity)
 			}
 		}
 	}
-}
+}

zone/client.h

@@ -1127,6 +1127,8 @@ public:
 	void GoFish(bool guarantee = false, bool use_bait = true);
 	void ForageItem(bool guarantee = false);
 	//Calculate vendor price modifier based on CHA: (reverse==selling)
+	float CalcClassicPriceMod(Mob* other = 0, bool reverse = false);
+	float CalcNewPriceMod(Mob* other = 0, bool reverse = false);
 	float CalcPriceMod(Mob* other = 0, bool reverse = false);
 	void ResetTrade();
 	void DropInst(const EQ::ItemInstance* inst);

zone/client_packet.cpp

@@ -14041,16 +14041,21 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 
 	EQ::ItemInstance* inst = database.CreateItem(item, charges);
 
-	int SinglePrice = 0;
-	if (RuleB(Merchant, UsePriceMod))
-		SinglePrice = (item->Price * (RuleR(Merchant, SellCostMod)) * item->SellRate * Client::CalcPriceMod(tmp, false));
-	else
-		SinglePrice = (item->Price * (RuleR(Merchant, SellCostMod)) * item->SellRate);
+	int single_price = (item->Price * item->SellRate);
+
+	// Don't use SellCostMod if using UseClassicPriceMod
+	if (!RuleB(Merchant, UseClassicPriceMod)) {
+		single_price *= RuleR(Merchant, SellCostMod);
+	}
+
+	if (RuleB(Merchant, UsePriceMod)) {
+		single_price *= Client::CalcPriceMod(tmp, false);
+	}
 
 	if (item->MaxCharges > 1)
-		mpo->price = SinglePrice;
+		mpo->price = single_price;
 	else
-		mpo->price = SinglePrice * mp->quantity;
+		mpo->price = single_price * mp->quantity;
 
 	if (mpo->price < 0)
 	{
@@ -14131,7 +14136,7 @@ void Client::Handle_OP_ShopPlayerBuy(const EQApplicationPacket *app)
 		else {
 			// Update the charges/quantity in the merchant window
 			inst->SetCharges(new_charges);
-			inst->SetPrice(SinglePrice);
+			inst->SetPrice(single_price);
 			inst->SetMerchantSlot(mp->itemslot);
 			inst->SetMerchantCount(new_charges);
 
@@ -14310,7 +14315,15 @@ void Client::Handle_OP_ShopPlayerSell(const EQApplicationPacket *app)
 
 	if (RuleB(Merchant, UsePriceMod)) {
 		for (i = 1; i <= cost_quantity; i++) {
-			price = (uint32)((item->Price * i)*(RuleR(Merchant, BuyCostMod))*Client::CalcPriceMod(vendor, true) + 0.5); // need to round up, because client does it automatically when displaying price
+			price = (uint32)(item->Price * i) * Client::CalcPriceMod(vendor, true);
+
+			// Don't use SellCostMod if using UseClassicPriceMod
+			if (!RuleB(Merchant, UseClassicPriceMod)) {
+				price *= RuleR(Merchant, BuyCostMod);
+			}
+
+			price += 0.5; // need to round up, because client does it automatically when displaying price
+
 			if (price > 4000000000) {
 				cost_quantity = i;
 				mp->quantity = i;
@@ -14360,11 +14373,12 @@ void Client::Handle_OP_ShopPlayerSell(const EQApplicationPacket *app)
 					break;
 				}
 
-				uint32 price = (
-					item->Price *
-					RuleR(Merchant, SellCostMod) *
-					item->SellRate
-				);
+				uint32 price = (item->Price * item->SellRate);
+
+				// Don't use SellCostMod if using UseClassicPriceMod
+				if (!RuleB(Merchant, UseClassicPriceMod)) {
+					price *= RuleR(Merchant, SellCostMod);
+				}
 
 				if (RuleB(Merchant, UsePriceMod)) {
 					price *= Client::CalcPriceMod(vendor, false);
@@ -14571,11 +14585,18 @@ void Client::Handle_OP_ShopRequest(const EQApplicationPacket *app)
 	mco->command     = action; // Merchant command 0x01 = open
 	mco->tab_display = tabs_to_display;
 
+	float buy_cost_mod = 1;
+
+	// Only use the BuyCostMod if we're not using the classic function.
+	if (!RuleB(Merchant, UseClassicPriceMod)) {
+		buy_cost_mod = RuleR(Merchant, BuyCostMod);
+	}
+
 	if (RuleB(Merchant, UsePriceMod)) {
-		mco->rate = 1 / ((RuleR(Merchant, BuyCostMod)) * Client::CalcPriceMod(tmp, true)); // works
+		mco->rate = 1 / (buy_cost_mod * Client::CalcPriceMod(tmp, true));
 	}
 	else {
-		mco->rate = 1 / (RuleR(Merchant, BuyCostMod));
+		mco->rate = 1 / buy_cost_mod;
 	}
 
 	outapp->priority = 6;

zone/client_process.cpp

@@ -902,9 +902,14 @@ void Client::BulkSendMerchantInventory(int merchant_id, int npcid) {
 
 			auto inst = database.CreateItem(item, charges);
 			if (inst) {
-				auto item_price = static_cast<uint32>(item->Price * RuleR(Merchant, SellCostMod) * item->SellRate);
+				auto item_price = static_cast<uint32>(item->Price * item->SellRate);
 				auto item_charges = charges ? charges : 1;
 
+				// Don't use SellCostMod if using UseClassicPriceMod
+				if (!RuleB(Merchant, UseClassicPriceMod)) {
+					item_price *= RuleR(Merchant, SellCostMod);
+				}
+
 				if (RuleB(Merchant, UsePriceMod)) {
 					item_price *= Client::CalcPriceMod(npc);
 				}
@@ -948,9 +953,14 @@ void Client::BulkSendMerchantInventory(int merchant_id, int npcid) {
 			auto charges = item->MaxCharges;
 			auto inst = database.CreateItem(item, charges);
 			if (inst) {
-				auto item_price = static_cast<uint32>(item->Price * RuleR(Merchant, SellCostMod) * item->SellRate);
+				auto item_price = static_cast<uint32>(item->Price * item->SellRate);
 				auto item_charges = charges ? charges : 1;
 
+				// Don't use SellCostMod if using UseClassicPriceMod
+				if (!RuleB(Merchant, UseClassicPriceMod)) {
+					item_price *= RuleR(Merchant, SellCostMod);
+				}
+
 				if (RuleB(Merchant, UsePriceMod)) {
 					item_price *= Client::CalcPriceMod(npc);
 				}

zone/npc.h

@@ -268,6 +268,7 @@ public:
 	inline void	MerchantOpenShop() { merchant_open = true; }
 	inline void	MerchantCloseShop() { merchant_open = false; }
 	inline bool	IsMerchantOpen() { return merchant_open; }
+	inline uint8 GetGreedPercent() { return NPCTypedata->greed; }
 	inline bool GetParcelMerchant() { return NPCTypedata->is_parcel_merchant; }
 	void	Depop(bool start_spawn_timer = false);
 	void	Stun(int duration);

zone/zonedb.cpp

@@ -1793,6 +1793,7 @@ const NPCType *ZoneDatabase::LoadNPCTypesData(uint32 npc_type_id, bool bulk_load
 		t->max_dmg            = n.maxdmg;
 		t->attack_count       = n.attack_count;
 		t->is_parcel_merchant = n.is_parcel_merchant ? true : false;
+		t->greed              = n.greed;
 
 		if (!n.special_abilities.empty()) {
 			strn0cpy(t->special_abilities, n.special_abilities.c_str(), 512);

zone/zonedump.h

@@ -155,6 +155,7 @@ struct NPCType
 	int             heroic_strikethrough;
 	bool            keeps_sold_items;
 	bool            is_parcel_merchant;
+	uint8			greed;
 };
 
 #pragma pack()